The epidemiology of lung cancer in Singapore.

Lung cancer has reached epidemic proportions in all developed countries and many of the urban centres of the developing world. It is the most frequent cancer site in Singapore, accounting for 23.4% (623 cases) of all cancer deaths and nearly 5% of all causes in 1982. Based on incidence data for 1968-1977, among males, there was an average of about 330 cases diagnosed each year, giving an annual incidence rate of 30.7 per 100,000 and a proportion of 21% against all sites. Among females, there was an average of about 115 cases, with the incidence rate at 11.2 and the proportion 10.3% (ranking third behind breast and cervix). The risks among the Chinese were more than double those of the other ethnic groups. The Hokkien (73.2 per 100,000) and Teochew (67.0) males had one of the highest age-standardized incidence rates in the world. Most of the cases were of the epidermoid carcinoma type. Among the females, the Cantonese (28.5) had about double the risks compared to the other dialect groups, and the rate was among the highest in the world. Adenocarcinomas accounted for almost 50% of the cases. The relevant host and environmental factors associated with lung cancer are discussed. Without doubt, cigarette smoking is the most important risk factor. The ultimate solution to this problem must lie in an effective smoking control programme, besides much-needed improvements in early diagnosis and treatment of the disease.