Durable complete radiographic and biochemical response to olaparib in BRCA2-mutated metastatic castration-resistant prostate cancer: a long-term responder case

Poly(ADP-ribose) polymerase inhibitors are an important option for metastatic castration-resistant prostate cancer (mCRPC) with homologous recombination repair gene alterations, although durable complete responses remain rare. We report a 72-year-old man with BRCA2-mutated mCRPC who achieved a sustained complete response to olaparib monotherapy. After progression on androgen deprivation therapy, abiraterone, enzalutamide, and docetaxel, genomic profiling identified a pathogenic BRCA2 alteration. Olaparib induced an undetectable prostate-specific antigen within three months, maintained for over 27 months, with complete resolution of bone metastases. This case highlights the potential for durable responses to olaparib and the importance of early genomic testing. • BRCA2-mutated metastatic castration-resistant prostate cancer may achieve exceptional and long-lasting complete remission with olaparib monotherapy. • Early implementation of comprehensive genomic profiling is essential to identify candidates for targeted therapy and optimize treatment sequencing. • Bone scan index-based assessment can objectively confirm profound radiographic response and support precise evaluation of disease control. • This case highlights that selected patients can experience durable benefit without toxicity, emphasizing the value of documenting and understanding “ultra-responder” phenotypes.