Interview
with Neil Love, MD Breast Cancer Update for Medical Oncologists,
Program 6 2000
Play
Audio Below:
The
problem now is we’ve switched to immunohistochemistry without
the same stringent quality control standardization of the procedure,
and I’m afraid that we’re going to, once again, have assays
that are not necessarily wrong – and they’re not necessarily
performed incorrectly, technically – but the cutoff for positive
and negative hasn’t been very well defined, certainly not on
patient outcome. Our group has done that, and we’ve found that
just a few percent positive cells will seem to permit a tamoxifen
benefit in the adjuvant setting. Some laboratories use a cutoff
of 20 percent. It’s hard to know how they came up with that.
Certainly, it’s not on patient outcome data. So, I’m concerned
that we’re in the same boat that we might have been with ligand
binding in the early years, where lack of standardization and really
paying attention to the quality of the assay is going to result
in misclassification of patients, and that’s going to have
a big damaging effect.
Youth
and hormone receptors in breast cancer: good or bad news first? Stockler, M. and Beith, J. (Reprint available from: Stockler
M Univ Sydney, Natl Hlth & Med Res Council, Clin Trials Ctr,
Dept Med Sydney NSW 2006 Australia). Lancet. 355(9218): 1839-1840,
2000 May 27. No abstract
