Colorectal cancer, or colon cancer, occurs in the large intestine (colon) or the rectum (end of the colon).
What is Colorectal Cancer?
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. It is also the most common cancer affecting men and second most common cancer affecting women in Malaysia.
Both the colon and rectum are parts of the large intestine, as well as 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 non-cancerous 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
- Narrow stools
- Weight loss with no reason
- Change in your normal bowel habit
The symptoms of colorectal cancers are so subtle, that the first sign of the cancer is often 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 in both men and women, and most patients are aged 50 or over.
Like 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. Namely, there are risk factors which cannot be controlled such as family history, but there are also certain factors which can like lifestyle habits, diet and weight exercises 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 ongoing studies to establish the link between colorectal cancer and a diet, researchers are certain there is a correlation between red and processed meat and colorectal cancer. A diet low in fruits and vegetables puts you at a higher risk
- Weight – Colorectal cancer is more common in people who are overweight or obese
- Destructive lifestyle habits - a high alcohol intake and excessive smoking may increase your chances of getting colorectal cancer. Being physically inactive also increases the risk.
- Family history – having a close relative (mother or father, brother or sister) who developed colorectal cancer under the age of 50 posts a greater lifetime risk for you
- Some people also have an increased risk of colorectal cancer due to other pre-existing medical conditions such as extensive ulcerative colitis or Crohn's disease
Our doctors at Sunway Cancer 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, a procedure that allows the doctor to look inside the entire rectum and colon while a patient is sedated. Another test includes a biopsy which describes the removal of a small amount of tissue for examination under a microscope. While other tests can suggest that cancer is present, only a biopsy can make a definite diagnosis of colorectal cancer.
At Sunway Cancer 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 most common treatment for colorectal cancer, involving the removal of the tumour and some surrounding healthy tissue during an operation. It is also often referred to as 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 and minimal blood loss. However, with an open surgery, the surgeon makes a large cut into your abdomen to remove the tumour which results in a longer hospital stay with a 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 utilised 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 tumour and the chances of the cancer returning.
Radiation therapy is the use of high-energy x-rays to destroy cancer cells. It is commonly used for treating rectal cancer because colorectal tumours tend to recur near where it originally formed. Doctors use different types of radiation therapy to treat cancer. Sometimes patients will receive a combination of external radiation, internal radiation, or the IORT.
Side effects depend mainly on the amount of the radiation dosage given and the part of your body that is treated. They can include nausea, vomiting, diarrhoea, bloody stools/ urgent bowel movements, urinary and skin sensitivity problems.