Soft tissue sarcoma grade does not differ between extremity and nonextremity locations

Abstract Objective To evaluate whether canine soft tissue sarcomas (STSs) located on the extremities are of lower histologic grade than those on nonextremity locations. The hypothesis was that the frequency of grade I and grade II/III tumors would be similar between extremity and nonextremity locations. Methods This retrospective cohort study evaluated canines undergoing surgical resection of an STS and subsequent histopathologic assessment during the period of November 20, 2018, to April 8, 2025, at a single institution. Results 134 STSs on 129 dogs were identified, with 129 STSs included in analysis. Seventy-two STSs (55.8%) were located on the extremities, while 57 (44.2%) were located on nonextremity locations. Forty-nine STSs (68.1%) on the extremities were grade I, and 23 (31.9%) were grade II/III; 40 nonextremity STSs (70.2%) were grade I, and 17 (29.3%) were grade II/III. Conclusions The distribution of STSs as grade I or grade II/III is similar for STSs located on extremity and nonextremity locations. Clinical Relevance STSs located on an extremity cannot be assumed to be of a low histologic grade. Risks of local recurrence and potential need for adjuvant therapy, particularly with a marginal excision, should be discussed during the preoperative period with clients for STSs located on the extremities, similar to other locations based on similar grade distributions.