A new study, published in the latest issue of the Journal of Small Animal Practice (JSAP), compared outcome in dogs with with Kiupel high-grade cutaneous mast cell tumours and overt regional lymph node metastasis. The prognosis for dogs with stage II Kiupel high-grade cutaneous mast cell tumours has historically been considered poor. However, the removal of metastatic regional lymph nodes in more recent research has been associated with a better outcome in canine cutaneous mast cell tumours.
The study “Lymphadenectomy improves outcome in dogs with resected Kiupel high-grade cutaneous mast cell tumours and overtly metastatic regional lymph nodes” was a multi-institutional retrospective cohort study, using electronic medical records from four European institutions to identify dogs for inclusion. Dogs with a histological diagnosis of overt lymph node metastasis that underwent lymphadenectomy (n = 31) were compared with those with a cytological diagnosis of regional lymph node metastasis, that did not undergo excision (n 18).
The study found that dogs with Kiupel high-grade cutaneous mast cell tumours undergoing lymphadenectomy of HN3 lymph nodes as part of their primary surgery in addition to adjuvant medical treatment had a significant improvement in time to progression and survival time compared with those dogs not undergoing the procedure. Lack of lymphadenectomy was the only variable significantly associated with a higher risk of nodal progression. Lymphadenectomy, along with the resection of the primary tumour and adjuvant medical treatment, improves outcome for dogs with Kiupel high-grade cutaneous mast cell tumours and overt nodal metastasis.
Dogs underwent lymphadenectomy of one peripheral lymph node in most cases, a higher number of lymph nodes or the removal of intracavitary lymph nodes might be associated with an increased incidence of postoperative morbidity. The findings warrant further exploration of the effect of surgical extirpation of metastatic sentinel lymph nodes and the number of lymph nodes removed on outcome in dogs with Kiupel high-grade cutaneous mast cell tumours.
Nicola Di Girolamo, Editor of JSAP concluded: “It is really encouraging to see collaborations from multiple institutions like the study presented here. Including multiple institutions in a retrospective cohort study, does not only ensure a higher sample size, but also ensure a higher generalisability of the results. Meaning that it is more likely that the differences observed in this study are also going to be observed at different practices and with different clinicians.”
The full article can be found in the September issue of the JSAP and can be read online at the website.
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