Comparison of Prognostic Gene Expression signatures for Breast Cancer
Haibe-Kains B*, Desmedt C*, Piette F, Buyse M, Cardoso F, van ‘t Veer L, Piccart MJ, Bontempi G and Sotiriou C
During the last years, several groups have identified prognostic gene
expression signatures with apparently similar performances. However,
signatures were never compared on an independent population of
untreated breast cancer patients, where risk assessment was computed
using the original algorithms and microarray platforms.
Results: We compared three gene expression signatures, the
70-gene, the 76-gene and the Gene expression Grade Index (GGI)
signatures, in terms of predicting distant metastasis free survival
(DMFS) for the individual patient. To this end, we used the previously
published TRANSBIG independent validation series of node-negative
untreated primary breast cancer patients. We observed agreement in
prediction for 135 of 198 patients (68%) when considering the three
signatures. When comparing the signatures two by two, the agreement in
prediction was 71% for the 70- and 76-gene signatures, 76% for the
76-gene signature and the GGI, and 88% for the 70-gene signature and
the GGI. The three signatures had similar capabilities of predicting
DMFS and added significant prognostic information to that provided by
the classical parameters.
Conclusions: Despite the difference in development of these
signatures and the limited overlap in gene identity, they showed
similar prognostic performance, adding to the growing evidence that
these prognostic signatures are of clinical relevance.