Risk and survival outcomes of secondary pelvic neoplasm after radiotherapy in female patients with genital neoplasms: A large Population-Based cohort study.

Objective: To investigate the impact of radiotherapy (RT) on the risk of secondary pelvic neoplasms (SPN) and the survival outcomes of patients following a diagnosis of female patients with genital neoplasm(FGN).

Methods: Utilizing SEER databases, this study involved 102,895 patients from nine oncology centers, spanning 1990 to 2015. We employed the Fine-Gray competing risks regression methodology to chart the trajectory of SPN development and used the Kaplan-Meier method to calculate the 10-year overall survival rates.

Results: This study included 25,774 patients in the RT group and 77,121 in the non-radiotherapy (NRT) group. The cumulative incidence rate of SPN was 5.10 % in the RT group and 3.42 % in the NRT group. The RT group showed a significantly higher incidence of bladder cancer (adjusted hazard ratio [HR]: 1.75; 95 % confidence interval [CI]: 1.43-2.14; P < 0.05), colon cancer (adjusted HR: 1.32; 95 % CI: 1.16-1.49; P < 0.05), and rectal cancer (adjusted HR: 1.34; 95 % CI: 1.10-1.65; P < 0.05) compared to the NRT group. After propensity score matching, patients in the RT group who developed bladder cancer had significantly reduced 10-year survival rates compared to patients with primary pelvic tumors (P = 0.01).

Conclusions: RT is identified as an independent risk factor for the development of SPN in patients with FGN. Patients with FGN who undergo RT demonstrate a significant increase in the risk of developing secondary neoplasms, specifically bladder cancers, and experience a reduction in 10-year survival rates.