Reduced nonspecific steroidal esterase activity in human malignant tumor tissue from liver, colon and breast when compared to peritumoral and normal tissue levels.

The levels of a nonspecific steroidal esterase estimated as alpha naphthyl acetate esterase (ANAE) activity were measured in apparently normal (peritumoral) tissue of liver, colon and breast cancer patients, in malignant tumor tissue from the same patients and in normal colon tissue from healthy individuals who never had colon cancer. Cancer tissue from all three organs showed 35-79% reduced levels of ANAE activity when compared to peritumoral tissue of the same organ (p < 0.03). When ANAE activity of normal colon tissue from healthy individuals who never had colon cancer was compared with peritumoral colon tissue from colon cancer patients, which were combined with colonic biopsies from cancer-free patients previously operated on for colon cancer, a 50% reduced ANAE activity was observed in these tissues compared to the normal (p < 0.005). A highly significant reduction of enzyme activity was also found when malignant colon tissue from the cancer patients was compared to normal colon tissue from healthy individuals who never had colon cancer.