Frequency of Muir–Torre Syndrome in the Lynch Syndrome

Abstract

A syndrome that increases the risk of some skin cancers may be a component of another syndrome that increases the risk of colorectal cancer, according to a February 20th report in the Journal of the National Cancer Institute.Some individuals with Lynch syndrome—an inherited predisposition to develop colorectal and other specific types of cancers—also have a tendency to develop certain kinds of skin tumors (ie, Muir–Torre syndrome). Cancerous lesions associated with both syndromes are characterized by inherited mutations in DNA mismatch repair (MMR) genes, including MSH2.The cohort study by Dr Albert de la Chapelle and colleagues at The Ohio State University examined the frequency of Muir–Torre syndrome–related skin tumors among 50 Lynch syndrome families (confirmed by MMR gene mutation analysis) who were ascertained from a population-based series of patients newly diagnosed with colorectal or endometrial cancer. Histories of Muir–Torre syndrome–associated skin tumors were documented during counseling of family members.Muir–Torre syndrome was observed in 28% of the 50 families and in 9.2% of the 152 individuals with Lynch syndrome. The frequency of Muir–Torre syndrome was 75% among families who carried a specific mutation in the MSH2 gene versus 25% among families who carried other mutations in this gene. There was a preponderance of the Muir–Torre syndrome–associated deleterious MSH2 gene mutation in the study cohort, the authors note. However, they point out that histories of skin lesions may have been subject to recall bias.“On the basis of our results, we suggest that Muir–Torre syndrome be defined as a variant of Lynch syndrome that is characterized by mutations in all [mismatch repair] genes. We propose that Muir–Torre syndrome-associated skin lesions be included as a component tumor of the Lynch syndrome and screened for accordingly,” the authors write.See, “The Frequency of Muir–Torre Syndrome Among Lynch Syndrome Families,” J Natl Cancer Inst 2008;100:277–281. A syndrome that increases the risk of some skin cancers may be a component of another syndrome that increases the risk of colorectal cancer, according to a February 20th report in the Journal of the National Cancer Institute. Some individuals with Lynch syndrome—an inherited predisposition to develop colorectal and other specific types of cancers—also have a tendency to develop certain kinds of skin tumors (ie, Muir–Torre syndrome). Cancerous lesions associated with both syndromes are characterized by inherited mutations in DNA mismatch repair (MMR) genes, including MSH2. The cohort study by Dr Albert de la Chapelle and colleagues at The Ohio State University examined the frequency of Muir–Torre syndrome–related skin tumors among 50 Lynch syndrome families (confirmed by MMR gene mutation analysis) who were ascertained from a population-based series of patients newly diagnosed with colorectal or endometrial cancer. Histories of Muir–Torre syndrome–associated skin tumors were documented during counseling of family members. Muir–Torre syndrome was observed in 28% of the 50 families and in 9.2% of the 152 individuals with Lynch syndrome. The frequency of Muir–Torre syndrome was 75% among families who carried a specific mutation in the MSH2 gene versus 25% among families who carried other mutations in this gene. There was a preponderance of the Muir–Torre syndrome–associated deleterious MSH2 gene mutation in the study cohort, the authors note. However, they point out that histories of skin lesions may have been subject to recall bias. “On the basis of our results, we suggest that Muir–Torre syndrome be defined as a variant of Lynch syndrome that is characterized by mutations in all [mismatch repair] genes. We propose that Muir–Torre syndrome-associated skin lesions be included as a component tumor of the Lynch syndrome and screened for accordingly,” the authors write. See, “The Frequency of Muir–Torre Syndrome Among Lynch Syndrome Families,” J Natl Cancer Inst 2008;100:277–281.