195P - The 70-gene signature in node positive breast cancer: 10-year follow-up of the observational RASTER study.

Date 11 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics Breast Cancer, Early Stage
Breast Cancer
Personalised Medicine
Presenter Sonja Vliek
Citation Annals of Oncology (2017) 28 (suppl_5): v43-v67. 10.1093/annonc/mdx362
Authors S.B. Vliek1, V. Retel2, C. Drukker3, J.M. Bueno-De-Mesquita1, E. Rutgers3, H. van Tinteren4, M.J. van de Vijver5, J. Wesseling6, W. van Harten2, S.C. Linn7
  • 1Molecular Pathology, The Netherlands Cancer Institute, 1066 CX - Amsterdam/NL
  • 2Health Technology Assessment, The Netherlands Cancer Institute Antoni van Leeuwenhoek Hospital, 1066 CX - Amsterdam/NL
  • 3Surgical Oncology, The Netherlands Cancer Institute Antoni van Leeuwenhoek Hospital, 1066 CX - Amsterdam/NL
  • 4Biometrics, The Netherlands Cancer Institute, 1066 CX - Amsterdam/NL
  • 5Pathology, Academic Medical Center, 1100 DD - Amsterdam/NL
  • 6Pathology, The Netherlands Cancer Institute Antoni van Leeuwenhoek Hospital, 1066 CX - Amsterdam/NL
  • 7Medical Oncology, The Netherlands Cancer Institute Antoni van Leeuwenhoek Hospital, 1066 CX - Amsterdam/NL

Abstract

Background

In early stage breast cancer patients, with axillary lymph node metastasis, the 70-gene signature, MammaPrint® (MP) identifies patients with a High or Low Risk of distant breast cancer (BC) recurrence. For MP Low Risk (G(enomic)-low) in patients with up to 3 positive lymph nodes (N1-3), the MINDACT trial (Cardoso, NEJM 2016) showed that it might be safe to forgo adjuvant chemotherapy. Here we evaluated the prognostic value of MP at 10 years follow-up in patients with lymph node positive early stage BC.

Methods

Between 2004 and 2006 812 women with early stage BC participated in the observational RASTER trial (Bueno de Mesquita, Lancet Oncol, 2007). 181 patients were node positive and not included in the primary analysis, 176 of them gave consent for future research. On 164 tumor samples (FFPE) MP was performed retrospectively. Survival data was collected and samples were allocated to clinical high (C-high) or C-low risk as used in MINDACT. Patients with over 3 axillary lymph node metastases (N4+) were all considered C-high. 10-year distant-recurrence-free-interval (DRFI) was compared between subgroups based on the MP and clinical assessment.

Results

In 3 patients the clinical assesment could not be determined. Over 95% of patients received chemotherapy, 82.9% (136/164) of tumors were ER-positive and 18.3% (30/164) of patients had N4+. MP identified 47% (n = 77/164) as Low Risk, including 16,9% (13/77) with N4+. 10-year DRFI in patients N1-3 and G-Low or G-High was 94.9% and 80.7% respectively (HR 4.7; 95%CI 1.3-16.2). With the clinical assessment 13.7% (n = 22/161) were low risk, only one was diagnosed with distant BC recurrence. 10-years DRFI was 94.4% in C-low and 85.8% in C-high (HR 3.7 95%CI 0.5-28.5). In N4+ 10-years DRFI was 69.7%. Combining the clinical assessment with MP risk assessment in patients N1-3 the 10-years DRFI in clinical high risk patients was 95.2% for G-Low (n = 44) and 79.6% for G-High (n = 65) (HR 4.83 95%CI 1.1-21.4).

Conclusions

We again confirm the prognostic value of Mammaprintin BC patients with axillary lymph node involvement after 10 years follow up. In N1-3 patients with clinical high risk, MP can identify a subgroup with excellent prognosis after standard adjuvant systemic therapy.

Clinical trial identification

Legal entity responsible for the study

S. Linn

Funding

None

Disclosure

All authors have declared no conflicts of interest.