Post-radiation pelvic sarcomas after radiotherapy treatment of prostate adenocarcinoma

Abstract

Background: The number of publications reporting the appearance of post-radiation secondary tumors has increased in parallel with the development of radiotherapy. However, little information is available about the presence of sarcomas associated with prostate radiotherapy. Objective: To review cases of pelvic sarcoma associated with prostate radiotherapy in a tertiary hospital. Methods: Following the criteria established by Cahan, 11 pelvic sarcoma patients with a history of radiotherapy treatment of prostatic adenocarcinoma between the years 2006 to 2016 were identified. A descriptive study was designed to review the characteristics of patients, tumors, therapy administered, and its effect on the outcome of the cancer. Results: The average age of patients upon diagnosis was 72.27 years (60-79), with an average latency time of 6.27 years (4-9 years) between radiotherapy and diagnosis of sarcoma. The mean radiotherapy dose was 74Gy (70-78). The most common location of the sarcoma was regions II-III of the pelvic girdle (72%), followed by the pelvic cavity. The main histological type was undifferentiated pleomorphic sarcoma (54%); two patients presented metastases at the time of diagnosis. In total, 81.8% of patients were treated surgically with curative intent, and of these, seven received adjuvant chemotherapy. Mean follow-up was 14 months, with a two-year survival rate of 18.2%. Conclusion: Given the poor prognosis of post-radiation pelvic sarcomas, efforts must be made to establish protocols for early diagnosis and to develop aggressive, standardized treatment guidelines.