56P - Soluble serum Fas as a biomarker of early detection of bone or liver metastases in women with advanced breast cancer. A preliminary case-control study

Date 07 May 2015
Event IMPAKT 2015
Session Welcome reception and Poster Walk
Topics Breast Cancer, Metastatic
Translational Research
Presenter Franco Lumachi
Citation Annals of Oncology (2015) 26 (suppl_3): 15-24. 10.1093/annonc/mdv117
Authors F. Lumachi1, G. Lo Re2, L. Foltran2, R. Tozzoli3, G.B. Chiara4, S.M.M. Basso4
  • 1Department Of Surgery, Oncology & Gastroenterology, University of Padua, School of Medicine, 35128 - Padova/IT
  • 2Medical Oncology, S. Maria degli Angeli Hospital, 33170 - Pordenone/IT
  • 3Clinical Pathology, S. Maria degli Angeli Hospital, 33170 - Pordenone/IT
  • 4Surgery 1, S. Maria degli Angeli Hospital, 33170 - Pordenone/IT

Abstract

Body

Background: The Fas (APO-1; CD95) antigen is a type I cell surface glycoprotein that transduces an apoptotic signal after interaction with its natural ligand. Membrane-bound Fas is a cell-surface receptor that transduces apoptosis after interaction with membrane-bound or FasL, while soluble Fas (sFas) binds FasL and inhibits its activity. Increased concentration of sFas has been reported in various diseases, including autoimmune diseases and several cancers, such as hematopoietic malignancy and solid tumors. The aim of this study was to evaluate the usefulness of sFas in the presence of bone (BMs) or liver (LMs) metastases in patients with advanced breast cancer (BC).

Patients & methods: In this study, we examined the plasma levels of sFas in 31 women with confirmed BMs (Group 1, N = 16) or LMs (Group 2, N = 15) from BC, and in 18 age- and stage-matched controls in whom the presence of metastases was excluded by whole body 18F-FDG PET/CT scanning, using a commercially available quantitative enzyme-linked immuno-sorbent assay (ELISA) kit. The intra-assay and inter-assay coefficients of variation were 2.9% to 4.1%, respectively.

Results: Thirty patients (30/49, 61.2%) had plasma sFas levels greater than the optimum cut point of 1.80 ng/ml (median 2.37, range 1.48-14.37 ng/ml) and were designated as sFas positive. The sensitivity and negative predictive value of sFas (Group 1 vs. 2) were 75.0% vs. 93.3% (χ2 = 12.05, OR = 4.42, 95%CI 1.81-10.80, p = 0.0008), and 80.0% vs. 94.1% (χ2 = 8.66, OR = 3.91, 95%CI 1.50-10.22, p = 0.005). The accuracy (82.0% vs. 91.0%, χ2 = 3.47, OR = 2.22, 95%CI 0.94-5.21, p = 0.06) was similar, while the specificity and positive predictive value were the same.

PARAMETER G1 vs. Controls G2 vs. Controls
Sensitivity 75.0% 93.3%
Specificity 88.9% 88.9%
Positive predictive value 85.7% 87.5%
Negative predictive value 80.0% 94.1%
Likelihood ratio for positive result 6.75 8.40
Likelihood ratio for negative result 0.28 0.08
False positive rate (α) 11.1% 11.1%
False negative rate (ß) 25.0% 6.7%
Accuracy 82.0% 91.0%

Conclusions: Our preliminary study shows that, in women with advanced BC, the measurement of serum sFas is significantly more sensitive in patients with LMs than in those with BMs, but the specificity and accuracy were similar.

Disclosure: All authors have declared no conflicts of interest.