兽研《兽医科学前沿》01 frontiersin.org 类型：病例报告 发表日期：2026年10月6日 DOI 10.3389/fvets.2026.1942682 开放获取 编辑：Niccolò Fonti，意大利帕多瓦大学 审稿人：刘光华，中国上海交通大学；Mohammad Arif，孟加拉国农业大学，孟加拉国 *通讯作者：Hee-Myung Park parkhee@konkuk.ac.kr 收稿日期：2026年7月20日 修回日期：2026年9月11日 接受日期：2026年9月21日 发表日期：2026年10月6日 引用格式：Dan T-J, Yang C-H, Kim Y-J, Kang M-H, Kang M-A, Lee K-S and Park H-M (2026) 病例报告：犬肝细胞癌多模式长期治疗并连续监测血清甲胎蛋白。Front. Vet. Sci. 13:1942682. doi: 10.3389/fvets.2026.1942682 版权：© 2026 Dan、Yang、Kim、Kang、Kang、Lee 和 Park。本文为开放获取文章，依据知识共享署名许可协议（CC BY）条款发布。允许在其他平台使用、分发和复制，但须正确署名原作者及版权所有者，并按照公认的学术惯例引用本期刊的原始发表文献。不符合上述条款的使用、分发或复制均不被允许。病例报告：犬肝细胞癌多模式长期治疗并连续监测血清甲胎蛋白 Tae-Jung Dan 1，Cheol-Ho Yang 2，Yeon-Jin Kim 1，Min-Hee Kang 3，Mi-Ae Kang 4，Kwang-Sup Lee 1 和 Hee-Myung Park 1 * 1 建国大学兽医学院兽医内科学教研室，韩国首尔；2 Times动物医疗中心，韩国京畿道水原市；3 长安大学生物动物健康系，韩国华城市；4 VET and GENE，韩国城南市 一只13岁已绝育雌性西施犬就诊，有数月进行性肝酶活性升高病史，同时合并接受管理的高肾上腺皮质功能。诊断影像学显示一个孤立性肝脏肿物，起源于尾状叶尾状突，与后腔静脉粘连。经超声引导下粗针活检的组织病理学检查确诊为肝细胞癌（HCC），同时血清甲胎蛋白（AFP）浓度显著升高。由于肿瘤与后腔静脉粘连导致无法实现完全手术切除，且常规化疗对犬HCC疗效有限，依据基因组分析结果，开始使用奥拉帕利进行分子靶向治疗。2个月后出现客观肿瘤进展及占位效应加重，遂行减瘤手术。术后采用奥拉帕利和犬白细胞介素-15（cIL-15）免疫治疗以控制潜在的微转移灶。患者在10个月随访期内达到临床和影像学稳定，同时血清AFP水平显著下降。然而，在停用cIL-15并因疑似不良反应而随后降低奥拉帕利剂量后，血清AFP水平进行性反弹，超声检查证实肿瘤复发。患者在最初发现肿物后20个月死亡。本病例描述了采用多模式治疗方法管理的犬HCC临床病程，并强调了血清AFP作为疾病监测辅助生物标志物的潜在价值。关键词：甲胎蛋白，犬肝细胞癌，免疫治疗，白细胞介素-15，奥拉帕利
Dan等，10.3389/fvets.2026.1942682，《兽医科学前沿》，02，frontiersin.org。引言：原发性肝细胞癌（HCC）约占所有犬肿瘤的1%，占犬原发性肝脏肿瘤的50%以上（1, 2）。该病主要影响老年患犬，平均年龄为12岁，约80%的病例发生于10岁以上的犬（1）。犬HCC呈现三种形态学模式：巨块型、结节型和弥漫型。巨块型占一半以上病例，通常表现为左外侧叶、左内侧叶或尾状叶的孤立性病变，报道的转移率为0至37%。相比之下，结节型和弥漫型各约占20%的病例，且与超过90%的转移率相关（1, 3）。手术性肝叶切除术仍是孤立性巨块型HCC的首选治疗。当实现完全切除时，中位生存时间可超过1,460天（1）。然而，犬HCC通常被认为对常规化疗反应不佳。在无法实现完全手术切除并采用全身化疗的病例中，临床结局通常较差。一项研究报道，未完全切除巨块型HCC的犬中位生存时间为765天，而接受完全切除的犬超过1,836天（3）。血清甲胎蛋白（AFP）已在人类和兽医学中被研究作为HCC的生物标志物。在人类中，AFP广泛用于诊断和治疗反应监测，尽管其敏感性和特异性有限（4）。在犬中，已有报道AFP浓度升高与HCC相关；然而，其临床效用仍不一致，其在纵向疾病监测中的作用尚未明确确立（5, 6）。因此，需要进一步的临床数据来阐明AFP作为犬HCC生物标志物的潜在价值。靶向治疗旨在干扰肿瘤发生和进展中涉及的特定分子通路。尽管基因组分析促进了人类肿瘤学中可操作突变的识别，但其在兽医学中的应用仍然有限，且许多检测到的变异的临床相关性尚未完全明确（7–9）。免疫治疗增强宿主对肿瘤细胞的免疫反应，已成为人类肿瘤学中的重要治疗方法，并日益在兽医学中得到探索。白细胞介素-15（IL-15）是一种由多种细胞类型产生的γc家族细胞因子，在连接先天性和适应性免疫中发挥核心作用。它促进T细胞和自然杀伤（NK）细胞的增殖和存活，并增强细胞毒性免疫反应（10–13）。这些特性支持其作为癌症治疗中免疫治疗剂的潜在应用。本病例报告描述了一只患有HCC的犬的临床过程，该犬采用了多模式治疗方法，包括减瘤手术、基于肿瘤基因组分析的靶向治疗以及犬IL-15（cIL-15）免疫治疗。此外，进行了血清AFP的连续测量，以评估其作为疾病监测生物标志物的潜在作用。病例描述：一只13岁绝育雌性西施犬，表现为持续数月的血清肝酶活性进行性升高。尽管使用曲洛司坦（10 mg/犬，口服，每日两次；Vetoryl®；Dechra，Shrewsbury，英国）管理先前诊断的肾上腺皮质功能亢进，并辅以熊去氧胆酸（7.5 mg/kg，口服，每日两次；Ursa®；Daewoong，首尔，韩国）和饮食管理（Royal Canin® Hepatic；Royal Canin，Aimargues，法国），这些异常仍持续存在。该犬表现为轻度多尿、多饮和多食。病史包括1年前手术切除乳腺肿瘤，随后接受术后cIL-15治疗，随访期间无复发证据。体格检查发现腹部膨隆和对称性躯干色素沉着。全血细胞计数显示淋巴细胞减少和相对嗜酸性粒细胞减少（表1，第0天）。血清化学显示丙氨酸氨基转移酶升高（423 U/L，参考范围[RR] 17–78 U/L）、碱性磷酸酶升高（2,649 U/L，RR 47–254 U/L）和γ-谷氨酰转移酶升高（259 U/L，RR 5–14 U/L）。基于患者的病史和病理发现，怀疑原发性肝胆疾病。因此，进行了腹部超声（US），发现一个孤立性肝脏结节（12.6 × 13.6 mm）。由于不能排除恶性肿瘤，2天后进行了计算机断层扫描（CT），发现一个起源于尾状叶尾状突的孤立性肝脏肿块（图1A,B）。尽管未发现区域淋巴结或远处转移的证据，但肿块紧密粘连于后腔静脉（CVC）。基于这些发现，主要鉴别诊断包括恶性和良性原发性肝胆肿瘤。由于肿块明显粘连于CVC，认为不太可能实现完全手术切除。因此，建议进行减瘤手术并组织病理学检查。然而，由于经济限制，主人拒绝手术，并选择继续对肾上腺皮质功能亢进进行内科管理以及现有的支持和饮食治疗。该犬随后出现间歇性厌食和嗜睡，在初次诊断4个月后通过超声重新评估肝脏肿块。由于肿块显著增大，表明进行性生长，进行了超声引导下Tru-Cut活检。Tru-cut活检标本的组织病理学检查显示肝细胞肿瘤，由多边形细胞组成，具有丰富的颗粒状细胞质和圆形至椭圆形细胞核。存在轻度至中度细胞大小不均和核大小不均，偶见显著核仁和多核细胞。基于整体组织病理学特征，肿瘤诊断为HCC。使用商业检测方法（VET chroma™，ANIVET，韩国）测量血清甲胎蛋白（AFP）浓度，结果升高（280.97 ng/mL，RR < 70 ng/mL）。考虑到常规细胞毒性化疗对该肿瘤的有限疗效，基于基因组分析采用了分子靶向治疗方法。将活检标本提交用于靶向癌症基因测序，使用针对120个癌症相关基因的商业面板（SearchLight DNA assay；Vidium Animal Health，Long Beach，CA，美国），鉴定出MEN1基因中的失活性移码突变（p.Arg663fs）。尽管该MEN1改变在犬HCC中的临床意义仍未知，但被认为可能与肿瘤抑制功能失调相关。基于这一发现和从人类肿瘤学推断的证据，在首次检测到肝脏肿块5个月后，以探索性方式开始使用奥拉帕利（Lynparza®；AstraZeneca，Cambridge，英国），剂量为1.4 mg/kg口服每日两次。开始奥拉帕利治疗两个月后，
Dan 等人。10.3389/fvets.2026.1942682《兽医科学前沿》03 frontiersin.org 表1 一只患有肝细胞癌（HCC）犬的全血细胞计数及血清生化数据。参数 D-147 D-84 D0 * D62 D118 D138 D201 D205 D226 D278 D348 D404 D439 D460 D488 D516 RR RBC（×10 6 / μL） – – 6.63 – 7.16 – – 5.73 5.53 7.01 6.69 7.06 6.5 6.92 5.76 5.94 5.50– 8.87 HCT（%） – – 44.7 – 46.5 – – 37.7 39.1 49.0 47.7 50.1 45.9 48.1 39.9 40.6 37.3– 61.7 HGB（g/dL） – – 15.3 – 16.1 – – 13.0 13.2 16.7 16.3 17.1 16.0 16.8 13.8 14.3 13.1– 20.5 RET（×10 3 / μL） – – 26.5 – 76.6 – – 44.7 21.6 69.4 58.2 66.4 56.6 49.1 48.4 36.0 10–110 PLT（×10 3 / μL） – – 372 – 551 – – 385 282 353 343 352 348 405 398 454 148– 484 WBC（×10 3 / μL） – – 7.55 – 8.64 – – 11.14 7.71 7.02 6.53 9.20 8.43 7.51 11.42 10.00 5.05– 16.76 NEU（×10 3 / μL） – – 5.90 – 6.87 – – 9.08 6.22 5.78 5.32 7.65 6.84 6.32 9.18 