Topic: Cancer disparities in American Indian and Alaska Native populations

Contents

TOPIC AT A GLANCE

What is this report about?

This report discusses disparities in cancer screening, diagnosis and survival rates in the American Indian and Alaska Native populations, as well as factors contributing to those disparities.

Background

About 3 percent of the United States population identifies as American Indian or Alaska Native (AIAN). AIANs are individuals who have origins in the first peoples of North and South America and are affiliated with a tribe or otherwise connected to the community. There are 574 federally recognized tribes and more than 200 unrecognized tribes spanning a diverse set of customs, languages and histories.

Because of persistent systemic racism and other factors, AIANs are more likely than whites to live in poverty without adequate health insurance. These two factors contribute to higher rates of chronic health conditions, many of which increase cancer risk. Because AIAN ethnicity is often not recorded correctly in health tracking systems, the cancer burden on these populations is likely higher than the current data suggest.

Despite these obstacles, AIAN communities continuously work toward improved health care, sovereignty and equity. This special section in the American Cancer Society’s 2022 Cancer Facts & Figures report, which highlights the cancer disparities in AIAN populations, advocates for increased funding for facilities that serve AIANs and better tracking of AIAN cancer statistics.

Why is this report important?

American Indians and Alaska Natives (AIANs) historically have unequal access to healthcare, high-quality education, economic opportunity and other services and resources that affect health compared with white people.  This is due in part to ongoing systemic racism. Poverty and low healthcare coverage are linked to increased cancer risk and worse survival outcomes, and this special report found that AIANs have higher rates of some types of cancer and tend to be diagnosed at a later stage than white people. Knowing the origin of cancer disparities can help policymakers and healthcare experts provide more resources and better care for this community.

Reducing cancer disparities benefits everyone: a significant number of cancer-related deaths among all US adults could be prevented if socioeconomic disparities were reduced. Eliminating health disparities saves money and lives.

Report findings

The American Cancer Society’s special section included the most recent cancer statistics in American Indian and Alaska Native (AIAN) populations. The following topics and research findings were discussed in the report:

Rates of some cancers are higher in AIAN people than in white people.
Overall, AIAN people have higher rates of lung, colorectal and kidney cancers than white people. In addition, they are more likely to be diagnosed with cancers caused by infectious diseases, including stomach, liver and cervical cancer.

AIANs are more likely to be diagnosed with advanced disease.
Compared to white people, AIAN people are more likely to be diagnosed at a later stage for many types of cancer, including breast, lung, colon and rectum, prostate, stomach and cervix cancers. For example, 41 percent of breast cancers in AIAN women are diagnosed after they have spread beyond the local stage, compared to 33 percent in white women. Later-stage diagnosis, which results in poorer survival outcomes, reflects the lack of access to high-quality health care and cancer screening in AIAN communities.

AIANs have poorer survival outcomes.
The percentage of cancer survivors living beyond five years of their diagnoses is lower in AIAN people than in white people. This pattern is especially pronounced in individuals with lung and stomach cancer. For example, the 5-year relative survival rate for local-stage lung cancer is 46 percent in AIANs but 60 percent in whites. For all stages of stomach cancer, 32 percent of whites survive beyond five years, compared to just 19 percent of AIANs.

Cancer disparities vary significantly across regions.
Partially because of genocide, forced displacement and relocation of American Indians and Alaska Natives, about two-thirds of AIAN people live in tribal areas known as Purchased/Referred Care Delivery Area (PRCDA) counties. In the US, these counties are located in six PRCDA regions: Alaska, East, Northern Plains, Pacific Coast, Southern Plains and Southwest (see map on page 1).  

Disparities in cancer incidences in AIANs are highly variable across regions. For example, fewer cancers were seen among AIANs than among whites in the Southwest region but more cancers were seen among AIANs in the Southern Plains. Fewer AIAN women in the Southwest region had breast cancer compared to whites but more AIAN women in the Northern Plains had breast cancer compared to whites.

What contributes to cancer disparities in American Indians and Alaska Natives?

The ACS report looked at various modifiable factors that may contribute to the cancer disparities that are described in more detail below. Notably, this report did not address the frequency of AIAN reporting of a family history of cancer or inherited mutations. PRCDA regions include different tribes with distinct ancestry that may contribute to cancer rates. Similarly, differences in potential environmental factors between regions are not addressed (e.g., nuclear testing sites in the Southwest).

Substandard access to healthcare and screening
More than half of AIAN people live in rural PRCDA counties with limited access to quality health services and specialty care.

The Indian Health Service (IHS) serves AIAN people in PRCDAs. IHS is a government-funded healthcare system that was created in 1955 as partial compensation to tribes for forcing them from their lands. However, the agency is consistently underfunded and understaffed. IHS facilities struggle to provide quality healthcare to AIANs, many of whom are uninsured and lack access to other health services. This affects cancer screening and care for AIANs and is likely responsible for the lower 5-year survival rate for many cancers in AIAN communities.

