Clinical predictors of survival in men with castration-resistant prostate cancer: evidence that Gleason score 6 cancer can evolve to lethal disease.

BACKGROUND: This study sought to characterize Modern patients with castration-resistant prostate cancer (CRPC) and identify pretreatment clinical predictors of survival. METHODS: A cohort of men with CRPC with and without metastases (M) treated with secondary hormonal therapy (2eHT) and/or chemotherapy (CT) was identified from the authors' institutional database. Associations of patient and disease characteristics at diagnosis, at androgen-deprivation therapy (ADT) initiation, at CRPC index date, and survival were evaluated. CRPC index date was defined as the start date of either 2eHT or CT, whichever came first. RESULTS: In the cohort of 622 men, 434 men (70%) had M-positive disease; 552 men (89%) received 2eHT and 70 men (11%) received CT as their initial CRPC treatment. There were 410 deaths (66%) at the time of analysis. Median overall survival (OS) was 35 months (quartile 1, quartile 3: 21 months, 61 months). In multivariate analyses, higher biopsy Gleason score, the presence of M at ADT initiation, shorter time from ADT start to CRPC, higher prostate-specific antigen and poorer Eastern Cooperative Oncology Group performance status at CRPC and M at CRPC were predictive of shorter OS. Interestingly, whereas some men with biopsy Gleason scores of 6 died of their disease (N = 42), they had a longer OS after CRPC compared with those with a Gleason score ≥ 7. CONCLUSIONS: This large retrospective study of patients with CRPC in a tertiary cancer center shows that biopsy Gleason score of 6 is associated with a less aggressive CRPC course, and the impact that M at ADT initiation and CRPC have on outcome is quantified.