Vulnerability cartography: A narrative review of the historical, epidemiological, and biocultural perspectives of cancer in indigenous women in Brazil over the last three decades.

Abstract

e22533 Background: The global indigenous population in 2021 is around 476 million in 90 countries, with lower life expectancy, cultural diversity and high poverty. The 2022 Indigenous Census revealed that the Brazilian indigenous population reached 1.693.535 people (0.83% of the national population). Indigenous literacy (84.9%) remains below the national average (93%). Basic precariousness affects 69.1% of Brazilian Amerindians, reinforcing structural inequalities and the need for specific policies to mitigate these inequalities. Until the beginning of the 20th century, cancer (Ca) was an epidemiological rarity among Brazilian indigenous peoples due to short life expectancy and traditional practices. Urbanization brought risk factors, promoting a pathological-epidemiological transition. Methods: This study systematically reviewed 31 national publications - SciELO, Pubmed, BVS, LILACS and Google Scholar (1990-2024) on Ca in Brazilian Amerindians, complemented by official demographic and epidemiological data, culminating in a narrative overview for in-depth analysis. Results: Indigenous women (IW) > mortality due to cervical cancer (adjusted MR: 1.80; 95% CI: 1.39-2.33), due to the high prevalence of HPV, early sexual debut and limited access to prevention and treatment. IW have < incidence and < mortality due to breast cancer (BC): 4.72/100,000 (2000) to 2.23/100,000 (2010). Protective factors include early first pregnancy (reproductive practices between 13-14 years), multiparity (average > 50% with 5 or more pregnancies), non-dense breasts, prolonged breastfeeding (average of 84 months) and early menopause (70% < 50 years), evidencing beneficial reproductive characteristics. The mammographic evaluation showed that IW had non-dense breasts, which is another protective factor in relation to BC. Clinical characteristics associated with mammographic density were age (P = 0.0001), FSH (P < 0.001), and estrogen levels (P < 0.01). Genomic architecture of Xavante women, highlighting the low prevalence of germline variants associated with BC. In comparison with data from TCGA and the 1000 Genomes Project, only 79/313 mutations were identified, and polygenic risk scores indicated significant differences (p < 0.0001). Ca in indigenous people presents high delays in diagnosis, with an average time of 9 months for detection and 3.4 months until the start of treatment, resulting in low OS. Fatal Ca among men are stomach, liver, colon, rectum, leukemia, and prostate, and among women, cervix, stomach, liver, leukemia, and uterus. Stomach, cervix, and liver ca account for 49.4% of deaths, with mortality rates > than expected, reflecting a scenario of ca related to infectious agents, socioeconomic vulnerability, and barriers to access to health services. Conclusions: Ensuring equitable Ca care for Indigenous populations requires culturally and geographically sensitive policies that address their needs, reduce inequities, and provide effective and appropriate care.