Stage D1 prostate cancer treated by radical prostatectomy and adjuvant hormonal treatment. Evidence for favorable survival in patients with DNA diploid tumors

BACKGROUND: Stage D1 disease is found in at least every sixth patient undergoing bilateral pelvic lymphadenectomy and radical retropubic prostatectomy (RRP) for clinically localized prostate cancer (PC). Previous recommendations for monotherapy using surgery, radiation, or systemic therapy alone for Stage D1 disease have usually been associated with a poor outcome in regard to progression and survival. Unlike other pathologic stages, D1 disease treated with RRP is mainly related to DNA ploidy pattern in regard to all end points (progression and survival) and immediate adjuvant hormonal treatment (AHT) rather than to the usual pathologic variables, including the number of positive nodes. METHODS: Complete DNA ploidy information was available in 370 patients with Stage D1 disease (age range, 40-77 years; mean, 64 years) undergoing RRP with or without AHT with a follow-up of up to 22 years (mean, 5 years). RESULTS: Overall, 80% of all DNA ploidy classes (diploid, 37%; tetraploid, 46%; and aneuploid, 17%) had AHT that highly significantly delayed progression for diploid (P less than 0.0001) more than tetraploid (P less than 0.0001) and more than aneuploid (P less than 0.0001) tumors. Significant prolongation of the disease-free interval might have improved the quality of life for tetraploid and aneuploid patients. Survival (crude and cause-specific) was significantly (P = 0.02) improved only for diploid patients who received AHT but not for tetraploid and aneuploid patients. This was due to the significantly accelerated death rate after progression in those patients with early AHT for tetraploid and aneuploid (but not diploid) tumors. Delayed (on progression only) AHT resulted in high progression rates for all DNA ploidy classes (aneuploid greater than tetraploid greater than diploid); e.g., 21 of 30 diploid patients progressed and 6 patients died from disease at a median of 31.5 months in spite of immediate hormone treatment on progression. RRP and AHT for patients with Stage D1 disease resulted in a highly significant delay in overall progression (76% at 10 years) and excellent local control, depending on DNA ploidy pattern (diploid greater than tetraploid greater than aneuploid) compared with a treatment regimen without AHT (24% overall nonprogression); only 20% of all patients with AHT are projected to die of disease at 10 years. Disease in diploid patients (37%) treated with AHT rarely progressed and those patients are unlikely to die of disease in 10 years or less; delayed (on progression) hormone treatment for diploid patients seemed ineffective. Inclusion of values for prostate specific antigen led to a higher failure rate on progression, and this is dependent on DNA ploidy class (diploid greater than tetraploid greater than aneuploid). CONCLUSION: Only patients with nondiploid tumors should be entered into prospective studies using innovative adjuvant treatment protocols to improve survival.