Lynch Syndrome

Genetically transmitted predisposition to develop colorectal cancers.

Cancer Family Syndrome; Familial Cancer Syndrome; Hereditary Nonpolyposis Colorectal Cancer (HNPCC); Hereditary Nonpolyposis Colorectal Carcinoma.

First described by Alder Scott Warthin, an American pathologist, in 1913.

Five percent of the colorectal cancer population.

Both clinical forms of HNPCC are autosomal dominant with a penetrance of 85 to 90%. Two DNA mismatch repair genes are closely linked to the disease: hMSH2 gene in chromosome 2p and hMLS1 gene in chromosome 3p. Mutations in these genes account for 90% of all known HNPCC families.

Defective DNA mismatch repair leads to accumulation of mutations. The mutation load can be identified as errors in long tandem repeat sequences, which produce microsatellite instability.

Familial history, colonic screening examinations, DNA genetic testing.

Two clinical forms described:

• Lynch Syndrome I: Familial predisposition to early-onset colorectal cancer (mainly right colon).
• Lynch Syndrome II: Same features and familial predisposition with an associated predisposition for other primary cancers (often female reproductive organs, particularly endometrial carcinoma). This variant is not easily recognized because of the lack of phenotypical expression as familiar adenomatous polyposis.

All precautions before anesthesia will be dictated by those associated with the patient's underlying medical condition.

Anesthetic considerations are those associated with the surgical procedure only or any associated medical conditions.

No specific pharmacological implications except for patients receiving chemotherapy.