The significance of DNA-ploidy and S-phase fraction in node-positive (stage D1) prostate cancer treated with androgen ablation.

BACKGROUND

The prognostic significance of primary tumor DNA-ploidy and S-phase fraction (SPF) was evaluated in patients treated with androgen ablation for regionally localized node-positive prostate cancer.

METHODS

All patients were diagnosed with lymph node involvement by pelvic lymphadenectomy between 1984 and 1992 and were treated only with androgen ablation. Median follow-up was 45 months. Adequate material for DNA/nuclear protein flow cytometric analysis was available in 33 patients.

RESULTS

The tumors were classified as diploid in 11, near-diploid in 4, tetraploid in 10, and aneuploid in 8 cases. Grouping the patients by nonaneuploidy (diploid and near-diploid and tetraploid) and aneuploidy revealed actuarial 4-year disease progression rates of 14 and 48% (log-rank, P = 0.04), and overall survival rates of 100 and 61% (P = 0.008); however, biochemical progression (rising prostate-specific antigen profile) rates were similar at around 70%. In contrast, SPF was not significantly related to any of the endpoints tested. Several other potential prognostic factors were examined and none correlated significantly with disease progression or survival.

CONCLUSIONS

The biochemical progression rates for patients with nonaneuploid and aneuploid tumors were comparable and high, while the disease progression rates were higher and survival rates lower for those with aneuploid tumors. These data indicate that the lead time from biochemical to disease progression and death was shorter with aneuploidy. That these relationships were observed in such a small patient population attest to the strength of DNA-ploidy as a prognostic factor in this cohort.