Hereditary nonpolyposis colorectal cancer: an update

Area of Science:

• Genetics and Oncology
• Cancer Epidemiology

Background:

• Sporadic colorectal cancer typically develops around age 65, with diet being a significant factor.
• Hereditary colorectal cancer presents earlier in life and is associated with a family history of neoplasia.
• The exact incidence of hereditary colorectal cancer is not well-established but is notably higher than conditions like familial adenomatous polyposis.

Observation:

• Analysis of 22 family pedigrees in Japan, including the largest known pedigree with 24 colorectal cancer cases over five generations.
• Investigation of 4,109 family pedigrees in 1995, with 394 cases in 109 pedigrees meeting the Amsterdam Minimum Criteria.
• Data collection involved questionnaires sent to major Japanese hospitals and incorporated updated information from international collaborative groups.

Findings:

• The identification of mismatch repair genes as causative agents for hereditary nonpolyposis colorectal cancer indicates a need to modify the current Amsterdam Criteria.
• Replication error, a phenotype of mismatch repair gene dysfunction, serves as a valuable predictor for the development of second primary malignancies.
• The optimal management strategies, including surveillance protocols and prophylactic surgery for hereditary colorectal cancer, remain subjects of ongoing debate.

Implications:

• Revised diagnostic criteria for hereditary colorectal cancer are essential following the discovery of mismatch repair gene involvement.
• Replication error analysis can aid in predicting additional cancer risks in affected individuals.
• Further research is needed to establish definitive guidelines for surveillance and surgical interventions in hereditary colorectal cancer management.