Colorectal cancer (CRC) or colon cancer is when the inner lining of the colon, commonly known as the long intestine, and the rectum, situated at its end develop malignancy. Also known as bowel cancer, CRC is usually diagnosed first as benign tumours or polyps, which in later stages advances to cancer. Often, a person is detected with CRC only during regular health check-ups. While, some patients may show clear signs such as, changes in bowel habits, abdominal pain, rectal mass, rectal bleeding, sudden weight loss and anaemia.
CRC usually occurs in individuals aged over 50. However, growing incidence of CRC in younger individuals too in recent times requires those at risk to undergo periodic screenings. Colorectal cancer is preventable and curable if diagnosed and treated early.
In 2018, the International Agency for Research on Cancer ranked colorectal cancer among the top three cancer types by incidence. It ranked second in terms of mortality. It is also the third most commonly diagnosed cancer.
With regards to its incidence in the population, the World Cancer Research Fund (WCRF) ranks it as the third most commonly occurring cancer in men and the second most commonly occurring cancer in women. Over 1.8 million new cases were reported world over in 2018.
It is interesting to know that in the United States, March is designated as the National Colorectal Cancer Awareness Month.
Important Facts About Colorectal Cancer (CRC)
Given the fact that both men and women are as likely to develop CRC, it helps to understand some important factors that lead to this condition. While a majority of the factors are not within one’s control, those that are, may be strictly controlled.
- Age: Age is an important determining factor of the incidence of CRC. CRC often occurs in people over the age of 50, though its incidence in younger people is becoming increasingly common. However, it cannot be known as to why CRC occurs in population aged younger.
- Ethnicity: Even as men and women are prone to developing CRC, men are at a higher risk of developing CRC at a younger age. CRC can afflict any race or ethnicity, and the African-Americans are more susceptible to CRC.
- Contributing risk factors: Some of the risk factors that contribute to developing CRC are, inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis. Also, a family history of cancer or polyps, genetic syndrome such as Familial Adenomatous Polyposis (FAP) and Lynch syndrome, which is an inherited condition, significantly increases the occurrence of CRC. A person with such family history is 2-5 times more likely to have CRC. Personal history of adenomatous polyps may increase the likelihood of developing CRC.
- Exposure to radiation: Any exposure of the abdomen to radiation to treat previous cancers adds to the likelihood of developing cancer.
- Screening: Colonoscopy is the standard test to examine the colon and the rectum for any polyps or lesions. Depending on the outcome, a biopsy may be required.
- Diagnosis: If after performing colonoscopy, CRC is suspected, a doctor may undertake any of the following tests to diagnose CRC:
- Flexible Sigmoidoscopy
- Molecular testing of tumour
- Blood Tests
- Stool Tests
- Computed Tomography
- Chest X-ray
- Barium Enema X-ray
- Positron Emission Tomography (PET)
- Lifestyle: People with an inactive lifestyle are more prone to developing CRC. Regular moderate, exercise can help in reducing the chances of developing CRC. Also, if a person is a chain smoker, consumes tobacco or alcohol regularly is prone to developing CRC.
- Diabetes: The risk of CRC is high in patients with diabetes and those who are resistant to insulin.
- Obesity: Patients with a heavier body frame are more likely to develop CRC.
- Adopting healthy eating habits: Changing dietary habits to fibre-rich, low-fat and low-calorie foods substantially reduces the likelihood of developing CRC. Adding fruits, vegetables, and carbohydrates and lessening the intake of meats may minimise the incidence of CRC.
Treatment for Colorectal Cancer
Depending on the stage of the spread of her/his cancer, a patient has advised polypectomy or minimally invasive surgeries such as Endoscopic Mucosal Resection and Laparoscopic Surgery in the early stages. If the cancer is advanced, doctors may perform a partial colectomy, colostomy or lymph node removal procedure. For cancer that is substantially advanced, doctors may perform surgery to relieve blockage, bleeding or pain to alleviate the symptoms. This is done if the patient’s health is poor. If cancer has spread to liver or lung and overall health is good, surgery is performed or other localised treatments are administered.