AIAN people are less likely than white people to have up to date screenings for breast, colorectal and cervical cancer, especially if they use IHS services. Colorectal screening is particularly difficult to access because many IHS and other facilities caring for AIAN communities do not offer colonoscopies. Moreover, a health plan for AIAN people that covers services at non-IHS facilities (called the Purchased/Referred Care program) designates cancer screening as priority level II, meaning that screening can be denied if the plan’s funding is low.

Programs such as Minnesota’s mobile mammography and Intertribal Colorectal Cancer Council are helping decrease disparities in access to screening services for AIANs living in rural areas.

Smoking
Cigarette smoking is a major risk factor for cancer, and AIAN people have the highest rates of smoking of any major racial or ethnic group in the US.

Social and cultural factors contribute to the high prevalence of smoking in AIAN communities. Cigarettes are cheaper on tribal lands because they are not subject to state taxes. Also, tobacco companies directly target AIAN people by using culturally specific names, symbols and icons in their advertising. Moreover, some AIAN tribes use tobacco for cultural practices in social relationships as well as spiritual and medicinal ceremonies.

Low socioeconomic status and income are linked to higher smoking rates, and AIAN people are more than twice as likely as whites to live in poverty. Racial bias toward AIAN people has contributed to a lack of opportunities in higher education and economic stability. Addressing these system-wide issues could decrease smoking rates and improve cancer outcomes in AIAN people.  

Excess body weight
Excess body weight increases the risk of many cancers. Overall, AIAN people are more likely to be obese than white people. Poverty, food insecurity and living in rural areas all contribute to excess body weight and substandard access to healthy food for AIAN people. Historical injustices and racism continue, decreasing AIAN people’s access to their traditional diets, which are high in fruits and vegetables and low in carbohydrates and fats, and reduce the risk for obesity and chronic disease. These injustices include historical trauma, boarding schools, adverse childhood experiences, poverty, federal food programs and food deserts. Expanding access to locally grown food and improving food sovereignty could help lower obesity in the AIAN population.

Diabetes and infectious
Type 2 diabetes increases the risk of colorectal, kidney and other cancers. AIAN adults are twice as likely as white adults to develop type 2 diabetes, and rates among AIAN youth in 2012 were more than 10 times higher than rates in white youth. Excess body weight, low socioeconomic status and food insecurity closely correlate with higher rates of type 2 diabetes.

AIAN people are more likely than white people to use non-city water sources and to live in crowded households and rural settings. These are risk factors for contracting H. pylori, a bacteria that infects the stomach. Persistent H. Pylori infection is a major cause of cancer in the main part of the stomach.  One study of 500 Alaska Natives found that about three-quarters were infected with H. pylori, compared to about one-quarter for all combined races and ethnicities in the US. However, guidelines do not recommend treatment with antibiotics because individuals are likely to be reinfected or develop resistance to antimicrobial drugs. Research is needed to understand if treating H. pylori in high-risk groups can prevent stomach cancer.

Hepatitis B and C viruses (HBV and HCV) can increase the risk of cancer, especially of the liver. While rates of chronic HBV infection are similar in AIAN people and other racial and ethnic groups in the US, rates of HCV are nearly three times higher in AIAN people. In part because of HCV infection, AIAN  people are 2.5 times more likely to develop liver cancer than their white counterparts. Treating HCV with antiviral drugs can clear the infection and reduce liver cancer risk, but many AIAN people cannot afford these expensive medications.

Clinical trials
More AIAN participants are needed in clinical trials, particularly studies looking at tumor features, to be certain that treatments that work against cancer in a study composed of mostly white participants also work the same in AIAN individuals. The Harper Cancer Research Institute at the University of Notre Dame is working to address this issue by building relationships with the Pokagon Band of Potawatomi Indians in northern Indiana and other Native American tribes. Their goal is to collect cancer tissue samples from native citizens that will be added to the National Cancer Institute’s Cancer Genome Atlas. This effort strives to increase the representation of AIAN individuals in the genomic database, which could lead to improved diagnosis and treatment.

What does this mean for me?

If you are an American Indian or Alaska Native, your risk of some cancers may be higher than the risk of people in other racial or ethnic groups. You may also be more likely to be diagnosed with cancer at a later stage, which can lead to poorer survival rates. Knowing your screening options and having access to high-quality health services could lead to earlier diagnosis and better survivorship. There may be programs available in your community that focus on improving cancer outcomes in AIAN populations. The American Indian Cancer Foundation provides educational resources on cancer in native communities as well as information on programs designed to improve your survival and other health outcomes.

Ask your doctor about factors that affect your cancer risk and lifestyle changes or other steps that can lower your risk. Talk with your relatives about your family history of cancer and speak with your doctor or a genetic counselor about a referral for genetic testing. Finally, ask your healthcare professional about recommended screenings and prevention options based on your age and risk. You may also be eligible for clinical trials, which you can find using the National Cancer Institute’s database.

Reference

American Cancer Society, Cancer Facts & Figures 2022, Special Section: cancer in the American Indian and Alaska Native population.

Disclosure: FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board prior to publication to assure scientific integrity.

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