The incidence of unplanned excision in patients with soft tissue sarcoma: Reports from the Bone and Soft Tissue Tumor registry in Japan

Background: Due to their rarity, soft tissue sarcomas (STS)s are often treated surgically as unplanned excisions (UE)s before referral to specialists. The Bone and Soft Tissue Tumor (BSTT) registry is a nationwide, organ-specific cancer registry for bone and soft-tissue tumors in Japan. The aim of this study was to elucidate the incidence and risk factors for UEs using data from the BSTT registry. Methods: Our study comprised 8761 patients with STS including 4826 males and 3935 females, with a mean age of 59 years (range, 0-105 years). Patients were classified into primary STS and UE groups. Results: Superficial and deep tumors were found in 2533 and 6120 patients, respectively. The mean STS size was 8.6 cm (range, 0.2-49 cm). We identified 6610 patients with high-grade, and 1758 patients with low-grade STS. Of the total 8761 patients, 7770 patients had primary STSs, whereas 991 patients were referred after undergoing UE. The UE mean incidence rate over 11 years was 11.3%. The UE incidence rates for leiomyosarcoma (LMS) (odds ratio [OR] = 1.75, p < 0.0001), fibrosarcoma (FS) (OR = 2.28, p < 0.0001), and epithelioid sarcoma (OR = 1.82, p = 0.01) were higher than the mean UE incidence rate (11.3%). Of 757 patients who underwent UE, 354 (47%) patients had superficial (<5 cm) STSs, whereas 156 (20.6%) of patients had deep STSs (>5 cm) (p < 0.0001). Logistic regression analysis revealed that UE was frequently associated with males and small, superficial, and trunk STSs. Conclusions: In the present study, the mean UE incidence rate (11.3%) was significantly different from the individual UE incidence rates of histological diagnoses suggesting that surgeons should consider STS, even with small tumors. Continuous education during training for medical students and surgeons is essential to ensure awareness and correct diagnostic procedures for STS. (c) 2021 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.