What You Should Know About Colorectal Cancer - and New Research

By Jane Farrell

Colorectal cancer is the second most common cause of cancer-related deaths among men and women, according to the Mayo Clinic. Roughly 140,000 people are diagnosed with colorectal cancer in the United States each year. Because of its frequency, it’s essential to know about the illness, its symptoms and its treatment. Here, colorectal surgeon Heidi Nelson, M.D., chair of surgery at Mayo Clinic, shares five things to know about colorectal cancer:

Early detection through screening is essential. The survival rate is roughly 90 percent when it is caught early, Nelson says. There are now multiple screening options, including colonoscopies; a stool DNA test called Cologuard co-invented by Mayo Clinic gastroenterologist David Ahlquist, M.D.; a virtual colonoscopy using a CT scan; and more.

According to Nelson, most colorectal-cancer patients will need an operation to remove cancerous tissue. But, she emphasizes, there is a big difference between colon cancer surgery and rectal cancer surgery.

“Colon cancer surgery is typically a fairly straightforward, minimally invasive procedure,” Nelson said in a video released by Mayo. “Roughly one foot of the colon is removed, and in those cases, patient can usually eat normally and have normal bowel movements after surgery. The implications of  rectal cancer are quite different.”

While rectal cancer surgery can also be minimally invasive, there are often long-term changes affecting the patient. Nelson says that some patients will resume normal bowel emptying after rectal cancer surgery, but some may require more frequent bowel emptying or have less control over emptying. Fewer than 40 percent need a stoma, an opening created in the abdomen to allow waste to leave the body. A bag is worn outside the stoma to collect stool; it can be temporary or permanent.

Although the illness is most common in people in their 60s, younger people are vulnerable as well, although those cases tend to be hereditary. Factors in other, more common cases include food habits, obesity and smoking.

Nelson said that Mayo is helping researchers look for genes responsible for hereditary colorectal cancer; these genes could vary from one family to another, she says.

“It’s not `one size fits all,’” she says. “There are multiple ways genes can cause cancer in families, and there could be different ways in each family.”

Additionally, Mayo researchers are studying intestinal microbes to see if they play a part in a process that results in colorectal cancer.

“We know that human papillomavirus and helicobacter pylori cause cancer, so are there bacteria or viruses in the gut that might actually cause cancer? I think there’s a lot to be learned by looking specifically at the environment in the gut,” Nelson says.

As a leading institution funded by the National Cancer Institute, Mayo Clinic Cancer Center conducts basic, clinical and population science research, translating discoveries into improved methods for prevention, diagnosis, prognosis and therapy. For information on cancer clinical trials, call 1-855-776-0015 (toll-free).