EGAPP recommendations for gene expression testing in breast cancer
Posted Feb 03 2009 12:00am
Another paper from the EGAPP Working Group in Jan. 09 Genetics in Medicine of great interest concerns recommendations for gene expression profiling in breast cancer (e.g. OncotypeDX). Bottom line: there is insufficient evidence to recommend for or against the use of tumor gene expression profiling in subpopulations (mostly, ER +, LN -) patients with breast cancer. In addition, they found "no direct evidence linking any of the three tests (OncotypeDX, MammaPrint, Quest H:I) to improved outcomes." As I mentioned in a recent post, such testing appears to have become "routine" without the necessary critical evaluation of analytical validity (comparison with "gold" standard--there is none (!) so no estimates of false positive or false negative rates) or of the clinical validity or utility of such testing. Pathologists should be aware of two clinical trials seeking to address clinical utility: TAILORx and MINDACT. Although interim results continue to be reported annually at ASCO, the final (meaningful) answers will be years down the road since we are talking about a subset of patients that one speaks of 10+ years of survival even without treatment. Get and read this paper as it has a lot of excellent information summarized and systematically reviewed (so you can shine at this week's Tumor Conference).