Leiomyosarcoma: investigation of prognostic factors for risk-stratification model

Background: We performed this study to define distinctive clinical features of leiomyosarcoma by assessing prognostic factors. Methods: Between 1988 and 2011, 129 leiomyosarcoma patients who underwent surgical resection with curative intent were retrospectively reviewed. Results: Of the 129 leiomyosarcoma patients, the distribution of anatomic locations was: extremity (n = 25), pelvis (n = 40), thoracic cavity (n = 11), intra-abdomen (n = 19), retroperitoneum (n = 23), and head/neck (n = 11). We classified the anatomic locations into two categories as abdominal (intra-abdomen and retroperitoneum, n = 42) and extra-abdominal (extremity, pelvis, thoracic cavity, and head/neck, n = 87). Prognosis was worse for the abdominal group than for the extra-abdominal group (median DFS 2.9 9.0 years, P = 0.04). Similarly, overall survival (OS) was also significantly worse for abdominal group (P = 0.027). Independent prognostic factors for survival were primary site (P = 0.041, hazard ratio (HR) 1.7; 95 % CI 1.2–2.8), tumor size (P = 0.038, HR 1.9;  95 % CI  1.13–3.38), margin status (P = 0.019, HR 2.1; 95 % CI 1.13–3.88), and histology grade (P = 0.01, HR 3.59; 95 % CI 1.64–7.87). We identified four different risk groups with different survival outcome: group 1 (n = 8), no adverse factors; groups 2 (n = 37) and 3 (n = 61) with one and two adverse factors, and group 4 (n = 23) with 3 or 4 adverse factors. Conclusion: Primary site, tumor size, resection margin, and histology subtype were independently associated with survival outcome. A prognostic model for leiomyosarcoma patients revealed four distinct groups of patients with good prognostic discrimination.