ELEVATED SERUM CATHEPSIN B1-LIKE ACTIVITY IN WOMEN WITH NEOPLASTIC DISEASE

Activities of selected hydrolytic enzymes were assessed in blind-coded sera of 121 women with invasive cancer of various organs. Acetylglucosaminidase, β-glucuronidase, and alkaline phosphatases were not markedly elevated above controls. In contrast, cathepsin B1-like (CB1) activity in sera before therapy averaged 45-fold greater than that of 56 normal controls (P < 0.001) and 95% of the values exceeded 0-20 units, the levels characteristic of 95% of healthy controls. CB1 also increased progressively during transition from preinvasive to invasive squamous cervical carcinoma (P < 0.001). Patients with recurrent or Stages III-IV disease had higher CB1 levels than those with Stages I-II tumors (P < 0.02). In women with gynecologic cancer who showed objective remissions to surgery or chemotherapy, mean pretreatment levels of CB1 fell from 226 and 330 units, respectively, to normal within 12-38 days of surgery or ca. 4 months of chemotherapy. CB1 remained elevated when tumors were refractory to treatment. Subjects with inflammatory, degenerative, or other non-neoplastic disease showed no CB1 elevation, but CB1 was enhanced in women with endometriosis or endometrial hyperplasia. A generalized increase in serum acid and alkaline hydrolases, including CB1, was found in advanced pregnancy. Although the nature of the increments in CB1-like activity in cancer remains to be determined, such analyses may help supplement present methods of physical diagnosis. © 1979.