Last updated on May 21, 2021.
Colon cancer is a type of cancer that starts in the large intestine (colon). When the cancer starts in the lowest end of the colon (rectum), it is called rectal cancer. The term colorectal cancer is thus often used. Here is a complete guide to colon cancer in Hong Kong including options for screening and treatment, with Dr. Ernest Li 李恒輝醫生, a Gastroenterologist and Hepatologist with experience in Hong Kong’s public and private healthcare sectors.
Colon cancer statistics in Hong Kong
Colorectal cancer is the most common cancer in Hong Kong. According to the Hong Kong Cancer Registry, it accounted for 17.3% of all new cancer cases in 2016 and is the 2nd leading cause of cancer deaths in Hong Kong. There were 5,437 new cases of colorectal cancer in 2016: 3,169 cases for males and 2,268 cases for females. The male to female ratio was about 1.4 to 1. The crude incidence rates were 93.9 for male and 57.3 for female per 100,000 population of respective sex. The age-standardised incidence rates were 50.6 for male and 31.4 for female per 100,000 standard population. In 2017, 2138 deaths were caused by colorectal cancer, accounting for 14.9% of all cancer deaths. More than 90% of colorectal cancer cases occurred in patients 50 years of age or older.
Signs and symptoms of colon cancer
People often experience little or no symptoms in early stages of colon cancer. Common symptoms include:
- diarrhea or constipation
- changes in stool consistency
- rectal bleeding or blood in the stool
- abdominal pain, cramps, bloating or gas
- pain during bowel movements
- feeling of incomplete emptying after bowel movements
- unusual weight loss
- iron deficiency anemia
Causes of colon cancer
Colon cancer occurs because of an abnormal growth of cells on the wall of the large bowel.
Most colorectal cancers begin as a small polyp. Polyps are usually benign, but some may gradually develop into cancer. The development of a polyp into cancer may take more than 10 years, but it must be treated as early as possible, otherwise these cancer cells may invade and damage nearby organs, and can also spread to other parts of the body via the bloodstream and lymphatic system.
Risk factors for colon cancer are diet of high animal fat and protein while low in fibre, obesity, lack of exercise, smoking, alcohol and hereditary factors.
Stages of colon cancer
Colorectal cancer stages are determined by the extent to which the disease has spread through those layers of the colon or rectum wall and/or into lymph nodes or other organs.
Stage 0: Polyps are found in the colon or rectum. The cancer is still in a very early stage and is inside the mucosal (innermost) layer of the colon. This stage is also known as carcinoma-in-situ.
Stage 1: The cancer has spread to the next layer of tissue but it has not touched the lymph nodes or other organs.
Stage 2: The cancer has reached the outer layers of the colon, but it has not spread beyond the colon. Lymph nodes or other organs are not touched.
Stage 3: The cancer has grown to the outer layers of the colon and it has reached lymph nodes. It has not spread to distant sites.
Stage 4: The cancer has reached other tissues beyond the wall of the colon. As stage 4 progresses, the cancer reaches distant parts of the body, such as the liver or lungs. The cancer may or may not have grown through the wall of the colon or rectum, and lymph nodes may or may not have been affected.
Prevention of colon cancer
Primary prevention needs to be implemented in our daily lives. These include:
- Increase intake of dietary fibre (fruits, vegetables, whole grains)
- Decrease consumption of saturated fat and red and processed meat
- Regular exercise
- Maintain a healthy body weight with body mass index between 18.5 to 22.9
- Avoid smoking and excessive alcohol
- Screening colon polyps: regular colonoscopy
Screening of colon cancer
Around 91 percent of patients who receive a diagnosis of colon cancer are over 45 years old. According to the American Cancer Society, it is recommended that people of average risk of colon cancer start regular screening at age of 45 and those with a family history of colon cancer consider colon cancer screening early. With early screening and testing, colon cancer is preventable, treatable and beatable.
There are 3 common screening tests for colon cancer. You should consult with your primary care doctor to decide which of these screening tests is most suitable for you.
1. Faecal Occult Blood Test (FOBT):
Participants must first consult a primary care doctor to be assessed on medical fitness. After that, participants must take a Faecal Occult Blood Test (FOBT) that can be done at home using the tubes provided by the doctor. This FOBT test can detect small amounts of blood in stool. Participants shall return the tubes and will be notified of the result by their primary care doctors.
If blood is visible and the result of the test is positive, it means that polyps or cancers might exist. These polyps have to be removed using colonoscopy immediately, in order to prevent and reduce the chance for them to develop into cancer. If the result of the FOBT is negative, make sure to keep track of the colorectal cancer symptoms and make sure to take the FOBT test again in every 2 years. Note that around 80% of colon polyps do not bleed, therefore FOBT would be negative.
Colonoscopy is the endoscopic examination of the large bowel and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It is currently the best method to examine the lower digestive tract. The procedure usually takes about 15 minutes to an hour. Before the test, participants must go on a low residue diet and bowel preparation. During the colonoscopy process, tissue samples for laboratory examination can be obtained and polyps can be removed. Colonoscopy is currently the best method to prevent the development of colon cancer, reducing the chance of colon cancer by up to 70%.
