Case Presentation: De Novo Metastatic Prostate Cancer With BRCA2 Loss
Patient Case:
A 74-year-old patient presented to his primary care provider with increasing urinary frequency and urgency, worsening lower back pain, and ~20 pound of unintentional weight loss over the past 6 months. His PSA was found to be elevated at 450, so he was referred to a Urologist where a PSMA PET/CT showed a prostate tumor, numerous bone metastases throughout the axial and appendicular skeleton, and multiple lung metastasis, which were all PSMA avid. A prostate biopsy showed prostate adenocarcinoma, Gleason grade group 5 (4+5) without neuroendocrine features, in multiple cores. His past medical history is notable for hypertension and hyperlipidemia, but no prior coronary artery disease or strokes.
He presents to a medical oncologist. At the initial visit, he receives a degarelix injection to lower his testosterone. He also undergoes germline DNA next-generation sequencing, somatic DNA next-generation sequencing (NGS), PTEN immunohistochemistry (IHC), and DECIPHER testing of his prostate biopsy tissue.
He returns to clinic one month thereafter where he receives a leuprolide injection to continue his androgen deprivation therapy (ADT). He reports that he has manageable fatigue and hot flashes. His PSA decreased to 20 with a testosterone level <3. Germline DNA NGS reveals no pathogenic variants, somatic DNA NGS testing shows BRCA2 gene loss, PTEN expression is intact by IHC, and DECIPHER score is 0.65 (intermediate-high). His stated goal is to live longer while maintaining quality-of-life to spend time with his grandchildren.
