PUBLICATION:
Br J Cancer. 2010 Dec 7; 103(12): 1788โ1793. Published online 2010 Nov 16. doi: 10.1038/sj.bjc.6605916.
AUTHORS:
M. Knauer, F. Cardoso, J. Wesseling, P.L. Bedard, S.C. Linn, E.J.T. Rutgers, and L.J. van’t Veer
Background:
Overexpression of HER-2 is observed in 15โ25% of breast cancers, and is associated with increased risk of recurrence. Current guidelines recommend trastuzumab and chemotherapy for most HER-2-positive patients. However, the majority of patients does not recur and might thus be overtreated with adjuvant systemic therapy. We investigated whether the 70-gene MammaPrint signature identifies HER-2-positive patients with favorable outcome.
Methods:
In all, 168 T1โ3, N0โ1, HER-2-positive patients were identified from a pooled database, classified by the 70-gene signature as good or poor prognosis, and correlated with long-term outcome. A total of 89 of these patients did not receive adjuvant chemotherapy.
Results:
In the group of 89 chemotherapy-naive patients, after a median follow-up of 7.4 years, 35 (39%) distant recurrences and 29 (33%) breast cancer-specific deaths occurred. The 70-gene signature classified 20 (22%) patients as good prognosis, with 10-year distant disease-free survival (DDFS) of 84%, compared with 69 (78%) poor prognosis patients with 10-year DDFS of 55%. The estimated hazard ratios (HRs) were 4.5 (95% confidence interval (CI) 1.1โ18.7,ย P=0.04) and 3.8 (95% CI 0.9โ15.8,ย P=0.07) for DDFS and breast cancer-specific survival (BCSS), respectively. In multivariate analysis adjusted for known prognostic factors and hormonal therapy, HRs were 5.8 (95% CI 1.3โ26.7,ย P=0.03) and 4.7 (95% CI 1.0โ21.7,ย P=0.05) for DDFS and BCSS, respectively.
Interpretation:
The 70-gene prognosis signature is an independent prognostic indicator that identifies a subgroup of HER-2-positive early breast cancer with a favourable long-term outcome.
Read more: Identification of a Low-Risk Subgroup… Knauer et al_British Journal of Cancer 2010
