The frequency of apoptosis correlates with the prognosis of Gleason Grade 3 adenocarcinoma of the prostate.

BACKGROUND

Although localized carcinomas are predominantly moderately differentiated (Gleason Grade 3), they demonstrate markedly different rates of progression. Previously, the authors reported a correlation between apoptosis and the malignant characteristics of carcinoma in the mouse prostate reconstitution model system and between apoptosis and Gleason grade in the human tumor. This study was undertaken to determine whether the frequency of apoptosis correlates with prognosis and to compare the prognostic significance of the apoptotic index with other prognostic features in Gleason Grade 3 carcinomas.

METHODS

The apoptotic and mitotic indices of malignant and nonmalignant epithelium in 28 consecutive radical prostatectomy specimens were determined for a carcinomas composed entirely of Gleason sum 6 (primary Grade 3, secondary Grade 3) with a clinical stage T2 classification. Each patient was followed for 5-9 years (median 6, years). The indices, defined as the number of apoptotic and mitotic bodies in an H & E-stained section per 100 grids delineated by an ocular measuring field, were determined. The actuarial time to progression, defined as a sustained rise in the serum prostate specific antigen level greater than or equal to 0.4 ng/ml, was correlated with the apoptotic index, the mitotic index, tumor volume, and pathologic stage.

RESULTS

Neither pathologic stage nor tumor volume differed significantly between the group of 19 patients (68%) with no progression and the other 9 whose tumor progressed. The median apoptotic index of the carcinomas was 0.87 (range, 0.12-3.91). For patients with a low apoptotic index (< 0.87), the actuarial progression rate at 5 years was 7% +/- 14% (+/- 2 SE) compared with 50% +/- 26% for those with a high apoptotic index (P < 0.007). Mitotic index had no prognostic significance.

CONCLUSIONS

In carcinoma of the prostate, apoptosis can be recognized in standard H & E sections and quantitated by light microscopy. The apoptotic index may provide additional prognostic information in the predominant grade of early stage carcinoma. Cancer 1995; 75:522-9.