The Cancer Belt: High Mortality Across the South
Memphis has long been considered the "buckle" of the Bible Belt that stretches across the Southern U.S. Statistics now show that it also sits squarely in the middle of the Cancer Belt.
In recent years, medical scientists have identified a swath of territory that stretches from Appalachia in West Virginia, down through Kentucky, Tennessee and the Deep South states, and into Oklahoma. It is well known that this thousand mile-swath across the southeastern U.S. exhibits a mortality profile that sets it apart from the rest of the nation. Now, research reveals that the South exhibits inordinately high rates of the most dreaded disease—cancer. This has led medical scientists to dub this region "The Cancer Belt."
Cancer Mortality in the RegionMany of the forms of cancer so common in the South are concentrated among certain high-risk populations in distinct geographic areas. The portions of the region that "jump off the map" are the historic plantation area in the Mississippi Delta, the rich agricultural region cutting across the Deep South states, and the Southern Appalachian area dipping down into Kentucky, North Carolina and Tennessee. While these areas may differ in terms of their demographics, the one attribute they share in addition to a history of rural poverty is high cancer mortality.
Cancer Research by Vanderbilt-Ingram Cancer Center Network on the Cancer BeltTennessee sits right in the middle of the Cancer Belt and exhibits more than its fair share of cancer mortality. The state has the fifth highest mortality rate for cancer, a rate 11 percent higher than the national average. More striking, however, is the fact that, while cancer mortality rates are dropping for the nation overall, rates are increasing for many types of cancer in Tennessee. For example, between 2001 and 2005 decreases in mortality were recorded nationwide for breast, ovary, brain, uterus, and esophagus cancers, while death rates for each of these types of cancer actually increased in Tennessee. "Until those numbers change, our work as cancer researchers and physician-scientists is not done," said Jennifer Pietenpol, PhD, director of the Vanderbilt-Ingram Cancer Center in Nashville. "It is essential not only that we conduct high-impact scientific research, but that everyone benefits from that research. We owe it to our patients and to future generations to ensure that the lessons we learn are shared with everyone who walks through our doors."
Cancer, like virtually every other health condition, is not evenly spread throughout the population but affects some groups more than others. According the Memphis and Shelby County Health Department, the overall figures for Shelby County mask the fact that its low-income, minority population is particularly hard hit by cancer. When the leading causes of cancer death in Shelby County are examined, the death rate among its disadvantaged population is 48 percent higher for lung cancer than the county average, 75 percent higher for colorectal cancer, 28 percent higher for breast cancer, and 60 percent higher for pancreatic cancer. The most striking difference, however, is for prostate cancer where the death rate for African-American males is 188 percent times greater that the Shelby County average.
Why So Much Cancer?Certain genetic markers have been linked to various forms of cancer. While lifestyle factors and access to preventive surveillance and treatment play a role in cancer, scientists increasingly are finding genetic differences that may explain some of the disparities. In the case of prostate cancer in certain groups of men, researchers discovered a combination of genes that appear to play a role in the more aggressive forms of the disease.
There are also differences in the way the healthcare system treats individuals from different groups within society. Research has found disparities in access to care and the treatment received if access is obtained. Low-income, minority and rural populations are less likely to have convenient access to specialty services and fewer resources for paying for care if they do get access.
Meeting the ChallengeNow that the extent of the problem is better understood, a number of initiatives have been undertaken in an attempt to address the disparities noted in cancer mortality. For example, the Southern Community Cohort Study (SCCS) is being undertaken to explore why the South has become the Cancer Belt and why certain groups experience higher rates of many types of cancer. The SCCS is nearing completion of recruitment of 90,000 people in twelve Southern states in order to study their lifestyles, their medical histories and their risk factors for cancer and other serious diseases. Two-thirds of the participants are African-Americans and many live in rural areas.
The SCCS is a collaborative project among the Vanderbilt-Ingram Cancer Center, Meharry Medical College and the International Epidemiology Institute, as well as participating community health centers across the South. "The study participants form one of the groups at highest risk for cancer that has ever been studied," said William Blot, PhD, principal investigator of the study. "Most other investigations have not included large numbers of African-Americans and few have included low-income individuals and people from rural parts of the country. This is the first large-scale study and the first in the South to include large numbers of all those groups."
A better understanding of the causes and management of cancer among residents of the Cancer Belt, coupled with improved diagnosis rates and treatment efficacy, will hopefully eventually mitigate the burden of cancer in the South.
* This article is part of a partnership between Memphis Medical News and local providers such as Jones Clinic to offer information on important health topics.