8.38 2.95– 11.64 LYM（×10 3 / μL） – – 1.02 – 1.09 – – 1.06 0.8 0.81 0.76 0.92 0.85 0.66 1.45 0.88 1.05– 5.10 MONO（×10 3 / μL） – – 0.51 – 0.54 – – 0.66 0.62 0.37 0.39 0.59 0.66 0.50 0.76 0.7 0.16– 1.12 ALT（U/L） 210 277 423 422 627 620 689 – 204 260 227 212 246 288 332 447 17–78 GGT（U/L） 124 186 259 286 525 581 516 – 72 50 54 69 86 128 183 358 5–14 ALP（U/L） 1,953 2,696 2,649 2,743 超过 3,500 超过 3,500 超过 3,500 – 超过 3,500 超过 3,500 超过 3,500 超过 3,500 超过 3,500 超过 3,500 2,995 2,989 47–254 BUN（mg/dL） – – 19.3 – – – – – 26.9 – 26.8 24.4 – – 20.0 22.0 9.2– 29.2 CREA（mg/dL） – – 0.43 – – – – – 0.4 – 0.34 0.38 – – – 0.32 0.4–1.4 * 首次检出肝脏肿物；RR，参考范围；RBC，红细胞；CREA，肌酐。HCT，血细胞比容；HGB；血红蛋白；RET，网织红细胞；PLT，血小板；WBC，白细胞；NEU，中性粒细胞；LYM，淋巴细胞；MONO，单核细胞；ALT，丙氨酸氨基转移酶；GGT，γ-谷氨酰转移酶；ALP，碱性磷酸酶；BUN，血尿素氮；CREA，肌酐。
Dan等，10.3389/fvets.2026.1942682，《兽医科学前沿》，04，frontiersin.org。随访CT显示肿瘤进一步增大，侧方延伸及占位效应增加，包括对CVC和胰腺的压迫加重，同时血清AFP浓度显著升高（750.11 ng/mL）。鉴于肿瘤持续增大导致疾病进一步进展的风险，且无区域或远处转移，6天后行减瘤手术（图1C）。通过肝叶切除术切除了含肿块的肝叶。肿瘤从CVC上小心分离，手术完成时未见明显肉眼残留肿瘤。然而，由于肿瘤与CVC紧密粘连，该部位无法获得宽阔的手术切缘，且无法确认显微镜下完全切除。术后25天，开始给予cIL-15（Vaxleukin-15®；Vaxcell-Bio Therapeutics，韩国和顺）20 μg/kg静脉注射，每2周一次，以控制潜在微转移并预防肿瘤复发。在奥拉帕利治疗开始8个月后，由于主人难以维持每日两次给药，奥拉帕利方案调整为3.0 mg/kg（口服，每日一次）。此次剂量调整时，血清AFP浓度为218.52 ng/mL，仍低于术前值。患者在10个月随访期内临床保持稳定，血清ALT和GGT活性下降，超声检查无肿瘤复发证据。血清AFP浓度仍高于参考区间，但在此期间未见明显升高（图1）。未观察到具有临床意义的不良反应。在随访期约9个月时，应主人要求停用cIL-15方案，原因是给药后观察到嗜睡。停药1个月后，血清AFP浓度从208.49 ng/mL升高至466.43 ng/mL，引起对肿瘤复发的怀疑。然而，应主人要求，随后将奥拉帕利给药方案减少至3.0 mg/kg口服，隔日一次，原因是认为可能与治疗相关的嗜睡和食欲减退。三周后，观察到血清ALT（288 U/L）和GGT（128 U/L）活性升高（表1，第460天），以及AFP升高（503.23 ng/mL）。奥拉帕利剂量重新调整为3.0 mg/kg口服，每日一次。然而，血清ALT和GGT活性及AFP浓度逐渐升高，约3个月后AFP达到1,213.15 ng/mL。连续腹部超声检查显示一个不均匀肝肿块，初次检测时大小为2.76 × 3.63 cm，随后检查中逐渐增大。虽未获得组织病理学确认，但该肿块被怀疑为复发性HCC（图1D，E）。该犬随后出现图1：一只肝细胞癌（HCC）犬的连续血清甲胎蛋白（AFP）浓度、治疗过程和影像学表现。x轴表示从初次发现肝肿块起的天数（D0），y轴表示血清AFP浓度（ng/mL）。折线图描绘血清AFP浓度的连续变化，各个数据点代表每次测量值。奥拉帕利治疗于D138开始，剂量为1.4 mg/kg口服，每日两次；减瘤手术于D201进行；犬白细胞介素-15（cIL-15）治疗于D226开始，剂量为20 μg/kg静脉注射。红点表示每次cIL-15给药。（A，B）显示D2获得的计算机断层扫描（CT）图像。（A）标准CT图像和（B）肝肿块的三维重建。肿块由箭头指示，可见周边对比增强。（C）切除肝肿块的大体外观。（D，E）显示腹部超声图像，提示肝肿块疑似复发。（D）D488时，肿块大小为2.76 × 3.63 cm，血清AFP浓度为901.04 ng/mL。（E）D516时，肿块大小为3.37 × 5.31 cm，血清AFP浓度为1,213.15 ng/mL。
Dan等，10.3389/fvets.2026.1942682，《兽医科学前沿》，frontiersin.org。癫痫发作和肺水肿，在首次发现肝脏肿块后20个月在家中死亡。无法确定确切的死亡原因。讨论：对于不可切除的犬肝细胞癌（HCC），尚未建立标准化的化疗方案，现有数据仍然有限。既往研究报道了细胞毒性化疗和靶向药物（包括吉西他滨、索拉非尼和托西尼布）的疗效结果不一（表2）（14–16）。然而，各研究之间肿瘤形态、临床分期和治疗策略的差异，以及样本量小，使得直接比较治疗效果具有挑战性，包括在本病例的背景下也是如此。在减瘤手术后，该犬接受了奥拉帕尼和cIL-15治疗。在超过200天的持续治疗期间，超声检查未检测到肝脏肿块，血清AFP浓度保持相对稳定。在后期的随访期间，cIL-15被停用，奥拉帕尼的给药方案由主人修改。血清AFP浓度显著升高（>1,000 ng/mL），诊断影像学证实肿瘤复发并呈进行性增大。奥拉帕尼抑制PARP-1、PARP-2和PARP-3，从而损害PARP介导的DNA修复，并在同源重组修复（HRR）功能受损的肿瘤细胞中促进合成致死（17, 18）。奥拉帕尼的治疗效果已在携带BRCA1或BRCA2突变的肿瘤中得到证实（19, 20）。除BRCA1/2缺陷外，实验研究表明，参与同源重组修复和DNA损伤信号传导的其他几种蛋白质的缺陷也会增加对表2所报告的用于不可切除或切除不完全的犬肝细胞癌的化疗和靶向治疗方案的敏感性。研究（参考文献号）所应用的治疗方案n肿瘤形态和可切除性手术治疗临床疗效和生存结局不良事件（VCOG-CTCAE分级）Elpiner等（14）吉西他滨350–400 mg/m² IV每周一次，共5周18巨块型（n=4；2例切除不完全，2例不可切除）结节型（n=10；9例切除不完全，1例不可切除）弥漫型（n=4；均不可切除）切除不完全（n=11）不可切除（n=7）总体：MST 983天，PFI 971天不可切除亚组：MST 197天，PFI 150天I-II级呕吐、厌食、腹泻、中性粒细胞减少和III级中性粒细胞减少（n=2）Marconato等（15）索拉非尼单药5 mg/kg PO BID 5不可切除未接受过手术（n=3）既往减瘤手术（n=2）个体TTP：363、1,579、1,250、228、168天个体OS：784、1706（存活）、1,398（存活）、255、361天缓解：CR（n=1）、PR（n=3）、SD（n=1）II级脱毛（n=1）、I级色素沉着过度（n=1）、I级红斑/脱毛（n=1）和I级腹泻（n=1）MC[环磷酰胺（10 mg/m² q24h）吡罗昔康（0.3 mg/kg q24h）沙利度胺（2 mg/kg q24h）]6不可切除未接受过手术（n=2）个体TTP：230、205天个体OS：327、279天缓解：SD（n=2）无索拉非尼后转为MC交叉2不可切除未接受过手术（n=5）既往减瘤手术（n=1）中位TTP：27天中位OS：32天缓解：SD（n=3）、PD（n=3）胃肠道；I级（n=2）、II级（n=1）、I级出血性膀胱炎（n=1）、I级肾毒性（n=1）Heishima等（16）托西尼布2.0–3.0 mg/kg PO隔日一次（至少60天）6不能手术，巨块型（原发性、转移性或复发性病灶）无缓解：PR（n=3）、SD（n=1）、PD（n=2）I级腹泻、厌食、中性粒细胞减少、嗜睡和II级腹泻（n=1）n，犬的数量；d，天；mo，月；MST，中位生存时间；PFI，无进展间期；TTP，至进展时间；OS，总生存期；CVC，后腔静脉；CR，完全缓解；PR，部分缓解；SD，疾病稳定；MC，节拍化疗；PD，疾病进展。
Dan等，10.3389/fvets.2026.1942682，《兽医科学前沿》06 frontiersin.org PARP抑制(21)。在人肝细胞癌(HCC)中，PARP1过表达与不良临床结局相关，且奥拉帕利已显示可抑制肿瘤生长(22)。在本病例中，基因组分析鉴定出一处移码变异，即MEN1 p.Arg663fs。在120基因panel所评估的基因中，与同源重组修复(HRR)和DNA损伤反应相关的关键基因（包括BRCA1/2、ATM、PALB2、CHEK2和FANCA）均未发现可报告的变异。因此，MEN1 p.Arg663fs是所分析的120个基因中唯一鉴定出的可报告基因组变异。MEN1编码肿瘤抑制因子menin(23)。实验研究表明，MEN1功能缺失可损害同源重组介导的DNA修复，并增加人胰腺神经内分泌肿瘤模型对PARP抑制剂他拉唑帕利的敏感性(24)。然而，MEN1并非已确立的同源重组缺陷(HRD)相关基因，仅存在MEN1变异不足以确立HRD，也不代表经验证的PARP抑制剂敏感性预测生物标志物。此外，MEN1变异与犬HCC中PARP抑制剂反应性的临床相关性尚未确立。因此，本病例中使用奥拉帕利属于探索性用药，主要基于来自人类和临床前研究的证据。重要的是，肿瘤在术前奥拉帕利单药治疗期间发生进展，未能证明可归因于奥拉帕利的治疗效果。在已确立的HRR相关基因中无可报告变异或其他HRD证据的情况下，奥拉帕利对后续疾病控制的贡献仍不确定，不能排除其提供很少或无治疗获益的可能性。