Primary Gleason pattern does not impact survival after permanent interstitial brachytherapy for Gleason score 7 prostate cancer.

BACKGROUND

The impact of primary Gleason pattern was determined on cause-specific (CSS), biochemical progression-free (bPFS), and overall survival (OS) after brachytherapy for Gleason score 7 prostate cancer.

METHODS

From April 1995 to October 2003, 530 patients underwent brachytherapy for Gleason score 3+4 (n = 300) or Gleason 4+3 (n = 230) prostate cancer. All patients underwent brachytherapy more than 3 years before analysis. The median follow-up was 5.7 years. Of the 530 patients, 412 (77.7%) received supplemental external beam radiation therapy (XRT) and 177 (33.4%) received androgen deprivation therapy. bPFS was defined by a prostate-specific antigen (PSA) </=0.40 ng/mL after nadir. Multiple parameters were evaluated as predictors of CSS, bPFS, and OS.

RESULTS

At 10 years, Gleason 3+4 versus 4+3 did not predict for CSS (96.7% vs 93.3%, P = .506), bPFS (97.0% vs 92.9%, P = .085), or OS (77.0% vs 78.0%, P = .933). Cox linear regression analysis demonstrated that clinical stage and radiation dose (D90) predicted for CSS, whereas pretreatment PSA, clinical stage, and prostate size predicted for bPFS. Patient age, diabetes, and tobacco were the strongest predictors for OS. To date, 57 patients have died, with 80.7% due to cardiovascular/pulmonary events or secondary malignancies. Five patients have died of prostate cancer.

CONCLUSIONS

The primary Gleason pattern did not impact CSS, bPFS, or OS in Gleason score 7 prostate cancer. Deaths from cardiovascular/pulmonary disease and second malignancies were 9.6 times more common than death from prostate cancer.