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Address:#09-09 Gleneagles
Medical Centre 6 Napier Rd.
Singapore 258499
Phone:+65 6476 0181 
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Colorectal Cancer

Colorectal Cancer Symptoms and Signs

In the pre-cancerous polyp stage or early stages of colorectal cancer, there are rarely any symptoms. By the time symptoms appear as a result of the cancer, it has usually reached the intermediate to late stages of cancer.
Common symptoms associated with colorectal cancer include blood in the stools, abnormal bowel habit, sensation of incomplete bowel movement, intermittent diarrhoea and constipation, mucus in the stools, unexplained weight loss and unexplained pallor. These symptoms are not specific to colorectal cancer and that is why it is important to get assessed by a colorectal surgeon to exclude the possibility of colorectal cancer. A more extensive list of symptoms associated with colorectal cancer is given below.
  1. Blood in the stools
  2. Mucus in the stools
  3. Persistent change in bowel frequency (e.g. if you usually have ONE bowel movement a day, having 3 bowel movements a day or one bowel movement every 3 days for the past 1 month is very different from your normal pattern)
  4. Sensation of incomplete bowel movement or persistent urge to have a bowel movement
  5. Decreased stool caliber (stools getting narrower or thinner than usual and persisting for more than a month)
  6. Fragmentation of stools (cannot have single piece of formed stools but fragmented into multiple smaller pieces)
  7. Alternating diarrhoea and constipation
  8. Unexplained weight loss
  9. Unexplained appetite loss
  10. Unexplained pallor
  11. Persistent lethargy
  12. Abdominal distension or bloating that is persistent for more than a month
  13. Abdominal pain that is intermittent but persists for more than a month
  14. Palpable lump in the abdomen
  15. Palpable lump protruding from the anus

Colorectal Cancer Stages

Colorectal cancer is classified into 4 stages. While each class is now further subdivided into more categories, the following (simpler) 5 year survival figures for each stage are good guides.
Colorectal Cancer Stage I
Description: Cancer involves inner layers of bowel wall, up to the muscle layer
Treatment Options: Surgery Only
5 Year Survival: 95-99%

Colorectal Cancer Stage II
Description: Cancer involves deeper layers of bowel wall and may involve the full thickness of bowel but no lymph nodes are involved
Treatment Options: Surgery only unless the tumour has breached the outermost layer of bowel wall, where chemotherapy and radiotherapy may be required
5 Year Survival: 80-90%

Colorectal Cancer Stage III
Description: Cancer can involve any layer of the bowel wall and has reached the lymph nodes outside the bowel wall
Treatment Options: Surgery followed by chemotherapy, radiotherapy only for certain cases only
5 Year Survival: 65-75%

Colorectal Cancer Stage IV
Description: Cancer has spread to other internal organs (metastasis)
Treatment Options: Surgery if colon is nearly obstructed by cancer or persistently bleeding, chemotherapy and radiotherapy to control symptoms
5 Year Survival: 5-15%
The last column mentions “5 year survival”. This is a term to denote when your doctor is confident that you are cured of cancer. That is because after the initial treatment, doctors can rarely be sure that you have been cured of all microscopic cancer cells. We now know that cancer recurrence happens extremely rarely after 5 years and your doctor can only confidently declare you “cured” after a 5 year period.

Colorectal Cancer Diagnosis - Colonoscopy

The best and most accurate way of confirming colorectal cancer is by colonoscopy. Colonoscopy allows the doctor to take a biopsy of the tumour to confirm the diagnosis, ascertain the exact location of the cancer and whether there is more than 1 cancer (synchronous cancers of colon). During colonoscopy, the surgeon can also tattoo the location of the cancer to help identification of the cancer during surgery.
Alternatives to colonoscopy will be CT colonography or barium enema. Both of these are radiologic tests involving low dose radiation. The weakness of either of these tests is that no tissue biopsy can be taken for confirmation of the cancer. Please click to read more about colonoscopy and alternative methods of colonic imaging.

Colorectal Cancer Treatment

Colorectal cancer is a highly curable cancer if detected in the earlier stages. Even for Stage IV cases, patients with cancer spread that is localized to a single area can potentially be cured. Surgery is the cornerstone of treatment for colorectal cancer. As colorectal cancers are not very sensitive to chemotherapy or radiotherapy, these modalities are only used to augment the result of surgery in certain cases (as highlighted in the table about stage of colorectal cancer and survival).
Surgery for colorectal cancer needs to be performed in a methodical and meticulous manner with the aim of removing all the cancer cells without allowing the cancer to spread inadvertently during surgery. While this sounds very daunting, it is important to note that only a short segment of the colon or rectum is removed at surgery and most of the colon (and hence your bowel pattern)  is preserved.
Great improvements in techniques of surgery, such as laparoscopic or robotic surgery, have also shortened the recovery time for surgery as well as reduce the risks of complications from surgery. In fact, more than 95% of patients who undergo colorectal cancer surgery do not develop complications and recover well enough to perform daily activities independently within 3-4 days. Chemotherapy and radiotherapy have also improved significantly and side effects and complications have become rarer. If side effects or complications happen, treatments for these are also better.
Therefore, when you or your loved one is diagnosed with colorectal cancer, it is important you seek an opinion from a surgeon experienced in colorectal cancer surgery and ensure that the surgeon has your best interests at heart.
If you have feedback or would like to know more about treatment for these conditions, feel free to contact us or make an appointment.