所观察到的临床病程可能反而主要受肿瘤减积手术影响，cIL-15可能有部分贡献，此外还受肿瘤生物学行为及其他未测量因素的影响。有必要开展进一步研究，评估奥拉帕利在具有确认的HRD相关变异的犬HCC以及缺乏可检测的经典HRR相关变异的肿瘤中的效果，以确定HRD状态是否可作为PARP抑制反应的预测生物标志物。除靶向治疗外，cIL-15作为免疫治疗辅助用药给药。IL-15是一种γc家族细胞因子，可促进细胞毒性淋巴细胞（包括NK细胞和CD8+ T细胞）的增殖和活化，并增强抗肿瘤免疫反应(10–13)。在一项健康犬研究中，重组cIL-15耐受性良好，并可诱导抗癌效应细胞扩增而不刺激调节性T细胞(25)。此外，在患有自然发生肿瘤（包括淋巴瘤和乳腺肿瘤）的犬中开展的临床研究表明，cIL-15联合常规疗法给药与肿瘤缓解率提高、肿瘤相关生物标志物降低和生活质量改善相关，且安全性特征可接受(26, 27)。这些发现支持cIL-15作为兽医肿瘤学辅助免疫治疗策略的可行性，尤其适用于残留或微转移性疾病。在本病例中，cIL-15在术后疾病稳定期间给药。然而，其治疗贡献无法直接证明，其在疾病控制中的作用仍不确定。本病例中使用的cIL-15剂量(20 μg/kg IV)是根据既往犬类研究(27)报告的给药方案选择的。然而，cIL-15在犬HCC中的最佳给药方案尚未确立，值得进一步研究。AFP是一种与胎儿发育相关的糖蛋白，由肝脏和卵黄囊产生，出生后由于基因表达受抑制通常以低浓度存在(28, 29)。在人HCC中，约60–80%的病例AFP升高，广泛用于诊断、预后判断和治疗监测(4, 29)。在兽医领域，已有报道AFP在患有HCC的犬中升高(6)。近期一项转录组分析显示，与正常肝组织相比，犬HCC组织中AFP显著上调(30)。然而，其诊断和监测效用仍不一致，尚未明确界定。在本病例中，术前血清AFP浓度超过参考区间十倍以上，肿瘤减积手术后迅速下降，在术后随访期间保持相对较低，随后在肿瘤复发的同时显著升高(1213.15 ng/mL)。由于血清AFP的初始下降发生在开始cIL-15治疗之前，最恰当的解释是主要反映肿瘤减积性切除，而奥拉帕利对这一变化的贡献仍不确定。既往报告同样记录了肿瘤减积手术后血清AFP的显著下降(5, 6)，提示连续AFP浓度可能反映临床病程中肿瘤负荷的变化，尽管其作为犬HCC可靠生物标志物的效用仍有待确立。此外，已有报道指出AFP浓度显著升高可支持HCC的怀疑，因为患有非肿瘤性肝病和非肝脏肿瘤的犬的浓度通常较低(6)。然而，鉴于犬中可获得的数据有限以及与其他疾病可能重叠，AFP应谨慎解读，并结合影像学和组织病理学发现，而非作为单一生物标志物。本病例存在若干局限性。作为单例病例报告，无法确立奥拉帕利或cIL-15在犬HCC中的疗效，每种治疗的个体贡献仍不确定。此外，主人发起的治疗调整使得无法在一致的治疗方案下进行评估，并限制了对任一疗法临床反应的解读。由于犬HCC尚无既定给药方案，对奥拉帕利疗效的解读进一步受限。由于区域淋巴结未进行组织病理学检查，且疑似复发性肝脏肿物未获组织病理学确认，无法完成完整的病理分期。由于未进行尸检，疾病的最终范围和直接死因仍未确定。最后，连续AFP测量用于监测犬HCC疾病进展和治疗反应的临床效用需要进一步验证。总之，本病例描述了一只患不可切除HCC的犬的临床病程，采用包括肿瘤减积手术、靶向治疗和免疫治疗在内的多模式方法进行管理。观察到的血清AFP与治疗和疾病进展相关的时间变化提示，AFP可能具有作为犬HCC疾病病程监测辅助生物标志物的潜在效用。数据可用性声明 本研究中呈现的原始贡献已包含在文章/补充材料中，进一步咨询可联系通讯作者。
Dan等。10.3389/fvets.2026.1942682《兽医科学前沿》07 frontiersin.org 伦理声明 根据当地法律和机构要求，涉及动物的研究无需伦理批准，因为这是一份关于一只私人拥有的犬因自然发生疾病而接受治疗的回顾性报告，而非前瞻性实验动物研究，且未仅为研究目的而进行任何额外操作。已获得动物所有者书面知情同意，同意其动物参与本研究。已获得所有者书面知情同意，同意发表本病例报告。作者贡献 T-JD：概念化、数据管理、形式分析、调查、可视化、写作——原稿、写作——审阅与编辑。C-HY：资源、写作——审阅与编辑。Y-JK：数据管理、形式分析、写作——审阅与编辑。M-HK：写作——审阅与编辑、监督。M-AK：资源、形式分析、调查、写作——审阅与编辑。K-SL：写作——审阅与编辑、数据管理。H-MP：写作——审阅与编辑、概念化、方法学、资源、监督。资助 作者声明未获得本工作和/或其发表的财务支持。利益冲突 作者M-AK受雇于VET and GENE公司。其余作者声明，本工作是在没有任何可被解释为潜在利益冲突的商业或财务关系的情况下进行的。生成式AI声明 作者声明在本手稿的创作中使用了生成式AI。生成式AI用于将韩语句子翻译成英语。本文中图表旁提供的任何替代文本（alt文本）均由Frontiers在人工智能支持下生成，并已做出合理努力确保准确性，包括在可能情况下由作者审阅。如果您发现任何问题，请联系我们。出版者注 本文中表达的所有主张仅代表作者本人，不一定代表其所属组织，也不一定代表出版者、编辑和审稿人的观点。本文中可能评估的任何产品或其制造商可能提出的任何主张，均不受出版者保证或认可。参考文献 1. Nick B. “肝脏和胆道树肿瘤”。见：Ettinger SJ、Feldman EC和Cote E编。《兽医内科学教科书》，第9版。费城：Elsevier Health Sciences（2024）。第1852–8页。2. Jonathan B. “肝脏肿瘤”。见：Lascelles D和Dobson J编。《BSAVA犬猫肿瘤学手册》，第3版。英国格洛斯特：英国小动物兽医协会（2016）。第229–34页。3. Matsuyama A、Takagi S、Hosoya K、Kagawa Y、Nakamura K、Deguchi T等。手术切缘对37只犬巨大肝细胞癌生存的影响。《N Z Vet J》（2017）65:227–31。doi: 10.1080/00480169.2017.1319304 4. Sauzay C、Petit A、Bourgeois AM、Barbare JC、Chauffert B、Galmiche A等。甲胎蛋白（AFP）：肝细胞癌中的多用途标志物。《Clin Chim Acta》（2016）463:39–44。doi: 10.1016/j.cca.2016.10.006 5. Kitao S、Yamada T、Ishikawa T、Madarame H、Furuichi M、Neo S等。肝细胞癌犬血清和肿瘤组织中的甲胎蛋白。《J Vet Diagn Invest》（2006）18:291–5。doi: 10.1177/104063870601800312 6. Yamada T、Fujita M、Kitao S、Ashida Y、Nishizono K、Tsuchiya R等。患有各种肝脏疾病的犬的血清甲胎蛋白值。《J Vet Med Sci》（1999）61:657–9。doi: 10.1292/jvms.61.657 7. Tsimberidou AM。癌症靶向治疗。《Cancer Chemother Pharmacol》（2015）76:1113–32。doi: 10.1007/s00280-015-2861-1 8. Ke X、Shen L。癌症分子靶向治疗：进展与未来展望。《Front Lab Med》（2017）1:69–75。doi: 10.1016/j.flm.2017.06.001 9. Lee YT、Tan YJ、Oon CE。分子靶向治疗：特异性治疗癌症。《Eur J Pharmacol》（2018）834:188–96。doi: 10.1016/j.ejphar.2018.07.034 10. Fiore PF、Di Matteo S、Tumino N、Mariotti FR、Pietra G、Ottonello S等。白细胞介素-15与癌症：一些已解决和许多未解决的问题。《J Immunother Cancer》（2020）8:e001428。doi: 10.1136/jitc-2020-001428 11. Guo Y、Luan L、Patil NK、Sherwood ER。IL-15/IL-15Rα复合物作为抗肿瘤和抗病毒剂的免疫生物学。《Cytokine Growth Factor Rev》（2017）38:10–21。doi: 10.1016/j.cytogfr.2017.08.002 12. Patidar M、Yadav N、Dalai SK。白细胞介素15：免疫治疗的关键细胞因子。《Cytokine Growth Factor Rev》（2016）31:49–59。doi: 10.1016/j.cytogfr.2016.06.001 13. Robinson TO、Schluns KS。IL-15在免疫肿瘤治疗中的潜力和前景。《Immunol Lett》（2017）190:159–68。doi: 10.1016/j.imlet.2017.08.010 14. Elpiner AK、Brodsky EM、Hazzah TN、Post GS。单药吉西他滨化疗治疗犬肝细胞癌。《Vet Comp Oncol》（2011）9:260–8。doi: 10.1111/j.1476-5829.2011.00262.x 15. Marconato L、Sabattini S、Marisi G、Rossi F、Leone VF、Casadei-Gardini A。索拉非尼治疗不可切除肝细胞癌：犬的初步毒性和活性数据。《Cancers》（2020）12:1272。doi: 10.3390/cancers12051272 16. Heishima K、Iwasaki R、Kawabe M、Murakami M、Sakai H、Maruo K等。单药toceranib短期给药治疗6例无法手术的巨大犬肝细胞癌。《J Am Anim Hosp Assoc》（2019）55:35–41。doi: 10.5326/JAAHA-MS-6788 17. Maiorano BA、Maiorano MFP、Maiello E。奥拉帕利与晚期卵巢癌：过去总结与未来展望。《Front Pharmacol》（2023）14:1162665。doi: 10.3389/fphar.2023.1162665 18. Bochum S、Berger S、Martens UM。“奥拉帕利”。见：《肿瘤学中的小分子》Cham：Springer（2018）。第217–33页。19. Robson M、Im SA、Senkus E、Xu B、Domchek SM、Masuda N等。奥拉帕利治疗种系BRCA突变患者的转移性乳腺癌。《N Engl J Med》（2017）377:523–33。doi: 10.1056/NEJMoa1706450 20. Ledermann J、Harter P、Gourley C、Friedlander M、Vergote I、Rustin G等。奥拉帕利维持治疗铂敏感复发性浆液性卵巢癌患者：随机2期试验中按BRCA状态预设的回顾性结局分析。《Lancet Oncol》（2014）15:852–61。doi: 10.1016/S1470-2045(14)70228-1 21. McCabe N、Turner NC、Lord CJ、Kluzek K、Białkowska A、Swift S等。同源重组修复DNA损伤缺陷与聚（ADP-核糖）聚合酶抑制敏感性。《Cancer Res》（2006）66:8109–15。doi: 10.1158/0008-5472.CAN-06-0140
