Olaparib is one of the earliest approved treatment options for metastatic castration-resistant prostate cancer (mCRPC). This systematic review and network meta-analysis aimed to determine the optimal olaparib strategy for treating mCRPC. The Cochrane, Embase, PubMed, and Web of Science databases were searched comprehensively using "mCRPC" and "olaparib" as keywords. Study quality was appraised with the National Institutes of Health tools. Data were analyzed in R version 4.4.1. The primary endpoints included progression-free (PFS) and overall (OS) survival. The secondary endpoints included adverse events and severe adverse events (grade ≥3). Effect sizes were reported as hazard ratios (HRs) and risk ratios, with 95% credibility intervals (CrIs). Nine studies from seven clinical trials involving 2355 patients were identified. For homologous recombination repair-mutated mCRPC, combination therapies did not demonstrate significant benefits compared with olaparib alone. However, for BRCA-mutated mCRPC, olaparib combined with abiraterone improved PFS (HR=0.61, 95% CrI=0.41-0.91) and OS (HR=0.41, 95% CrI=0.21-0.80) significantly. These significant advantages of olaparib combined with abiraterone were also observed in patients from different prostate-specific antigen subgroups. These findings suggest that olaparib combined with abiraterone offers substantial benefits in BRCA mutated type (BRCAmt) mCRPC patients. For those with BRCA wild type homologous recombination repair-mutated mCRPC, olaparib monotherapy is effective. We reviewed the published studies comparing different treatment options using the drug olaparib (alone or combined with other therapies) for advanced prostate cancer that has spread and no longer responds to standard hormone therapy (metastatic castration-resistant prostate cancer). We found evidence that the effectiveness of olaparib depends significantly on specific genetic features of the cancer. For patients whose cancer has changes in the BRCA genes, the combination of olaparib and the drug abiraterone was more effective in delaying cancer growth and improving survival than olaparib alone. For patients with changes in other related DNA repair genes (but not BRCA), olaparib alone was an effective treatment. This information may assist doctors and patients in choosing the most suitable treatment based on the cancer's genetic characteristics.

Observation remains the recommended management approach for low-risk prostate cancer (PCa), aiming to balance oncological control and avoidance of overtreatment. This study investigated the use of observation and its association with patients' socioeconomic position (SEP), age, and prostate-specific antigen (PSA) level on treatment choice in Switzerland. This cohort study analyzed Gleason score 6 PCa diagnoses in 2020 and 2021 from the Swiss National Agency for Cancer Registration dataset. Variables included age, PSA value, residence, and treatment codes. Municipality-based SEP deciles were linked to patients. Multivariable regression assessed the associations between SEP and observational management. Of 4296 men, 2876 (65.4%) received observational management, 792 (18.0%) underwent active treatment, and management was unknown in 728 (16.6%). Compared with men from low SEP areas, those from middle (odds ratio [OR] 1.11, 95% confidence interval [CI]: 0.92-1.35) and high SEP (OR 1.29, 95% CI: 1.06-1.58) areas had higher odds of observation. Men aged 60-70yr (OR 1.53, 95% CI: 1.24-1.89) and >70yr (OR 2.10, 95% CI: 1.68-2.62) were more likely to undergo observation than those aged <60yr. PSA 5-10ng/ml (OR 0.67, 95% CI: 0.55-0.82) and >10ng/ml (OR 0.60, 95% CI: 0.46-0.78) were associated with lower odds of observation compared with PSA <5ng/ml. Most men diagnosed with localized low-risk PCa in Switzerland underwent observational management as the primary strategy in 2020 and 2021. However, at least 18% of men still received active treatment. Lower SEP, younger age, and higher PSA values were risk factors for active treatment within low-risk PCa patients. We looked at how men in Switzerland with low-risk prostate cancer were treated in 2020 and 2021. We found that most men chose observation instead of immediate treatment, but men with lower socioeconomic position, younger age, or higher prostate-specific antigen levels were more likely to have active treatment. This suggests that there are opportunities to reduce unnecessary treatment for certain patient groups.