Urinary DNA as a Tool for Germline and Somatic Mutation Detection in Castration-Resistant Prostate Cancer Patients

Germline DNA Damage Response Gene Mutations in Localized Prostate Cancer

Background and Objectives: Germline DNA damage response (DDR) gene mutations correlate with increased prostate cancer (PCa) risk and a more aggressive form of the disease. DDR mutation testing is recommended for metastatic PCa cases, while eligible information about the mutations' burden in the early-stage localized PCa is still limited. This study is aimed at the prospective detection of DDR pathway mutations in cases with localized PCa and correlation with clinical, histopathological, and radiological data. A comparison to the previously assessed cohort of the advanced PCa was performed. Materials and Methods: Germline DDR gene mutations were assessed prospectively in DNA samples from 139 patients, using a five-gene panel (BRCA1, BRCA2, ATM, CHEK2, and NBN) targeted next-generation sequencing. Results: This study revealed an almost three-fold higher risk of localized PCa among mutation carriers as compared to non-carriers (OR 2.84 and 95% CI: 0.75-20.23, p = 0.16). The prevalence of germline DDR gene mutations in PCa cases was 16.8% (18/107) and they were detected only in cases with PI-RADS 4/5 lesions. BRCA1/BRCA2/ATM mutation carriers were 2.6 times more likely to have a higher (>1) cISUP grade group compared to those with a CHEK2 mutation (p = 0.27). However, the number of cISUP > 1-grade patients with a CHEK2 mutation was significantly higher in advanced PCa than in localized PCa: 66.67% vs. 23.08% (p = 0.047). Conclusions: The results of our study suggest the potential of genetic screening for selected DDR gene mutations for early identification of cases at risk of aggressive PCa.

Genetic aberrations of homologous recombination repair pathways in prostate cancer: The prognostic and therapeutic implications

Prostate cancer (PC) is the second most common cancer in men worldwide. Homologous recombination repair (HRR) gene defects have been identified in a significant proportion of metastatic castration-resistant PC (mCRPC) and are associated with an increased risk of PC and more aggressive PC. Importantly, it has been well-documented that poly ADP-ribose polymerase (PARP) inhibition in cells with HR deficiency (HRD) can cause cell death. This has been exploited for the targeted treatment of PC patients with HRD by PARP inhibitors. Moreover, it has been shown that platinum-based chemotherapy is more effective in mCRPC patients with HRR gene alterations. This review highlights the prognosis and therapeutic implications of HRR gene alterations in PC.