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Frontiers in Veterinary Science01frontiersin.org TYPE Case Report PUBLISHED 06 October 2026 DOI 10.3389/fvets.2026.1942682 OPEN ACCESS EDITED BY Niccolò Fonti, University of Padua, Italy REVIEWED BY Guanghua Liu, Shanghai Jiao Tong University, China Mohammad Arif, Bangladesh Agricultural University, Bangladesh *CORRESPONDENCE Hee-Myung Park parkhee@konkuk.ac.kr RECEIVED 20 July 2026 REVISED 11 September 2026 ACCEPTED 21 September 2026 PUBLISHED 06 October 2026 CITATION Dan T-J, Yang C-H, Kim Y-J, Kang M-H, Kang M-A, Lee K-S and Park H-M (2026) Case Report: Long term multimodality treatment of canine hepatocellular carcinoma with serial monitoring of serum alpha-fetoprotein. Front. Vet. Sci. 13:1942682. doi: 10.3389/fvets.2026.1942682 COPYRIGHT © 2026 Dan, Yang, Kim, Kang, Kang, Lee and Park. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Case Report: Long term multimodality treatment of canine hepatocellular carcinoma with serial monitoring of serum alpha-fetoprotein Tae-Jung Dan 1 , Cheol-Ho Yang 2 , Yeon-Jin Kim 1 , Min-Hee Kang 3 , Mi-Ae Kang 4 , Kwang-Sup Lee 1 and Hee-Myung Park 1 * 1 Department of Veterinary Internal Medicine, College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea, 2 Times Animal Medical Center, Suwon-si, Gyeonggi-do, Republic of Korea, 3 Department of Bio-animal Health, Jangan University, Hwaseong, Republic of Korea, 4 VET and GENE, Seongnam, Republic of Korea A 13-year-old spayed female Shih Tzu presented with a several-month history of progressively increasing liver enzyme activities concurrent with managed hyperadrenocorticism. Diagnostic imaging revealed a solitary hepatic mass originating from the caudate process of the caudate lobe adhering to the caudal vena cava. Hepatocellular carcinoma (HCC) was confirmed via histopathological examination of an ultrasound-guided tru-cut biopsy, accompanied by a markedly elevated serum alpha-fetoprotein (AFP) concentration. Molecular targeted therapy with olaparib was initiated since complete surgical resection was unachievable due to tumor adherence to the caudal vena cava and conventional chemotherapy has limited efficacy for canine HCC, based on genomic profiling. Following objective tumor progression and worsening mass effect after 2 months, cytoreductive surgery was performed. Postoperatively, olaparib and canine interleukin-15 (cIL-15) immunotherapy were instituted to control potential micrometastases. The patient achieved clinical and radiographic stability for a 10-month followup period, accompanied by a significant drop in serum AFP levels. However, following the discontinuation of cIL-15 and subsequent reduction of olaparib dosage because of suspected adverse effects, serum AFP levels rebounded progressively, and tumor recurrence was confirmed via ultrasonography. The patient died 20 months after the initial detection of the mass. This case describes the clinical course of canine HCC managed with a multimodal therapeutic approach and highlights the potential utility of serum AFP as an adjunctive biomarker for disease monitoring. KEYWORDS alpha-fetoprotein, canine hepatocellular carcinoma, immunotherapy, interleukin-15, olaparib
