Tackling Cancer Health Disparities: Small Steps, Big Hopes

Several studies have documented that African American men are far more likely than non-Hispanic white men to die of prostate cancer. Other studies have shown that Hispanic women are more likely to be diagnosed with cervical cancer than non-Hispanic white women. Do disparities like these reflect differences in health insurance status, diet, genetics, or a combination of those factors? In many cases, the explanation is unclear.

Cancer research has produced notable achievements over the past several decades, including a vaccine that prevents the viral infection that causes the majority of cervical cancers and a host of treatments that target the molecular changes that drive several cancers. But, by and large, cancer-related health disparities in the United States have been an intractable problem.

Numerous studies have documented cancer health disparities (as well as disparities in other health conditions that may be linked to an increased cancer risk, such as obesity and diabetes). Researchers believe the time is now ripe for actively developing and testing ways to reduce—or better yet, eliminate—these disparities.

“We’ve accomplished a lot, and I’m pleased to see where things are going,” said Sanya Springfield, Ph.D., director of NCI’s Center to Reduce Cancer Health Disparities (CRCHD). “However, there’s still much work to be done.”

The increased attention on disparities is important and a big step forward, Dr. Springfield continued, as is “the growing recognition that the solutions to disparities frequently lie within communities themselves.”

A Multi-Factorial Problem

Although discussions of health disparities are often framed around race, much of the published evidence indicates that the problem is more complex.

For example, when researchers from Johns Hopkins University looked at the health of people who live in a racially integrated, low-income neighborhood in Baltimore, they found that white residents had higher rates of medical conditions like diabetes and hypertension than the national average for whites. And their rates of these conditions, in most cases, were essentially the same as those among African American residents in the neighborhood—which were similar to the national average for African Americans. The health status of both racial groups in that Baltimore neighborhood was, in effect, the same.

The results seem to support what American Cancer Society Chief Medical Officer Otis Brawley, M.D., believes is one of the chief contributors to health care disparities in general and cancer disparities specifically: access to health care.

Access, Dr. Brawley said, is influenced by several factors, including health insurance status and a person’s proximity to physicians and health care facilities.

Two studies conducted in the metropolitan Atlanta area offer good examples. In a 2008 study of women diagnosed with early-stage breast cancer, African American women were four- to five-times more likely than white women to have a delay in treatment of 60 days or longer. A more recent study, meanwhile, found that women who lived in predominantly African American neighborhoods had far longer travel times to reach radiation therapy facilities than women who lived in predominantly white neighborhoods.

“That’s an access problem,” Dr. Brawley said.

“We know that many treatments work in all populations,” continued Dr. Brawley. “But there are certain populations, often defined by race or socioeconomic status, that are not getting those treatments.”

For example, in a large cohort study in which patients with metastatic colorectal cancer received essentially identical treatments, there were no differences in how long African American and white patients lived. Yet, in the real world setting, African Americans diagnosed with colorectal cancer are more likely to die of their disease than white patients.

But access to care isn’t the only contributor to cancer health disparities. Mistrust of the health care system or long-held beliefs about cancer (e.g., a fatalistic attitude that death is inevitable following a cancer diagnosis)—which often lead to delays in diagnosis and treatment—also play a role. Higher rates of tobacco use, alcohol abuse, obesity, and inactivity among minority groups and populations with a lower socioeconomic status contribute as well.

Dr. Springfield and other researchers also believe that, in some cases, biological factors may be at play.

Several studies (e.g., here and here) have suggested that the higher risk of prostate cancer in African American men may be due to several genetic variants that occur more often in men of African descent than in white men.

Other studies have pinpointed genetics as a possible contributor to the higher rates of a particularly aggressive form of breast cancer, called triple-negative, in African American women. One recent study even found distinct genetic differences, many of them associated with more aggressive disease, between tumors in African American women diagnosed with triple-negative breast cancer and those in white women with the same diagnosis.

The available data suggest that these biological factors “contribute, at least in part, to the aggressiveness of the disease and poor outcomes experienced by certain racially/ethnically diverse populations,” Dr. Springfield noted.

Blase Polite, M.D., of the University of Chicago Cancer Center, who has studied disparities in colorectal cancer, said he isn’t convinced that genetic and biologic differences have a substantial impact on cancer health disparities. But their influence needs to be more thoroughly researched, he added.

Dr. Springfield agrees that more research is needed, noting that CRCHD has developed funding opportunities to further explore the extent to which biological and genetic factors might affect cancer disparities.

Testing Solutions

Although access and insurance status remain entrenched as barriers to reducing disparities, there have been modest signs of progress. For example, a number of changes have been implemented as a result of the  Affordable Care Act, such as easier access to recommended health screenings and Medicaid expansion.

Patient navigation, which helps patients maneuver through the complexities of the health care system, is one of the most widely studied interventions to reduce disparities. Navigators can help patients with the multitude of issues that can derail quality care, such as financial difficulties and a lack of transportation to and from procedures.

A number of studies, including several small clinical trials, have suggested that patient navigation programs have the potential to reduce disparities. Several studies funded through the CRCHD Patient Navigation Research Program have demonstrated that navigation can increase cancer screening rates and help patients get the appropriate follow-up care after an abnormal result on a screening test.

Some researchers believe that improvements like these could help to address a serious problem: the fact that a disproportionate number of minority and underserved patients are diagnosed with advanced cancers.

“Patient navigation has a role in addressing disparities,” said Worta McCaskill-Stevens, M.D., chief of the Community Oncology and Prevention Trials Research Group in NCI’s Division of Cancer Prevention. “But it’s also an area that requires further definition and research, given the different approaches that are being used in different health care organizations.”

As part of its focus on cancer care delivery research, the recently launched NCI Community Oncology Research Program (NCORP) will support studies on cancer-related disparities, noted Dr. McCaskill-Stevens, who directs the program.

“NCORP investigators will integrate cancer disparities research questions into clinical trials and cancer care delivery research studies,” including studies that test interventions to reduce disparities, she explained.

“Disparities research is challenging,” said Dr. Polite. It’s very different from lab work or treatment-based clinical trials comparing one drug or regimen with another. Often, disparities research entails working closely with, and gaining the trust of, organizations and individuals at the community level.

For many studies, “it can take 2 to 3 years to embed yourself in the community and do the basic ground work” before you can even begin collecting data or testing an intervention, he said.

The need to work at the community level is the impetus for a number of CRCHD-supported programs, such as the Community Networks Program Centers (CNPC) program. The 23 NCI-funded CNPCs use a community-based participatory research approach to improve health outcomes and reduce cancer health disparities in specific target communities.

One example is the Spirit of the Eagles, a CNPC that works with Native American and Alaskan Native populations. Spirit of the Eagles is collaborating with CRCHD-funded researchers from the University of Wisconsin on a 3-year tobacco cessation study—the first tribal-sponsored clinical trial in the United States. The study is testing a tobacco cessation approach tailored specifically to a Native American population, including ensuring that it does not interfere with tobacco use in traditional prayers and ceremonies.

“Some of our CNPC grantees have a 10-year history of gaining the trust of communities, building the necessary infrastructure, and knowing how to invite people to participate in cancer research,” Dr. Springfield said. “It takes time and patience to really see the full effects of this kind of research. It doesn’t happen overnight.”