Colorectal cancer awareness
Published:Wednesday | February 28, 2024 | 12:05 AM
CANCER IS a disease in which a group of cells in the body start to grow rapidly and out of control. When cancer starts in the colon or rectum, it is called colorectal cancer. The colon and rectum collectively make up the large intestine. While cancers of the colon and rectum are similar, they are considered to be two separate diseases and are treated differently.
The diagnosis of colorectal cancer may be accomplished in different ways, including screening of a person who does not have any symptoms, or through the investigation of a person who is having symptoms.
Screening methods include colonoscopy, CT Colonography (use of a CT scan to look at the colon in detail), stool testing for blood, and stool testing for tumour DNA. Screening should start at age 45 years.
According to Dr Toni Barnes, consultant haematologist and medical oncologist at the Hope Institute Hospital, almost all cases of colorectal cancer start as polyps, which are overgrowths of the lining of the intestines.
“Most polyps are not cancerous, and if a non-cancerous or benign polyp is removed early, the development of cancer in that polyp is prevented. If there is an abnormality discovered on screening, such as a polyp or suspected cancerous (malignant) tumour, a biopsy of the abnormal area must be done to make a diagnosis. If a colonoscopy is performed, a biopsy can be done at the same time of the procedure,” Dr Barnes said.
Symptoms of colorectal cancer may include signs of anaemia, or low blood count, such as tiredness; racing heart/palpitation;, shortness of breath; pallor; blood in the stool; change in bowel habit, such as the development of constipation, alternating constipation and diarrhea, or change in how often a person passes stool and abdominal pain or swelling.
According to the World Health Organization’s International Agency for Research on Cancer ( Globocan 2022), colorectal cancer has the third most common incidence in the world and this is also true in Jamaica. More men are affected by colorectal cancer than women. It is also the third-deadliest type of cancer in Jamaica, with men being more likely to die of the disease than women.
“The male majority is concerning and possibly has to do with men being less likely to go to the doctor for screening, and being less likely to seek medical attention for symptoms,” Dr Barnes said.
STAGES OF COLORECTAL CANCER
• Stage I colon or rectal cancer generally refers to a small tumour confined to the colon or rectum.
• Stage II colon or rectal cancer is a larger tumour still confined to the colon.
• Stage III colon cancer is a large tumour which has spread to the lymph nodes.
• Stage IV colon cancer has spread to an organ outside of the colon or rectum, such as the liver. Stage IV colorectal cancer is also called metastatic.
The treatment of colon cancer and rectal cancer are different, but share some similarities:
COLON CANCER
• Stage I tumours may be cured with surgical removal of the affected part of the colon.
• Stage II: Some of these tumours are cured with surgery alone, but others are treated with both surgery and chemotherapy. This decision is based on many factors which are considered by the oncologist.
• Stage III: These tumours are treated with surgical removal of all or part of the colon, and chemotherapy is recommended.
• Stage IV or metastatic colon cancer may be treated in several ways: Stage IV colon cancer has spread to other organs. Specialised surgeons can remove the areas to which the cancer has spread.
Genetic testing and biomarker testing, Dr Barnes said, should be done on all persons diagnosed with colon cancer to check for genetic mutations which may be present as a part of the disease.
“In recent times, biomarker testing has become an absolute necessity for making treatment decisions. Based on these tests, the treatment options may be expanded beyond chemotherapy, to be combined with other treatments such as targeted therapy; treatments chosen based on specific genetic mutations a person may have; and immunotherapy, which uses a person’s immune system to fight the cancer. The combination of chemotherapy and these newer agents has become the new standard of treatment,” she said.
The survival rates of cancer are often represented as a percentage – what percentage of persons who have been diagnosed with colorectal cancer are alive five years after the diagnosis was made.
The survival rate is better for early-stage cancer. The five-year survival rate for colorectal cancer (all stages included) is 63 per cent. For patients with early-stage colon cancer, the five-year survival rate is 91 per cent at five years for persons with stage I disease.
If the cancer is stage II or III, the survival rate is 73 per cent at five years. While if the cancer is at stage IV, the survival rate is 14 per cent at five years.
“After a person is treated for colorectal cancer, they are monitored over a period of time to ensure that if there is a recurrence of cancer, it is discovered early and can be treated in a timely manner. This period is called surveillance,” Dr Barnes said.
“Persons with early-stage colorectal cancer should have a colonoscopy every year initially. A CT scan is also done every year, and blood testing for a tumour marker called CEA (a special test which can be used as an approximation of cancer activity in the body) are to be done every six months. This process should last at least five years. After five years, surveillance is complete,” Dr Barnes added.