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Colon Cancer: A Worryingly Common Disease


  • People who overindulge in the following types of food are at a greater risk of colon cancer than the general population: fatty foods, large amounts of red meat, meat that has been grilled and charred, pickled marinated foods, salty foods and foods that are low in fiber.
  • If you experience any irregular symptoms, such as alternating between constipation and diarrhea or chronic constipation, it could be a signal that you are developing colon cancer. An appointment with a doctor is necessary to carry out a thorough diagnosis.
  • NBI (narrow band imaging) technology involving a colonoscopy provides a highly detailed and accurate picture of the colon tissue, so that any abnormalities can be identified from the outset.


From the latest statistics released in 2018, it was found that cancer is the 2nd biggest killer worldwide and the 3rd in new cases found*.

Additionally, it is estimated that more than 3,000 deaths per year resulting from colon cancer are not officially reported, with those over the age of 45 and those under the age of 45 with a family history of colon cancer especially at risk.

The trend clearly suggests that if Thai people do not undergo colon cancer screening in greater numbers, aforementioned cancer rates could be doubling over the next decade.

These numbers and statistics may come as a shock to many of you, but this form of cancer can be identified early on through a colonoscopy. Where a pre-cancerous polyp is found, it can be removed in up to 90% of cases. Alternatively, in cases of early stage colon cancer, treatment is available that can provide a cure for the disease.

Colon cancer tends to arise from adenomatous polyps and, while the reason behind their occurrence still remains unclear, they are usually found to affect people over the age of 45. As these types of polyps have the potential to develop into colon cancer, doctors recommend that people should undergo regular screening for colon cancer. Where the aforementioned polyps are identified, they can be removed before they can develop into cancer. Alternatively, where those polyps already represent cancer in its initial stages, treatment can be provided before the cancer can spread to other organs, which is seen as another effective form of protection against colon cancer.

Risk Factors

Many forms of cancer develop with no clear cause. Colon cancer is no different in this regard, although there are certain risk factors as follows:

  • A previously diagnosed colonic polyp can, if left untreated, potentially transform into colon cancer.
  • Being over the age of 45 means the risk of colon cancer is twice as high. However, the disease can also be found in young men and women, as well as teenagers.
  • Having a family history of colon cancer, especially when the person who developed the disease was younger than 60. Research has found that hereditary nonpolyposis colorectal cancer (HNPCC), or Lynch syndrome, is a genetically transferable condition capable of causing colon cancer, which has the added danger of developing into said cancer before the patient reaches the age of 45*. Additionally, familial adenomatous polyposis (FAP) is another genetically transferable disorder that increases the likelihood of developing colon cancer before the age of 40. Nevertheless, both FAP and HNPCC conditions can be identified through genetic screening, which is currently relatively simple to perform, thus offering peace of mind when carried out alongside a consultation with a specialist. Click here to read more
  • Having chronic constipation
  • Regularly eating fatty food, large amounts of red meat, chargrilled meats, pickled or marinated foods, and salty foods, as well as foods that are low in fiber.
  • Being overweight and no regular exercise
  • Smoking
  • Inflammatory bowel disease
  • Diabetics who are resistant to insulin medication have an increased risk of developing colon cancer.


 Warning signs that should precipitate a consultation with a doctor

Early stage colon cancer tends not to display any symptoms. Patients often neglect the proper care of their colon and digestive system. That being said, if you experience any of the following irregular symptoms, please consult your doctor in order to undergo a thorough diagnosis: alternating between constipation and diarrhea or chronic constipation, reduction in stool size, bloody stools, sudden and undiagnosed loss of weight, nausea, exhaustion or feeling overly tired.

  • Noticeable changes in the colon, including bouts of constipation or diarrhea that last over two weeks
  • Bleeding from the anus or bloody stools
  • Abdominal discomfort, such as cramps and severe indigestion
  • Feeling exhausted and experiencing sudden loss of weight for no apparent reason

Colon cancer patients often do not experience any symptoms whatsoever during the disease’s early stages, while the symptoms that are displayed can differ greatly from case to case, depending on the size and location of the cancer within the colon. Therefore, where any one or more of these warning signs are identified, especially in those who are categorized as being high risk, a consultation with a doctor should be made immediately in order to undergo colon cancer screening.


