What is Colorectal Cancer?

Colorectal cancer, or colon cancer, occurs in the large intestine (colon) or the rectum (end of the colon). Though the location of both cancers is different, colon and rectal cancer are often grouped together because they have many features in common. Colorectal Cancer is common to both men and women and most patients are aged 50 or over when they are diagnosed. Also, it is the most common cancer affecting men and second most common cancer in women in Malaysia.

Both the colon and rectum are parts of the large intestine, and the final part of the body’s digestive system. During digestion, the colon helps to reabsorb fluids and process waste products from the body and prepare for its elimination.

Colorectal cancer often begins as a growth called a polyp or adenoma, a noncancerous growth that may develop on the inner wall of the colon or rectum as people get older. If not treated or removed, a polyp can become a potentially life-threatening cancer .


Colorectal cancer first develops with few, if any, symptoms. The symptoms of colorectal cancer can be subtle. Symptoms to watch out for are:

  • Abdominal pain and tenderness
  • Blood in the stool
  • Diarrhea
  • Narrow stools
  • Weight loss with no reason
  • Change in your normal bowel habit

The symptoms of colorectal cancers are so subtle, that often the first sign of the cancer is a blood test showing a low red blood cell count due to bleeding in the digestive tract.

It is important to note that the symptoms mentioned above may be caused by other medical conditions. Many of these are much less serious than cancer, such as piles (haemorrhoids), infections or inflammatory bowel disease.

Colorectal Cancer is common to both men and women and most patients are aged 50 or over.

Risk Factors

Just as with most cancers cases, the exact reason for what causes colorectal cancer are not known, but there are a number of factors that can increase your risk. Some risks factors like family history which can't be changed, but certain factors like lifestyle habits – diet, weight exercise can be controlled, which help lower the development of cancer.

Other risk factors include:

  • Age – Your risk of getting colorectal cancer increases as you get older. More than 90% of cases occur in people who are 50 years old or older
  • Diet – While there are still studies to prove the link between colorectal cancer and a diet, researchers are certain about the link between red and processed meat and colorectal cancer. A diet low in fruits and vegetables puts you in higher risk
  • Weight – Colorectal cancer is more common in people who are overweight or obese and being inactive increases your risk of cancer
  • Lifestyle habits like alcohol and smoking – a high alcohol intake and smoking may increase your chances of getting colorectal cancer
  • Family history – having a close relative (mother or father, brother or sister) who developed colorectal cancer under the age of 50 offers a greater lifetime risk
  • Some people also have an increased risk of colorectal cancer because they have another medical condition, such as extensive ulcerative colitis or Crohn's disease


Our doctors are Sunway Medical Centre employ a number of tests to diagnose and learn which treatments work best for colorectal cancer. Factors like the symptoms, type of cancer suspected, age and medical history are taken into consideration before a test is prescribed for colorectal cancer.

Some of the common tests include a Colonoscopy, which allows the doctor to look inside the entire rectum and colon while a patient is sedated as well as a Biopsy, which is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis of colorectal cancer.


At Sunway Medical Centre, we work with a multidisciplinary team to create a treatment plan that is best suited for the patient. The treatment of colorectal cancer depends on several factors including the patients’ health history, the stage of the cancer etc. The three most common treatment options are:


Surgery is the removal of the tumor and some surrounding healthy tissue during an operation. This is the most common treatment for colorectal cancer and is often called surgical resection. Surgical options for colorectal cancer include the Laparoscopic surgery or the traditional open surgery.

With Laparoscopic surgery, three or four tiny cuts are made which allows for a quicker recovery time with minimal blood loss. However, with an Open surgery, the surgeon makes a large cut into your abdomen to remove the tumor and this leads to a longer hospital stay with slower recovery time.


Chemotherapy refers to treatment using medicines to kill cancer cells. Chemotherapy is usually given in cycles, administering a treatment for a period of time followed by a rest to allow your body time to recover . Chemotherapy may be given after a surgery to eliminate any remaining cancer cells. For patients with rectal cancer, chemotherapy and radiation therapy are given before a surgery to reduce the size of the tumor and reduce the chances of the cancer returning.

Radiation Therapy

Radiation therapy is the use of high-energy x-rays to destroy cancer cells. It is commonly used for treating rectal cancer because colorectal tumor tends to recur near where it originally started. Doctors use different types of radiation therapy to treat cancer. Sometimes people receive a combination of external or internal radiation as well as the Intraoperative radiation therapy.

Side effects depend mainly on the amount of radiation given and the part of your body that is treated. They can include nausea, vomiting, diarrhoea, bloody stools or urgent bowel movements, urinary and skin sensitivity problems.