Colorectal cancer is the second most common cancer for both females and males over the age of 50 in Singapore. Yet, it is preventable and detectable with early screening. In this article, we will discuss the prevalence of colorectal cancer in Singapore, factors that put an individual at higher risk, and the signs and symptoms of colorectal cancer. We will also discuss why symptoms may go unnoticed in the early stage, treatment options available if diagnosed with colorectal cancer, including the role of palliative care, as well as the national screening guidelines. Understanding these key areas can help you take proactive steps towards safeguarding the gut health of yourself and your loved ones.
Table of Contents
How does Colorectal Cancer Develop?
Colorectal cancer is cancer of the colon or rectum. It occurs when a malignant tumour forms and grows out of control in the colon (also called the large bowel or large intestine), or the rectum. Generally, the cells of the gastrointestinal tract die off when they endure excessive physiological stress or when their lifespan has passed. This process gets regulated by a dozen of biological checkpoints. In cancer, however, cells undergo a genetic mutation that drives its growth exponentially. As a result, the cancerous cells multiply and develop into a small collection of cells that grows over time.
During the early stages, newly-formed cancer has not yet spread to other tissues, which facilitates the treatment plan. Unfortunately, when cancer grows large enough to spread through the bloodstream to other tissues, the therapeutic success rate drops significantly.
The Prevalence of Colorectal Cancer in Singapore
According to reports, colorectal cancer is the most common type of cancer in Singapore, together with lung cancer and breast cancer. By itself, colorectal cancer accounts for:
- 1 in 6 cancer diagnoses among males
- 1 in 7 cancer diagnoses among females
Worldwide, numbers are not looking better, with colorectal cancer being the second most deadly cancer. In 2020, this cancer caused over 930,000 deaths.
The Risk Factors of Colorectal Cancer
Risk factors in health care refer to aspects that affect the chance of someone developing a disease. Knowing the risk factors helps you aware of your susceptibility to a medical condition and take appropriate actions to lower your risk. Some of the risk factors are modifiable, which means you can make changes to your lifestyle to reduce your risk.
Over the years, researchers identified several risk factors of colorectal cancer, including:
- Advanced age (most cases are diagnosed after the age of 50)
- Obesity
- Smoking
- Sedentary lifestyle (no physical activity)
- A diet rich in animal protein and saturated fats
- Low fiber diet
- Excessive alcohol consumption
- Having a medical history of other types of cancer (e.g., breast, ovarian, uterine)
- Having a family history of colorectal cancer or colorectal polyps
- Long-time diagnosis of inflammatory bowel diseases (IBD) such as ulcerative colitis or Crohn’s disease
- The presence of polyps in the colon or rectum. A number of colorectal cancer cases are found to start within polyps, which develop inside the bowel wall and are confirmed through colonoscopy.
Colorectal Cancer Risk Factors
Signs and Symptoms of Colorectal Cancer
The signs and symptoms of colorectal cancer vary from one individual to another. Here are the common symptoms to watch out for:
- Changes in bowel habits, such as constipation, diarrhea
- Reporting a sensation that the bowel is not empty despite bowel movement
- Melena, which is the presence of blood in the feaces that turn the stools black
- Rectal bleeding, or incidents of bright, red blood coming from the rectum
- Pain and cramping in the abdomen
- Unexplained weight loss
- Severe fatigue
- Iron deficiency anemia in men
- Iron deficiency anaemia in women after menopause
As you may notice, the symptoms of colorectal cancer are highly non-specific, which explains the difficulty of diagnosing this condition during the early stages. If you or your loved ones experience any of these symptoms for more than a few weeks, it might be a good idea to visit your doctor for further evaluation. Do not assume the worst at this stage! It is possible that these symptoms are caused by a other common gastrointestinal (GI) disorders. We discussed these common gastrointestinal conditions in our blog article here.
Signs and Symptoms of Colorectal Cancer
The Staging of Colorectal Cancer
If colorectal cancer is indeed confirmed via a diagnosis, doctors will try to stage it. The staging of colorectal cancer is important for several reasons. It helps with predicting the prognosis (i.e., outcome) of patients and determining the best treatment approach to follow. The stages of colorectal cancer are:
Stage 0 – this is the earliest stage when cancer has not yet penetrated the basal membrane of the tissue. Doctors refer to this stage as carcinoma in situ.
Stage 1 – cancer penetrates the basal membrane of the bowel; however, it does not spread beyond the wall of the rectum or colon.
Stage 2 – cancer reaches and grows through the wall of the colon or rectum. It does not reach nearby lymph nodes.
Stage 3 – cancer invades nearby lymph nodes but does not affect other organs.
Stage 4 – cancer reaches other organs (e.g., liver, lungs, ovaries, peritoneum).
Unfortunately, 40% of colorectal cancer cases get diagnosed in an advanced stage, which means treatment options are more limited or less effective. In the fight against colorectal cancer, prevention and screening to improve early detection is our best medicine.
