Challenges in the diagnosis and management of Lynch Syndrome in an Indigenous family living in a remote West Australian community

Abstract

Context: Lynch syndrome (LS), also referred to as hereditary non-polyposis colorectal cancer, is a familial cancer syndrome characterised by young age of onset of colorectal and other extra-colonic cancers. Most studies suggest that LS accounts for approximately 1% of all colorectal cancers (CRC). The identification of persons with a mutation for this syndrome is of major clinical importance because regular and life-long surveillance has been shown to improve their survival through early cancer detection. However, the identification of LS among CRC patients is a major challenge because there are no specific distinguishing clinical features. Clinical criteria based on family history of cancer and age of cancer diagnosis have been proposed. For various reasons, these are not well utilised and clinicians often fail to refer high-risk CRC patients for genetic assessment of LS. The low rate of referrals to the single, state-wide familial cancer program in Western Australia led to calls for a more sensitive and specific means of detecting LS cases. Virtually all tumours from LS patients are characterised by the molecular features of microsatellite instability (MSI) and loss of expression of mismatch repair proteins detected by immunohistochemistry (IHC). It was recently established that routine MSI and IHC testing in CRC patients aged under 60 years was an effective screening tool to identify previously unrecognized LS cases. This approach has now become routine practice in Western Australia and has led to the identification of more than 20 new LS families, including the Indigenous family described in this report.

Issues: Population-based screening programs can identify individuals who may not be aware of their at-risk status, who may have little prior knowledge of their medical condition and who may have limited access to tertiary health services. This report describes some challenges met when following up a positive screening result for LS in an individual residing in a remote community more than 2000 km from the state's only Family Cancer Clinic. The challenges included finding the patient, arranging genetic counselling and testing, informing him of the result and providing advice regarding life-long surveillance. Also discussed are issues relating to management of the extended kindred in terms of cultural sensitivities, intra-familial communication and involvement of the local health providers, as well as the provision of genetic counselling, testing and surveillance services for patients living in remote regions. Prior to this study, there were no known Indigenous families with LS in Australia.

Lessons learned: The likelihood of finding hereditary cancer syndromes in Indigenous families living in remote communities is low. However, advances in modern diagnostic screening technologies will result in the identification of an increased number of at-risk individuals, some of whom will be from minority groups or from remote communities. Despite geographical isolation and cultural differences, hereditary cancer syndromes can be managed in individuals and families living in rural and remote areas. The key issues identified from this case are flexibility with standard clinical genetic protocols and the presence of a local medical practitioner who takes an active interest in delivery of the genetic testing and surveillance strategies.