Mismatch repair-deficient prostate cancer with parenchymal brain metastases treated with immune checkpoint blockade.

ABSTRACT: Parenchymal brain metastases from prostate cancer are unusual and are associated with poor prognosis. Given the rarity of this entity, little is known about its molecular and histologic characteristics. Here we describe a patient with metastatic castration-resistant, mismatch repair-deficient (dMMR) prostate cancer with parenchymal brain metastases. Analysis of a brain metastasis revealed MLH1 loss consistent with dMMR, yet few tumor-infiltrating lymphocytes (TILs). He was treated with immune checkpoint blockade (ICB) and exhibited an extra-central nervous system (CNS) systemic response but CNS progression. Subsequent assessment of a brain metastasis following ICB treatment surprisingly showed increased TIL density and depletion of macrophages, suggestive of an enhanced antitumor im

SUBMITTER: Sena LA 

PROVIDER: S-EPMC8327884 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature