Disparities in cancer epidemiology and care delivery among Brazilian indigenous populations

Cervical cancer screening in Brazilian Amazon Indigenous women: Towards the intensification of public policies for prevention

BACKGROUND

Indigenous women are vulnerable to cervical cancer. Screening is a strategy to reduce the burden of the disease.

OBJECTIVE

To evaluate the prevalence profile of cervical cancer screening cytological results in Brazilian indigenous women by age and frequency of tests compared to non-indigenous women.

METHODS

A cross-sectional study evaluating the prevalences of screening test results in indigenous women assisted in the Brazilian Amazon from 2007 to 2019 (3,231 tests), compared to non-indigenous women (698,415 tests). The main outcome was the cytological result. Other variables were frequency, age groups, and population. The frequency was categorized as "1st test", the first test performed by the women in their lifetime, or "screening test," tests from women who had previously participated in screening. Analyzes were based on prevalences by age group and population. We used Prevalence Ratios (PR) and 95% Confidence Intervals for risks and linear regression for trends.

RESULTS

Data from the 1st test showed a higher prevalence of Low-grade Squamous Intraepithelial Lesion (LSIL) in indigenous women. Peaks were observed in indigenous under 25, 35 to 39, 45 to 49, and 60 to 64. The prevalence of High-grade Squamous Intraepithelial Lesion or more severe (HSIL+) was low in both groups in women younger than 25. The indigenous HSIL+ prevalence curve showed a rapid increase, reaching peaks in women from 25 to 34 years, following a slight decrease and a plateau. In screening tests, HSIL+ was more prevalent in indigenous from 25 to 39 (PR 4.0,2.3;6.8) and 40 to 64 (PR 3.8,1.6;9.0). In indigenous, the PR of HSIL+ results in screening tests over 1st tests showed no screening effect in all age groups. In non-indigenous, there was a significant effect toward protection in the age groups over 25.

CONCLUSION

This screening study of indigenous women from diverse ethnicities showed a higher prevalence of cytological LSIL and HSIl+ than in non-indigenous women. The protective screening effect in reducing HSIL+ prevalence was not observed in indigenous.

Improving equity in access to early diagnosis of cancer in different healthcare systems of Latin America: protocol for the EquityCancer-LA implementation-effectiveness hybrid study

INTRODUCTION

Healthcare fragmentation, a main cause for delay in cancer diagnosis and treatment, contributes to high mortality in Latin America (LA), particularly among disadvantaged populations. This research focuses on integrated care interventions, which have been limitedly implemented in the region. The objective is to evaluate the contextual effectiveness of scaling-up an integrated care intervention to improve early diagnosis of frequent cancers in healthcare networks of Chile, Colombia and Ecuador.

METHODS AND ANALYSIS

This research is two pronged: (A) quasi-experimental design (controlled before and after) with an intervention and a control healthcare network in each LA country, using an implementation-effectiveness hybrid approach to assess the intervention process, effectiveness and costs; and (B) case study design to analyse access to diagnosis of most frequent cancers. Focusing on the most vulnerable socioeconomic population, it develops in four phases: (1) analysis of delays and barriers to early diagnosis (baseline); (2) intervention adaptation and implementation (primary care training, fast-track referral pathway and patient information); (3) intracountry evaluation of intervention and (4) cross-country analysis. Baseline and evaluation studies adopt mixed-methods qualitative (semistructured individual interviews) and quantitative (patient questionnaire survey) methods. For the latter, a sample size of 174 patients with cancer diagnosis per healthcare network and year was calculated to detect a proportions difference of 15%, before and after intervention (α=0.05; β=0.2) in a two-sided test. A participatory approach will be used to tailor the intervention to each context, led by a local steering committee (professionals, managers, policy makers, patients and researchers).

ETHICS AND DISSEMINATION

This study complies with international and national legal stipulations on ethics. It was approved by each country's ethical committee and informed consent will be obtained from participants. Besides the coproduction of knowledge with key stakeholders, it will be disseminated through strategies such as policy briefs, workshops, e-tools and scientific papers.

Cancer incidence in indigenous populations of Western Amazon, Brazil

OBJECTIVES

This study aims to estimate a population-based cancer incidence among indigenous populations in the State of Acre, Brazilian Western Amazon, to provide knowledge about cancer epidemiological profiles contributing to healthcare policies and service planning. Although cancer epidemiology in Brazil is well described through incidence and mortality estimate in the general population, cancer estimates among indigenous peoples are still unknown.

DESIGN

This is a descriptive study of cancer incidence among the indigenous population (2000-2012) in the State of Acre, Brazil. The sources used were population-based cancer registries of Goiânia, hospital-based cancer registry of Acre, São Paulo, and Porto Velho; Special Indigenous Health Districts databases of Acre, Goiânia, and São Paulo; Mortality Information System, and Rio Branco's public and private laboratories' reports. Standardized Incidence Ratio (SIR) was calculated using cancer incidence rates of Goiânia as reference.

RESULTS

From 137 cancer cases, 51.8% occurred in women and 32.1% in people aged 70 + . Among men, the most frequent cancer sites were stomach (25.8%), liver (15.1%), colorectal (7.6%), leukemia (7.6%), and prostate (6.1%). Among women, the most frequent were cervical (50.7%), stomach (8.5%), leukemia (5.6%), liver (4.3%), and breast (4.3%). Among men, there was an excess of cancer cases for stomach (SIR=1.75; 95%CI:1.67-1.83), liver (SIR=1.77; 95%CI:1.66-1.88), and leukemia (SIR=1.64; 95%CI:1.49-1.78). In women, an excess of cancer cases was observed for cervical (SIR=4.49; 95%CI:4.34-4.64) and liver (SIR=2.11; 95%CI:1.88-2.34). A lower cancer incidence for prostate (SIR=0.06; 95%CI:0.05-0.07) and female breast (SIR=0.12; 95%CI:0.11-0.14) was observed.

CONCLUSIONS

Cervical, stomach, and liver cancers corresponded to 52% of the cases and were highly incident among the Brazilian indigenous population of Western Amazon compared to non-indigenous counterparts. Despite the low frequency of breast and prostate cancer, the fact they were present among indigenous peoples suggests a complex epidemiological transition framework in these populations.