Colon cancer screening, especially for at-risk patients, should be carried out from the age of 45 onwards, in line with the 2018 recommendations of the American Cancer Society. For patients with a family history of colon cancer, however, screening may need to begin earlier.

  • Eat a wide variety of vegetables, fruits and grains to provide your body with plenty of vitamins, minerals, dietary fiber and antioxidants, all of which play an important role in preventing colon cancer.
  • Alcohol should be consumed in moderation, not exceeding one glass per day for women and two glasses per day for men.
  • Abstain from smoking. A doctor may need to be consulted to help patients stop smoking completely.
  • Exercise for at least 30 minutes every day.
  • Maintain a healthy weight and avoid retaining excess weight or becoming overweight.


Colon cancer screening techniques

Screening for colon cancer during its initial stages is the most effective way to prevent or halt the disease. Doctors recommend that the following forms of screening should be carried out from the age of 45 upwards, regardless of gender:

  • A fecal occult blood test (FOBT) should be done annually. The test takes a small fecal sample for analysis, while patients are required to stop the consumption of any meat or blood nourishing vitamin supplements for three days prior to the test.
  • A fecal immunochemical test (FIT) should be done annually. The test takes a small fecal sample for analysis, while patients are not required to stop the consumption of any types of food prior to the test.
  • A sigmoidoscopy is recommended every five years. This form of screening involves insertion of an endoscopic device into the anus to check for any irregularities affecting the distal colon. It can also be used to cut a small tissue sample to be sent for analysis.
  • A colonoscopy provides a full and clear image of the patient’s entire colon and is also suitable for removing suspicious tissue samples for pathological examination.
  • Narrow band imaging (NBI) uses the latest endoscopic technology, providing a more accurate and detailed picture of colon tissue than ever before. The technique allows medical staff to identify any abnormalities in the tissue of the colon during its initial stages or when the polyp is smaller than 0.5 centimeter in length. Additionally, NBI gives doctors the opportunity to cut out any suspicious polyps immediately. Samitivej has been working in collaboration with SANO Hospital from Japan – an institution with world-leading expertise in all related GI endoscopies – to bring the Japanese technique to Thailand, enabling Samitivej to double the rate of accurate diagnoses and remove the polyps before they develop into cancer.


Colon cancer treatment

If a patient’s cancer is in the 1st stage, doctors will usually perform surgery to remove the cancerous tissue. However, if the cancer is in its 2nd or 3rd stages, with a higher chance of making a return, chemotherapy medication and radiation therapy will also be considered, both of which can be undertaken either pre- or post-surgery.

In addition to surgical removal of the cancer and radiation therapy, patients whose cancer is in the 4th stage may be required to undergo supplementary courses of chemotherapy. Furthermore, where the cancer has spread to the surrounding organs, doctors will need to give careful consideration to how they will treat those organs on a case-by-case basis.


Treatment in the form of targeted therapy

We have seen that although the true causes of colon cancer remain unknown, the disease can affect any of us. That being said, the risk factors mentioned above are the result of a person’s lifestyle. Therefore, the most effective form of prevention is to make suitable modifications to our diet and lifestyle habits. This means avoiding foods that are high in fat, increasing the amount of fiber we consume, drinking plenty of water and not forgetting to exercise regularly, as well as training ourselves to excrete properly in order to prevent constipation.

Moreover, people over the age of 45 or those with a heightened genetic risk of colon cancer should undergo annual screening assessments, including an FOBT, which has been proven to lower the rates of colon cancer fatalities, while colonoscopy examinations should be carried out every 10 years. All of these steps can help protect against colon cancer, or successfully treat the disease where it is identified in its initial stages.


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