Cancer Patterns in Different Racial and Ethnic Groups in Singapore, With Some Reference to Other Asia-Pacific Groups

Abstract

Singapore is a veritable human laboratory for the study of cancer patterns, with a compact population (3m) on a small island (640 km2). The ethnic distribution indicates that 78% are Chinese, 14% Malays, 7% Indians and 1 % Others. The validity of ethnic distribution remains, with less than 5% of marriages being inter-ethnic even today. Recently, a full analysis of incidence trends over 25 years (1968-1992) was completed. The age-adjusted relative risks confirmed high risk in Chinese for nasopharynx, oesophagus, stomach, colon, rectum, liver and lung. In Indians, high risk sites were mouth and cervix, and in Malays, ovary and non-Hodgkin's lymphoma. Of special interest are the following: (a) sharp increse in female breast cancer, attributed to a strong cohort effect, thus suggesting the role of lifestyle changes and the finding of a likely protective effect of soya bean products; (b) marked increase in colorectal cancer, partially explained by the high meat: vagetable intake ratio and reduced cruciferous vegetable intake in the high risk group; (c) unchanging incidence of nasopharyngeal carcinoma, and the finding of salted and picked vegetables as a risk factor; (d) increasing proportion of adenocarcinomas (50%) of the lung in female Chinese, which cannot be explained by cigarette smoking and remains a research topic. J Epidemiol, 1996 ; 6 : S165-S168.