Gleason 7 prostate cancer treated with low-dose-rate brachytherapy: lack of impact of primary Gleason pattern on biochemical failure.

ABSTRACT

UNLABELLED What's known on the subject? and What does the study add? There appears to be a clear difference in cancer control outcomes for patients with Gleason scores of 3+4 and those with scores of 4+3 after radical prostatectomy. It has been documented that patients with Gleason 4+3 prostate cancer have higher incidences of non-organ-confined disease than those with primary pattern 3. Higher rates of extracapsular extension, seminal vesicle invasion and positive margins have been found to be associated with primary pattern 4 over 3. These higher rates of non-organ-confined disease can lead to increased biochemical failure, which, in turn, can lead to higher mortality rates. This study provides information on the prognostic significance of primary Gleason pattern in the brachytherapy management of prostate cancer. Study Type - Prognosis (case series) Level of Evidence 4. OBJECTIVES: • To report the biochemical outcomes for Gleason 7 prostate cancer treated with brachytherapy. • To analyse the impact of the primary Gleason pattern as well as other disease- and treatment-related factors on outcome. PATIENTS AND METHODS: • A total of 560 patients with Gleason 7 prostate cancer were treated between 1990 and 2008 with brachytherapy, alone or in combination with hormonal therapy and/or external beam radiation therapy. • There were 352 patients with Gleason pattern 3+4 and 208 with Gleason pattern 4+3. • The mean (range) presenting PSA level was 11.2 (1-300) ng/mL, and the median was 7.8 ng/mL. • The presenting clinical stages were T1b in 1%, T1c in 33%, T2a in 16%, T2b in 32%, T2c in 16% and T3 in 2% of patients. RESULTS: • The actuarial freedom from biochemical failure rate at 10 years was 82%. • There was no significant difference between 10-year freedom from biochemical failure rates for patients with Gleason scores of 3+4 (79%) and those with scores of 4+3 (82%). • Biologically effective dose and presenting PSA level were both significant predictors of biochemical failure in multivariate analysis. CONCLUSIONS: • The primary Gleason pattern in Gleason 7 prostate cancer shows no significant effect on biochemical failure when treated with brachytherapy. • These results are different from those found after radical prostatectomy and are probably attributable to the enhanced local control afforded by a brachytherapy approach to this disease subset.