Trends in histopathology of lung cancer in Alberta.

OBJECTIVE: To describe the trends over calendar period and birth cohort in lung cancer incidence by histopathology and sex, in Alberta.
METHODS: Lung cancer data were extracted from the Alberta Cancer Registry for the years 1979 to 1998. Trends in age-standardized rates over calendar period and trends of age-specific rates over birth cohorts are presented. These trends are discussed in relation to historic smoking patterns.
RESULTS: Lung cancer incidence is increasing over calendar period in females for all lung cancers and the histological types, adenocarcinoma, squamous cell, and small cell carcinoma. In males, all lung cancer incidence increases until 1988 and then decreases. Adenocarcinoma incidence in males increases over the whole time period, while squamous cell and small cell carcinoma incidence decreases. For females born before 1939, the incidence of all lung cancer and the three histological types increases over birth cohorts for all age groups. For those born after 1939, there is a slight decline. Male lung cancer incidence shows no marked increases over birth cohorts. In males born after 1929, all lung cancer and squamous cell and small cell carcinoma incidence decreases over birth cohorts for all age groups. Incidence of adenocarcinoma increases over all birth cohorts in males.
CONCLUSION: In Alberta, incidence of adenocarcinoma of the lung is increasing in both males and females, while squamous cell and small cell carcinoma are decreasing in males, but increasing in females. These trends may reflect changes in smoking habits.