Recent decline in cancer mortality in Catalonia (Spain). A joinpoint regression analysis

The aim of this paper was to analyse recent changes in cancer mortality in Catalonia (Spain) between 1975 and 1998 using joinpoint regression models. Mortality data were obtained from the Mortality Registry of Catalonia. For each sex, age-standardised (standard world population) mortality rates were computed by the direct method, and joinpoint analysis was used to identify the best fitting points where a statistically significant change in the rates had occurred. In men, the overall cancer mortality (except skin non-melanoma) was highest in 1991 and decreased thereafter. Lung cancer was the main cause of cancer mortality, with an increase until 1989, and a subsequent levelling off (-0.8% annual between 1989 and 1998). Colorectal cancer was the second cause of cancer death, both in men and women, with a levelling-off of the rates since 1991 and 1989, respectively. In women, the mortality rate decreased for total cancer (except skin non-melanoma) since 1991 (-0.9% annually). Breast cancer increased until 1975, levelled-off and begun to decline since 1992 (-3.8% annual). Lung cancer increased since 1988 (+2.1%) and became the third cancer cause of death among women in 1998. These changes are mainly due to the decline of smoking prevalence in males, but not in females, and to the introduction of new diagnostic techniques and improved therapies for female breast cancer.