Comparative effectiveness of surgery and radiotherapy for survival of clinically localized prostate cancer patients: A population-based coarsened exact matching retrospective cohort study

Abstract

Background. Radical prostatectomy and radiotherapy are currently the main treatment options for localized prostate cancer. However, not yet a large cohort study of comparison between surgery and radiation has been investigated in Japan nor Asia. Objective of this study was to compare the survival outcome between surgery and radiotherapy among patients with clinically localized prostate cancer and in the elderly and young patients. Methods. We retrospectively evaluated survival outcomes of localized prostate cancer patients (age at diagnosis ≤79 years, cT1-3) initially treated with surgery or radiotherapy. Data were collected from the population-based cancer registry of Kanagawa Prefecture, Japan. A 1:1 coarsened exact matching of age at diagnosis, clinical T stage, and cancer differentiation was made between the two treatment groups. Patients were also categorized into two groups by age at a cut-off of 70 years for analysis. Results. The cohort comprised 4,810 patients aged 50-79 years. No significant difference in CSS was observed between the two groups (p=0.612), but the surgery group had significantly better prognosis in OS (p=0.004). When stratified for age, similar tendencies were seen in the elderly group (aged 70-79 years) (p=0.961 and p=0.007, respectively). By contrast, no significant difference in either CSS or OS was found in the younger group (p=0.550 and p=0.408, respectively). Intrinsic deaths were more likely to occur in elderly patients treated with radiotherapy than in those undergoing surgery (69.3% vs 78.2%, p=0.128).Conclusions. Our data suggests that surgery provided significantly better OS than radiotherapy, particularly among the elderly. However, radiotherapy may be more appropriate in elderly patients due to less invasiveness of the procedure. Prospective trials evaluating these therapies are warranted.