Cancer. It is a disease that most of us know all too well. Many of us have experienced it personally, many of us know survivors, and many of us know people who have lost their lives to the disease. Cancer is the second leading cause of death in United States, and some types of cancer are more common than others. Colon cancer is one of these more common cancers; it is the third most diagnosed kind of cancer in both men and women and the second most deadly kind of cancer. Colon cancer is expected to affect about 135,000 people this year and about 50,000 people will pass away from it. Given its prevalence, it’s important to know what it is, factors that can put you at a higher risk, and how it can be prevented and treated.
What is it?
It is a cancer that occurs in the colon or rectum. It can also be called “colorectal cancer” and abbreviated “CRC.” The colon is part of the large intestine, and the rectum connects the colon to the anus. About 71% of cases begin in the colon, and 29% begin in the rectum. The first sign of colon cancer is usually the presence of abnormal growths in the intestine called polyps. However, not all polyps cause cancer. There are 2 main kinds of polyps, adenomatous polyps which can develop into cancer and hyperplastic/inflammatory polyps which are more common, and generally don’t cause cancer.
Symptoms:
A change in bowel habits (this can include diarrhea, constipation, or change in consistency of stool)
Persistent cramps, gas or pain in the abdomen, or the feeling that your bowel doesn’t completely empty
Rectal bleeding (can be bright red or very dark blood
Weakness or fatigue, sudden weight loss, nausea, vomiting
What are the risk factors?
Being older than 50: We see colon cancer more often as people age
Family history of polyps
Family history of colorectal cancer
Genetic changes: Changes in some genes have been linked with a higher risk for colon cancer
Ulcerative colitis or Crohn’s disease
Personal history of colon, ovarian, breast or uterine cancer
Diet and lifestyle: Diets high in fat and red meat and low in fruits and vegetables seem to increase risk, but more studies need to be done
Cigarette smoking
There are also inherited forms of colon cancer:
Lynch syndrome (or hereditary nonpolyposis colorectal cancer, HNPCC): This is the most common kind of inherited colon cancer, accounting for about 2% of all colon cancer. It is caused by a change in the MLH1, MSH2, MSH6 or PMS2 gene. These genes are responsible for repairing errors in DNA that happen when cells prepare for division. If one of these genes does not work properly, cells can accumulate errors and this can lead to cancer. Lynch syndrome can also be caused by the EPCAM gene, which can cause MSH2 to not work properly. People with Lynch syndrome usually develop colon cancer at younger ages, with the average age being 44. In addition to colon cancer, people with Lynch syndrome are also at increased risk for cancers of stomach, small intestine, liver, gallbladder ducts, urinary tract, brain, skin, ovaries, and endometrium.
Familial adenomatous polyposis (FAP): This disorder is less common and is caused by mutations in the APC gene. It is characterized by the presence of >100 adenomas. People with FAP usually develop colon cancer before age 40. It can be accompanied by CHRPE (congenital hypertrophy of retinal pigment epithelium), which is flat pigmented regions of the retina. Osteomas can also be seen with FAP as well asesmoids, adrenal masses, and gastric fundic gland polyps. In people with FAP, cancer is inevitable without management. There is also an increased risk for dudodenal cancer, thyroid cancer, hepatoblastoma, and pancreatic cancer.
Genetic testing is available to diagnose/confirm Lynch syndrome or FAP for people who meet criteria.
Screening and Treatment:
People with an average risk of colon cancer usually begin screening by colonoscopy at age 50, and have one every 10 years. CT colonoscopy should be performed every 5 years, as well as a flexible sigmoidoscopy and double-contrast barium enema.
People at increased or high risk for colon cancer can begin screening by colonoscopy earlier and more frequently, depending on the specific risk category. For example, someone with Lynch syndrome should have a colonoscopy every 1 to 2 years starting at age 20-25, or 10 years before youngest case of colon cancer in the family.
Treatment of cancer depends on where it started and how much it has spread. Some treatments can include surgery, chemotherapy, radiation, immune-oncology, biological therapy and liver directed therapy.
Support and Awareness:
Kemopalooza: Friday, March 9th 7-11 pm at Music Farm Columbia: http://events.palmettohealthfoundation.org/site/PageServer?pagename=kemopalooza_info
http://www.hcctakesguts.org/
Unmasking Colon Cancer Gala: https://discoversouthcarolina.com/products/27871
http://www.sccancer.org/workgroups/colorectal-cancer/
https://coloncancercoalition.org/