Lymph node (LN) metastasis is a negative prognostic factor in dogs with cutaneous mast cell tumours (cMCTs). While elective lymphadenectomy of metastatic LNs improves outcome, the benefit of adjuvant medical therapy in dogs with early metastatic (HN2) LNs is debated. The aim of this retrospective multicentre study was to evaluate the therapeutic benefit of adjuvant medical therapy following surgical removal of the primary low‐grade cMCT (Patnaik grade 1‐2 and Kiupel low‐grade) and lymphadenectomy of HN2 LNs by analysing survival rates and patterns of recurrence. Seventy‐three dogs were included: 42 received adjuvant medical treatment (chemotherapy and/or kinase inhibitors), and 31 did not. The median follow‐up time for medically treated dogs was 619 days: two experienced local recurrence, three nodal relapse and four distant relapse. For dogs undergoing surgery only, the median follow‐up time was 545 days. None of them experienced local recurrence, nodal, or distant relapse. Time to progression was significantly shorter in dogs receiving adjuvant medical treatment (P = .021). A similar tendency was observed for overall survival (P = .056). The current study shows that dogs with low‐grade cMCTs, that undergo surgical excision of the primary tumour and elective lymphadenectomy of the HN2 regional LN harbour a good prognosis. The use of adjuvant medical treatment in these dogs does not seem to provide any benefit in terms of progression and survival.

中文翻译：

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辅助药物疗法在治疗患有低度肥大细胞瘤和接受手术的早期淋巴结转移的狗中没有治疗效果。

淋巴结（LN）转移是患有皮肤肥大细胞瘤（cMCT）的狗的阴性预后因素。尽管选择性转移淋巴结清扫术可改善结局，但对于早期转移性（HN2）LNs犬辅助治疗的益处尚有争议。这项回顾性多中心研究的目的是通过分析生存率和生存模式，评估手术切除原发性低度cMCT（Patnaik 1-2级和Kiupel低度）和行HN2 LN淋巴结清扫术后辅助药物治疗的疗效。复发。其中包括73只狗：42例接受了辅助治疗（化学疗法和/或激酶抑制剂），而31例则没有。接受药物治疗的狗的中位随访时间为619天：两次局部复发，三个淋巴结复发和四个远处复发。仅对于接受手术的狗，中位随访时间为545天。他们都没有经历局部复发，淋巴结转移或远处复发。接受辅助治疗的狗的进展时间明显缩短（P = .021）。总体生存率也观察到类似趋势（P = .056）。当前的研究表明，患有低度cMCT的犬，经过手术切除原发肿瘤并进行HN2区域性LN择期淋巴结清扫术，预后良好。在这些犬中使用辅助药物治疗似乎在进展和存活方面没有提供任何益处。