Tumor angiogenesis correlates with progression after radical prostatectomy but not with pathologic stage in Gleason sum 5 to 7 adenocarcinoma of the prostate.

BACKGROUND

Prior studies have suggested that tumor angiogenesis (microvessel density [MVD]) may be of prognostic significance in patients with prostate carcinoma.

METHODS

The authors examined the relationship of MVD in intermediate grade prostate carcinomas with stage at radical prostatectomy (RP) and progression after RP. For the former group, 109 RP specimens with Gleason sums of 6 and 7 were studied: 34 organ-confined tumors, 37 with capsular penetration, 21 with seminal vesicle involvement, and 17 with pelvic lymph node metastasis. For the latter group, 87 RP specimens were studied that had a Gleason sum of 5 to 7 for which the patients underwent follow-up of at least 7 years or until progression. Thirty-seven patients (43%) progressed at a mean of 3.5 years (range, 1-8 years). Representative sections of each tumor were stained for CD31 and "hot spot" microvessels were quantitated in a 3.14-mm2 area.

RESULTS

In the first arm, there was no relationship between MVD and stage at RP. In the second arm, the mean MVD in tumors that progressed was significantly higher than in nonprogressors (43.0 +/- 26.1 vs. 29.0 +/- 13.1; P < 0.0001 by Wilcoxon-Gehan statistic). MVD and Gleason sum were independent statistically significant predictors of progression (MVD, P < 0.0001; Gleason sum, P < 0.0001 by Cox proportional hazards model).

CONCLUSIONS

MVD is an independent significant predictor of progression after RP for tumors with a Gleason sum of 5 to 7. Because these comprise the majority of RP specimens, it is this group for which discrimination of biologic potential is most needed. Angiogenesis may be useful in the prognostic stratification of patients beyond that possible using stage and grade alone.