Prostate Specific Antigen in the Diagnosis and Treatment of Adenocarcinoma of the Prostate. II. Radical Prostatectomy Treated Patients

Abstract

Serum prostate specific antigen was determined (Yang polyclonal radioimmunoassay) in 102 men before hospitalization for radical prostatectomy. Prostate specimens were subjected to detailed histological and morphometric analysis. Levels of prostate specific antigen were significantly different between patients with and without a Gleason score of 7 or greater (p < 0.001), capsular penetration greater than 1 cm. in linear extent (p < 0.001), seminal vesicle invasion (p < 0.001) and pelvic lymph node metastasis (p less than 0.05). Prstate specific antigen was strongly corelated with volume of prostate cancer (r equals 0.70). Bivariate and multivariate analyses indicate that cancer volume is the primary determinant of serum prostate specific antigen levels. Prostate specific antigen was elevated 3.5 ng. per ml. for every cc of cancer, a level at least 10 times that observed for benign prostatic hyperplasia. Prostate specific antigen is useful as a preoperative marker because no patient with lymph node metastasis had serum levels of less than 10 ng. per ml. (4 times the upper limit of normal range). Of the patients with greater than 50 ng. per ml. two-thirds had microscopic lymph node metastasis and 90 per cent had seminal vesicle invasion. Serum prostatic acid phosphatase levels showed a significantly weaker correlation with cancer volume (r = 0.51) and every other pathological parameter. Of the patients 73 per cent had serum prostatic acid phosphatase levels in the normal range (0 to 2.1 ng. per ml.), including 7 per cent who had pelvic lymph node metastasis. Postoperative prostate specific antigen values were available in 97 of 102 patients, with a mean and maximum followup of 12 and 38 months. No patient with pelvic lymph node metastasis achieved an undetectable prostate specific antigen level without adjunctive therapy (hormonal or radiation). No difference in preoperative or postoperative prostate specific antigen levels, cancer volume, seminal vesicle invasion or incidence of pelvic lymph node metastasis was seen between patients with no capsular penetration and those with minimal capsular penetration (1 cm. or less total linear extent of full thickness penetration), providing the first quantitative evidence that small amounts of capsular penetration may not be of biological or prognostic significance.