[Evolution and prognostic factors of adenocarcinomas of the prostate metastasizing at diagnosis]

In 30-40% patients, prostate adenocarcinoma is diagnosed already in the metastatic phase, a percentage that will depend on the number of patients with localized cancer that we are unable to detect. Hormonal suppression is the most widely accepted therapeutical option, although there are doubts on the value of rescue treatment after the hormone-refractive stage. This paper analyses those parameters as well as the main prognostic factors in a series of 135 patients with metastatic prostate cancer at diagnosis.

Between 1983 and 1996, 414 patients were diagnosed with prostate adenocarcinoma in the Urology Unit. Móstoles Hospital, 135 of which (32.6%) were metastatic at the time of diagnosis and were managed as follows: 113 (84%) were treated with maximum androgenic blockade (MAB). 13 (9.6%) with orchiectomy and antiandrogens, 5 (3.7%) with various treatments, and only 4 received symptomatic treatment. Of those treated with MAB, 97 (72%) continued treatment after the hormone-refractive stage and 16 (12%) were given stramustine phosphate instead of the antiandrogen. Response monitoring was done basically by means of serial PSA determination. The parameters analyzed included survival and the following potential prognostic factors: age, performance status, metastatic bone pain, tumour diagnosis based on number of metastasis, prior PSA level, Gleason, local stage, M1 type at diagnosis based on the 1992 TNM classification, and response to the various treatment applied.

Mean age: 72 years. Over an average of 25 (0-127) months, 80 (59%) patients have died; mean follow-up of patients alive at end of study: 24 months (3-111). Lost to follow-up: 6 patients (4.4%). Up to 1991, the proportion of patients with metastasis was 48%; since 1992, 24%. Percentage of patients diagnosed due to clinical manifestations of the metastasis (25 patients) over these two periods increased, mean age decreased and the proportion of patients with highly aggressive tumours increased. Mean overall survival, 26 months: influential prognostic factors: diagnosis due to metastasis and Gleason greater than 7; very poor prognosis for those receiving no hormonal therapy, with no differences between drug versus surgical treatment. Tumour-dependent mean survival, 32 months; influential prognostic factors: performance status, metastatic bone pain, diagnosis due to metastasis and Gleason greater than 7; very poor prognosis for those receiving no hormonal therapy. Progression-free interval, 19 months; influential prognostic factors: metastatic bone pain, PSA higher or lower than 90. Gleason greater than 7 and local stage: no differences between treatments. Mean survival after progression, 6 months; influential prognostic factors: diagnosis due to metastasis, M1b versus M1c patients: increased survival in patients rescued with stramustine phosphate.

The proportion of prostate adenocarcinomas with metastasis at diagnosis shows a trend to decrease, although the percentage of patients who are diagnosed by the sings and symptoms of their metastasis is increasing. These patients should be treated with pharmacological or surgical hormone-suppression. Rescue treatment with stramustine phosphate prolongs survival. Influential prognostic factors: Gleason greater than 7, metastatic bone pain, tumour extent and previous PSA.