Despite the medical advances in recent years that allow researchers to better understand the mechanisms of cancer development, the causes of rectal cancer are still not well known. But a group of risk factors such as heredity, lifestyle, and exposure to carcinogenic chemicals or substances are suspected in the occurrence of the cancer.
- Age: colorectal cancers are rare in people less than fifty years old; they are more common in individual 65 or older.
- Heredity: the risk of having a colorectal cancer is higher if a close relative has (had) it. The risk is even stronger when there is more than one close relative in the family with the disease: father, mother, brother, sister. However, some scientists believe that cancer is not genetic but the reason it sometimes runs in a family is simply lifestyle tends to pass from generation to another.
Studies, however, have some researchers to identify high-risk families where people have a specific mutation that predisposes them to cancer. These familial cases represent only 5% of colorectal cancers and include:
- Familial Adenomatous Polyposis(FAP) – this condition is characterized by the appearance of multitude polyps in all carriers of APC mutated gene. In adulthood, one of these polyps degenerate necessarily in cancer unless the colon is surgically removed
- Lynch syndrome (HNPCCor hereditary nonpolyposis colorectal cancer) – in this condition, the patient has fewer polyps than in FAP, and lower risk of cancer, but needregular colonoscopy check-up as preventive measure.
- Chronic Inflammatory Bowel Disease– certain diseases of the colon, including Crohn’s disease and ulcerative colitis increase the risk for colorectal cancer. After twenty years, the risk of getting the cancer is about 1/3 if the entire colon is affected.
- Lifestyle – this play a major role in the occurrence of most cancers, including rectal cancer. Indeed, if people cannot change their age or heredity, they can quit smoking, avoid drinking alcohol, eat less meat, consume more cruciferous vegetables, and exercise regularly.