Place as a Risk Factor: How Geography Shapes Where Cancer Strikes

Can where you live impact your cancer risk? The answer is “yes.”

While we have always heard that “your genes dictate how long you will live,” or “your choices, like smoking or obesity, cause cancer,” where you live is also very important to your chance of developing, dying from, or surviving cancer.

This fact has been confirmed by many studies that have focused on mixing geography with cancer outcomes. For example, the U.S. Centers for Disease Control and Prevention has published a report identifying the 10 states with the highest rates of new cancers. These include: Kentucky, Delaware, Pennsylvania, Maine, New Hampshire, Louisiana, Connecticut, New York, Iowa, and Michigan – all states east of the Mississippi. 

In addition, certain risky behaviors such as smoking, obesity or HPV vaccination rates can be mapped to show “hotspots.” 

For example, a study by the American Cancer Society showed that three hotspot areas, mapped by counties, had higher rates of dying from colorectal cancer. 

What do these 3 areas – the Mississippi Delta, Appalachia, and Virginia/North Carolina – have in common? Why do we see these trends? There are several reasons.

A mix of factors

First, environmental exposures – factors such as toxins in the air or water, which are very “place-centered”- can cause some cancers.

Next, certain geographic locations may have cultural or economic factors that promote cancer-causing behaviors. Regions with lower incomes have higher cancer rates, for example. 

Regions that are known for tobacco growing have higher tobacco use rates, and in turn higher rates of lung and other tobacco-related cancers. 

Several geographic regions also have poor access to health care. For example, Appalachian Ohio, an area with both high poverty and high rates of cancer deaths, is an area with few health care professionals. Some counties in the region have no hospital or mammography facility.

Geographic residence can also impact risky behaviors that raise the risk of developing cancer. For example, certain neighborhoods in poorer areas have a higher incidence of tobacco advertising, contributing to higher smoking initiation and prevalence rates, as well as tobacco-related cancers. 

“Food deserts” often exist in some areas. Many lower-income neighborhoods with limited access to healthy foods also have increasing rates of both obesity and cancer. Many of these same neighborhoods have little access to sidewalks or other exercise facilities, and in some areas crime dissuades many from moving about outdoors.

Poorer screening and care

Quality of care also varies by geographic location – in Chicago, poorer quality mammogram facilities were located in predominately African-American zip codes, resulting in a 60 percent increase in mortality from breast cancer among African-American women compared to white women. 

Access to state-of-the-art cancer treatment services are also limited geographically, with not all U.S. residents within driving distance of an NCI-designated cancer center.

So let’s go back to the example of those three colorectal cancer “hotspots” – the Mississippi Delta, Appalachia, and Virginia/North Carolina. What do these three geographical areas have in common that contribute to these high death rates? 

Could it be genetic – do people with high-risk genes simply settle in common areas? Probably not.

So are there environmental exposures that increase the risk of developing cancer? Certainly, tobacco use, obesity and poor diet are very plausible risk factors in these areas. 

A lack of opportunities for exercise, as outlined above, can also play a role in these hotspots. 

Use of early-detection services – in this case, colonoscopy – may also be lower in these areas, due to a lack of facilities and/or reluctance to get screened. People living in these regions may also lack access to quality cancer treatment facilities. 

And over all this looms poverty – a carcinogen in and of itself.

The Delaware Example

So, what can be done to change this picture? A multi-level approach is the best option, meaning that all factors need to be engaged — from policy to biology — to address these regional disparities.

One success story can be found in the state of Delaware. It took 10 years and some legislation, but racial disparities in colorectal cancer screening, incidence and death rates, as well as late stage of diagnosis, were all eliminated. 

Efforts in Delaware focused on going into at-risk communities with community workers to educate and assist residents to get screening, whether those residents were covered by insurance or not.

Once screening was done, residents were then encouraged to get proper and prompt treatment – again, regardless of insurance status. 

These efforts were cost-effective, and more of these types of geographically based, multi-level interventions need to happen if we are going to beat cancer in all populations.

So, where you live does impact whether you get or die from cancer. Do you know your risk of developing or dying of cancer based on where you live? 

“Place is a risk factor” – find out if it is for you and your neighbors. Know your risk and how to reduce your chances of developing or dying from cancer. Get your neighbors and governmental leaders involved. 

Delaware may be a small state, but they showed us how to beat cancer. 

Electra D. Paskett

Electra D. Paskett, PhD
Marion N. Rowley Professor of Cancer Research
Division of Cancer Prevention and Control
Department of Internal Medicine
College of Medicine
Ohio State University
Columbus, OH