According to the Singapore Cancer Registry Interim Annual Report: Trends in Cancer Incidence in Singapore 2010-2014, colorectal cancer is among the leading cancers in the country today. In fact, in the world, Singapore is at No. 16 in the list of countries with the highest incidence of this type of cancer. Colorectal cancer is ranked No. 1 among the Ten Most Frequent Cancers among men while it is ranked No. 2 among the Ten Most Frequent Cancers among women. The disease was more frequently diagnosed among men and women between the ages of 40 and 49, with the incidence rate rising steeply past the age of 50. It was also noted that there is a higher incidence of colorectal cancer among Chinese residents compared to their Malay and Indian counterparts.
In a recent article, it was reported that one out of five people are diagnosed with the disease, with two dying from it. Although this dramatic figure seems alarming, it can be attributed to Singaporean government’s push for early detection. In fact, it was reported that the survival of early stage colon cancer patients (those wherein the cancer is localized within the large intestines) had increased from 36 to 66 percent in men and 23 to 66 percent in women.
What is Colorectal Cancer?
Colorectal cancer is a type of cancer that affects the colon and/or the rectum, the latter two segments of the gastrointestinal tract. It is in the colon where water is absorbed from consumed food and the remaining residue is transformed into waste matter, also known as faeces, by gut bacteria. Faeces is later stored in the rectum where it will eventually be eliminated through the anus.
What happens with colorectal cancer is that polyps develop on the colon and rectum’s inner wall. While these polyps are benign at first, in some individuals, they may transform into cancer.
Malignancy should be suspected if the polyp detected presents with the following characteristics…
- The polyp is more than one centimetre in diameter
- Polyp is sessile (or does not have a stalk)
- Presence of multiple polyps
In its earliest stages, colorectal cancer cells are mainly confined within the colon and rectum. If not detected early, the cells project through the colon’s lumen and begins to invade nearby intestines and other organs within the abdominal cavity. With time, the cancer cells invade the lymphatic system and enter into the mesenteric lymph nodes. From these nodes, the cancer enters the blood stream and spreads to the liver, a secondary site for this malignancy.
Risk Factors for Colorectal Cancer
An individual is at risk of developing colorectal cancer if they have the following risk factors…
1) Age = risk for the disease is increased at the ages of 50 and above
2) Ethnicity = as was mentioned earlier, Chinese have a higher risk compared to Malays and Indians
3) Personal History = colorectal polyps were detected in the past or if the individual has been previously diagnosed with colorectal cancer (higher risk of recurrence)
4) Family History = there is an increased risk for the disease if a rare condition known as familial polyposis occurs in the family
5) Diagnosis of Ulcerative Colitis = an inflammatory condition of the bowels that may ultimately cause cancerous changes
6) Obesity and living a sedentary lifestyle
7) Regular consumption of foods that increase cancer risk, such as meats cooked at high temperatures (causes the release of carcinogens)
8) Smoking and heavy alcohol consumption = increases the risk of polyp formation.
Factors that Reduce the Risk of Colorectal Cancer
Just as there are factors that increase a person’s risk for colorectal cancer, there are also factors that can reduce this risk, such as…
1) Goods rich in fibre, like vegetables, fruits, and bran = promotes faster elimination of faeces and carcinogens from the colon
2) Regular intake of multivitamins and folate
3) Regular intake of calcium and other minerals
4) Drugs such as aspirin and NSAIDs have been found to reduce colorectal cancer risk. Hormone Replacement Therapy (HRT) also lowers risk for this disease. However, this protective quality is lost upon stopping intake within five years.
Colorectal Cancer Symptoms
Singapore’s Ministry of Health urges people who present with colorectal cancer symptoms to see their doctors immediately.
Usually, the disease does not present with any signs or symptoms in the early stages. However, examination by a doctor is warranted if there is blood in the stool, changes of bowel habits, abdominal pain, anaemia, or a lump is felt in the abdomen.
Again, if these symptoms are detected, see a doctor right away so that additional screening tests can be performed in order to treat the disease early.