Dan et al. 10.3389/fvets.2026.1942682 Frontiers in Veterinary Science02frontiersin.org Introduction Primary hepatocellular carcinoma (HCC) accounts for approximately 1% of all canine neoplasms and over 50% of primary liver tumors in dogs (1, 2). It predominantly affects geriatric patients, with a mean age of 12 years, and approximately 80% of cases occur in dogs older than 10 years (1). Canine HCC presents in three morphological patterns: massive, nodular, and diffuse. The massive form comprises more than half of cases and typically appears as a solitary lesion in the left lateral, left medial, or caudate lobes, with reported metastatic rates ranging from 0 to 37%. In contrast, the nodular and diffuse forms each account for approximately 20% of cases and are associated with metastatic rates exceeding 90% (1, 3). Surgical lobectomy remains the treatment of choice for solitary massive HCC. When complete excision is achieved, median survival times can exceed 1,460 days (1). However, canine HCC is generally considered poorly responsive to conventional chemotherapy. In cases where complete surgical resection is not feasible and systemic chemotherapy is pursued, clinical outcomes are typically less favorable. One study reported a median survival time of 765 days in dogs without complete resection of massive HCC, compared with over 1,836 days in dogs that underwent complete excision (3). Serum alpha-fetoprotein (AFP) has been investigated as a biomarker for HCC in both human and veterinary medicine. In humans, AFP is widely used for diagnosis and monitoring of treatment response, although its sensitivity and specificity are limited (4). In dogs, increased AFP concentrations have been reported in association with HCC; however, its clinical utility remains inconsistent, and its role in longitudinal disease monitoring has not been well established (5, 6). Therefore, further clinical data are needed to clarify the potential value of AFP as a biomarker in canine HCC. Targeted therapy aims to interfere with specific molecular pathways involved in tumor development and progression. Although genomic profiling has facilitated the identification of actionable mutations in human oncology, its application in veterinary medicine remains limited, and the clinical relevance of many detected alterations is not fully defined (7–9). Immunotherapy, which enhances host immune responses against tumor cells, has emerged as an important therapeutic approach in human oncology and is increasingly being explored in veterinary medicine. Interleukin-15 (IL-15) is a γc family cytokine produced by multiple cell types that plays a central role in bridging innate and adaptive immunity. It promotes the proliferation and survival of T cells and natural killer (NK) cells and enhances cytotoxic immune responses (10–13). These properties support its potential application as an immunotherapeutic agent in cancer treatment. The present case report describes the clinical course of a dog with HCC managed with a multimodal therapeutic approach, including cytoreductive surgery, targeted therapy based on tumor genomic profiling, and canine IL-15 (cIL-15) immunotherapy. In addition, serial measurement of serum AFP was performed to evaluate its potential role as a biomarker for disease monitoring. Case description A 13-year-old spayed female Shih Tzu presented with a severalmonth history of progressive increases in serum liver enzyme activities. These abnormalities persisted despite management of previously diagnosed hyperadrenocorticism with trilostane (10 mg/dog, PO, BID; Vetoryl ® ; Dechra, Shrewsbury, UK) together with adjunctive treatment using ursodeoxycholic acid (7.5 mg/kg, PO, BID; Ursa ® ; Daewoong, Seoul, South Korea) and dietary management (Royal Canin ® Hepatic; Royal Canin, Aimargues, France). The dog presented with mild polyuria, polydipsia, and polyphagia. The medical history included surgical excision of mammary gland tumors 1 year earlier, followed by postoperative cIL-15 therapy, with no evidence of recurrence during follow-up. Physical examination revealed abdominal distension and symmetrical truncal hyperpigmentation. Complete blood count revealed lymphopenia and relative eosinopenia (Table 1, day 0). Serum chemistry revealed elevated alanine aminotransferase (423 U/L, reference range [RR] 17–78 U/L), alkaline phosphatase (2,649 U/L, RR 47–254 U/L), and γ-glutamyltransferase (259 U/L, RR 5–14 U/L). Based on the patient’s medical history and pathological findings, suspicion of a primary hepatobiliary disorder was suspected. Accordingly, abdominal ultrasonography (US) was performed and revealed a solitary hepatic nodule (12.6 × 13.6 mm). As malignancy could not be excluded, computed tomography (CT) was performed 2 days later and revealed a solitary hepatic mass arising from the caudate process of the