Analysis of the results of the micronucleus test in patients presenting upper digestive tract cancers and in non-cancerous subjects.

A micronucleus test was performed on 75 subjects of whom 38 presented with cancer of the upper digestive tract and 37 were free of disease; the absence of cancerous or pre-cancerous lesions in this latter group was confirmed by endoscopy and vital staining. The daily levels of alcohol and tobacco consumption of the 75 subjects were determined by precise questioning: 78% of the non-cancerous subjects smoked less than 10 g of tobacco per day whereas 79% of the cancer patients smoked 10 g or more daily. The alcohol intake of 78% of the non-cancerous subjects and 63% of the cancer patients was less than 101 ml per day. Only 10% of the cancer patients had combined daily intake levels corresponding to the threshold of sensitivity of the micronucleus test as defined by previous studies. The mean frequency of micronucleated buccal cells was 0.26% in the cancer patients and 0.13% in the non-cancerous subjects. All non-cancerous patients presented a negative test. Only 5% of the cancer patients presented a micronucleated cell frequency above 1% and could thus be considered as positive. It thus appears that the micronucleus test was not significantly positive in our population of 38 cancer patients.