From a scientific standpoint, the effectiveness of cancer screenings are measured in the number of deaths prevented. Researchers recently looked at the impact one type of colorectal cancer screening had on saving lives.
Fecal occult-blood testing (FOBT) looks for blood in the stool. It’s a simple test that people can do in their homes and is the least expensive colorectal cancer screening method. But does it work?
According to a 30-year follow-up study, FOBT reduced the risk of dying from colorectal cancer by more than 30 percent.
Men benefited more than women from the test, the study found.
This study was conducted by Aasma Shaukat, MD, MPH, from the Divisions of Gastroenterology and Internal Medicine with the Minneapolis Veterans Affairs Health Care System, and colleagues from the Department of Medicine, School of Medicine and the Division of Environmental Health Sciences, School of Public Health of the University of Minnesota in Minneapolis.
Previous randomized, controlled trials have determined that FOBT does reduce colorectal cancer mortality (death).
Researchers sought to learn how long the mortality benefits of FOBT lasted and to study the effects specific to age and sex.
The Minnesota Colon Cancer Control Study involved 46,551 participants between the ages of 50 and 80 years of age. They were randomly assigned to have annual or biennial (every two years) FOBT screening or usual care in which screening is recommended but not provided.
Study members were screened from 1976 through 1982 and from 1986 through 1992. The research team followed up to learn if and how the study members had died through 2008.
After 30 years, 33,020 individuals in the study had died, included 732 deaths linked to colorectal cancer.
Of those who lost their lives to colorectal cancer, 200 (1.8 percent) of the individuals had undergone annual FOBT screening, 237 (2.2 percent) people were in the biennial screening group and 295 (2.7 percent) of the people had not been screened.
The researchers examined all the data and discovered the following:
- Annual FOBT screening reduced the risk of dying from colorectal cancer by 32 percent.
- Biennial screening reduced colorectal cancer mortality risks by 22 percent.
- Colorectal cancer mortality risks were 27 percent lower in the screened groups compared to the control (usual care) group.
- FOBT screening did not impact all-cause mortality risks.
- Mortality risk reduction was greater for men than women in both groups — 39 percent for men versus 25 percent for women in the annual group and 37 percent for men versus 8 percent for women in the biennial group.
- FOBT screening of women under the age of 60 did not result in a reduction in colorectal cancer mortality risk.
"Although it's the second leading cause of cancer death in America, colorectal cancer is one of the few that can treated and cured when caught in the early stages," Eric Haas, MD, colorectal surgeon at Houston Methodist Center for Restorative Pelvic Medicine, told dailyRx News.
This study was published September 18 in The New England Journal of Medicine, and was supported by the Veterans Affairs Merit Review Award Program, the National Institutes of Health and the National Cancer Institute.
Another study in the same issue found that colonoscopy (internal exam of the entire colon) was the most effective colorectal cancer screening method that could potentially prevent up to 40 percent of all colorectal cancers.