|Johns Hopkins Medicine image|
The study notes that cancer outcomes are often worse for rural patients, with various studies finding they have an 8 to 15 percent greater chance of dying from colon cancer.
"While rural communities overall have lower incidence of cancers compared to urban populations, they have higher cancer-related mortality rates," says the report. In other words, people in the most rural areas are more likely to die from colon cancer even though they are less likely to get it in the first place.
The researchers identified 132,777 patients in 10 states who had colorectal cancer in 2010-14. After placing patients in five rural-to-urban categories, the study found that the adjusted percentages of stage 4 colon-cancer patients by county geography were: metropolitan areas, 19.3%; micropolitan areas (with a city of 10,000 to 50,000) adjacent to a metro area, 20.4%; non-adjacent micropolitan areas, 19.2%; small rural places, 20.2%; and remote rural places, 22.7%.
"Patients living in remote, small counties were significantly more likely to present with stage 4 colorectal cancer than patients living in other counties," the study report says.
The data came from registries in 10 states, including California, Connecticut, Georgia, Hawaii, Iowa, Kentucky, Louisiana, New Mexico, Utah and Washington. Overall, the study found that these registries included 352 rural and 235 urban counties, which represents 18% and 20% of all rural and urban U.S. counties, respectively.
In addition to the rural/urban factor, the study found that younger patients, black patients and single or widowed patients were more likely to present with late-stage colorectal cancer. The researchers note that these findings are consistent with decades of data and suggest that little or no improvement has been made in addressing these disparities.
It also found that a lack of insurance was the most significant predictor of late-stage diagnosis, which was also consistent with other research.
"Patient medical insurance categories had the greatest effects on the rate of stage 4 colorectal cancer at diagnosis. The rate was highest among uninsured patients (28.6%) compared to patients with any type of Medicaid insurance (24.4%) and other insured patients (18.4%)."
There were also differences in the rate of stage 4 colorectal cancer diagnosis across states. "Patients in Kentucky had the lowest adjusted rate (18.2%) of stage 4 diagnosis while New Mexico and Washington State had the highest rates (21.6% and 22.1% respectively)," says the report.
In addition to a known lack of screening services in rural areas, "The high cost of colonoscopy, access to specialty referral networks, lack of transportation, and lower health literacy may all play a role in these findings," says the report.
The researchers point out several limitations to the study, noting that while the data allowed for a patients' urban/rural status to be determined at a county level, some patients may not have been designated appropriately especially in states out West which have very large counties. It also recognized that only 10 states were included in the study, representing about one-third of all cancer patients nationally.
The report also notes that this study is consistent with the findings of several others that look at the rural/urban relationship to late-stage colorectal diagnosis, but not with all of them. It says this could be related to the studies using different geographic stratifications.
The American Cancer Society recommends colorectal screening for average risk individuals to begin at the age of 45. Those with a family history of colon or rectal cancer should check with their doctor about getting screened earlier. Colon cancer is 90 percent curable when detected early.