[A 10-year prolective study on cancer of the digestive system].

OBJECTIVE: A ten year prolective and multicentre study of cancer of the Digestive Tract aims to evaluate the variations on frequency and to identify risk factors. METHODS: Ten hospitals are participating five in Mexico City and five in other states. Data were obtained through the hospitals files and specially designed questionnaires, the latter mainly diet and habits oriented. RESULTS: Through this ten years in the 4,715 cases studied we can appreciate a decreasing tendency of the carcinoma of the stomach (GC) that has been the most frequent until 1984 in the general group General Hospital and Instituto Nacional de la Nutricion. Since then and up to date, first place in frequency in shared between the stomach and colorectal carcinoma (CRC). CRC has been increasing even in the General Hospital in which GC was very high. Eighth years ago we found that people in those hospitals in which GC was high the diet was poor in proteins, fat A and C vitamin. People in those hospitals with high frequency of CRC had diet high in protein, fat and low in fiber. A new study on diet is ongoing. Gallbladder and biliary tract carcinoma has been increasing in all the hospitals. A high O blood group was found in the Juarez Hospital in which gallbladder carcinoma was the highest. O group is highest in the indian people. Cancer of the gallbladder is very high in Pimas and Navajos indians. A plan to study litogenic index and culture of salmonella is going to be practiced in bile from normal and gallbladder carcinoma. Concerning habits, tobacco and alcohol consumption are most frequent in cancer of the esophagus and pancreas. Also coffee consumption is high in the latter. CONCLUSIONS: Along this 10-year study, the frequency of gastric cancer has been decreasing. Instead, the frequencies of colo rectal and biliary tract cancers have been increasing. Variations in frequencies correlated with the composition of the diet, fiber consumption habits and racial characteristics of the different groups.