Colorectal Cancer

What is colorectal cancer?

Colorectal cancer is malignant cells found in the colon or rectum. The colon and the rectum are parts of the large intestine, which is part of the digestive system. Because colon cancer and rectal cancers have many features in common, they are sometimes referred to together as colorectal cancer. Cancerous tumors found in the colon or rectum also may spread to other parts of the body.

Excluding skin cancers, colorectal cancer is the third most common cancer in both men and women. It is estimated by the American Cancer Society that 146,970 colorectal cancer cases are expected in 2009. The number of deaths due to colorectal cancer has decreased, which is attributed to increased screening and polyp removal.

What are the types of colorectal cancer?

A type of cancer called adenocarcinoma accounts for more than 95 percent of colorectal cancers. It is the type we focus on in this section. These are other types of cancer that can be found in the colon and rectum, but they are rare.

Here is an overview of the types of colorectal cancer:

  • adenocarcinoma
    Adenocarcinomas are tumors that start in the lining of internal organs. "Adeno" means gland. These tumors start in cells with glandular properties, or cells that secrete. They can form in many different organs, such as the lung or the breast. In colorectal cancer, early tumors start as small adenomatous polyps that continue to grow and can then turn into malignant tumors. The vast majority of colorectal cancers are adenocarcinomas.

  • gastrointestinal stromal tumors (GIST)
    These are tumors that start in the muscle tissue of the colon. They can be benign (noncancerous) at first, but many do turn into cancer. When this happens, they are called sarcomas. Surgery is the usual treatment.

  • lymphoma
    A lymphoma is a cancer that typically starts in a lymph node, which is part of the immune system. However, it can also start in the colon or rectum. There are different kinds of lymphomas. In general, lymphomas fall into two categories - Hodgkin disease and non-Hodgkin lymphoma.

  • carcinoids
    Carcinoids are tumors caused by hormones. They start in special hormone-producing cells in the intestine. Often they cause no symptoms. Surgery is the usual treatment.

What are the symptoms of colorectal cancer?

The following are the most common symptoms of colorectal cancer. However, each individual may experience symptoms differently.

People who have any of the following symptoms should check with their physicians, especially if they are over 50 years old or have a personal or family history of the disease:

  • a change in bowel habits such as diarrhea, constipation, or narrowing of the stool that lasts for more than a few days

  • rectal bleeding or blood in the stool

  • cramping or gnawing stomach pain

  • decreased appetite

  • vomiting

  • weakness and fatigue

  • jaundice - yellowing of the skin and eyes

The symptoms of colorectal cancer may resemble other conditions, such as infections, hemorrhoids, and inflammatory bowel disease. It is also possible to have colon cancer and not have any symptoms. Always consult your physician for a diagnosis.

What are the risk factors for colorectal cancer?

Risk factors may include:

  • age
    Most people who have colorectal cancer are over age 50, however, it can occur at any age.

  • race
    African Americans have the highest risk for colorectal cancer.

  • diet
    Colorectal cancer is often associated with a diet high in red and processed meats.

  • polyps
    Benign growths on the wall of the colon or rectum are common in people over age 50, and are believed to lead to colorectal cancer.

  • personal history
    People who have had colorectal cancer or a history of adenomatous polyps have an increased risk for colorectal cancer.

  • family history
    People with a strong family history of colorectal cancer or polyps in a first-degree relative (especially in a parent or sibling before the age of 60 or in two first-degree relatives of any age), have an increased risk for colorectal cancer.

  • ulcerative colitis or Crohn's disease
    People who have an inflamed lining of the colon have an increased risk for colorectal cancer.

  • inherited syndromes, such as familial adenomatous polyposis (FAP) or hereditary nonpolyposis colon cancer (HNPCC)

  • obesity

  • physical inactivity

  • heavy alcohol consumption

  • type 2 diabetes

  • smoking

Did You Know?

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