Abstract 162P
Background
MammaPrint (MP) is a 70-gene signature, which has been validated in multiple studies and has proven to be a powerful predictor of risk of recurrence in patients with breast cancer (BC). In a German validation study using samples from the Patients Tumor Bank of Hope (PATH), the degree of concordance between MP and clinical risk classifications valid at that time has been determined retrospectively. MP use was shown to be feasible in a German study population revealing a change in treatment recommendation in 40% of patients (Gevensleben H et al. Int J Mol Med 2010;26:837-843). In this analysis, we present the prognostic value of MP at 10 years of follow-up.
Methods
Tumor samples from 140 German patients were classified by MP as low risk (LR) or high risk (HR) of recurrence and compared to the then-current adjuvant treatment guidelines. The patients were treated based on the clinical risk assessment. We collected 10-year data from 117 patients and compared overall survival (OS) between subgroups based on MP.
Results
In the cohort of 117 patients MP identified 57.3% (n=67) LR, and 42.7% (n=50) HR patients. The 10-year overall survival (OS) in patients with LR and HR was 93.4% and 71.2%, respectively. The OS in the lymph-node positive population was 93.3% for the LR group (n=20%) and 40.4% for the HR group (n=18), respectively. Treatment received and overall survival stratified per treatment are presented in Table. Table: 162P
10-year OS and treatment received in patients from the German PATH cohort stratified by MammaPrint
| MP LR n = 67 | MP HR n = 50 | |
| Treatment received, n (%) | ||
| CT+ET | 29 (43) | 14 (28) |
| CT only | 0 (0) | 10 (20) |
| ET only | 29 (43) | 13 (26) |
| No AST | -(-) | 1 (2) |
| Unknown | 9 (13) | 12 (24) |
| 10-year OS (%) | ||
| Overall | 93.4 | 71.2 |
| CT | 96.3 | 9.9 |
| no CT | 92.5 | 61.5 |
AST, adjuvant systemic therapy; CT, chemotherapy; ET, endocrine therapy; MP LR, MammaPrint Low Risk; MP HR, MammaPrint High Risk; OS, overall survival.
Conclusions
Patients with a MP LR had an excellent OS at 10 years, regardless of lymph node status and treatment, thus confirming its prognostic value. In a cohort treated based on clinical risk assessments only, about a third of patients received a treatment not in line with their MP results, possibly affecting their quality of life and outcomes.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
PATH.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.