The website
Historically, molecular pathology resources targeted at histopathologists have been difficult to find. The goal of this website is to bring together resources to help histopathologists to access and make best use of molecular pathology in cancer, and to help histopathology trainees to acquire the skills and knowledge to complete their training.
The material contained on this website is chiefly geared towards histopathologists working in the UK. The particular details of requesting molecular testing relate to specifically to the situation in England, but similar principles apply throughout the UK.
Molecular pathology
Historically, all cancers with similar morphology have been treated in similar ways. Immunohistochemistry allowed finer distinctions to be drawn between tumours which look identical morphologically, but which show different responses to treatment and which have different prognoses.
More recently, it has become clear that the identification of molecular alterations within tumours can help to personalise care for patients with cancer to an even greater degree.
Diagnostic molecular markers can help to bundle together tumours which have very similar behaviours and responses to treatment. They may also suggest the presence of an underlying familial cancer syndrome.
Prognostic molecular markers provide information about the likely aggressiveness of a tumour and, by extension, how well or poorly the patient is likely to do. They may also give treating clinicians an indication of how aggressively they ought to treat a patient.
Predictive molecular markers provide information about which treatment is likely to be most suitable for a given patient. They may indicate which type of chemotherapy would be most suitable, or whether the patient is likely to respond to targeted agents or to immunotherapy.
The success of molecular pathology in cancer hinges upon histopathologists’ knowledge and enthusiasm for molecular testing: if histopathologists are not aware of the existence of tests or are not equipped to select the optimal tissue for testing, patients will not benefit.
Likewise, the relevance of histopathology hinges upon histopathologists’ engagement with molecular pathology. Cancer treatment will inevitably become more personalised by ever-greater uptake of molecular tests. If histopathologists do not emphasise their importance in this by taking an active role, they will invariably be seen as irrelevant and will be bypassed. This is clearly a terrible outcome for the specialty, but is also bad for clinicians and for patients.
Molecular pathology in England
The delivery of molecular pathology testing in England is changing dramatically. There is a distinction here between genomic and non-genomic molecular testing.
Genomic Molecular Testing
From a practical perspective, ‘genomic’ tests are those which are included in the National Genomic Test Directory for Cancer. The NHS in England is now transitioning to a position where these tests are delivered by Genomic Laboratory Hubs (GLHs). Between them, seven GLHs cover the entire population of England.
Learn more about requesting tests from Genomic Laboratory Hubs →
Through the NHS Genomic Medicine Service, a subset of patients with cancer can access whole-genome sequencing (WGS). This allows for complete genomic profiling of the cancer. It may allow patients who have rare cancers, who have difficult to treat cancers, or who have exhausted standard treatment options to access clinical trials or compassionate-used medicines. It may also allow for identification of germline variants and may contribute to research.
Learn more about requesting whole-genome sequencing →
Non-Genomic Molecular Testing
Molecular testing (used in the broadest sense) need not necessarily always be genomic. Techniques such as immunohistochemistry can powerfully contribute prognostic and predictive information. Any molecular test not included on the National Genomic Test Directory for Cancer can be considered non-genomic. The funding for this testing is different to that for genomic testing and in many respects there is more freedom for histopathology services to decide how and where this testing occurs.
Disclaimers
This website is intended to provide educational resources to healthcare professionals. None of the content should be interpreted as medical advice. Although every effort has been made to ensure the accuracy of the content, no liability can be assumed for errors or omissions. Where reference is made to the Royal College of Pathologists curricula or examinations, it is emphasised that this not officially-sanctioned information from the College. Reference to specific manufacturers or providers should not be interpreted as endorsement.
