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Colorectal Cancer

Colorectal Cancer - What it is

Colorectal cancer refers to cancer of the colon (the main part of the large intestine) or rectum (the final ~15 cm of the large intestine). Often, benign (non-cancerous) growths (polyps) may appear within the colon and rectum. Over time, these polyps can turn malignant and develop into cancer.

Most patients diagnosed with colorectal cancer are older than 50 years old. However, patients who were diagnosed at an early age (for example, at age 20-40) may have a hereditary form of colorectal cancer, such as familial adenomatous polyposis (FAP).

Colorectal Cancer - Symptoms

Colorectal Cancer Unexplained Weight LossThere are warning signs which the patient should look out for and seek medical advice early. They include:

  • Blood in the stools
  • A change from your usual bowel habit (pattern)
  • Abdominal pain or discomfort
  • Anemia (low blood count)
  • A presence of a mass (lump) in the abdomen
  • Unexplained loss of appetite and/or weight

Colorectal Cancer - How to prevent?

Colorectal Cancer - Causes and Risk Factors

Below is a summary of possible risk factors associated with colorectal cancer.

  • Age: The incidence of colorectal cancer increases for people of age 50 and above.
  • Family & personal history: The patient was previously diagnosed (and treated) colorectal polyps or cancer. Relatives of people diagnosed with colorectal cancer, and particularly in cases where genetic colorectal cancer syndromes have been diagnosed e.g. FAP or hereditary non-polyposis colorectal cancer (HNPCC).
  • Diet: Patients on a diet low in fibre and/or high in fat are thought to develop colorectal cancer more easily than those who are not. Consumption of alcohol and tobacco smoking are also linked to increased risk of developing colorectal cancer.
  • Inflammatory bowel disease: This refers to a group of uncommon conditions (ulcerative colitis and Crohn’s disease) that cause chronic inflammation in the colon and/ or rectum. Such patients do have an increased risk of developing colorectal cancer.

Colorectal Cancer - Diagnosis

Colorectal Cancer DiagnosisRegular screening is still the main key in detecting colorectal polyps or cancer early. In Singapore, the recommended age of screening is 50 years old for individuals with no symptoms. Patients with a strong family history of colorectal cancer are advised to start screening earlier than the recommended age. Screening tools currently available include:

  • Faecal Occult Blood Test (FOBT) – A positive FOBT requires a diagnostic workup with colonoscopy to examine the entire colon in order to rule out the presence of a malignant lesion.
  • Double contrast Barium Enema – X-rays that show extra detail in the large intestines than normal (plain) x-rays.
  • Computed Tomographic Colonography (CTC) – Advanced x-ray study using computer reconstruction to show details in the large intestines.
  • Colonoscopy – A procedure that examines the colon and rectum using a special flexible camera inserted through the anus. This is the most accurate of all tests and also allows procedures such as removal of small polyps and biopsy of any abnormal areas.

Colorectal Cancer - Treatments

The mainstay of treatment for colorectal cancer is surgery. This aims to remove the tumour as well as the surrounding lymph nodes. Most of the time, the two ends of the cut section can be joined together to restore continuity of the colon and rectum. In recent years, keyhole (laparoscopic) surgery can be performed which avoids long scars after surgery.

A full detailed microscopic examination of the tumour is performed to determine the stage of the cancer. Depending on the stage, chemotherapy with or without radiotherapy may be required.

Locally, the mortality (death) rate of colorectal cancer has seen a slight decline over the past decade. This is likely due to the progress in treatment Main treatment for colorectal cancer is surgery. of colorectal cancer, as well as increased awareness for screening. As a result, more patients are treated at an early stage of the disease with a 5-year survival rate of as high as 95% in Stage 1 colorectal cancer. Therefore regular screening is important and early medical advice should be sought before it is too late.

If you have any of the abovementioned symptoms or signs, it is advisable to consult a general practitioner (GP) first. A referral to a specialist center for further investigation is warranted should there be no resolution of symptoms despite initial treatment by the GP. It is also advisable to be seen by a specialist should you have risk factors or if there is suspicion of colorectal cancer.

Colorectal Cancer - Preparing for surgery

Colorectal Cancer - Post-surgery care

Colorectal Cancer - Other Information

The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth