Family-based screening for colorectal cancer: The Australian perspective

Over the last 20 years, the rapid expansion of genetic technology has allowed much progress to be made in understanding the molecular basis of inherited bowel cancer. At the same time, improvements in endoscopic and surgical techniques have meant that very effective surveillance can be offered to subjects known to be at high risk. The genes underlying the major polyposis syndromes have been identified and the genetic basis for Lynch Syndrome (Hereditary NonPolypsis Syndrome) is well understood. In Australia, this new knowledge has been incorporated in a multidisciplinary model of care involving clinical geneticists, gastroenterologists and gastrointestinal surgeons, pathologists, and family cancer registries. Challenges for the future include identifying families which would benefit from referral to these services but also encouraging the uptake of predictive testing and appropriate surveillance by at risk members of families where the genetic mutation is known. Surprisingly high numbers of individuals for whom a predictive blood test and surveillance program is freely available fail to participate and the reasons for this choice are still poorly understood. This has implications for the utilization of new genetic knowledge in other diseases. Another major challenge for the future is identifying the genes underlying the increased risk of bowel cancer in families which do not have the syndromes described above. Australian clinicians and scientists are actively participating in the global research effort to discover these genes.