The epidemiology of malignant neoplasia of the larynx in Canada: 1931-1984.

Canadian patterns of morbidity and mortality from laryngeal carcinoma were examined for the periods 1970-1980 and 1931-1984, respectively. Age-standardized morbidity rates had risen significantly in both males and females (P = 0.0001 and 0.0116) during 1970-1980 with rates for males increasing by more than 0.28 additional cases per 100,000 population per year since 1970. Analysis of age-specific rates over time indicates that the rise in standardized rates is attributable to significant increases in rates for males aged 45-54, 55-64 and 65-74 (P less than 0.006) and females aged 45-54, 55-64, and 75-84 (P less than 0.045). Rates for males aged 55-64 demonstrated the most dramatic rate of change of any age group at over 1.8 additional new cases per 100,000 population per year since 1970. Analysis of age-standardized mortality rates reveals that rates for males have risen significantly during the period 1931-1984 whereas rates for females have declined significantly (P = 0.0001 and 0.005, respectively). The rise in age-standardized mortality rates for males is associated with corresponding significant rates of increase in age-specific rates for males aged 45-54, 55-64, 65-74, 75-84 and 85 + (P less than 0.02) whereas the decline in rates for females is associated with significant declines in rates for women aged 35-44, 45-54, and 75-84 (P less than 0.05). Males aged 75-84 had the greatest rate of change at 0.20 additional new deaths per 100,000 population per year since 1931.