What Is Colorectal Cancer? Here Are 8 Facts You Should Know

February 26, 2020

Did you know that colorectal cancer isn’t actually just one type of cancer? What people refer to as colorectal cancer can refer to two types of cancers, both affecting the large intestine. If the cancer is due to a tumour in the colon (the long part of the large intestine), it is called colon cancer. If the cancer occurs in the lower 6-8cm of the intestine, it is referred to as rectal cancer.

Many people have heard of colorectal cancer, but not many are clear about what it is. So, here are 8 facts about colorectal cancer that will give you a quick overview of the condition, its occurrence, and prognosis.

1. Colorectal cancer is on the rise in young people

Commonly thought of as a cancer for the aged, colorectal cancer can in fact inflict persons of any age. Recently, doctors and medical researchers have noticed a trend of rising colorectal cancer diagnoses in younger individuals.

Prior to 2010, only about one in 10 cases of colorectal cancer were in persons below 50 years old. This occurrence has since risen to one in five cases. Of those aged 40-49, the incidence of colorectal cancer is 10-20% higher than it was 15 years ago.

2. Colorectal cancer is the most common cancer in Singapore

The Singapore Cancer Registry recorded more than 9,800 new cases of colorectal cancer between 2011 and 2015. This makes colorectal cancer the most common cancer to inflict people in Singapore. Amongst men, colorectal cancer is the most highly diagnosed cancer, and in women, it is the second – with breast cancer taking the top spot.

3. Survival rates for colorectal cancer have been increasing

Despite the high incidence rate of rectal and colon cancer in Singapore, there is a relatively low mortality rate arising from it. This is thanks to more advanced treatment methods that make the prognosis for colorectal cancer quite favourable.

Rising awareness and more people going for screenings also help to detect the cancer earlier, increasing the likelihood of cure and survival. About 75% of colorectal cancer patients in Singapore are diagnosed at Stage I, II, or III, before the cancer cells have spread to distant organs.

4. Colorectal cancer has no early warning signs

More than half of those diagnosed with colorectal cancer exhibit no symptoms, especially if the cancer is in its early stages. This highlights the crucial nature of screenings in detecting the cancer early.

In patients where symptoms are present, they typically have to do with the bowel, for instance, diarrhoea, constipation, the feeling of incomplete bowel movement, bloody stools, recurring abdominal painbloated stomach, or rapid, unexplained weight loss.

5. Poor diet choices increase the risk for colorectal cancer

A widely reported risk for colorectal cancer is diet. Alcohol consumption and obesity are contributors to the risk of developing colorectal cancer, as they are for a number of other health issues.

In particular, processed meat seems to be a big culprit. A World Health Organisation group’s meta-analysis of over 800 studies found that every 50g of processed meat consumed daily increases one’s risk of getting colorectal cancer by as much as 18%.

6. Family history can put one at higher risk

Inherited conditions like familial adenomatous polyposis and Lynch Syndrome makes one more prone to developing colorectal cancer. Even without these conditions, a family history of colorectal cancer also puts one at higher risk for the disease due to the increased likelihood of common environments and lifestyles.

Other risk factors include a personal history of colorectal cancer, or pre-existing conditions like inflammatory bowel disease.

7. Not all colon polyps are dangerous

Colorectal cancer tumours form from growths in the large intestine called polyps. However, not all polyps are cancerous. In fact, polyps are pretty common, with 25% of people getting at least one polyp by the time they reach 50 years of age.

A polyp with a length of 1cm has an estimated 17% chance of developing into a malignant tumour in 10 years. For this reason, doctors still usually recommend that polyps be removed even if they are deemed non-cancerous.

8. Colonoscopy is one of the best screening methods

The best guard against colorectal cancer is timely screenings. Colonoscopy is widely regarded as the golden standard for colorectal cancer screening as it is able to detect polyps along the whole length of the large intestine with high reliability. Through colonoscopy, biopsies or removal of small polyps can also be performed.

Other screening methods include CT colonography, barium enema, and faecal immunochemical testing. Although they are not as reliable as colonoscopy, they are still useful for preliminary tests or in cases where a patient is not suitable for colonoscopy.

Assess your risk for colorectal cancer

Knowledge isn’t enough to guard yourself against colorectal cancer. Instead, you have to put it into action to assess your own risk: Do you have a family history of colorectal cancer? Does your diet put you at high risk of colorectal cancer? The higher risk you face, the earlier you should begin going for colorectal cancer screenings.

To learn more about colon cancer or rectal cancer, don’t hesitate to consult a colon cancer specialist in Singapore. Your doctor can also advise you on the best time to start colorectal cancer screenings.