Guidance needed on biomarker counseling

Specialist centers vary considerably in their practice when counseling patients with mild cognitive impairment about the implications of biomarker testing, according to a Europe-wide survey. Presenting these findings, Kristian Steen Frederiksen (Rigshospitalet, Copenhagen, Denmark) suggested they demonstrate the need for clinicians to be offered further guidance in this difficult area.

All 69 centers in the European Alzheimer’s Disease Consortium were invited to participate in the on-line survey. Responses came from 35 centers, with a total of 110 individual physicians taking part. 

Uncertainties in the concept of MCI and the implication of biomarker data are difficult to communicate

Difficulties in disclosure and interpretation

Around 70% said that they always or almost always had a general discussion with the patient prior to sampling about the decision to measure biomarkers, but 30% of respondents do not routinely offer patients the chance to have this discussion.

In relation to more specific points, only 40% of respondents always or almost always discuss how biomarker results may affect the ability to predict risk of progression. A little over 60% discuss ahead of sampling how testing may affect the ability to diagnose the underlying pathology or disease.

Both the concept of MCI itself and the implications of biomarker results are uncertain, and this uncertainty is difficult to communicate to patients.

Amyloid and tau markers rated more valuable than MRI as predictors of progression 

In disclosing diagnosis, a little fewer than 70% of respondents always or almost always use the term “mild cognitive impairment”. Around a quarter speak in terms of “cognitive impairment but not dementia”. Fewer than 5% use the term “predementia” or “mild dementia”.

In discussing implications of the diagnosis, 40% of respondents always or almost always cover risk of progression and 31% discuss the probable underlying cause. Only 21% routinely discuss driving, and 14% other legal matters.

In relation to the biomarkers assessed, more than 70% of respondents always or almost always use MRI, but only around 10% use FDG-PET or CSF that frequently, and fewer than 5% are routine users of amyloid PET. But, in terms of predicting progression in people with MCI, respondents rate amyloid and tau markers as more valuable than MRI or FDG-PET.

Further reading

Visser PJ, et al. Biomarkers in Medicine 2012;6:4