%0 Journal Article
%T Comparison of Prognostic Gene Profiles Using qRT-PCR in Paraffin Samples: A Retrospective Study in Patients with Early Breast Cancer
%A Enrique Espinosa
%A Iker S¨˘nchez-Navarro
%A Angelo G¨˘mez-Pozo
%A ¨˘lvaro Pinto Marin
%A David Hardisson
%A Rosario Madero
%A Andr¨¦s Redondo
%A Pilar Zamora
%A Bel¨¦n San Jos¨¦ Valiente
%A Marta Mendiola
%A Manuel Gonz¨˘lez Bar¨®n
%A Juan ¨˘ngel Fresno Vara
%J PLOS ONE
%D 2009
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0005911
%X Introduction Gene profiling may improve prognostic accuracy in patients with early breast cancer, but this technology is not widely available. We used commercial assays for qRT-PCR to assess the performance of the gene profiles included in the 70-Gene Signature, the Recurrence Score and the Two-Gene Ratio. Methods 153 patients with early breast cancer and a minimum follow-up of 5 years were included. All tumours were positive for hormonal receptors and 38% had positive lymph nodes; 64% of patients received adjuvant chemotherapy. RNA was extracted from formalin-fixed paraffin-embedded (FFPE) specimens using a specific kit. qRT-PCR amplifications were performed with TaqMan Gene Expression Assays products. We applied the three gene-expression-based models to our patient cohort to compare the predictions derived from these gene sets. Results After a median follow-up of 91 months, 22% of patients relapsed. The distant metastasis-free survival (DMFS) at 5 years was calculated for each profile. For the 70-Gene Signature, DMFS was 95% -good prognosis- versus 66% -poor prognosis. In the case of the Recurrence Score, DMFS was 98%, 81% and 69% for low, intermediate and high-risk groups, respectively. Finally, for the Two-Gene Ratio, DMFS was 86% versus 70%. The 70-Gene Signature and the Recurrence Score were highly informative in identifying patients with distant metastasis, even in multivariate analysis. Conclusion Commercially available assays for qRT-PCR can be used to assess the prognostic utility of previously published gene expression profiles in FFPE material from patients with early breast cancer. Our results, with the use of a different platform and with different material, confirm the robustness of the 70-Gene Signature and represent an independent test for the Recurrence Score, using different primer/probe sets.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005911