Cancer risk factors and screening in First Nations in Ontario

Assessing Breast Cancer Screening and Outcomes Among First Nations Women in Alberta

BACKGROUND

Breast cancer (BC) incidence rates for First Nations (FN) women in Canada have been steadily increasing and are often diagnosed at a later stage. Despite efforts to expand the reach of BC screening programs for FN populations in Alberta (AB), gaps in screening and outcomes exist.

METHODS

Existing population-based administrative databases including the AB BC Screening Program, the AB Cancer Registry, and an AB-specific FN registry data were linked to evaluate BC screening participation, detection, and timeliness of outcomes in this retrospective study. Tests of proportions and trends compared the findings between FN and non-FN women, aged 50-74 years, beginning in 2008. Incorporation of FN principles of ownership, control, access, and possession (OCAP®) managed respectful sharing and utilization of FN data and findings.

RESULTS

The average age-standardized participation (2013-8) and retention rates (2015-6) for FN women compared to non-FN women in AB were 23.8% (P < .0001) and 10.3% (P = .059) lower per year, respectively. FN women were diagnosed with an invasive cancer more often in Stage II (P-value = .02). Following 90% completion of diagnostic assessments, it took 2-4 weeks longer for FN women to receive their first diagnosis as well as definitive diagnoses than non-FN women.

CONCLUSION

Collectively, these findings suggest that access to and provision of screening services for FN women may not be equitable and may contribute to higher BC incidence and mortality rates. Collaborations between FN groups and screening programs are needed to eliminate these inequities to prevent more cancers in FN women.

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.

Creating a Canadian Indigenous Research Network Against Cancer to Address Indigenous Cancer Disparities

PURPOSE

In Canada, Indigenous peoples’ cancer rates have increased, but cancer screening rates tend to be lower. When coupled with poor cancer prognosis, treatment barriers, and inaccessible health care, Indigenous patients with cancer experience many unmet needs. Further complicating their journey is a multijurisdictional system that complicates cancer control services, treatments, patient supports, and cancer surveillance. To address these issues, the Canadian Indigenous Research Network Against Cancer (CIRNAC) was developed. This article describes the forerunners and consultative process that created the network and the consensus model developed to ground this network with, by, and for Indigenous peoples.

METHODS

A consultative workshop was held to (1) establish and increase network membership, (2) enhance partnerships with Indigenous communities and other researchers, and (3) develop an Indigenous-led research program, new funding, and related initiatives.

RESULTS

Participants viewed the CIRNAC as a reflective parallel network led by Indigenous peoples that would identify research priorities within Canada, assess how these priorities align with Indigenous patients’ cancer care and research needs, and cross-check to see if these priorities align with each other. The network would also advocate for Indigenous elders/knowledge holders and community grassroot processes to drive research and training, thus demonstrating the power of the community voice and lived experience in research. In addition, the network would foster research partnerships to investigate alternative Indigenous models for cancer prevention, care, treatment, and support.

CONCLUSION

The CIRNAC evolved as a viable vehicle to address cancer with, for, and by Indigenous peoples. The network is guided by a preamble, a set of aims, and an inclusion engagement circle model. It is evolving through major world initiatives, with the aim of formally becoming an internationally linked national network.

Association between known risk factors and colorectal cancer risk in Indigenous people participating in the Ontario Familial Colon Cancer Registry

Introduction

Colorectal cancer is one of the most common cancers in Ontario and imposes a high burden on many Indigenous populations. There are two aims for this short communication: ■ Highlight colorectal risk factor findings from a population-based case-control study■ Highlight trends and challenges of colorectal cancer research in Indigenous populations in Ontario.

Methods

Prevalences of cigarette smoking, obesity, fruit and vegetable consumption, and family history of colorectal cancer were estimated using the Indigenous identifier in the Ontario Familial Colon Cancer Registry for 1999-2007 and then compared for cases and controls using age-adjusted odds ratios (ors) with 95% confidence intervals (cis).

Results

The registry search identified 66 Indigenous cases and 23 Indigenous controls. Cigarette smoking (or: 1.88; 95% ci: 0.63 to 5.60) and obesity (or: 2.16; 95% ci: 0.72 to 6.46) were higher in cases, but not statistically significantly so.

Conclusions

Findings were consistent with previous literature describing Indigenous populations. A small sample size and poor Indigenous identification questions make it challenging to comprehensively understand cancer risk factors and burden in Indigenous populations.

Characterizing risk of type 2 diabetes in First Nations people living in First Nations communities in Ontario: a population-based analysis using cross-sectional survey data

BACKGROUND

Population-based planning tools are important for informing diabetes-prevention efforts in First Nations communities. We used the Diabetes Population Risk Tool (DPoRT) to predict 10-year diabetes risk and describe the factors that contribute to diabetes risk in First Nations adults living in Ontario First Nations communities.

METHODS

We examined population data from adult (≥ 20 yr) respondents to the First Nations Regional Health Survey (RHS) phase 3, a representative cohort of First Nations people living in Ontario First Nations communities. We applied the DPoRT to risk factor information in the survey to predict the distribution of 10-year type 2 diabetes incidence and number of new diabetes cases from 2015/16 to 2025/26.

RESULTS

There were 993 respondents to the RHS phase 3 adult survey, of whom 936 (708 without diabetes and 228 with a diagnosis of type 2 diabetes) were eligible for inclusion. The DPoRT predicted a type 2 diabetes risk of 9.6% (confidence interval [CI] 8.3-10.8) between 2015/16 and 2025/26, corresponding to 3501 (95% CI 2653-4348) new diabetes cases. Diabetes cases were predicted to occur disproportionately among those experiencing food insecurity, low income, overweight, obesity and physical inactivity. Reduced diabetes risk was predicted among those who reported connections to Indigenous culture, as measured by eating traditional vegetative foods a few times or often in the previous 12 months.

INTERPRETATION

Socioeconomic conditions and known risk factors for type 2 diabetes are important determinants of diabetes risk in First Nations communities. Culturally appropriate policies, programming and services that address socioeconomic disadvantage and other diabetes risk factors in First Nations communities likely have an important role for diabetes prevention in First Nations adults.