Screening for upper digestive tract cancer with an occult blood bead detector. Investigation of a normal north China population.

Screening of the general population for cancer of the upper digestive tract using an occult blood bead detector supplemented by fibergastroscopy was able to detect 126 cancers of the esophagus, gastric cardia, and stomach. This screening was carried out in two of the high-risk areas, Yangzhong and Wun counties, located in central eastern and north China. The occult blood bead detector, swallowed and retained in the stomach for 3 minutes, was able to sort out the suspected persons by its coloration from sky blue (+) to dark blue ( ) on removal. The subsequent fibergastroscopy could make a definite diagnosis by biopsy specimen. A preliminary trial performed on patients with established cancers was 100% (18 of 18) positive for stomach cancer and 81% (13 of 16) positive for esophageal cancer. A public survey of the high-risk areas, screening 38,073 normal persons ranging in age from 35 to 70 years, showed positive results in 9204 (24.2%) persons. Subsequent fibergastroscopy carried out in 4023 occult blood bead detector positive persons showed 126 cancers (41 of the esophagus, 46 of the gastric cardia, and 39 of the stomach). Factors influencing the cancer detection rate were sex, age, and degree of positivity of the occult blood bead detector test. Seventy per cent (89 of 126) of the cancers discovered were in an early stage. The occult blood bead detector costs the primary screened person only 30 cents and may be practical for the large-scale screening of cancer of the upper digestive tract in developing areas.