The Treatment Options of Colorectal Cancer
Colorectal cancer is one of the most treatable cancers if detected at an early stage. The available treatment options include:
- Surgery
- Chemotherapy
- Radiotherapy
Surgery for colorectal cancer
Surgery is an indispensable tool in treating colorectal cancer. The surgeon will remove the malignant tumour and the nearby lymph nodes to reduce the risk of metastasis (i.e., cancer spreading to other tissues). In some cases, the rectum is completely removed, with a colostomy bag attached for drainage. The purpose of the colostomy bag is to collect stool, which is a temporary solution in many cases.We wrote about colostomy and ostomy care in another article here.
If the diagnosis of colorectal cancer is early, surgery is the most effective way to treat it. It may also benefit some cases of advanced stages as part of palliative care.
Chemotherapy for colorectal cancer
Chemotherapy revolves around using pharmacological drugs to destroy cancerous cells. When the tumour is large enough, your doctor may recommend chemotherapy before the surgery to shrink it. Recently, scientists developed new treatments that target specific proteins, which are responsible for promoting cancer growth. These drugs have fewer side effects relative to conventional chemotherapy. Such drugs include:
- Bevacizumab (Avastin)
- Ramucirumab (Cyramza)
Radiation therapy for colorectal cancer
Radiation therapy uses high-energy radiation beams to disintegrate the tumour. Similar to chemotherapy, radiation therapy may be beneficial before surgery to shrink the tumour.
Palliative Treatment for Colorectal Cancer
Palliative care refers to measures that alleviate the suffering of the patient. Palliative care becomes an option when the patient has an advanced case of colorectal cancer that does not improve with the treatments listed above. Persistent symptoms such as nausea, vomiting, pain and constipation may be disruptive to the patient's well being. Palliative care can provide the necessary relief and improve quality of life for the patient as well as their caregiver and family. It can be provided at home by palliative care specialists, alongside with other treatment or by itself. Learn more about how palliative care can support you in your battle against cancer from our article here.
Preventing Colorectal Cancer
Making healthy lifestyle choices are crucial to lower your risk of colorectal cancer, and it is in our control. As we discussed in the Risk Factors section above, this cancer is linked to a number of unhealthy dietary and lifestyle habits. Exercising, maintaining a healthy weight, stop smoking, adding fiber to your meals, avoiding excessive consumption of saturated fats and unwholesome protein such as red meat, full fat dairy products, and baked goods, all contribute to reducing your chance of developing colorectal cancer.
Screening is another important preventive measure for this cancer. It can detect pre-cancerous polyp or cancer at early stages and is recommended for everyone above 50 years old, with or without any symptoms. Those younger with high risk factors are also recommended to participate in regular screening to detect the disease. It can be done as part of your annual health screening or independently. Read our guide to health screening by age here, or talk to your GP or family doctor for a personal evaluation of your risk of colorectal cancer and the optimal way to screen.
There are 2 main ways to screen for colorectal cancer in Singapore:
- The Faecal Immunochemical Test (FIT): this test detects blood in stool from a sample, including traces of blood that are not visible to normal eyes. Under the national screening program - Screen For Life, Singaporeans and Permanent Residents above the age of 50 can enquire and collect the FIT kit from your CHAS GP clinics during your next visit (at a $5 fee for eligible Singaporeans and $2 for eligible CHAS cardholders) or from Singapore Cancer Society (for free). The test is painless and easy to do in the comfort of your home without any preparation. Results will be informed to you via mail or phone. FIT should be repeated every year. In the event of positive test result, it indicates presence of blood in your stool but not necessarily colorectal cancer. You will advised to go for further checking, possibly a colonoscope which we discuss below.
- Colonoscopy: This procedure is conducted at a hospital or clinic and requires bowel preparation. A specialist uses a lighted tube to look inside the rectum and colon, checking for polyps or signs of cancers, while you are sedated. It is considered the gold standard of colorectal screening. However, it involves a much higher cost compared to FIT and bowel preparation for 2-3 days prior to colonoscopy. It is therefore recommended for individuals with high risks, or those testing positive from FIT. The test can be repeated every 10 years, unless advised otherwise by your doctor.
Takeaway Message
Colorectal cancer is one of the most common cancer that affects over 1,000 Singaporeans every year. It is the leading cause of cancer-related death in Singapore. Early detection helps to improve treatment effectiveness and save lives. You can protect yourself by adopting healthy lifestyle and dietary habits and go for the recommended screening. Spreading awareness of the condition and available subsidised screening programs is also important, whether you hit 50 or not.
Chat with us below if you have questions about home care for colorectal cancer, whether it is stoma care at home, palliative care, or respite care.
If you are around our clinic, please feel free to drop by for your FIT kit. We are located at:
Charazoi Medical Clinic - Dr Choo Dee Pheng
Address: 380 Jalan Besar, #05-01, ARC 380 Singapore 209000 (Find direction here)
Tel: 6802 7972 (Monday to Friday, 9:00AM - 12:00PM, 2:00PM - 5:00PM)
Charazoi Medical is a CHAS, Healthier SG and accredited clinic.
