What you need to know about Colorectal Cancer

According to the WHO Global Cancer Observatory, Colorectal cancer is the third most common occurring type cancer among Filipinos (2nd most common among men and 3rd most common among women). 

The colon and the rectum are tubular muscular structures that are part of the digestive system. Together, they form the large intestine. The colon is the initial 4 to 5 feet (1.2-1.5 meters) while the rectum is the final 6 inches (15 cm) of the large intestine. The colon is the final part of the digestive system where nutrients and water are absorbed. The remaining undigested food is turned to waste material or fecal matter. The fecal matter passes through the rectum before exits the body through its opening called the anus.

Colon and rectal cancer occur as a result of two processes. First is the growth of new cells that differ from normal occurring cells in the colon and/ or rectum. Second is the resistance of older cells to the signal for programmed destruction or apoptosis. Both processes are made possible by mutations in genes such as the adenomatous polyposis gene (APC) and the p53 tumor suppressor gene. 

Risk factors for Colorectal Cancer

1) Age >50: 90% of cases are diagnosed after age 50.

2) Diet: High fat (especially animal fat) and low calcium, folate and fiber diets increase the risk of colorectal cancer.

3) Colorectal polyps: Polyps are small fingerlike masses that grow on the inner lining of the colon or rectum. These are common in patients >50 years old. While most are benign/ non- cancerous, some may progress to cancer. Therefore finding and removing polyps reduce the risk for colon cancer.

4) Family history of colorectal cancer: There is an increased risk of developing colorectal cancer if you have a first degree relative (parents, siblings or offspring) with colorectal cancer as well. The risk is especially higher, if your first degree relative developed it at an earlier age. The more first degree relatives with colorectal cancer, the higher the risk you have of developing it.

5) Cigarette smoking: According to a meta-analysis of several studies, there is a modest but significant risk for developing colorectal cancer among smokers both current and those who have quit smoking.

(source:TsoiKK,Pau CY, Wu WK, Chan FK, Griffiths S, Sung JJ. Cigarette smoking and the risk of colorectal cancer: a meta-analysis of prospective cohort studies. Clin Gastroenterol Hepatol. 2009 Jun. 7(6):682-688.e1-5.)

Risk factors for Colorectal Cancer

There is a 64.6% overall 5 year survival rate for colorectal cancer. The earlier it is discovered and treated, a patient’s 5 year survival rate can reach up to 90%. However, this can fall to 14.3% once the disease has spread or metastasized to other organs. (source: Surveillance, Epidemiology, and End Results Program. SEER Stat Fact Sheets: Colorectal Cancer. National Cancer Institute. 

Symptoms of Colorectal
  1. blood in stool (may be bright red or very dark red)
  2. feeling that your bowel does not completely empty
  3. sudden changes in bowel habit (sudden diarrhea or constipation)
  4. stools that are narrower than usual (thinner, pencil like)
  5. crampy abdominal pain or feeling bloated
  6. sudden weight loss
  7. nausea and/ or vomiting.

The symptoms may vary depending on the location of the cancer. If the cancer is located on the right side of the colon, the patient presents with blood in stool and diarrhea.