%0 Journal Article %T Prognostic Impact of Src, CDKN1B, and JAK2 Expression in Metastatic Breast Cancer Patients Treated with Trastuzumab %A Amanta Psyrri %A Angelos Koutras %A Athanasios Kotsakis %A Christos Christodoulou %A Dimitrios Pectasides %A Dimitris Bafaloukos %A Epaminondas Samantas %A Evangelia Razis %A George Fountzilas %A George Pentheroudakis %A Georgia-Angeliki Koliou %A Georgios Lazaridis %A Gerasimos Aravantinos %A Helen Patsea %A Kitty Pavlakis %A Konstantine T. Kalogeras %A Kyriaki Papadopoulou %A Panagiota Economopoulou %A Pavlos Papakostas %A Petroula Arapantoni-Dadioti %A Theofanis Economopoulos %A Vassiliki Kotoula %J Archive of "Translational Oncology". %D 2019 %R 10.1016/j.tranon.2019.02.010 %X BACKGROUND: Src, CDKN1B, and JAK2 play a crucial role in the coordination of cell signaling pathways. In the present study, we aim to investigate the prognostic significance of these biomarkers in HER2-positive metastatic breast cancer (MBC) patients treated with trastuzumab (T). METHODS: Formalin-fixed paraffin-embedded tumor tissue samples from 197 patients with HER2-positive MBC treated with T were retrospectively collected. All tissue samples were centrally assessed for ER, PgR, Ki67, HER2, and PTEN protein expression; EGFR gene amplification; PI3KCA mutational status; and tumor-infiltrating lympocytes density. Src, CDKN1B, and JAK2 mRNA expression was evaluated using quantitative reverse transcription-polymerase chain reaction. RESULTS: Only 133 of the 197 patients (67.5%) were found to be HER2-positive by central assessment. CDKN1B mRNA expression was strongly correlated with Src (rho£¿=£¿0.71) and JAK2 (rho£¿=£¿0.54). In HER2-positive patients, low CDKN1B conferred higher risk for progression [hazard ratio (HR)£¿=£¿1.58, 95% confidence interval (CI) 1.08-2.32, P£¿=£¿.018]. In HER2-negative patients, low Src was associated with longer survival (HR£¿=£¿0.56, 95% CI 0.32-0.99, P£¿=£¿.045). Upon multivariate analyses, only low CDKN1B and JAK2 mRNA expression remained unfavorable factors for PFS in de novo and relapsed (R)-MBC patients, respectively (HR£¿=£¿2.36, 95% CI 1.01-5.48, P£¿=£¿.046 and HR£¿=£¿1.76, 95% CI 1.01-3.06, P£¿=£¿.047, respectively). CONCLUSIONS: Low CDKN1B and JAK2 mRNA expressions were unfavorable prognosticators in a cohort of T-treated MBC patients. Our results suggest that CDKN1B and JAK2, if validated, may serve as prognostic factors potentially implicated in T resistance, which seems to be associated with distinct pathways in de novo and R-MBC %U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6423363/