Cowden syndrome is a genetically inherited disease that causes the formation of growths called hamartomas. Hamartomas are similar to tumors in some respects, but are not malignant; however, the syndrome does increase the risk of some types of cancer. Cowden syndrome is also known as Cowden’s disease or multiple hamartoma syndrome.
Most cases of Cowden syndrome develop as a result of a mutation in a tumor suppressor gene called phosphatase and tensin homolog, or PTEN. Tumor suppressor genes are those that can lead to the development of cancer when they become mutated. PTEN mutations cause cancer because the gene is involved in the cell’s cycle of division. When PTEN is mutated, the cell divides uncontrollably and can give rise to a tumor. A PTEN mutation therefore promotes the formation of hamartomas and, at the same time, causes an increased risk of cancer.
Hamartomas can form in a variety of locations in the body. Possible sites of hamartoma development include the skin; mucosal surfaces such as the nasal passages, urogenital system and gastrointestinal tract; bones; and central nervous system. Skin hamartomas develop in almost all cases. The risk of thyroid cancer is markedly increased in people with this disease, and the risk of breast cancer is greatly increased in women.
Cowden syndrome is a rare disease with an approximate prevalence of one case per 200,000 people. This figure is a rough estimate, however, because the disease is not easily diagnosed. In most cases, diagnosis occurs after one or more hamartomas have developed on the body; this can occur at any time and any stage of life.
This condition is not curable, as it is caused by an inherited cellular mutation that cannot be prevented. Cowden syndrome treatment involves regular screening for the development of cancers to which the individual with the disease is susceptible. Upon diagnosis, an individual typically will undergo a complete physical examination to establish a baseline for the disease. At regular intervals, he or she will undergo a new examination to detect cancer or cellular changes that might lead to cancer. Examinations are carried out on an annual basis and include diagnostic imaging tests such as MRI and CT scans, as well as blood and other laboratory tests.
Cancer is the most common possible complication of the syndrome. One or more types can develop, including cancer of the breast, thyroid, colon, lung, uterus, bladder and bone. About 40 percent of people with the syndrome will develop at least one type of cancer; many are curable, providing the disease is detected early.