Trends in cancer incidence among Singapore Malays: a low-risk population.

Introduction: Inspection of trends in cancer incidence in ethnically or geographically diverse populations is important for the understanding of cancer patterns and also to provide clues for aetiologic studies. There is little information on cancer incidence among Malays, a low-risk population. The population-based cancer registration system in Singapore offers the opportunity in this regard.
Materials and Methods: A review of all newly diagnosed cancer cases among Singapore Malay residents in the period 1968 to 1997 was conducted to determine the time trends using data from Singapore Cancer Registry. Age-standardised incidence rates and average annual percentage change, using Poisson regression, were calculated.
Results: During the 30-year study period, a total of 9101 incident cases of cancer were diagnosed among Malays in Singapore. The 3 most common sites of cancer were lung, liver and colorectum in males; and breast, colorectum and ovary in females in the period 1983 to 1997. Leukaemia was among the top 10 cancer sites in both sexes. Malays generally experienced lower cancer incidence rates compared to Chinese, but rates have been increasing at 1.5% to 2% annually. Statistically significant increases in incidence were observed for most of the cancer sites. The incidence of nasopharyngeal carcinoma increased, while there were no significant changes in the general population.
Conclusion: The relatively lower cancer risk among Singapore Malays might be attributed to genetic factors or closer adherence to a more traditional lifestyle. This study provides a baseline for comparisons with other populations with diverse cancer risk patterns in order to obtain a better understanding of possible aetiologic factors.