Colorectal cancer is a disease characterised by abnormal tumour growth in the colon or rectum (bowel). The colon refers to the large intestine, while the rectum is the passageway connecting the colon to the anus.
The first signs and symptoms of colorectal cancers start as a polyp or a benign and non-cancerous growth on the intestine lining. When left untreated, it will metastasise or develop into abnormal growth.
Colonoscopy screening tests are the best possible way to identify colon cancer symptoms early. Screening tests can also help detect colorectal cancer early when it is still treatable.
1. What Are The Symptoms Of Colorectal Cancer?
It’s crucial to understand that most people who have colon cancer typically don’t experience any symptoms in the first stages of the disease.
When the symptoms appear, they vary from patient to patient, depending on the size of the growth and location in the large intestine.
Nevertheless, there are a few critical symptoms of colorectal cancer you should watch out for:
- Bleeding in the rectum or blood in the stool
- Persistent pain in the abdomen, including cramps, pain, or gas
- Full feeling in the bowel that doesn’t empty out
- Unexplained weight loss
- Feeling exhausted or weakness
- Recurring stomach cramps, bloatedness, or gas pains
2. Stages Of Colon Cancer
After a doctor diagnoses a patient with colorectal cancer, they will try to determine if the cancer has spread and to what extent. This entire process is known as colorectal cancer staging.
Each stage of colorectal cancer describes the level of cancer in the body. It determines the severity of the tumour and allows doctors to find the best ways to treat it. Doctors also use the stages of cancer when describing survival statistics.
In colorectal cancers, the earliest stage is called stage 0. It ranges from stages I through IV (1 to 4). In principle, the earlier the stage, the less the cancer has spread.
Each colorectal cancer varies from patient to patient. However, cancers in similar stages generally have a similar outlook and often require the same level of treatment.
Here are the stages of colorectal cancer:
- Stage 0: The cancer is still in the colon or rectum’s inner layer. It is referred to as carcinoma in situ.
- Stage 1: The cancer has spread into the inner layer. It has not yet spread to the wall of the colon or the rectum.
- Stage 2: The cancer is already in the colon and rectum’s wall.
- Stage 3: The cancer has spread throughout the first two layers of the rectal wall (mucosa and submucosa) or colon. It may have also reached the third layer (muscularis propria). Cancer cells may already have been present near the lymph nodes.
- Stage 4: The cancer has spread from the colon area towards organs and tissues. Colon cancer usually spreads to the liver. However, it may also spread to other organs, like the brain, lungs, abdominal cavity lining (peritoneum), or distant lymph nodes.
- Recurrent: Recurrent colorectal cancer means it has come back after disappearing for at least one year. In more advanced colorectal cancers, it may return in just a few months. This may mean that the first round of chemotherapy has not been able to remove all of the cancer cells.
3. Risk Factors Of Colorectal Cancer
Risk factors refer to anything that increases your chance of getting a disease, like cancer. Some risk factors are hereditary, while others, such as smoking, can be changed.
Having a risk factor, however, does not necessarily mean you will have the disease. Additionally, some people who get colorectal cancer may not have any known risks.
Risk factors of colorectal cancer may include:
- Age – People 50 and above tend to be at a higher risk of developing cancer. The majority of colorectal cancer cases are diagnosed in individuals of that age.
- Weight – Overweight or obese individuals are at a higher risk of developing and dying from colorectal cancer. The risk is the same in men and women, but it seems to be far stronger in men. Following a healthy lifestyle and maintaining a good diet may help lower the risk.
- Medical history of polyps – Individuals with colorectal polyps are also at high risk. The polyps may potentially develop into colorectal cancer.
- Medical history of cancer – Individuals who have had colorectal cancer before and women who have had ovarian, endometrial, or breast cancer may also face a higher risk.
- Inflammatory bowel disease – Chronic inflammatory intestinal diseases like ulcerative colitis or Crohn’s disease (colon inflammation) may also increase the risk of developing colorectal cancer.
- Smoking and alcohol intake – This is also a high-risk factor for cancers and colorectal cancer.
4. How To Reduce The Risk Of Developing Colorectal Cancer
Ultimately, the most effective way to reduce your risk of colorectal disease is to undergo screening, starting at age 45.
Below are also other healthy habits to follow:
- Exercise regularly
- Reduce consumption of vices like smoking and alcohol
- Eat fruits, vegetables, and whole grain foods
- Consume less red meat and processed meats
5. How Do Doctors Diagnose Colon Cancer
Detecting cancer cells and precancerous polyps can be done through screening tests. These are recommended for people aged 50 and above.
Once symptoms appear, doctors will recommend diagnostic tests to confirm if it is colorectal cancer and identify the most effective treatment.
The following tests are often used to diagnose colorectal cancer:
A sigmoidoscope is a small tube inserted into the anus, passing through the rectum and into the sigmoid colon. Sigmoidoscopy helps detect polyps or colon cancer. A colonoscopy may be recommended if either is detected.
Like sigmoidoscopy, colonoscopy involves a tube with a tiny camera attached to the end. This allows the doctor to examine the entire length of the colon and rectum. A doctor can remove polyps or get tissue samples for further tests through a colonoscopy.
Faecal Occult Blood Test
A faecal occult blood test or FOBT is a lab test to examine stool samples. It checks for blood in the faeces or stool, but a positive result may not necessarily be sufficient to confirm a colorectal cancer diagnosis.
Also known as virtual colonoscopy, CT colonography involves x-ray equipment to examine the large intestine for cancer and colon polyps.
A barium enema is another x-ray exam that detects abnormalities in the large intestine or colon. It’s also referred to as a colon x-ray.
An enema is the injection of liquid into the rectum through a small tube. The liquid contains barium, a metallic substance coating the colon lining. This allows for more detailed imaging of the inner lining of the colon.
6. Treatment For Colorectal Cancer
40% of colorectal cancer cases occur at an advanced stage, and wherein surgery is the best option. Laparoscopic or keyhole surgery can be performed in such cases of early to mid-stage cancers.
Open surgery is needed to completely remove the tumour and affected lymph nodes for the more advanced colorectal cancer. Open surgery may be done for emergencies, like a tumour obstruction.
Chemotherapy involves using specific drugs to help destroy cancer cells, especially if they have spread to the lymph nodes. This treatment may also be recommended pre-surgery to shrink the tumour.
Targeted therapy targets specific cancer cell abnormalities. It is usually done for the more advanced colon cancer.
Using high-energy x-rays and protons, radiation therapy helps destroy cancer cells or shrink tumours before surgery. This treatment may be used alongside chemotherapy.
Conclusion About Colon Cancer Symptoms
Colon cancers start as benign growths on the rectal lining. The best way to prevent colorectal cancer is to undergo a screening test. This helps determine any potential presence of abnormalities.
If you’re worried about colon cancer and want professional advice regarding cancer treatment, seek the help of Dr QM Leong, an experienced colorectal surgeon in Singapore. You can inquire about the cost of a colonoscopy as well as what to expect during the procedure.
Frequently Asked Questions
About Symptoms Of Colon Cancer In Singapore
Yes. Colon cancer is highly treatable, primarily if the disease is localised to the bowel. Surgery can cure about 50% of patients.
The rate of progression varies depending on the cellular makeup of the tumour and other health factors. The progression generally tends to be slow, but it still needs immediate medical attention.
Colon cancer first spreads to the liver and lungs but may also spread to other organs.
Colon cancer symptoms may also be characterised as recurring pain in the lower abdomen.