Free alpha subunit of human chorionic gonadotropin in women with non-trophoblastic tumors

Patterns of secretion of free alpha subunit in 242 women with non-trophoblastic tumors were studied. In 4 patients molecular forms of alpha subunit were investigated. In normal menstruating women, day to day fluctuations of alpha subunit (36 to 4871 ng/day) with a peak at midcycle were commonly observed. This makes measurement of the alpha subunit as a tumor marker difficult to interpret in this group of women. On the other hand, the secretion of alpha subunit in postmenopausal women was relatively stable (from 50 to 450 ng/day). Thus the incidence of elevated alpha subunit secretion (greater than 400 ng/day) in postmenopausal patients with non-trophoblastic tumors was as follows; cervical cancer (29.9%), ovarian cancer (50%), corpus cancer (37.5%), vulvar cancer (33.3%), lung cancer (53.3%), gastrointestinal tract cancer (80%). The elevation of the alpha subunit was unrelated to the histological type of cancer. Discordant secretion of hCG and its subunits were noted. The incidence of elevated hCG secretion (greater than 100 ng/day) for the same group of postmenopausal patients with non-trophoblastic tumors was 44.8% for cervical cancer, 100% for ovarian cancer, 62.5% for corpus cancer, 33.3% for vulvar cancer, 26.7% for lung cancer and 40% for gastrointestinal tract cancer. The incidence of isolated alpha subunit secretion in cervical cancer stages III and IV, lung cancer and gastrointestinal tract cancer (40-43%) was higher than that in other cancers (0-27%). For cervical cancer, the more advanced disease was associated with higher alpha subunit levels. The molecular forms of alpha subunit in 4 patients with non-trophoblastic tumors were studied by gel HPLC.(ABSTRACT TRUNCATED AT 250 WORDS)