RATE OF RELAPSE FOLLOWING TREATMENT FOR LOCALIZED PROSTATE-CANCER - ACRITICAL ANALYSIS OF RETROSPECTIVE REPORTS

Purpose: Controversy exists over the optimal treatment for patients wi th clinically localized prostate cancer. Almost all of the treatment r esults are from non-randomized trials and interseries comparison is di fficult since the apparent success of a treatment, as judged by the ac tuarial freedom from relapse and survival data, depends on patient sel ection criteria and post-treatment evaluation, in addition to the effi cacy of the therapeutic intervention. In this report the calculation o f a hazard function is used to estimate and compare the rate of relaps e for the different treatments. Methods and Materials: Clinical report s from major surgery and radiation oncology treatment institutions wer e analyzed. The actuarial recurrence data were used to calculate the a nnual rate of recurrence within each series. Results: For all but the lowest volume tumors, patients continue to be at risk of relapse for a s long as these series have been followed. Despite the heterogeneity o f patient populations, the recurrence rates by stage are similar for p atients treated with surgery or irradiation. This result is consistent with pathologic data from prostatectomy specimens which indicate that for lesions > 12 cm(3) (approx. 3 cm in diameter) there is high likel ihood of extra-prostatic disease. Conclusion: Treatment outcome for pa tients with localized prostate cancer may be more dependent on the inh erent tumor biology than the particular type of treatment. Accordingly , the expectation and recommendation of a treatment must take into con sideration the continued risk of relapse with either radiation therapy or surgery. There are, as yet, insufficient data regarding the impact of screening and earlier diagnosis on the curability of patients with localized prostate cancer.