Use of the cell cycle progression (CCP) score for predicting systemic disease and response to radiation of biochemical recurrence.

BACKGROUND Determining the optimal treatment for biochemical recurrence (BCR) after radical prostatectomy (RP) is challenging. OBJECTIVE We evaluated the ability of CCP score (a prognostic RNA expression signature) to discriminate between systemic disease and local recurrence in patients with BCR after RP. METHODS Sixty patients with BCR after RP were selected for analysis based on: 1) metastatic disease, 2) non-response to salvage external beam radiotherapy (EBRT), and 3) durable response to salvage EBRT. CCP scores were generated from the RNA expression of 46 genes. Logistic regression assessed the association between CCP score and patient group. RESULTS Passing CCP scores were generated for 47 patients with complete clinical and pathologic data. CCP score predicted clinical status when comparing patients with metastatic disease or non-responders to salvage therapy to patients with durable response (p = 0.006). CCP score remained significantly predictive of clinical status after accounting for time to BCR, PSA level at BCR, and Gleason score (p = 0.0031). CONCLUSIONS Elevated CCP score was associated with increased risk of systemic disease, indicating that CCP score may be useful in identifying patients with BCR who are most likely to benefit from salvage radiation therapy.