AN ECOLOGICAL STUDY OF TRENDS IN CANCER INCIDENCE AND DIETARY-CHANGESIN HONG-KONG

Cancer incidence rates from the Hong Kong Cancer Registry show signifi cant increases in lung and colon cancers and decreases in nasopharynge al cancer in both sexes from 1973 to 1992. Moreover, cervical cancer a nd male esophageal cancer have declined significantly and changes in t he trends of cancer of the following sites were of borderline signific ance: decreasing male laryngeal and female esophageal cancers and incr easing prostate and female breast cancers. These changes have occurred along with dietary shifts in the population, from a diet predominantl y of rice and small portions of meat, vegetables, and fish to one with larger portions of all foods but rice and eggs. The latter data were gathered from six government household surveys from 1963-64 to 1994-95 . By combining the two data sets, correlation coefficients were calcul ated for per capita consumption patterns of eight foods (rice, pork, b eef poultry, saltwater fish, freshwater fish, fresh vegetables, and eg gs) and cancer incidence data of the same year or IO years later. High er meat intakes were significantly and positively correlated with canc ers of the colon, rectum, prostate, and female breast. The correlation s also suggested that current diets were more influential than diets a decade before for cancers of the lung, esophagus, rectum, and prostat e. Cancers of the nasopharynx and colon were significantly correlated with current and past diets. These results support the hypothesis that intakes of meat and its associated fat ave risk factors for colon, re ctal, prostate, and female breast cancers.