Colorectal cancer is a cancer involving the colon or the rectum. Each year in the United States, around 150,000 individuals receive a diagnosis of colorectal cancer, making it the second most common cancer diagnosis, according to the University of Maryland Medical Center. Signs and symptoms of colorectal cancer include bowel changes, abdominal pain, bloating, weight loss and bloody stool. Screening for colorectal cancer can prevent the disease. Survival rates increase when the treatment begins in the early stages of the cancer. Many cases of colorectal cancers have no known cause, but some conditions and risk factors increase the likelihood of developing the disease, according to the Merck Manuals.
Colon Growths
Growths in the colon and rectum include polyps and nonpolypoid lesions, which are growths found on the inside lining and the wall of the colon. These normally benign growths can become cancerous and they continue to grow and change over years. Polyps may not cause any symptoms and a physician can detect them during a colonoscopy. Removing polyps can help to prevent them from becoming cancerous.
Genes
Several genetic causes can predispose a person to developing colorectal cancer. A specific type of cancer, referred to as hereditary nonpolyposis colorectal carcinoma, occurs due to a genetic mutation. Around 70 to 80 percent of individuals with this mutation will develop colorectal cancer, usually before the age of 50, according to the Merck Manuals. Another genetic condition that can cause colorectal cancer includes Peutz-Jeghers syndrome. Both of these conditions cause polyps to grow inside the gastrointestinal tract. The polyps are more likely to become cancerous than regular polyps, according to Genetics Home Reference.
Lifestyle Habits
Lifestyle habits that can cause colorectal cancer include eating a high-fat and low-fiber diet, smoking, obesity and heavy alcohol intake, according to the University of Maryland Medical Center. Each of these factors increases the risk of developing colorectal cancer due to the damage and stress they cause to the organ. Exposure to air or pollution and exposure to cancerous substances in the workplace can cause the cancer.
Family History
Individuals with a family history of colorectal cancers, especially a sibling, parent or child with the condition, have an increased risk of developing the cancer, according to MayoClinic.com. The shared risk may relate back to a genetic cause, an environmental exposure or lifestyle habits.
Inflammatory Bowel Disease
Inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease, can cause colorectal cancer. The inflammation in the colon caused by these conditions can causes the cells in the lining of the large intestine to change. These changes can lead to cancerous cells and growths, according to the American Cancer Society.
