In Press August 2012
Aim: Life-time risk of a metachronous colorectal cancer (CRC) is 0.6%-3% following sporadic CRC and 15-26% in Lynch syndrome (LS). The life-time incidence of CRC in individuals with moderate familial risk is 8-17%. Risk of metachronous CRC (mCRC) is unknown.
Method: A retrospective longitudinal study of the Regional Familial CRC Registry was performed. Patients who had at least one CRC were categorised as follows: moderate risk (n=383), LS (n=528) and population risk (n=409). Kaplan-Meier estimate (1-KM) and cumulative incidence function (CI) were used to calculate the risk of mCRC. 1-KM gives the risk for individuals remaining at risk (alive) at a given time point thus is useful for counselling. CI gives the risk for the whole population.
Results: 1-KM and CI demonstrated that the risk of mCRC was significantly higher in moderate risk patients compared with population risk (1-KM p= 0.008, CI p= 0.00097). Both were lower than LS. Moderate risk 1-KM was 2.7%, 6.3% and 23.5% at 5,10 and 20 years. Population risk 1-KM was 1.3%, 3.1% and 7.0% at 5, 10 and 20 years and CI was 0.3%, 0.6% and 2.4%.
Conclusion: These data indicate that the risk of mCRC is significantly higher in patients with a moderate family history than in those at population risk. This justifies pro-active life-long surveillance.
- BSG Guidelines for Moderate Risk Family History Groups (familyhistorybowelcancer.wordpress.com)
- The Elucidation of Familial Colorectal Cancer Type X (familyhistorybowelcancer.wordpress.com)
- A dedicated service for the Management of Hereditary Colorectal Cancer Improves Adherence with Molecular Testing for Lynch Syndrome (familyhistorybowelcancer.wordpress.com)
- EGAPP™ Recommendation Statement: Genetic testing for Lynch Syndrome (familyhistorybowelcancer.wordpress.com)