caudate lobe (Figures 1A,B). Although no evidence of regional lymph node or distant metastasis was identified, the mass was closely adherent to the caudal vena cava (CVC). Based on these findings, the primary differential diagnoses included malignant and benign primary hepatobiliary neoplasms. Owing to the marked adherence of the mass to the CVC, complete surgical resection was considered unlikely to be achievable. Therefore, cytoreductive surgery with histopathologic examination was recommended. However, the owner declined surgery because of financial constraints and elected to continue medical management of hyperadrenocorticism together with the existing supportive and dietary therapies. The dog subsequently developed intermittent anorexia and lethargy, and the hepatic mass was re-evaluated by ultrasonography 4 months after the initial diagnosis. Because the mass had increased substantially in size, indicating progressive growth, an ultrasound-guided Tru-Cut biopsy was performed. Histopathological examination of the Tru-cut biopsy specimen revealed a hepatocellular neoplasm composed of polygonal cells with abundant granular cytoplasm and round to oval nuclei. Mild to moderate anisocytosis and anisokaryosis were present, with occasional prominent nucleoli and multinucleated cells. Based on the overall histopathological features, the tumor was diagnosed as HCC. Serum alpha-fetoprotein (AFP) concentration was measured using a commercial assay (VET chroma™, ANIVET, Republic of Korea) and was elevated (280.97 ng/mL, RR < 70 ng/mL). Considering the limited efficacy of conventional cytotoxic chemotherapy for this tumor, a molecularly targeted therapeutic approach was pursued based on genomic profiling. The biopsy specimen was submitted for targeted cancer gene sequencing using a commercial panel targeting 120 cancer-related genes (SearchLight DNA assay; Vidium Animal Health, Long Beach, CA, USA), which identified an inactivating frameshift mutation (p.Arg663fs) in the MEN1 gene. Although the clinical significance of this MEN1 alteration in canine HCC remains unknown, it was considered potentially relevant to tumor suppressor dysfunction. Based on this finding and evidence extrapolated from human oncology, olaparib (Lynparza ® ; AstraZeneca, Cambridge, UK) was initiated on an exploratory basis at 1.4 mg/kg PO twice daily, 5 months after the initial detection of the hepatic mass. Two months after initiation of olaparib treatment,
Dan et al. 10.3389/fvets.2026.1942682 Frontiers in Veterinary Science03frontiersin.org TABLE 1 Complete blood counts and serum biochemistry data of a dog with HCC. Parameters D-147 D-84 D0 * D62 D118 D138 D201 D205 D226 D278 D348 D404 D439 D460 D488 D516 RR RBC (×10 6 / μ L) – – 6.63 – 7.16 – – 5.73 5.53 7.01 6.69 7.06 6.5 6.92 5.76 5.94 5.50– 8.87 HCT (%) – – 44.7 – 46.5 – – 37.7 39.1 49.0 47.7 50.1 45.9 48.1 39.9 40.6 37.3– 61.7 HGB (g/dL) – – 15.3 – 16.1 – – 13.0 13.2 16.7 16.3 17.1 16.0 16.8 13.8 14.3 13.1– 20.5 RET (×10 3 / μ L) – – 26.5 – 76.6 – – 44.7 21.6 69.4 58.2 66.4 56.6 49.1 48.4 36.0 10–110 PLT (×10 3 / μ L) – – 372 – 551 – – 385 282 353 343 352 348 405 398 454 148– 484 WBC (×10 3 / μ L) – – 7.55 – 8.64 – – 11.14 7.71 7.02 6.53 9.20 8.43 7.51 11.42 10.00 5.05– 16.76 NEU (×10 3 / μ L) – – 5.90 – 6.87 – – 9.08 6.22 5.78 5.32 7.65 6.84 6.32 9.18 8.38 2.95– 11.64 LYM (×10 3 / μ L) – – 1.02 – 1.09 – – 1.06 0.8 0.81 0.76 0.92 0.85 0.66 1.45 0.88 1.05– 5.10 MONO (×10 3 / μ L) – – 0.51 – 0.54 – – 0.66 0.62 0.37 0.39 0.59 0.66 0.50 0.76 0.7 0.16– 1.12 ALT (U/L) 210 277 423 422 627 620 689 – 204 260 227 212 246 288 332 447 17–78 GGT (U/L) 124 186 259 286 525 581 516 – 72 50 54 69 86 128 183 358 5–14 ALP (U/L) 1,953 2,696 2,649 2,743 Over 3,500 Over 3,500 Over 3,500 – Over 3,500 Over 3,500 Over 3,500 Over 3,500 Over 3,500 Over 3,500 2,995 2,989 47–254 BUN (mg/dL) – – 19.3 – – – – – 26.9 – 26.8 24.4 – – 20.0 22.0 9.2– 29.2 CREA (mg/dL) – – 0.43 – – – – – 0.4 – 0.34 0.38 – – – 0.32 0.4–1.4 * The initial detection of the hepatic mass; RR, reference range; RBC, red blood cells; CREA, creatinine. HCT, hematocrit; HGB; hemoglobin; RET, reticulocytes; PLT, platelets; WBC, white blood cells; NEU, neutrophils; LYM, lymphocytes; MONO, monocytes; ALT, alanine aminotransferase; GGT, γ -glutamyltransferase; ALP, alkaline phosphatase; BUN, blood urea nitrogen; CREA, creatinine.
