The news last weekend that actor Chadwick Boseman had died of colorectal cancer at age 43 left a big question: How could someone who looked so fit in "Black Panther" have been living with colorectal cancer for four years?
It shattered the idea of colon cancer being an older person’s cancer. It might have even called into question why historically first colonoscopies aren’t recommended until age 50.
Dr. Anna Capasso, an assistant professor at the University of Texas at Austin Dell Medical School and an oncologist at the Livestrong Cancer Institutes, has been treating and studying colorectal cancer, which follows lung cancer and breast and prostate cancer for most common cause of cancer deaths in the United States, according to the Centers for Disease Control and Prevention.
One of the mysteries that she and other researchers are trying to solve is why they are seeing an increase in early-onset colorectal cancers (those typically found in people ages 18 to 36) and why early-onset colorectal cancers don’t seem to respond to the current medications as well as colorectal cancers found in older people.
Capasso says that while the rates of colorectal cancer in people older than 60 are decreasing, the rates of that cancer in younger people are increasing. Perhaps it is access to screening, she says, which can identify pre-cancerous lesions and remove them. More doctor’s groups such as the American Society of Clinical Oncologists are recommending and pushing for screenings to begin at age 45 instead of 50.
For people with a family history, the recommendation is to start screenings 10 years before the age at which their family member was diagnosed.
Screenings typically mean a colonoscopy, but for people who do not have known risk factors, it could be a stool sample test, followed by a colonoscopy if needed.
Researchers are also trying to figure out why there are more incidents of colorectal cancers in African American people. The rate for African Americans is 40.4 new cases per 100,000 people, compared with 36.3 in whites, 32.5 in Hispanics, 28.5 in Asians and 29.0 in American Indians, according to the CDC.
Unlike other cancers, there isn’t as strong a link to genetics. As much as 5% of new cases have an identified genetic syndrome and only about 10% have a family history, Capasso says.
There are links to risk factors such as eating a high-fat diet, being overweight, smoking, drinking alcohol regularly and not being active, Capasso says, but she has treated her share of younger patients who have an active lifestyle, are not smokers or regular drinkers and are vegetarians or vegans.
"That's why it's so hard to understand what are the reasons or causes," Capasso says.
A lot of research has been done to figure out what is going on, especially with the early-onset cases, Capasso says, including looking at if there’s a difference in the tumor markers or genetic mutations between younger and older colorectal patients.
They haven’t found anything. "Something else is going on," she says.
Last year, Dell Medical School researchers studied whether there was a difference in colorectal rates in urban populations compared with rural populations and didn’t find a statistical difference.
Capasso is currently working with the tumor cells from patient she treats to genetically sequence the tumors and see how they respond to different treatments.
Capasso would like there to be a consortium of shared data to help researchers like there is for other cancers and diseases.
"If we want to make a difference, we have to join our efforts and energy," she says.