IBMS Congress

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A Molecular Future for Cellular Pathology – an interactive debate

Breakfast session

Cellular Pathology

This session is a debate about the role of molecular techniques within cellular pathology. Please come prepared to contribute.

Molecular pathology represents the most exciting investigative technique within modern day histopathology and is set to expand its role within laboratory diagnostics. The key fact is that molecular techniques will identify specific abnormalities, which when detected are diagnostic of that particular disease. These techniques offer a degree of sensitivity and accuracy, which is unparalleled in patient diagnostics. Currently the focus has been on identifying inherited genetic disorders and the expanding field of typing various cancers.

However, molecular pathology also enables us to gather information on predictive forecasting specifically relating to how these detected changes affect a patient’s response to drugs. In brief, molecular techniques provide us with a tool which can be used to enable a ‘tailored’ approach to patient treatment and management on an individual basis. Examples include assessments of KRAS mutations in colorectal cancers and EGFR in non-small cell lung cancer.

Will this advancement affect many or a few of the cases we see in our laboratories?
Will the focus for molecular testing reside in regional centres or in local laboratories?

How then will molecular biology affect traditional techniques employed in the cellular pathology laboratory? Undoubtedly, there will be gradual changes. Already special stains have been largely replaced by immunocytochemistry or molecular based assays. This trend is set to continue. The H&E stain will still be required because no other molecular technique can provide an equivalent amount of interpretable information. The importance of cellular localisation of biomarkers should not be underestimated, ensuring the future of in situ techniques either at the protein or nucleic acid level.

One should not also forget the significant impact of cost! Some of the recent molecular techniques involving multi-arrays (multiplexing) for broad based cancer screening are complex to perform and require fully automated equipment with elaborate algorithms for interpretation. This is currently beyond the reach of most NHS Trusts.

This panel believes that there will be an expanding role for molecular techniques within cellular pathology. Undeniably, molecular techniques provide information on transcriptional changes at the DNA level. However, protein expression (translation) will rely heavily on immunocytochemistry at the light microscope level. It would seem that a complimentary relationship exists between H&E staining, immunocytochemistry and molecular based techniques.