Dan et al. 10.3389/fvets.2026.1942682 Frontiers in Veterinary Science04frontiersin.org follow-up CT revealed further tumor enlargement with increased lateral extension and mass effect, including greater compression of the CVC and pancreas, accompanied by a marked increase in serum AFP concentration (750.11 ng/mL). Given the risk of further disease progression with continued tumor enlargement and the absence of regional or distant metastasis, cytoreductive surgery was performed 6 days later (Figure 1C). The hepatic lobe containing the mass was resected by lobectomy. The tumor was carefully dissected from the CVC, and no gross residual tumor was evident at the completion of surgery. However, because the tumor was closely adherent to the CVC, a wide surgical margin could not be obtained at this site, and complete microscopic excision could not be confirmed. Twenty-five days postoperatively, cIL-15 (Vaxleukin-15 ® ; Vaxcell- Bio Therapeutics, Hwasun, Republic of Korea) was initiated at 20 μg/ kg intravenously every 2 weeks to control potential micrometastases and prevent tumor recurrence. The olaparib regimen was adjusted to 3.0 mg/kg (PO, SID) owing to the owner’s difficulty in maintaining twice-daily administration, 8 months after initiation of olaparib treatment. At the time of this dose modification, the serum AFP concentration was 218.52 ng/mL, which remained lower than the preoperative value. The patient remained clinically stable throughout a 10-month follow-up period, with decreases in serum ALT and GGT activities and no ultrasonographic evidence of tumor recurrence. Serum AFP concentrations remained above the reference interval but showed no marked increase during this period (Figure 1). No clinically significant adverse effects were observed. The cIL-15 regimen was discontinued approximately 9 months into the follow-up period at the owner’s request because of lethargy observed after administration. One month after discontinuation, serum AFP concentration increased from 208.49 ng/mL to 466.43 ng/ mL, raising suspicion of tumor recurrence. However, at the owner’s request, the olaparib dosing regimen was subsequently reduced to 3.0 mg/kg PO every other day because of lethargy and hyporexia considered potentially treatment-related. Three weeks later, elevations in serum ALT (288 U/L) and GGT (128 U/L) activities (Table 1, day 460), and AFP (503.23 ng/mL) were observed. The olaparib dosage was readjusted to 3.0 mg/kg PO once daily. However, serum ALT and GGT activities and AFP concentrations progressively increased, with AFP reaching 1,213.15 ng/mL approximately 3 months later. Serial abdominal ultrasonography demonstrated a heterogeneous hepatic mass, measuring 2.76 × 3.63 cm at initial detection, with progressive enlargement on subsequent examinations. Although histopathologic confirmation was not obtained, the mass was considered suspicious for recurrent HCC (Figures 1D,E). The dog subsequently developed FIGURE 1 Serial serum alpha-fetoprotein (AFP) concentrations, treatment course, and imaging findings in a dog with hepatocellular carcinoma (HCC). The x-axis represents days from the initial detection of the hepatic mass (D0), and the y-axis represents serum AFP concentration (ng/mL). The line graph depicts serial changes in serum AFP concentration, with individual data points representing each measurement. Olaparib treatment was initiated on D138 at 1.4 mg/kg PO twice daily, cytoreductive surgery was performed on D201, and canine interleukin-15 (cIL-15) therapy was initiated on D226 at 20 μg/kg IV. Red dots indicate individual administration of cIL-15. (A,B) Show computed tomography (CT) images obtained on D2. (A) Standard CT image and (B) three-dimensional reconstruction of the hepatic mass. The mass is indicated by arrows, and peripheral contrast enhancement is evident. (C) Gross appearance of the resected hepatic mass. (D,E) Show abdominal ultrasonographic images demonstrating suspected recurrence of the hepatic mass. (D) On D488, the mass measured 2.76 × 3.63 cm, with serum AFP concentration of 901.04 ng/mL. (E) On D516, the mass measured 3.37 × 5.31 cm, with serum AFP concentration of 1,213.15 ng/mL.
Dan et al. 10.3389/fvets.2026.1942682 Frontiers in Veterinary Science05frontiersin.org seizures and pulmonary edema and died at home 20 months after initial detection of the hepatic mass. The definitive cause of death could not be determined. Discussion Standardized chemotherapy protocols for unresectable canine HCC have not been established, and available data remains limited. Previous studies have reported variable outcomes with cytotoxic chemotherapy and targeted agents, including gemcitabine, sorafenib, and toceranib (Table 2) (14–16). However, differences in tumor morphology, clinical stage, and treatment strategies across studies, along with small sample sizes, make direct comparison of therapeutic efficacy challenging, including in the context of the present case. Following cytoreductive surgery, the dog received olaparib and cIL-15 therapy. During more than 200 days of continued treatment, no hepatic mass was detected on ultrasonography, and serum AFP concentrations remained relatively stable. During the later follow-up period, cIL-15 was discontinued and the olaparib dosing regimen was modified by the owner. Serum AFP concentrations increased markedly (>1,000 ng/mL), and diagnostic imaging confirmed tumor recurrence with progressive enlargement. Olaparib inhibits PARP-1, PARP-2, and PARP-3, thereby impairing PARP-mediated DNA repair and promoting synthetic lethality in tumor cells with impaired homologous recombination repair (HRR) (17, 18). The therapeutic efficacy of olaparib has been demonstrated in tumors harboring mutations in BRCA1 or BRCA2 (19, 20). In addition to BRCA1/2 deficiency, deficiencies in several other proteins involved in homologous recombination repair and DNA damage signaling have been shown experimentally to increase sensitivity to TABLE 2 Reported chemotherapy and targeted therapy protocols for unresectable or incompletely resected canine hepatocellular carcinoma. Study (reference no.) Treatment protocol applied nTumor morphology and resectability Surgical treatment Clinical efficacy and survival outcomes Adverse events (VCOG-CTCAE grade) Elpiner et al. (14)Gemcitabine 350–400 mg/ m 2 IV weekly for 5 weeks 18Massive (n = 4; 2 incomplete, 2 unresectable) Nodular (n = 10; 9 incomplete, 1 unresectable) Diffuse (n = 4; all unresectable) Incompletely excised (n = 11) Nonresectable (n = 7) Overall: MST 983 d, PFI 971 d Unresectable subset: MST 197 d, PFI 150 d Grade I-II Vomiting, anorexia, diarrhea, neutropenia and Grade III Neutropenia (n = 2) Marconato et al. (15)Sorafenib alone 5 mg/kg PO BID 5UnresectableNo prior surgery (n = 3) Prior cytoreductive surgery (n = 2) Individual TTP: 363, 1,579, 1,250, 228, 168 d Individual OS: 784, 1706 (alive), 1,398 (alive), 255, 361 d Response: CR (n = 1), PR (n = 3), SD (n = 1) Grade II alopecia (n = 1), Grade I hyperpigmentation (n = 1), Grade I erythema/alopecia (n = 1) and Grade I diarrhea (n = 1) MC [Cyclophosphamide (10 mg/m 2 q24h) Piroxicam (0.3 mg/kg q24h) Thalidomide (2 mg/kg q24h)] 6UnresectableNo prior surgery (n = 2) Individual TTP: 230, 205 d Individual OS: 327, 279 d Response: SD (n = 2) None Sorafenib then MC crossover 2UnresectableNo prior surgery (n = 5) Prior cytoreductive surgery (n = 1) Median TTP: 27 d Median OS: 32 d Response: SD (n = 3), PD (n = 3) Gastrointestinal; Grade I (n = 2), Grade II (n = 1), Grade I hemorrhagic cystitis (n = 1), Grade I renal toxicity (n = 1) Heishima et al. (16)Toceranib 2.0–3.0 mg/kg PO EOD (minimum 60 days) 6Inoperable, massive (primary, metastatic, or recurrent lesion) NoneResponse: PR (n = 3), SD (n = 1), PD (n = 2) Grade I diarrhea, anorexia, neutropenia, lethargy and Grade II diarrhea (n = 1) n, number of dogs; d, days; mo, months; MST, median survival time; PFI, progression-free interval; TTP, time to progression; OS, overall survival; CVC, caudal vena cava; CR, complete response; PR, partial response; SD, stable disease; MC, metronomic chemotherapy; PD, progressive disease.
