Turcot syndrome is a genetic disorder that puts affected individuals at an increased risk for developing different types of cancers. They typically develop colon cancer or brain cancer as a result of having mutations in different genes. Diagnosis of the syndrome can be made after developing the characteristic cancers, or on the basis of genetic testing identifying mutations known to be associated with the syndrome. Patients known to have the syndrome are subjected to aggressive screening processes in order to identify nascent cancers at a stage when they can still be treated.
The name Turcot syndrome was initially used to describe families in which members had increased risk for developing colon cancer and different brain cancers. With further research into the etiology of this condition, scientists determined that the disease was not an independent and clearly-defined entity. Instead, it represented a subset of other syndromes putting patients at risk for different cancers. Patients with both familial adenomatous polyposis syndrome or Lynch syndrome who develop brain cancers are considered to have Turcot syndrome.
A number of different genetic mutations can cause Turcot syndrome. Often, the disease develops due to a mutation in a gene called the adenomatous polyposis coli (APC) gene; abnormalities in this gene are typically associated with a syndrome called familial adenomatous polyposis (FAP). In other cases, mutations in S genes, which are responsible for repairing other genes, known as mismatch repair genes, can cause the syndrome to occur. When Turcot syndrome is secondary to this type of defect, it is often considered to be a subset of Lynch syndrome.
Symptoms of Turcot syndrome vary according to the type of cancer that develops in an affected person. Patients who develop colon cancer can have symptoms such as abdominal pain, a change in stool habits, or the presence of blood in the stool. Brain cancers can cause many different problems, including personality changes, memory loss, incoordination, and weakness of different parts of the body.
Diagnosis of Turcot syndrome can be done in a number of different ways. Colon cancer is most often diagnosed with the use of a colonoscopy. Imaging studies, such as a computed tomography (CT) scan or contrast-enhanced x-ray could also suggest the diagnosis. Brain cancer is most often identified with the help of magnetic resonance imaging (MRI).
One of the most important aspects of management for Turcot syndrome is identification of individuals at risk for developing cancers. Often, the diagnosis is suggested on the basis of having family members with these specific diseases. The risk for the disease can be determined by testing these individuals' genetic material for genetic mutations known to cause the syndrome. Patients who have mutations known to cause Turcot syndrome could be subjected to aggressive screening tests, or in some cases prophylactic removal of the colon, in order to either identify the cancers while they can still be treated, or to prevent the cancers from occurring in the first place.