Mortality distribution due to tracheal, lung, and bronchial cancer by gender, Brazil, 1980-2010

Lung cancer is the most common type of cancer worldwide in terms of mortality and incidence. The Brazilian National Cancer Institute estimates that, in 2010 in Brazil, there were 27,630 new cases of lung cancer, which became the second and fourth most common type of cancer among men and women, respectively, (2) with a high burden of disease attributable to it. (4) evaluating the age-period-cohort effect, stated that, with respect to the age effect, the risk of mortality increases with age, beginning at an early age. Regarding the cohort effect, those authors reported that there is a lower risk of mortality among men born after 1950 and an increasing risk in all groups of women. Finally, the results regarding younger generations indicate that the current trend is likely to continue; the cohort effect among women suggests a trend toward an increase in mortality rates, whereas a decrease in mortality rates among men under 65 years of age suggests that this trend will continue. Studies of trends in lung cancer mortality in Brazil, published in the Brazilian Journal of Pulmonology, revealed that the age-adjusted mortality rate among men increased from 10.6 deaths/100,000 population in 1979 to 13.1 deaths/100,00 population in 2004. Over the same period, that rate increased from 3.0 to 5.4 deaths/100,000 population among women. Mendonça et al. (7) observed that, although the magnitude of lung cancer mortality is greater among men, the increase in the age-adjusted mortality rate was much greater among women (80%) than among men (23.6%) in the study period (1979-2003). Five years after those studies were published, however, a different behavior can be seen by observing the trend in mortality, stratified by gender. Figure 1 shows the linear trend in mortality from tracheal, lung, and bronchial cancer by gender. Between 1980 and 2010, the linear trend shows an increase in mortality for both genders, although of different magnitudes for the rate and the trend. However, joinpoint regression analysis, which allows adjustment of data from a series on the basis of the smallest possible number of joinpoints (zero, i.e., a line with no joinpoints) and tests whether the inclusion of more joinpoints is statistically significant, showed that the trend behavior is different for each gender (Table 1). After adjustment, the apparent fluctuation for the male gender is explained by different trends in the period, with an increase in mortality between 1980 and 1995 (significant) and between 2000 …