Radiation-Associated Sarcoma in a Resource-Constrained Setting: A Decade of Real-World Outcomes From a Tertiary Care Sarcoma Center in India.

Abstract

Radiation-associated sarcomas (RAS) are rare tumors developing in previously irradiated areas. Most data come from high-income countries, with limited reports from low- and middle-income countries (LMICs). To our knowledge, this is the largest RAS cohort from India, examining clinical features, genetic predisposition, systemic therapies, and outcomes, in a resource-limited setting. We conducted a retrospective analysis of a sarcoma database at AIIMS, New Delhi, from January 2015 to June 2025. Patients ≥18 year with biopsy-confirmed RAS, meeting modified Cahan criteria, were included. Twenty-three patients (0.32% of 7,138 sarcoma cases evaluated) were diagnosed with RAS. The median age at diagnosis was 51.1 years, with a median latency of 13.25 years following radiotherapy. Breast cancer was the most common antecedent malignancy (21.7%). Soft tissue sarcomas were predominant (14, 60.9%), with undifferentiated pleomorphic sarcoma (8, 34.8%) being the most frequent histologic subtype. At presentation, 12 patients (52.2%) had metastatic disease, while three (13.1%) had locally unresectable tumors. The majority of tumors were high-grade (20, 87.0%), with a median tumor size of 6.9 cm. Among eight patients with resectable disease, seven underwent surgery, achieving R0 resection in 62.5% of cases. Re-irradiation was performed in three patients (13.0%). Sixteen patients (69.6%) received systemic therapy: 12.5% had partial response, 25% had stable disease, and two patients on immunotherapy had progressive disease. At a median follow-up of 68.2 months, the median overall survival was 59.2 months and 13.4 months for patients with nonmetastatic and metastatic disease, respectively. Despite large, high-grade, and advanced tumors, curative surgery was feasible in most nonmetastatic cases, and systemic therapies were widely used. The favorable survival outcomes underscore the importance of centralized, multidisciplinary sarcoma care in LMICs. Lack of immunotherapy responses calls for investigation into resistance mechanisms and histology-specific treatments.