Clinical outcomes of soft tissue sarcoma in the Philippines: A single-center experience.

Abstract

160 Background: Soft-tissue sarcomas (STS) are a heterogeneous group of uncommon tumors that account for less than 1 percent of all adult malignant tumors. Data are scarce in the Asia-Pacific region, especially in the Philippines. This study aims to evaluate the epidemiology and clinical outcomes of STS from a private tertiary hospital in the Philippines. Methods: All adult patients treated at St. Luke’s Medical Center (SLMC), Quezon City and Global City, between January 2010 and December 2020 were reviewed. Continuous variables are described in median and categorical variables are described in count and percentage. Kaplan-Meier curves for OS and RFS were compared by the Log-Rank test. Results: One hundred eighty-seven patients diagnosed with STS were eligible for the study. The median age at diagnosis was 53 years old; the majority were male (54.55%). The most common histologic subtypes were liposarcoma (19.79%), pleomorphic sarcoma, undiff (16.58%), and leiomyosarcoma (11.76%). Most were diagnosed with localized disease (90.9%), with the lower extremities (44.39%) as the most common primary site. The median tumor size was 10.3 cm, primarily high grade (46.52%). Nodal involvement on diagnosis was 4.28%. Twelve patients (6.42%) presented with de novo mets; lung (45%) was the most common site. The majority had surgery (81.82%) on the primary tumor, with 56.86% achieving R0. Eighty patients (42.78%) had radiotherapy; the majority were given post-operatively (N=60). Sixty-three patients (33.68%) received systemic therapy. Out of 170 patients with localized disease, 70 (40%) had disease recurrence, mostly local recurrence (57.14%). The 3-year OS and RFS were 58.67% and 55.20%, respectively, for the entire cohort; for localized disease was 95.06%. There was a statistical difference in OS between distant vs local recurrence (23.28% vs 49.11%) (p<0.001), nodal involvement (p=0.041), surgery (p<0.001), and radiotherapy (p=0.001). Conclusions: Most STS seen in SLMC is localized disease but with lower rates of resection than in other countries in the Asia-Pacific region. The histological subtype and primary anatomical site are similar to other data. The low survival rate may be attributed to the site of recurrence, nodal involvement, and treatment pattern received.