Background: The aim of this study was to evaluate the current role of local treatment in prostate cancer with a low metastatic burden (or oligometastatic) in relation to survival and safety.
Methods: We performed a meta-analysis of studies published in the MEDLINE, EMBASE, and Cochrane databases until December 2021. Studies comparing local and nonlocal treatment in patients with metastatic prostate cancer were included. The risk of bias within studies was assessed using the Newcastle-Ottawa and Cochrane risk of bias tool. Oligo-metastasis was defined as low-volume metastasis with up to five lesions. The local treatment used was radical prostatectomy or external beam radiation therapy associated with systemic therapy (i.e., androgen deprivation therapy ± abiraterone, docetaxel, enzalutamide, or apalutamide). The endpoints evaluated were overall survival, cancer-specific survival, failure-free survival, and complication rates.
Results: Thirteen studies including 46,541 patients were included. The 5-year overall survival (16.0% vs. 6.5%, respectively; odds ratio (OR) 2.74; 95% confidence interval (CI), 2.18, 3.44; I2 = 0%; p < .00001) and 3-year cancer-specific survival (48.2% vs. 26.3%, respectively; OR 1.87; 95% CI: 1.44, 2.44; I2 = 0%; p < .00001) were higher in the local treatment group than that of the nonlocal treatment group. In addition, failure-free survival at 3 years was higher in the local treatment group than that of the nonlocal treatment group (40.5% vs. 28.4%, respectively; OR 1.72; 95% CI, 1.38, 2.14; I2 = 0%; p < .00001). The low complication rate of Clavien-Dindo grade ≥3 indicated that local treatment is feasible and safe in this setting.
Conclusion: Recent data have shown that local treatment combined with systematic therapy, might improve the overall, cancer-specific, and failure-free survivals of patients diagnosed with metastatic prostate cancer. Furthermore, local treatment is both feasible and safe. Further studies evaluating the quality of life of these patients are needed.
Keywords: Oligometastatic; radical prostatectomy; radical treatment; radiotherapy.