Login to Access Video or Poster Abstract: MP28-19
Sources of Funding: none

Introduction

The cell cycle progression score (CCP score, based on measuring the expression levels of CCP genes) has proven to be a robust predictor of prostate cancer outcomes in various clinical settings and patient populations. However data regarding the ability to predict outcomes in African American (AA) men are sparse. Here, we evaluate the utility of the CCP score generated from diagnostic biopsy to predict BCR and metastatic disease in a large cohort of treated patients at an academic teaching institution that is highly enriched with AA patient population.

Methods

Patients were diagnosed with clinically localized adenocarcinoma of the prostate and treated at the Ochsner Clinic (New Orleans, LA) between January 2006 and December 2011 who had available FFPE biopsy tissue. The final cohort consisted of 694 men with both a passing CCP score and complete clinical information for calculation of CAPRA. Thirty-eight (38) percent of the cohort was AA. Study outcomes included time from disease diagnosis to either metastatic disease (N = 33, 5%), or time to BCR (N = 94, 17%) after primary treatment (EBRT or RP). Median follow-up time for patients who did not experience an event or death before the study end was 6 years. Association with outcomes was evaluated by CoxPH survival analysis and likelihood ratio tests.

Results

The CCP score distribution was not different by race (p = 0.66) and had an overall mean of 0.42 (IQR = -0.20, 1.00). The primary pre-planned analysis called for evaluating the association of CCP score with outcome after adjusting for CAPRA and race. In this multivariable analysis the CCP score strongly predicted both BCR [HR per unit score = 1.50, 95%CI (1.22, 1.86), p = 0.00029] and metastatic disease [HR per unit score = 2.02, 95%CI (1.48, 2.77), p = 4.2 x 10^-5]. Race was not significantly associated with either outcome (p=0.51 for BCR; p=0.28 for metastatic disease). Further, there was no interaction between CCP score and race (p = 0.21), indicating that a unit increase in the score confers the same relative increase in risk to either Caucasian or African American patients. There was also no interaction between CCP score and treatment type (p = 0.34).

Conclusions

The CCP score provides significant prognostic information to AA patients that cannot be obtained from clinicopathologic variables. Therefore, the score is a useful tool to help differentiate risk among AA men and enables more informed clinical management of their disease.

Funding

none