Tumor-associated antigen levels (carcinoembryonic antigen, human chorionic gonadotropin, and alpha-fetoprotein) antedating the diagnosis of cancer in the Framingham study.

Determinations of carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), and alpha-fetoprotein (AFP) were done by use of frozen serum samples antedating the diagnosis of cancer for 9 pancreatic and 8 gastric carcinoma patients from the Framingham Heart Study. The longest intervals for elevated antigens before cancer diagnosis were 10 months for CEA and 26 months for HCG. (The single elevated AFP was found in a sample 10 days before clinical diagnosis.) Samples from 31 controls matched with the cancer subjects by age, sex, vital capacity, and smoking status showed over 20% "false" positive CEA elevations (all smokers with low vital capacities) and over 20% borderline false positive HCG elevations in postmenopausal females. Although 10-26 months' lead time could infer some potential for use of these tumor-associated antigens to help detect malignant neoplasms at an earlier stage, a serious problem of frequent false positives prevents CEA and HCG levels from being useful as cancer-screening tests at this time.