LAUSR

137Background: PLZF (ZBTB16) is an androgen-regulated tumor suppressor gene. Homozygous PLZF deletions are seen in a proportion of localized as well as castration-resistant prostate cancers (PC). Since PTEN has been shown to regulate PLZF expression in vitro, we hypothesized that PTEN status impacts PLZF expression in men with PC. We further hypothesized that low PLZF is associated with a poorer PC prognosis. Methods: We studied patients diagnosed with PC during prospective follow-up of the Health Professionals Follow-up Study (HPFS; n = 254) and the Physicians’ Health Study (PHS; n = 150). We performed whole transcriptome profiling of tumor specimens from cancer diagnosis and, in a subset of patients (n = 253), a genomically-validated immunohistochemistry for PTEN. Patients were followed for metastases and PC-specific mortality (lethal cancer) after primary treatment for a median of 14 years. Univariable linear and multivariable logistic regression models for cancer outcomes, adjusted for age and calenda...