Histological types of gastric cancer in Mexico.

BACKGROUND Gastric cancer is the second leading cause of malignant tumours in Mexico. The distribution of the histological types of this tumour has not been estimated from a population-based representative sample. METHODS The histological types of gastric cancer according to the Lauren classification and selected socio-demographic characteristics for 220 patients from different socioeconomic levels are reported. The study population represents 66% of all new gastric cancer cases during 1989-1990 reported to the Mexico City Cancer Registry. The patients attended four public hospitals, seven social security hospitals and four private hospitals in Mexico City. A second histological diagnosis was performed by one pathologist. RESULTS No specific histological type of gastric cancer predominated since the estimated distribution for intestinal gastric cancer was 44.5%, for diffuse gastric cancer 43.2% (and the remaining 12.3% corresponded to indeterminate tumours). The distribution of intestinal and diffuse gastric cancer did not vary significantly according to socioeconomic level or medical care unit and it showed a clear relationship with gender, the intestinal type of gastric cancer being more common among males. CONCLUSIONS Mexico may not have been affected by the gastric cancer epidemic at the beginning of the twentieth century but the available information and the results of this study are only useful to demonstrate that, currently, no histological type of gastric cancer (according to Lauren's classification) predominates significantly in this country.