To learn more about colonoscopy in Hong Kong:
3. Flexible sigmoidoscopy
A flexible sigmoidoscopy is used to evaluate the lower part of the large intestine (colon). A thin, flexible tube (sigmoidoscope) is inserted into the rectum with a tiny video camera at the tip of the tube allowing the doctor to see the inside of the rectum and most of the sigmoid colon. When necessary, tissue samples (biopsies) can be taken through the scope during a flexible sigmoidoscopy exam. However, flexible sigmoidoscopy alone cannot detect any cancers or polyps located further inside the colon because it doesn’t allow to show the entire colon to the doctor.
Hong Kong’s Colorectal Cancer Screening Programme
To learn more, click here.
Where to get colon cancer screening in Hong Kong?
Here is an updated list of the private and public primary care doctors and clinics under the Colorectal Cancer Screening Programme, providing consultations across Hong Kong.
How to treat colon cancer?
Colon or colorectal cancer has a high curability if detected and treated early. If screening results detect cancerous cells, specialist doctors will conduct consultation and discuss the most suitable treatment each patient needs to take considering its size and location, the possible side effects of the treatment and the current health condition of the patient itself.
The 3 most common ways to treat colorectal cancer are through tumour removal surgery, chemotherapy and radiation therapy.
1. Tumour removal surgery
Surgery is the removal of the tumor, nearby lymph nodes, and some surrounding healthy tissue or colon, often called surgical resection. This is the most common treatment for colorectal cancer. Side effects of the surgery include pain in the stomach, constipation, diarrhea and irritation around the stomach. However, recently there are more and more ways that doctors use to minimize the complications of the surgery as well as speeding up the recovery, such as by using minimally invasive surgical techniques or sedatives.
Chemotherapy is the use of anti-cancer drugs to destroy cancer cells. Chemotherapy can be used to treat other forms of cancers as well but for colon cancer it is usually given post surgery if the cancer is larger or has spread to the lymph nodes. It may help to kill any cancer cells that remain in the body and thus reduce the risk of cancer recurrence. If used before the surgery, it may shrink a larger cancer and make it easier to be removed. Chemotherapy can also be used to relieve symptoms of colon cancer that can’t be removed with surgery or that has spread to other areas of the body. Sometimes it’s combined with radiation therapy. Side effects include vomiting, nausea, diarrhea, neuropathy, or mouth sores but medications exist to help prevent or reduce these side effects.
3. Radiation therapy
Radiation therapy is the use of high energy radiation to destroy cancer cells. It is commonly conducted together with chemotherapy. At high doses, radiation therapy kills cancer cells or slows their growth by damaging the cancer cells’ DNA. Damaged DNA will stop dividing or die. When the damaged cells die, they are broken down and removed by the body.
What is the cost of colon cancer treatment in Hong Kong?
For eligible persons with a HKID card, the cost is $75 admission fee and $120 per day, covering surgery fee, chemotherapy fee, and radiotherapy fee. Extra medications or other injections needed are not included.
For non-eligible persons without a HKID card, the cost is $5,100 per day.
Beware of waiting times which can be very long in the public sector.
For details, call the Hospital Authority at 2300 6555.
Cost of colon cancer treatment in Hong Kong’s private sector:
The cost of colon cancer surgery (tumour removal surgery) depends on the patient’s condition. Different stages require different surgical procedures therefore it is best to consult a doctor and discuss the options that best suit your situation. In Hong Kong, fees are also determined according to the choice of room (private, semi private, ward), doctor fees, medication fees, and administration fees of each hospital or clinic, therefore it may vary significantly. Chemotherapy in private sectors range from $925 to $21,050 and the colorectal surgery can range from $62,500 to $185,000. Cases referred by the Hospital Authority’s (HA) will receive up to 35% discount for all kinds of examinations to be conducted as outpatient cases. Fee for radiation therapy can reach up to $12,000 but it depends highly on the number of doses assigned by your doctor.
What is the best test to detect colon cancer?
Colonoscopy is the most reliable screening option over Faecal Occult Blood Test (FOBT) and flexible sigmoidooscopy. The 3 screening tests may be ordered by doctors selectively to suit the specific medical needs. Consult your doctor before choosing your option.
What is the main reason for colon cancer?
Colon cancer is a result of abnormal cell growth on the wall of the colon. Low-fiber diet, obesity, lack of exercise, smoking, alcohol and genetic composition are all risk factors for the cancer.
When do symptoms of colon cancer appear?
For most cases, colon cancer exhibits mild or no symptoms in the early stages and thus may easily go unnoticed.
Does insurance usually cover colon cancer treatment in Hong Kong?
According to AD MediLink, colon cancer surgery is usually reimbursed under hospital/surgical benefits whereas chemotherapy/radiation therapies are usually reimbursed under cancer cover. Generally, high-end medical plans will reimburse cancer treatments in full without any sub-limit whereas local plans will have sub-limits. If you have health insurance questions, contact an expert at AD MediLink at [email protected].