Tumor volume does not predict for biochemical recurrence after radical prostatectomy in patients with surgical Gleason score 6 or less prostate cancer.

OBJECTIVES

No consensus exists regarding the prognostic value of tumor volume (TV) in predicting biochemical recurrence (BCR) of prostate cancer, especially late in the prostate-specific antigen (PSA) era. We assessed this relationship in a large cohort of patients treated at one institution with standardized pathologic assessment from 1998 to 2005.

METHODS

Data were collected for 1833 patients undergoing radical prostatectomy for clinically localized prostate cancer since 1998. Patients receiving neoadjuvant or adjuvant therapy or with node-positive disease were excluded. Along with the routine pathologic assessment, TV was prospectively assessed in all specimens. BCR was defined as two consecutive PSA levels of 0.2 ng/mL or one PSA level of greater than 0.2 ng/mL.

RESULTS

Although a larger TV correlated with lower rates of biochemical relapse-free survival in patients with a surgical Gleason score of 7 (P <0.0001) and surgical Gleason score of 8 or greater (P = 0.0459), the biochemical relapse-free survival rate at 4 years for low, medium, and extensive surgical Gleason score 6 or less tumors was 95%, 96%, and 97%, respectively (P = 0.65). In a multivariate model, including TV, initial PSA, EPE, seminal vesicle invasion, and surgical Gleason score, the TV predicted for BCR (P = 0.0176).

CONCLUSIONS

The results of this large study suggest that a large TV is an independent predictor of BCR in patients with tumors of specimen Gleason score 7 or higher. In contrast, most grade 6 tumors will be organ confined, even if of high volume, and TV will not predict for BCR in these patients.