What is colon cancer?
Colon cancer is cancer of the colon (the first part of the large intestine. The colon is about 5 feet long, and colon cancer usually begins on the inside of this area as non-cancerous, bu abnormal growths called polyps. Due to many common features of colon cancer and rectal cancer, colon cancer is also termed colorectal cancer, even when rectum (the last part of the large intestine) may not be involved.
How common is colon cancer?
Colon cancer is the third most common cancer in the world; 1.8 million new cases of colorectal cancer were identified in the year 2018. The top countries affected by colorectal cancer include Barbados, Jamaica, Hungary, South Korea, Denmark, Norway, Slovakia, and Portugal.
Considering age-standardization*, among African-Caribbean countries Barbados has the 11th, and Jamaica has the 14th highest rate of colorectal cancer in the female population globally.
Barbados has the 6th highest rate of colon cancer among males, and 8th highest overall globally.
Colorectal cancer is also the second most common cause of cancer-related deaths, contributing to 862,000 out of 9.6 million total deaths from all forms of cancer in 2018. It is expected to increase by 60 percent by 2030, with the potential to cause 1.1 million deaths. Caribbean, Latin America, North America, and European countries are at high risk and are predicted to have an even heavier burden of colorectal cancer in the coming years.
The age-standardized colorectal cancer rates per 100,000 people in the top affected countries are given in ascending order below:
- Barbados (38.9)
- Portugal (40.0)
- Denmark (41.0)
- Slovenia (41.1)
- Norway (42.9)
- Slovakia (43.8)
- South Korea (44.5)
- Hungary (51.2)
* Age-standardized rates help us compare populations of different age profiles from different geographic areas.
Risk factors and causes of colon cancer
While the specific cause remains unknown, several risk factors contribute to the likelihood of developing colon cancer.
- Age: Although colon cancer can occur in any age group, it usually develops in individuals who are older than 50.
- Race: African-Caribbean and African-American people have a high risk of colorectal cancer. Mortality rates from colon cancer are also high in this population.
- Obesity: As with many non-communicable diseases, obesity increases the risk of developing colon cancer. According to a new global health ranking that covers 191 countries, Jamaica and Barbados are among the 20 least healthy countries in terms of overweight and obesity. Further, almost half of the population in the Caribbean region was identified as overweight by the UN, with the highest rates of obesity observed in the Bahamas. Because obesity is more prevalent in the African-Caribbean population, the risk of colorectal cancer may be even higher in these individuals.
- Personal history: Individuals with a history of previous colorectal cancer, ovarian cancer, ulcerative colitis, and Crohn’s disease are at a higher risk of colon cancer.
- Family history: Having a close relative with colorectal cancer doubles a person’s risk. The risk is even higher if more than one family member has had colon cancer.
- Smoking: Tobacco smoke increases the risk of colorectal cancer. Smokers are also more likely to die from this cancer when compared to non-smokers. Moreover, individuals who smoke and have a history of surgery for colorectal cancer are at high risk of recurrent disease.
- Alcohol: Consuming alcohol can increase the risk of colon cancer. Health professionals recommend limiting alcohol intake to 1 – 2 drinks per day.
- Inherited syndromes: A small percentage of colon cancer is also linked to inherited genes. Genetic disorders like Familial Adenomatous Polyposis (FAP) and hereditary nonpolyposis colorectal cancer (Lynch syndrome) are linked to colorectal cancer.
- Low physical activity: Sedentary lifestyle and lack of physical activity also contribute to colon cancer risk.
- Diet: Some researchers have found a link between low-fiber and high-fat diet (the Western diet) and colon cancer.
- Radiotherapy: Radiation therapy to treat tumors in the abdominal region also predisposes a person to high risk of colon cancer.
Signs and symptoms of colon cancer
The most common signs of colorectal cancer are bright or dark red blood in the stool and/or changes in bowel movements. Other signs and symptoms may include:
- Unexplained weight loss
- Frequent bloating or fullness
- Abdominal pain
- Feeling of incomplete bowel emptying
- Stools narrower than usual
- Fatigue and weakness
- Rectal bleeding