Expert Commentary

National study highlights rural-urban and racial disparities in cancer survivorship

Between 1975 and 2011, not only did survival rates for common cancers in rural areas trail behind urban areas in the US, but also the cancer survival rates for Black individuals in both rural and urban areas remained lower than for other races and ethnicities.

cancer disparities
Photo by Marcelo Leal on Unsplash

Although cancer survival rates have improved in the U.S. in recent decades, patients living in rural areas continued to have consistently lower survival rates for some of the most common types of cancer compared with those living in urban areas, according to a large national study that examines 40 years of data.

The study, published in May in JAMA Network Open, also examines rural-urban disparities by race and ethnicity for four types of cancer: breast, lung, prostate and colorectal cancer. It finds that Black patients in rural and urban areas had lower cancer survival rates compared with other races and ethnicities for all four cancers. Meanwhile, non-Hispanic white patients generally had the highest cancer survival rates in urban and rural areas.

“These findings punctuate the need for elevated health care resources and education for racially and ethnically minoritized groups, especially those in rural settings,” writes Marquita Lewis-Thames and her co-authors in “Racial and Ethnic Differences in Rural-Urban Trends in 5-Year Survival of Patients With Lung, Prostate, Breast, and Colorectal Cancers: 1975-2011 Surveillance, Epidemiology, and End Results (SEER).”

Cancer survival rates indicate the percentage of people who survive a certain type of cancer for a specific amount of time, according to the Mayo Clinic, a nonprofit academic medical center in the U.S. The five-year survival rate is most commonly used statistic used by doctors and researchers.

Previous research has shown that people in rural areas have a 2.7% increased risk of developing cancer and a 9.6% higher risk of dying from it. This study builds on previous findings that show rural-urban disparities in cancer survivorship.

The drivers of these disparities are upstream factors such as systemic and structural racism, segregation, poverty, lack of health insurance and reduced access to health care services, all of which can lead to delayed cancer diagnosis, worse outcomes — such as more cancer-related health complications — and increased risk of dying from cancer, the authors explain.

To be sure, overall rates of new cancers and cancer deaths have declined in the U.S. in recent decades among all racial and ethnic groups and among people who live in rural or urban areas. Also, overall five-year survival rates for most cancers have improved due to advancements in screening, treatment and quality of clinical care. The risk of death from cancer in the U.S. has decreased by 32% since 1991 and approximately 3.5 million cancer deaths have been averted as of 2019, according to the most recent cancer data.

But disparities remain.

The data

Researchers used the Surveillance, Epidemiology, and End Results, or SEER, which is a source of cancer statistics maintained by the National Cancer Institute, from 1975 to 2011. SEER collects cancer data from 20 cancer registries, capturing about 47.9% of the U.S. population. Races and ethnicities included in the data were Asian and Pacific Islander, Hispanic, non-Hispanic Black and non-Hispanic white. Cancer registries collect and store data on people with cancer and play an important role in cancer surveillance.

They analyzed data from 3,659,417 patients who had lung, breast, prostate or colorectal cancer and were diagnosed no later than 2011. They then followed their outcomes in SEER until 2016.

Patients were classified as living in rural or urban counties based on the 2013 Rural-Urban Continuum Codes, which classify metropolitan counties by the population size of their metro area, and nonmetropolitan counties by degree of urbanization and adjacency to a metro area, according to the U.S. Department of Agriculture’s Economic Research Services, which created the codes in 1975.

The median age of patients was 76; 4.6% were Asian; 6.5% Hispanic, 11% Black, and 77% were white.

A quick note on cancer trends in the U.S.: The most common cancers in the U.S. are breast, prostate, lung, colorectal, skin and bladder cancers, according to the American Cancer Society. Worldwide, the most common cancers are breast, lung, colorectal, prostate, skin and stomach cancers, according to the World Health Organization.

Even though white individuals have the highest rate of new cancer cases in the U.S., Black individuals have the highest death rate from cancer, according to the National Cancer Institute.

The overall five-year survival rate for breast cancer in the U.S. is 90%. It is 22% for lung cancer; 98% for prostate cancer; and 65% for colorectal cancer, according to the American Cancer Society.

