Aug. 8, 2017 -- A new report about colorectal cancer reveals an unexplained trend: Death rates are rising among white people under the age of 55 but dropping for African-Americans in the same age group.
“The rise is confined to whites, and that’s very surprising,” says the report’s lead author, Rebecca Siegel, the strategic director of surveillance information services at the American Cancer Society.
The Cancer Society report covers the years 1970 to 2014. It tracks changes in the death rate from colorectal cancer among people between the ages of 20 and 54, who have historically been less likely than older people to develop the disease. The report’s authors analyzed 242,637 deaths to reach their conclusions.
In 1970, 6.3 out of 100,000 people under 55 died from the disease. That rate dropped to 3.9 by 2004. That’s when it started to climb among white people. Over the next 10 years, their death rate increased from 3.6 to 4.1 out of 100,000.
It’s a much different story for young African-Americans. Their death rate has remained higher than that of whites, but it has continued to slowly and consistently decline, from 8.1 per 100,000 in 1970 to 6.3 in 2014.
“Death rates are the gold standard for progress against cancer,” says Siegel. “If you have declining death rates for cancer, it’s always a good thing.”
Cleveland Clinic colorectal cancer specialist James M. Church, MD, says he thinks improved access to care for African-Americans helps explain the continuing drop in deaths.
“Care has been changing and improving,” he says.
"Declines in blacks are due primarily to improvements in treatment for [colorectal cancer], which very likely attenuated the rise in whites.
"Also of note, in 2015 alone -- the most recent year for which we have mortality data -- there were more than 6,600 [colorectal cancer] deaths in people younger than 55 years in the U.S. -- 6,606 to be exact," she says.
Darrell M. Gray II, MD, a gastroenterologist at Ohio State University Comprehensive Cancer Center, says researchers don't know what's behind the change in mortality rates.
"This study did not examine income, geography, insurance status, or history of prior colonoscopy or screening, factors that we know influence colorectal cancer outcomes," says Gray, who specializes in prevention and screening of colorectal cancer. "We can't assume access to care is what is contributing to the disparity, particularly as access has traditionally been most limited among minority and low-income populations."
Obesity, which greatly raises the odds of having colorectal cancer, has increased in whites and African-Americans, Siegel says. And both groups get too little physical activity, which also is linked to the disease. These similar patterns should lead to similar outcomes, but they don’t.
“That’s concerning, because we don’t know why,” says Siegel.
Church suggests that things like dietary or environmental changes over the years may contribute to colorectal cancers in young people. Normally, he says, the cell mutations that lead to such cancers mostly happen in older people.
“Scientists have to look at the biology to determine what’s happening,” he says.
One difference, he points out, is that colon cancers in the young tend to happen in the left side of the colon. In older patients, it’s more evenly spread throughout the colon. Also, young people more often develop rectal cancer than colon cancer. That, he hopes, will provide clues.
“What is it about the rectum that makes this happen in young people?” he asks. “That’s where a good part of the diagnoses and death are coming from."
Lack of Screening
The report reveals another mystery: Colorectal cancer deaths in whites also rose among people ages 50 to 54, about when screening for the disease should begin. Federal health guidelines recommend that most men and women get a colonoscopy every 10 years, beginning at age 50. Stool tests also can screen for cancer, but colonoscopies better detect suspicious growths and can remove them before they develop into cancer.
“It’s quite surprising that this age group, which we’re supposed to be screening, is seeing an increase in death rates,” Siegel says. “It’s a small increase, but it’s just begun.”
A possible explanation: Only 46% of people in this age group get screened, says Siegel.
“We need to encourage people to call their doctor on their 50th birthday and schedule a test,” she says.
People with a higher chance of having the disease may need to be screened earlier than age 50. Things that raise your odds of colorectal cancer include:
- Family history of the disease
- Inflammatory bowel diseases, such as ulcerative colitis
- Genetic conditions like familial adenomatous polyposis and Lynch syndrome
The new report also helps confirm recent research that has shown a rise in colorectal cancer cases in young people. Meanwhile, cases of the disease have dropped dramatically in older people, says Siegel.
The rise in colorectal cancer cases and deaths in young people may eventually lead to changes in screening guidelines. Siegel says the American Cancer Society is reviewing its own guidelines.
Church recently shared research that suggests a different screening strategy. Because many colorectal cancers in young people develop in easy-to-reach areas, 40-year-olds may benefit from a flexible sigmoidoscopy, a less invasive screening procedure than a colonoscopy.
Know the Signs
Colorectal cancer starts in either the colon or the rectum. Though they are different cancers, they are often grouped together because they share several common features. In both, precancerous growths, or polyps, appear in the inner lining of the colon or rectum. Some of these growths remain harmless; others lead to disease.
For most young people -- and, often, their primary care doctors -- colorectal cancer is not a concern, even when symptoms suggest that it should be. Such symptoms include:
- Lasting changes in bowel habits, like constipation, diarrhea, or narrow stools
- Feeling that you still have to go after having a bowel movement
- Rectal bleeding
- Bloody stools
- Unexplained weight loss
- Abdominal discomfort, cramping, or pain
- Weakness and fatigue
“I can’t tell you how many times a young adult has been referred to me for a colonoscopy for vague abdominal pains that they’ve been dealing with for years,” says Gray. “Young adults can’t ignore these symptoms, even though they may be vague and nonspecific. They should seek medical attention.”
“If you have rectal bleeding, you can’t just say that it’s hemorrhoids. It has to be investigated,” he says. “That’s my philosophy now, and that should be every primary care doctor’s philosophy.”
Church recalls two patients he saw last year. Both were 36-year-old men with families. Both were diagnosed with stage IV cancer. Both died.
“It’s a tragedy,” he says. “You see them on a daily or weekly basis as they fade away, and it makes you want to cry.”