Abstract:

Introduction: This study aimed to investigate the survival, treatment-related toxicities, and prognostic factors in the elderly (≥65) with prostate cancer treated with definitive radiotherapy (RT). Patients divided into two groups as young-old (65-74 years) and old (over 75 years) were examined. Methods: A total of 178 patients with prostate cancer treated with definitive RT were retrospectively reviewed. The prognostic factors for survival, metastasis-free survival (MFS), biochemical recurrence-free survival (BFS), and treatment-related toxicities were analyzed. Results: Pretreatment prostate-specific antigen (PSA), last PSA value, and Charlson comorbidity score (5-6) were significantly different between the two groups (p=0.001, p=0.004, and p=0.012, respectively). The elderly showed high pretreatment PSA, last PSA value, and Charlson comorbidity score (5-6). None of the other treatment or patient characteristics differed significantly between the groups. The median follow-up time was 68 months (range: 12-116 months) for the young-elderly. The 5-year overall survival (OS), BFS, and MFS were 86.4%, 91.5%, and 92.8%, respectively, in the young-elderly. Median follow-up time in the elderly patients was 60 months (range: 7-118 months) and 5-year OS, MFS, and BFS rates were 79.6%, 93.1%, and 93.4%, respectively. No statistical difference was found when the OS, BFS, and MFS were evaluated in 5 years in both groups. The multivariate analysis revealed that high radiation doses (76 Gy and ≥78 Gy) and high T-stage (T3-4) was a significant prognostic factor for the BFS in all patients (p=0.013, p=0.007, and p=0.026, respectively). The presence of high-risk patients in the risk stratification was borderline significant for the BFS (p=0.051). Acute hematological toxicity, such as leucopenia (38%), and late toxicity, such as rectal bleeding (10%), were frequently observed in the elderly. Conclusion: No differences were found in the OS, BFS, and MFS between the two groups. High radiation doses and high T-stage was found as a prognostic factor for the BFS in all patients.

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