posters International Association for Breast Cancer Research 2014

Novel serum protein biomarker panel predicts disease-free survival in patients with ER-negative breast cancer (#24)

Liping Chung 1 , Katrina Moore 2 , Leo Phillips 1 , Fran M. Boyle 3 , Deborah J. Marsh 1 , Robert C. Baxter 1
  1. Hormones and Cancer Division, Kolling Institute of Medical Research, Sydney, NSW, Australia
  2. Department of Surgery, Royal North Shore Hospital, St Leonards, NSW, Australia
  3. Patricia Ritchie Centre for Cancer Care, Mater Hospital, Crows Nest, NSW, Australia

Background: There is a need for improved prognostic tools to assist in the management of patients with breast cancer. We recently reported a panel of five serum protein biomarkers (a fragment of apolipoprotein H (ApoH), ApoCI, complement C3a, transthyretin, and ApoAI), identified by mass spectrometry (MS) and validated immunologically, that can distinguish sera from women with breast cancer with high specificity and sensitivity (Chung et al., Breast Cancer Research 16:in press, 2014).
Methods: To investigate how the serum protein panel associates with clinicopathological characteristics of patients including receptor status (ER, PR, HER2), patients were subdivided into six groups based on receptor status. Survival estimates were analysed by the Kaplan-Meier method and compared by the log-rank test. Cox regression was used to examine the relationship between the clinicopathological characteristics of patients and a parameter derived from serum levels of the five proteins (determined by MS).
Results: Kaplan-Meier analysis on 181 subjects after median follow-up of >5 years demonstrated that the 5-protein parameter significantly predicted disease-free survival (DFS) (P=0.005), its efficacy apparently greater in women with ER-negative tumours (n=50, P=0.003) compared to ER-positive (n=131, P=0.161). By multivariate analysis, histologic grade (HR=2.30, 95% CI 1.10-4.81, P=0.028), lymph node involvement (HR=2.83, 95% CI 1.23-6.52, P=0.015) and the 5-protein parameter (HR=2.86, 95% CI 1.15-7.13, P=0.024) were significantly associated with DFS. To further validate the prognostic utility of this protein panel, we are currently quantifying protein levels from the same cohort of patients by ELISA assays.
Conclusion: This serum protein panel significantly predicts DFS in women with ER-negative tumours. The influence of ER status needs to be confirmed after longer follow-up. The development of this marker panel in an immunoassay format will allow its further evaluation as a tool for the management of patients with breast cancer.
Supported by NHMRC Australia and Cancer Institute NSW.