Dan et al. 10.3389/fvets.2026.1942682 Frontiers in Veterinary Science06frontiersin.org PARP inhibition (21). In human HCC, PARP1 overexpression has been associated with poor clinical outcomes, and olaparib has been shown to suppress tumor growth (22). In the present case, genomic analysis identified a frameshift alteration, MEN1 p.Arg663fs. No reportable alterations were identified in key genes associated with homologous recombination repair (HRR) and DNA damage response, including BRCA1/2, AT M, PALB2, CHEK2, and FANCA, among those assessed by the 120-gene panel. Accordingly, MEN1 p.Arg663fs was the only reportable genomic alteration identified among the 120 genes analyzed. MEN1 encodes the tumor suppressor menin (23). Experimental studies have demonstrated that loss of MEN1 function can impair homologous recombination-mediated DNA repair and increase sensitivity to the PARP inhibitor talazoparib in human pancreatic neuroendocrine tumor models (24). However, MEN1 is not an established homologous recombination deficiency (HRD)-associated gene, and the presence of a MEN1 alteration alone is insufficient to establish HRD and does not represent a validated predictive biomarker of PARP inhibitor sensitivity. Furthermore, the clinical relevance of MEN1 alterations to PARP inhibitor responsiveness in canine HCC has not been established. Therefore, the use of olaparib in the present case was exploratory and was based primarily on evidence derived from human and preclinical studies. Importantly, tumor progression occurred during preoperative olaparib monotherapy, and no therapeutic effect attributable to olaparib could be demonstrated. In the absence of reportable alterations in established HRR-associated genes or other evidence of HRD, the contribution of olaparib to subsequent disease control remains uncertain, and the possibility that it provided little or no therapeutic benefit cannot be excluded. The observed clinical course may instead have been influenced predominantly by cytoreductive surgery, with a possible contribution from cIL-15, as well as by the biological behavior of the tumor and other unmeasured factors. Further studies evaluating olaparib in canine HCC with confirmed HRD-associated alterations and in tumors lacking detectable canonical HRR-associated alterations are warranted to determine whether HRD status may serve as a predictive biomarker for response to PARP inhibition. In addition to targeted therapy, cIL-15 was administered as an immunotherapeutic adjunct. IL-15 is a γc family cytokine that promotes the proliferation and activation of cytotoxic lymphocytes, including NK cells and CD8 + T cells, and enhances antitumor immune responses (10–13). In a study of healthy dogs, recombinant cIL-15 was well tolerated and induced expansion of anticancer effector cells without stimulating regulatory T cells (25). In addition, clinical studies in dogs with naturally occurring tumors, including lymphoma and mammary gland tumors, have demonstrated that cIL-15 administration in conjunction with conventional therapies was associated with improved tumor response rates, reductions in tumor-related biomarkers, and enhanced quality of life, with an acceptable safety profile (26, 27). These findings support the feasibility of cIL-15 as an adjunctive immunotherapeutic strategy in veterinary oncology, particularly for residual or micrometastatic disease. In the present case, cIL-15 was administered during postoperative period while the disease remained stable. However, its therapeutic contribution could not be directly demonstrated, and its role in disease control remains uncertain. The cIL-15 dose used in the present case (20 μg/kg IV) was selected based on a dosing regimen reported in a previous canine study (27). However, an optimal dosing regimen for cIL-15 in canine HCC has not been established and warrants further investigation. AFP is a glycoprotein associated with fetal development, produced by the liver and yolk sac, and is typically present at low concentrations after birth due to suppression of gene expression (28, 29). In human HCC, AFP is elevated in approximately 60–80% of cases and is widely used for diagnosis, prognostication, and treatment monitoring (4, 29). In veterinary medicine, AFP has been reported to increase in dogs with HCC (6). A recent transcriptomic analysis demonstrated marked upregulation of AFP in canine HCC tissue relative to normal hepatic tissue (30). However, its diagnostic and monitoring utility remains inconsistent and is not yet well defined. In the present case, serum AFP concentrations exceeded the reference interval by more than tenfold prior to surgery, declined rapidly after cytoreductive surgery, and remained relatively low during the postoperative follow-up period before increasing markedly (1213.15 ng/ mL) in parallel with tumor recurrence. Because the initial decrease in serum AFP occurred before initiation of cIL-15 therapy, it is most appropriately interpreted as primarily reflecting cytoreductive tumor removal, whereas the contribution of olaparib to this change remains uncertain. Previous reports have similarly documented a marked decrease in serum AFP after cytoreductive surgery (5, 6), suggesting that serial AFP concentrations may reflect changes in tumor burden over the clinical course, although their utility as a reliable biomarker in canine HCC remains to be established. Additionally, markedly elevated AFP concentrations have been reported to support suspicion of HCC, as concentrations in dogs with non-neoplastic liver disease and non-hepatic tumors are generally lower (6). However, given the limited data available in dogs and the potential overlap with other conditions, AFP should be interpreted cautiously and in conjunction with imaging and histopathological findings rather than as a sole biomarker. This case has several limitations. As a single case report, it cannot establish the efficacy of olaparib or cIL-15 in canine HCC, and the individual contribution of each treatment remains uncertain. Furthermore, owner-initiated treatment modifications precluded evaluation under a consistent therapeutic protocol and limited interpretation of the clinical response to either therapy. Interpretation of olaparib efficacy was further limited by the lack of an established dosing regimen for canine HCC. Complete pathological staging was not possible because regional lymph nodes were not histopathologically examined, and the suspected recurrent hepatic mass was not histopathologically confirmed. Because necropsy was not performed, the final extent of disease and direct cause of death remained undetermined. Finally, the clinical utility of serial AFP measurements for monitoring disease progression and treatment response in dogs with HCC requires further validation. In conclusion, this case describes the clinical course of a dog with unresectable HCC managed with a multimodal approach including cytoreductive surgery, targeted therapy, and immunotherapy. The observed temporal changes in serum AFP in relation to treatment and disease progression suggest that AFP may have potential utility as an adjunctive biomarker for monitoring disease course in canine HCC. Data availability statement The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.
Dan et al. 10.3389/fvets.2026.1942682 Frontiers in Veterinary Science07frontiersin.org Ethics statement Ethical approval was not required for the studies involving animals in accordance with the local legislation and institutional requirements because this was a retrospective report of a single privately owned dog treated for a naturally occurring disease, rather than a prospective experimental animal study, and no additional procedures were performed solely for research purposes. Written informed consent was obtained from the owners for the participation of their animals in this study. Written informed consent was obtained from the owner for the publication of this case report. Author contributions T-JD: Conceptualization, Data curation, Formal analysis, Investigation, Visualization, Writing – original draft, Writing – review & editing. C-HY: Resources, Writing – review & editing. Y-JK: Data curation, Formal analysis, Writing – review & editing. M-HK: Writing – review & editing, Supervision. M-AK: Resources, Formal analysis, Investigation, Writing – review & editing. K-SL: Writing – review & editing, Data curation. H-MP: Writing – review & editing, Conceptualization, Methodology, Resources, Supervision. Funding The author(s) declared that financial support was not received for this work and/or its publication. Conflict of interest Author M-AK was employed by company VET and GENE. The remaining author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Generative AI statement The author(s) declared that Generative AI was used in the creation of this manuscript. Generative AI was used to translate Korean sentences into English. 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