Comparative effectiveness of surgery versus external beam radiation with/without brachytherapy in intermediate and high-risk localized prostate cancer.

Abstract

e16602 Background: Radical prostatectomy (RP) and definitive radiation with androgen deprivation therapy (ADT) are both standard of care options for intermediate and high-risk localized prostate cancer (PCa). It remains controversial if the two modalities produce equivalent outcomes because the PROTECT trial (2016) and three recent retrospective studies (2018) drew inconsistent conclusions. Methods: The Surveillance, Epidemiology and End Results (SEER) database was queried from 2004 to 2015 for localized PCa (TxN0M0) who received upfront surgery or who were recommended for surgery but instead received external beam radiation (EBRT) with or without brachytherapy boost to control selection bias. The Kaplan-Meier method was used to generate overall survival (OS) curves and the Cox regression analysis was performed to compare survival outcomes. Results: A total of 175,349 patients were eligible with a median age of 62 years old (age range: 26 to 99). 167,234 patients had upfront surgery and 8,115 patients had upfront radiotherapy, including 7,099 EBRT and 1,016 EBRT with brachytherapy. Overall, upfront surgery was associated with a better OS, compared with patients who received radiotherapy (all patients: adjusted HR [adjHR], 0.79; 95% CI, 0.74–0.83, P < 0.001). The survival benefit is more pronounced in patients of intermediate-risk group (adjHR, 0.61; 95% CI, 0.57–0.66, P < 0.001; N = 112,816), and remains significant in patients of high-risk group (adjHR, 0.91; 95% CI, 0.84–0.98, P = 0.02; N = 62,533). However, in elderly high-risk PCa patients (age ≥ 70), surgery was associated with a significantly inferior OS, compared with radiotherapy (adjHR, 1.16; 95% CI, 1.06–1.28, P = 0.002). Conclusions: Compared with upfront radiation therapy, definitive surgery was associated with overall survival benefit in intermediate- and high-risk localized PCa, except patients with old age and high-risk features, who should be considered for radiation therapy.