# Radiation-induced sarcoma after radiotherapy for breast cancer: A retrospective case series

## TL;DR

This study reports four cases of rare radiation-induced breast sarcomas in Saudi Arabia, highlighting short latency periods and unusual tumor types.

## Contribution

The study presents a rare case series of RIBS from the Middle East with a focus on genetic and histological features.

## Key findings

- RIBS developed with a mean latency of 43 months and occurred in patients with an average age of 48.25 years.
- All cases were undifferentiated pleomorphic sarcomas, not the more common angiosarcoma, and one patient had a TP53 mutation.
- Outcomes varied, with recurrence and progression observed during follow-up, emphasizing the need for long-term surveillance.

## Abstract

Radiation-induced breast sarcoma (RIBS) is a rare yet serious complication of radiotherapy for breast cancer, with limited data from the Middle East. This case series examines four patients with RIBS at a tertiary healthcare center in Saudi Arabia, highlighting a notably short latency period and an uncommon histological pattern. The mean age at breast cancer diagnosis was 44.75 years, and RIBS developed at a mean age of 48.25 years after an average latency of 43 months. One patient with a TP53 mutation had the shortest latency (28 months), suggesting a possible genetic predisposition. Histopathological evaluation confirmed undifferentiated pleomorphic sarcoma in all cases, distinct from the more commonly reported angiosarcoma. Radiologic assessments, including mammography, ultrasound, PET-CT, and MRI, revealed diverse tumor locations, with no cases of lymphadenopathy at presentation. Management varied, with three patients undergoing surgical excision and two receiving chemotherapy, while one patient with metastatic disease was ineligible for surgery. Follow-up over a mean duration of 34.7 months demonstrated variable outcomes, including recurrence and progression. These findings emphasize the need for heightened awareness of RIBS, particularly in genetically predisposed patients, and highlight the importance of long-term surveillance in breast cancer survivors. The predominance of undifferentiated pleomorphic sarcoma raises questions regarding genetic and environmental factors in RIBS development. Further research is necessary to explore risk stratification, optimize treatment strategies, and improve outcomes for this rare but aggressive malignancy.