Transição do câncer no Brasil: efeito da transição etária ou mudança no risco?

Abstract

The demographic transition has increased the importance of non-communicable chronic diseases as part of the morbidity and mortality profiles. Cardiovascular diseases and neoplasms are the leading causes of death among adults and the elderly in industrialized societies. However, in some countries, mortality rates from neoplasms have declined, motivated by reducing deaths from cancers related to infectious processes. Concomitantly, there has been an increase in cancer types associated with behavioral factors or factors inherent to population aging and economic and social development (cancers of the pancreas, lung, breast, prostate, and colon rectum). These tendencies raise questions about how the transition process, seen in developed countries, occurs in developing ones. This dissertation investigates the transition of cancer in Brazil from changes in mortality and incidence rates in recent decades. Data from the Sistema de Informação sobre Mortalidade (SIM), from 1996 to 2019 (pre-pandemic period), were used to estimate the mortality rates. Also, data from the Registro de Câncer de Base Populacional (SisRCBP) for the years 2000 and 2010 were used to calculate incidence rates. We examine time trends, regional patterns, and differences by sex. Crude mortality and incidence rates are decomposed into two factors (age and state of residence), according to compositional and risk effects. Also, we measure changes in the relative participation of types of cancer in the total of neoplasms of interest. We use the decomposition method from Das Gupta (1994) and its refinement proposed by Chevan and Sutherland (2009). The results show a decline in mortality rates from total neoplasms in Brazil and most states. This reduction is due to a decrease in mortality rates from cancers typical of the 1st phase of the cancer transition. However, there is an increase in mortality rates from cancers specific to the 2nd phase of the cancer transition. These patterns reveal an ongoing cancer transition in Brazil, with different time trends, regional patterns, and differences by sex. Even within the same group of cancers (1st or 2nd stages of the cancer transition), there are essential differences, confirming the need to analyze each type of cancer individually. Pancreas and colon-rectum cancers stand out for having the highest growth in standardized mortality rates and having a distribution of the risk of death that favors increases during population aging. The results vary between the capitals and states, suggesting the existence of regional patterns (main cities and the countryside). Incidence rates generally follow mortality trends. However, it is necessary to get a deeper understanding of the dynamics between incidence-survival-mortality. Finally, Brazilian states that show higher mortality rates from total neoplasms are experiencing an increase in mortality rates from cancers typical of the 2nd phase of the cancer transition and a practically constant trend in mortality rates from cancers associated with infectious processes. The control of cancers from the 2nd stage of the cancer transition is limited compared to the cancers from the 1st stage, making it necessary to intensify the public health measures already implemented in Brazil and evaluate new cancer prevention and control procedures.