The findings

Researchers find that overall, the five-year survival probabilities for lung, prostate, breast, and colorectal cancers among rural patients were consistently lower than those who lived in urban areas.

However, when looking at the 40-year period trends, the rural and urban five-year survival rates became equivalent for most cancer types in years approaching 2011, except for breast cancer.

Black patients in rural and urban areas had the lowest survival rates for the four cancer types, although their survival rates improved from 1975 to 2011.

For instance, the prostate cancer survival rate for Black patients in rural areas improved from 74% in 1975 to 95% in 2011. The prostate cancer survival rate for Black patients in urban areas improved from 81% to 96%. In comparison, the survival rate for white patients in rural areas was 96.5% in 2011 and in urban areas 96.9%. Asian and Pacific Islanders had a survival rate of 96.9% in rural areas and 96.7% in urban areas in 2011. And Hispanic patients’ survival rate in 2011 was 96.1% in rural areas and 96.2% in urban areas.

The study also finds that while urban-rural disparities in colorectal cancer survival rates narrowed within most racial and ethnic groups, it widened among Hispanic individuals.

The findings “highlight that the association between place of residence and survival after a cancer diagnosis is complex,” writes Dr. Zachary A. K. Frosch in an invited commentary in JAMA Network Open. “Therefore, a detailed understanding of the barriers to optimal care faced by rural patients, and how those barriers differ between populations residing in the same geographic location, is critical.”

Frosch lists several barriers to optimal cancer care in rural areas, including lack of access to local cancer screening, which can lead to delayed cancer diagnoses.

The disparity continues after diagnosis.

“Once diagnosed, rural patients also have reduced access to clinicians who provide cancer treatment,” Frosch writes. A 2019 study, “State of Physician and Pharmacist Oncology Workforce in the United States in 2019,” led by Ya-Chen Tina Shih, finds 12% of counties in the U.S. had no oncologists locally or in the adjacent counties.

“For those able to travel for treatment, greater travel requirements may also result in more frequent hospitalizations, higher out-of-pocket costs for patients, and reduced care continuity,” he writes, referencing the 2019 study, “Impact of Travel Time on Health Care Costs and Resource Use by Phase of Care for Older Patients With Cancer,” led by Dr. Gabrielle Rocque.

Potential solutions

In his commentary, Frosch points to efforts such as partnerships between urban and rural care sites and improving communication via telemedicine as some of the solutions toward closing the cancer disparity gap. A 2020 report published in JCO Oncology Practice lists several such approaches at the Ohio State University Comprehensive Cancer Center’s Center for Cancer Health Equity and the New Mexico Cancer Care Alliance.

Access to health insurance can also play a role.

A May 2022 study published in the Journal of the National Cancer Institute examines the potential impact of Medicaid expansion under the Affordable Care Act on the two-year cancer survival among newly-diagnosed patients. It finds that Medicaid expansion is associated with improved cancer survival, particularly among Black patients and in rural areas. The association was also strong for lung, pancreas, liver and colorectal cancers, which can be detected by screening.

The findings provide “further evidence for the importance of expanding Medicaid eligibility in all states, particularly considering the economic crisis and health-care disruptions caused by the COVID-19 pandemic,” the authors write. They add that the study highlights the role of Medicaid expansion in reducing health disparities.

Medicaid is the United States’ public health insurance program for people with low income. It covers one in five Americans, according to the Kaiser Family Foundation, a nonprofit health policy research group.

The authors of the JAMA Network Open study also call for more funding through National Cancer Institute grants for cancer control and management in rural areas. The number of funded grants solely focused on rural populations rather than rural-urban differences are also low, and policy reform that targets rural cancer control remains minimal, they add.

“Additional research, programming, financial resources, and policy changes are needed to comprehensively address rural-urban cancer disparities along the cancer continuum,” they write.

In June, the Centers for Disease Control and Prevention announced the first round of funding from a $1.1 billion investment into three national programs to prevent and control cancer as part of President Joe Biden’s Cancer Moonshot initiative.  

“This funding helps organizations work together to take action, address preventable health disparities, and close gaps in cancer care access, quality, and outcomes,” said Dr. Lisa Richardson, director of CDC’s Division of Cancer Prevention and Control, in a news release.

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