Colorectal Cancer

Colon Cancer

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

Colon cancer occurs when cancerous cells develop in the tissue of the colon. The colon makes up the last six feet of the large intestines and absorbs water, electrolytes and nutrients from food and transports them into the bloodstream.

Colon cancer is fairly common, affecting about 7 percent of the American population. Although it is a life-threatening disease, it is a highly curable form of cancer if found early. Therefore, regular check-ups and screenings are very important.

Although the exact cause of colon cancer is unknown, certain risk factors have been identified that may increase a persons chance of developing the disease. These include:

• Age: The majority of colon cancers are diagnosed in people aged 50 or older, although the disease affects all ages.
• Bowel disease: A history of colorectal cancer, intestinal polyps, and diseases such as chronic ulcerative colitis and Crohn's disease increase a person's chance of developing colon cancer.
• Diet and exercise: A diet high in fat, particularly from animal sources, and an inactive, sedentary lifestyle can increase a person's chance of developing colon cancer.
• Ethnic background and race: Jews of Eastern European descent called, Ashkenazi Jews have a higher rate of colon cancer. African-Americans and Hispanics have a higher death rate caused by colon cancer, which may be caused by insufficient screenings, poor diet and lack of exercise.
• Family history/genetic factors: Specific genes have been identified that significantly increase a person's chance of having colon cancer. People with a strong family history of colorectal cancer, as defined by cancer or polyps in a first-degree relative younger than 60 or two first-degree relatives of any age, are also at increased risk for developing colon cancer.
• Smoking and alcohol: Research suggests that smokers and heavy drinkers have an increased chance of developing colon cancer.

Common signs and symptoms of colon cancer include:

• A change in bowel habits
• Diarrhea, constipation or feeling that the bowel does not empty completely
• Blood, either bright red or very dark in the stool
• Stools that are narrower than usual
• General abdominal discomfort such as frequent gas pains, bloating, fullness or cramps
• Weight loss with no known reason
• Constant tiredness
• Vomiting

Reviewed by health care specialists at UCSF Medical Center.
Last updated July 31, 2007