Abstract A034: DNA repair capacity in metastatic castration-resistant prostate cancer patients using lymphocytes as surrogate markers

Abstract Prostate cancer (PCa) is one of the most commonly diagnosed cancers in men from the United States (US) and Puerto Rico (PR). In 2024, around 35,250 PCa-related deaths will occur in the US, making PCa the second leading cause of cancer-related mortality in men in the US. In Puerto Rican men, PCa represents the first cause of cancer incidence (38%) and mortality (19%). Metastatic castrate-resistant prostate cancer (mCRPC) remains among the most frequent causes of cancer-related mortality in males. Patients with mCRPC become progressively resistant to androgen deprivation therapy, and the median survival for these patients is around two years. Ortiz-Sanchez et al. (2022) previously reported that the nucleotide excision repair (NER) pathway is dysregulated in the lymphocytes from patients with indolent and aggressive PCa; nevertheless, mCRPC cases were not included in the study design. Therefore, this pilot study aimed to evaluate the DNA repair capacity (DRC) in Puerto Rican men with and without mCRPC through the CometChip assay using lymphocytes as surrogate markers. Variations in mean DRC values were expected among the study groups. DRC measurements through the NER pathway were performed in a cohort of 96 participants, including PCa cases (n=71) and controls (n=25). The mean DRC value for the control group was 17.63%, and for the cases, it was 7.90%. When comparing mCRPC (n=16), non-mCRPC (n=55), and controls, significant differences were observed between the controls and each cancer group. However, no significant differences were found between PCa cases stratified by disease aggressiveness. Currently, we are evaluating the functionality of the homologous recombination repair pathway to gain additional insights into the role of DRC in PCa. Our results represent the first effort to apply a phenotypic assay to evaluate the overall DRC in mCRPC. This may improve patient diagnosis and patient stratification in terms of disease progression. Citation Format: Jaime Matta, Jarline Encarnación-Medina, Gilberto Ruiz-Deya, Valerie Rodriguez-Baez, Carmen Ortiz-Sanchez. DNA repair capacity in metastatic castration-resistant prostate cancer patients using lymphocytes as surrogate markers [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A034.