Tendências e projeções da mortalidade pelos cânceres específicos ao gênero no Brasil / Trends and projections of mortality for specific cancers gender in Brazil

RESUMO

Os cânceres que acometem os órgãos genitais masculinos e femininos, em conjunto com o câncer de mama, são responsáveis por cerca de 20% dos óbitos por câncer no mundo. Conhecer os padrões de mortalidade por esses cânceres no Brasil, as mudanças que se produziram ao longo do tempo, os grupos mais vulneráveis e a carga de mortalidade que se apresentará no futuro são elementos básicos para a estruturação das ações assistenciais e de vigilância do câncer. O objetivo desse estudo foi analisar as tendências de mortalidade pelos cânceres que acometem órgãos que são específicos a cada gênero e projetar a mortalidade por esses cânceres até o ano de 2030, para o Brasil, regiões e estados da federação. Trata-se de um estudo ecológico de base populacional que analisou os óbitos, ocorridos no período 1996 a 2010, decorrentes dos cânceres de colo do útero, corpo do útero, mama feminina, ovários, vulva, vagina, próstata, pênis e testículos, registrados no Sistema de Informação sobre Mortalidade; as informações sobre população foram obtidas do Instituto Brasileiro de Geografia e Estatística. Foi aplicada a Regressão loglineal (Joinpoint regression) com taxas padronizadas (população mundial ASR-W) para estimar o Annual Percentage Change (APC), o Average Annual Percentage Change (AAPC), o intervalo de confiança 95% e os pontos de inflexão da curva; as projeções foram calculadas através do programa Nordpred, inscrito no programa R, utilizando o modelo idade-período-coorte, analisando posteriormente se as mudanças que se produzirão no futuro serão decorrentes da exposição aos fatores de risco e/ou da estrutura da população exposta ao risco. Todas as análises também foram aplicadas para o conjunto de todos os óbitos por câncer (com exceção dos cânceres de pele não-melanoma).

ABSTRACT

Cancers that attack male and female genital organs, along with breast cancer, are responsible for approximately 20% of cancer-related deaths in the world. Knowledge on the mortality patterns for these cancers in Brazil, the changes produced throughout time, the most vulnerable groups and the mortality burden in the future are basic elements for structuring assistance and vigilance actions for cancer. The objective of this study was to analyze the mortality trends of cancers that attack gender-specific organs, and project mortality until the year 2030, for Brazil, its geographic regions, and federation states. A population-based ecological study is presented herein, which analyzed deaths occurring within the period 1996-2010, due to cancers of the uterine cervix, uterine corpus, female breast, ovary, vulva, vagina, prostrate, penis and testicles, registered in the Mortality Information System. Data on population was obtained from the Brazilian Institute of Geography and Statistics. Joinpoint regression was applied with standardized rates (world population ASR-W) to estimate the Annual Percentage Change (APC), the Average Annual Percentage Change (AAPC), the confidence interval 95% and the inflection points of the curve. The projections were calculated by the Norpred program, inscribed within the R program, utilizing the age-period-cohort model, with posterior analysis of whether the changes produced in the future will be consequences of exposition to risk factors and/or structure of the population exposed to risk. The analyses were also applied to the set of all cancer-related deaths (with exception for non-melanoma skin cancers). For Brazil, mortality due to cancers of penis (APC=1.5% CI95% 0.7;2.3 p<0.05), testicles (APC=1.6% CI95% 0.5;2.8 p<0.05) and ovary (APC=0.8% CI95% 0.1; 1.5 p<0.05) showed increasing trends, while cancers of vulva and vagina (APC=-0.1% IC95% -0.9; 0.7 p=0.8), uterine corpus (APC=-0.3 CI95% - 1.0; 0.5 p=0.4), breast (APC=0.4% CI95% -0.2;1.0 p=0.2) and prostrate (AAPC= 1.1% CI95% -0.2; 2.4 p=0.1) presented stable trends. Mortality due to cervical cancer presented reducing trends (APC=-1.7% ICI95%-2.2; -1.1 p<0.05). Analysis of the grouping of all cancer-related deaths presented increasing mortality trends for the male gender until the year 2006 (APC= 1.2% CI95% 0.6; 1.8 p<0.01), followed by a stability period. For females, the trend was stable (APC=0.4% CI95% -0.2;-1.8 p=0.2). The mortality rates for all analyzed cancers revealed, generally, reducing trends for the South and Southeast regions, increasing trends for the North and Northeast regions, and stability for the Midwest region. Mortality projections for the year 2030 indicate that the North and Northeast regions will suffer the highest mortality rates for the analyzed cancers; however, for the remaining regions, reduced rates will be observed in comparison with the last period analyzed. It must be highlighted that, for testicle cancer, there will be an increase of 33% in mortality burden until the year 2030. For the remaining cancers, significant variations will not be observed in mortality rates for the last observed period and the last projected period in Brazil. The structure and size of the Brazilian population are the factors explaining the mortality patterns for these cancers in the future, although for the Northeast region, the variations will be explained mostly by the increase in risk for these cancers. It is concluded that there is a pronounced inequality in the distribution of gender-specific cancer mortality in Brazil, where the poorer regions present a significant increasing situation of the number of deaths throughout a historical series. In 2030, these regions will present the highest mortality rates in the country, with emphasis on penis, testicle and ovarian cancers. (AU)