Zinc65 absorption in patients with carcinoma of the prostate

The intestinal absorption of 65Zn was determined in patients with carcinoma of the prostate prior to treatment and during estrogen therapy. Following an oral tracer dose of 65 ZnCl2, plasma levels and urinary and fecal excretions of 65Zn were determined. The absorption of 65Zn was low in six of eight patients, particularly in three patients who had extensive metastatic bone involvement. During estrogen therapy the absorption of 65Zn increased markedly in these patients, and this increase correlated with the clinical remission of the neo‐plastic process. In one patient who did not respond to estrogen therapy, 65Zn absorption was normal prior to treatment and did not increase during estrogen therapy. In patients free of neoplasia estrogen administration did not increase 65Zn absorption, and even decreased it. These results indicate that the intestinal absorption of 65Zn is decreased during the active phase of carcinoma of the prostate and improves during clinical remission induced by estrogen therapy.