Lymphadenectomy improves outcome in dogs with resected Kiupel high‐grade cutaneous mast cell tumours and overtly metastatic regional lymph nodes

Abstract

Introduction Historically, the prognosis for dogs with stage II Kiupel high‐grade cutaneous mast cell tumours has been considered poor. Objectives The aim of this study was to explore the impact of lymphadenectomy on outcome in dogs with Kiupel high‐grade cutaneous mast cell tumours and overt regional lymph node metastasis. Material and Methods Data from dogs with completely staged Kiupel high‐grade cutaneous mast cell tumours with overt and/or certain regional lymph node metastasis undergoing excision of the primary tumours and adjuvant medical treatment were extracted. Dogs with a cytological diagnosis of regional lymph node metastasis that did not undergo lymphadenectomy were compared with dogs that underwent lymphadenectomy and had a histological diagnosis of overt lymph node metastasis. Results Forty‐nine dogs were included, 18 did not undergo lymphadenectomy while 31 underwent lymphadenectomy. Median time to progression was significantly shorter in dogs that did not undergo lymphadenectomy (150 days, 95% confidence interval: 129 to 170) compared to the other dogs (229 days, 95% confidence interval: 191 to 266). Median survival time was also shorter in dogs that did not undergo lymphadenectomy (250 days, 95% confidence interval: 191 to 308) compared to dogs that underwent lymphadenectomy (371 days, 95% confidence interval: 311 to 430). On multivariable analysis, lack of lymphadenectomy was associated with higher risk of overall tumour progression (hazard ratio: 2.05, 95% confidence interval: 1.02 to 4.13), nodal progression (hazard ratio: 3.4, 95% confidence interval: 1.65 to 7.02) and tumour‐related death (hazard ratio 3.63, 95% confidence interval: 1.72 to 7.66), whereas tumour size was associated with higher risk of local recurrence (hazard ratio: 3.61, 95% confidence interval: 1.06 to 13). Clinical significance Regional lymphadenectomy may improve outcome in dogs with biologically aggressive cutaneous mast cell tumours.

The Role of Sentinel Node Mapping and Lymphadenectomies in Veterinary Surgical Oncology

“…Lymph node (LN) status is an important prognostic factor for the staging of various cancers in human and veterinary medicine, and the resection of metastatic nodes can improve outcomes in selected cancer types [1][2][3][4][5][6]. Virchow and Halsted already recognized the importance of the lymphatic system serving as a major barrier for cancer cells [7,8].…”

Sentinel Lymph Node Biopsy Is Feasible in Dogs with Scars from Prior Local Excision of Solid Malignancies

“…In recent years, implementation of SLNB in the surgical management of various solid tumors in dogs has been advocated due to the recognized impact of accurate detection of nodal metastases on tumor staging [ 2 , 3 , 5 , 6 , 8 , 11 , 16 ]. The therapeutic benefits both of prophylactic lymphadenectomy (HN1) and excision of early and overt metastatic lymph nodes (HN2—HN3) [ 24 ] in dogs with integumentary MCT have further corroborated the importance of a guided surgical approach to the lymphatic basin [ 29 , 30 , 31 , 32 ]. However, specific investigations of the feasibility of SLN mapping and extirpation in dogs presenting with scars after primary tumor excision have not been previously performed.…”

“…The fact that a metastatic lymph node was excised in nearly half of the dogs included in this study also underlines the importance of performing a surgical approach to the SLN in dogs that already had surgical excision of the primary tumor and that are referred for further staging and/or adjuvant treatment recommendations, especially in the case of MCT. This consideration holds particularly true when considering the therapeutic effect of the excision of early and overtly metastatic lymph node in cutaneous canine MCT [ 29 , 30 , 31 , 32 ].…”

Sentinel Lymph Node Mapping and Biopsy in Cats with Solid Malignancies: An Explorative Study

“…Prompt identification of nodal metastases is a mainstay of surgical oncology, given its impact on staging and, therefore, therapeutic suggestions and reliable prognostication [ 3 , 26 , 27 , 37 , 43 ]. Several investigations have been conducted in the last decade on the assessment of the lymphatic basin in dogs with various spontaneous tumors.…”

“…Similarly, in tumor-bearing dogs, a benefit in terms of accuracy in staging has been documented, and morbidity of the procedure is reportedly low, although studies that compare the morbidity of RLN vs. SLN extirpation are currently not available in the veterinary literature [ 1 , 7 , 22 , 23 , 24 ]. Disadvantages of SLN extirpation include the need for dedicated technologies and the learning curve for the mapping procedure, although the incorporation of SLN biopsy seems to be justified by the well-documented impact of correct nodal staging on prognosis and treatment recommendations for various tumor types [ 3 , 25 , 26 , 27 ]. Comparable data on the feasibility and advantages of incorporation of SLN mapping in the feline species are lacking.…”