Prognosis of early breast cancer (EBC) after surgery seems to be tied to both clinical and molecular features. Based on this, the addition of adjuvant chemotherapy (ACT) in ER+ HER2-, moderately differentiated, low ER expression or moderate tumor burden EBC is made, assuming a predictive role of these features in ACT benefit. There are patients who, based on these data, could abstain ACT without an increase in the risk of early relapse or decrease in survival. It is in these patients that molecular platforms, either 70-gene (Mammaprint®) or 21-gene (OncotypeDx®) signatures, combined with clinical features, would help decision making, sparing toxicities to these patients.
We analyzed 89 of 850 first visits (2014/17) with ER+ HER2- EBC,
Mean 57 year-old patients at diagnosis, 60% postmenopausal. 53% Luminal B, all Luminal type by Blueprint®. 79% T1 and 16% N1mic. Bad prognosis encouraging ACT in 57% and 33% of patients based on clinical and statistical characteristics, respectively. 36% ACT indication on molecular basis, 25% of reduction of ACT indication. In subgroup analysis, 55% of high-risk patients according to clinical criteria were low-risk Mammaprint, with 33% who went from low to high risk of relapse. This implies a 20% decrease in chemotherapy treatments. In addition, 2 or more clinical risk factors may predict a high-risk result in the 70-gene signature assay, with likeliness of poor prognosis and ACT potential benefit. With a median follow-up of 15 months, no relapses have been noticed.
Prognosis based on clinically significant reduction of the indication of ACT (around 25%) without affecting the rate of relapse has been noticed, with data suggesting prediction of gene-signature assay results according to the number of clinical risk factor present. A longer follow-up time and a larger number of patients are needed to confirm these results.
Clinical trial identification
Legal entity responsible for the study
Consorcio Hospital General Universitario Valencia
All authors have declared no conflicts of interest.