(Reuters Health) – The proportion of US adults receiving colorectal cancer screening has never been as high as physicians desire, but a new study suggests it is much lower than expected in some parts of the country.
To detect bowel cancer early, when it is easier to treat and less fatal, physicians generally recommend that adults aged 50 to 75 years be examined every 10 years with a colonoscopy or annually with faeces samples. Nationwide, only about 67 percent of adults at that age were screened with screening, the study said.
At the state level, screening rates ranged from a low of 59 percent in Wyoming to a high of 75 percent in Massachusetts.
Researchers found even greater variability within some states. Screening rates were lowest in a district in Alaska at 40 percent and highest in a district in Florida at 80 percent.
The largest divide between the districts was in South Dakota, with a difference of 29 percentage points between the lowest and highest scoring counties; the smallest gap was in Connecticut, with about 4 percentage points separating the districts with the highest and lowest screening rates.
"We expected differences in colorectal cancer screening in each state due to differences in educational and income levels and geographic inequalities, but in some states we were still affected by differences in counties of more than 20 percentage points," the lead study said Author Zahava Berkowitz of the National Center for the Prevention and Health Promotion of Chronic Diseases at the US Centers for Disease Control and Prevention in Atlanta.
"Although most vendors recommend a colonoscopy, some refuse to undergo preparation for the procedure and / or are afraid of invasive surgery," Berkowitz said via email. "Therefore, it is important that multiple screening options are offered to meet patients' preferences."
The most common screening method is a colonoscopy exam, which snakes a tiny camera through the rectum to seek out the colon for abnormal tissue growth. Patients may need to use laxatives or an enema to empty the colon prior to examination, and sedation is usually required during the procedure.
An alternative is the fecal occult blood test (FOBT), which looks for blood in stool samples ̵
The US Preventive Services Task Force, a government-sponsored independent body that evaluates evidence for medical procedures, recommends using one of these methods, starting at the age of 50, for adults without inflammatory bowel disease or a family history of colon cancer , People with these additional risk factors or other specific conditions may require earlier or more intensive screening.
For the current study, researchers modeled district-level screening rates using CDC survey data for 251,360 adults aged 50 to 75, taking into account US population estimates for 3,142 countries across the country.
Screening varies by ethnicity, with approximately 69 percent of white adults currently on recommended screenings, compared to 57 percent of Hispanics, the study found.
A limitation of the study is that researchers rely on survey respondents to accurately retrieve and report their screening examinations, and inaccurate responses could weaken estimated screening rates, such as researchers in cancer, epidemiology, biomarkers, and prevention determine.
The study also fails to reveal why so many people are out of date with their recommended screenings, and there are many factors that can help, said Electra Paskett, a cancer researcher at Ohio State University in Columbus involved.
Screening rates are lowest in locations where there are no guidelines to cover all of these tests, or that have no providers in the community to conduct the tests, Paskett said by email. Doctors may also not recommend any check-ups, or people do not want it or want to travel too far to get it.
"All of this works and interacts in different ways to keep people from screening," Paskett added. "It's important because colon cancer is completely preventable, as well as death from colorectal cancer when people are being examined regularly."
SOURCE: bit.ly/2GkLQn0 Cancer, Epidemiology, Biomarkers and Prevention, online March 1, 2018.