Colorectal cancer develops from abnormalities in cells of the colon or rectum that lead to the formation of a tumor. According to the American Cancer Society, colon or rectal cancer accounted for almost 150,000 new diagnoses and almost 50,000 deaths in the United States in 2009. These cancers develop when cells acquire genetic mutations that allow the cells to proliferate uncontrollably and indefinitely, evading cell death mechanisms. Cancer cells also have the ability to metatasize--travel from the initial primary tumor throughout the body, forming secondary tumors in other tissues. Colorectal cancer cells most commonly metastasize to a few regions throughout the body, leading to a range of potentially fatal symptoms.
Liver
Colorectal cancer most commonly metatasizes to the liver, the organ responsible for detoxifying the body. In a 2006 study published in "Cancer Control," Dr. J. McLoughlin reported that around 50 percent of colorectal cancer patients developed secondary tumors in the liver. Common metastasis to the liver is thought to be due to the path of blood flow from the colon, which facilitates migration of cancer cells from the colon to the liver.
Metatasis to the liver can lead to a number of potentially fatal side effects. As a secondary tumor grows within the liver, the neighboring regions of the organ have difficulty functioning. As the liver begins to fail, patients will often experience a loss of appetite and weight loss. In later stages of metastasis, patients may experience jaundice, a yellowing of the skin, which indicates that the liver is shutting down. Early detection of liver metastasis is required to treat the cancer.
Lungs
Colorectal cancer often metatasizes to the lungs. Although the reason for common metastasis of colorectal cancer to the lungs is not yet known, it may be related to the path of blood flow from the colon. Since almost all cancers have the ability to metastasize to the lung, metastasis of colorectal cancer to the lung may be due to intrinsic characteristics of lung tissue that facilitate the growth of additional tumors.
Lung cancer metatasis can lead to a number of harmful symptoms. Some common symptoms of lung metastasis, according to the University of Rochester, are shortness of breath, chest pain, and coughing up blood. If detected early, the secondary tumor can be treated with surgery to remove the cancerous tissue.
Muscle
Colorectal cancer can rarely metatasize to muscle tissue. In a 2006 study published in the "American Journal of Pathology," Dr. K. Schlüter discovered that metastatic colon cancer cells had some ability to colonize muscle tissue, but that the cells' capacity for invading muscle tissue was much less than that of liver or lung tissue. In general, metastasis to muscle tissue is extremely rare.
Metastasis to the muscle can lead to the development of a painful mass within the muscle. Tumors within the muscle are treated by surgical removal, followed by surgical repair of the muscle and re-attachment of muscle tissue to the bone.
References
- American Cancer Society: How Many People Get Colorectal Cancer?
- Cancer Control: Resection of Colorectal Liver Metastases: Current Perspectives
- University of Rochester: Lung Metastasis
- American Journal of Pathology: Organ-Specific Metastatic Tumor Cell Adhesion and Extravasation of Colon Carcinoma Cells with Different Metastatic Potential
- National Institutes of Health: Metastasis to the forearm skeletal muscle from an adenocarcinoma of the colon: report of a case.
