'Diagnostics' is the Cinderella of health technology assessment
The several papers on evaluating new health care interventions in
this week’s BMJ omit any mention of a crucial sector of healthcare;
diagnostics. The National Institute for Health and Clinical Excellence
shares this blindspot.
Its importance has recently been highlighted by the sudden
introduction of Herceptin (Trastuzumab) treatment for all women with
breast cancer who could benefit. Quality-controlled laboratory assessment
of HER2 status, essential to define those who could benefit, was not
adequately considered and serious problems resulted.
The problem is being exacerbated by the advances of molecular
biology. For example, a paper in last month’s Journal of Pathology argues
cogently that all new colorectal cancers should be tested for DNA mismatch
repair deficiency.(1) So should NHS pathology laboratories all be doing
this? Perhaps not yet - the very next paper in the same issue illustrates
quality control problems with this investigation.(2)
A systematic and authoritative approach to evaluating new diagnostic
tests is lacking, but is needed just as much as a system for evaluating
new drugs and procedures.
At present, whether or not patients can benefit from new diagnostic
modalities is a ‘postcode lottery’.
1 Ward R L, Turner J, Williams R et al. Routine testing for mismatch
repair deficiency in sporadic colorectal cancer is justified. J Pathol
2 Mangold E, Pagenstecher C, Friedl W et al. Tumours from MSH2
mutation carriers show loss of MSH2 expression but many tumours from MLH1
mutation carriers exhibit weak positive MLH1 staining. J Pathol 2005;
The author is an NHS diagnostic histopathologist
Competing interests: No competing interests