Comprehensive Transcriptome Profiling Reveals Multigene Signatures in Triple-Negative Breast Cancer

Purpose: By integrating expression profiles of mRNAs and long noncoding RNAs (lncRNA), we tried to develop and validate novel multigene signatures to facilitate individualized treatment of triple-negative breast cancer (TNBC) patients.

Experimental Design: We analyzed 165 TNBC samples and 33 paired normal breast tissues using transcriptome microarrays. Tumor-specific mRNAs and lncRNAs were identified and correlated with patients' recurrence-free survival (RFS). Using Cox regression model, we built two multigene signatures incorporating mRNAs and lncRNAs. The prognostic and predictive accuracy of the signatures were tested in a training set of 165 TNBC patients and validated in other 101 TNBC patients.

Results: We successfully developed an mRNA and an integrated mRNA-lncRNA signature based on eight mRNAs and two lncRNAs. In the training set, patients in the high-risk group were more likely to suffer from recurrent disease than patients in the low-risk group in both signatures [HR, 10.00; 95% confidence interval (CI), 2.53-39.47, P= 0.001; HR = 4.46, 95% CI, 1.34-14.91, P= 0.015 for integrated signature and mRNA signature, respectively). Results were validated in the validation set (P= 0.019 and 0.030, respectively). In addition, time-dependent receiver operating curve showed that the integrated mRNA-lncRNA signature had a better prognostic value than both the eight-mRNA-only signature and the clinicopathologic risk factors in both sets. We also found through interaction analysis that patients classified into the low-risk group by the integrated mRNA-lncRNA signature had a more favorable response to adjuvant taxane chemotherapy.

Conclusions: The multigene signature we developed can accurately predict clinical outcome and benefit of taxane chemotherapy in TNBC patients.