Increased Jab1/COPS5 is associated with therapeutic response and adverse outcome in lung cancer and breast cancer patients.

Adjuvant chemotherapy has been established as standard treatment for advanced cancer among multidisciplinary therapies. A simple and instructive biomarker for therapeutic response and recurrence is needed to evaluate the therapeutic effect. Jab1/COPS5 level has been shown to be associated with tumor progression and poor outcomes in many types of cancer patients. This study aims to further evaluate the clinical and prognostic value of Jab1/COPS5 level as a biomarker in lung and breast cancer patients receiving adjuvant chemotherapy. In this study, data of 88 lung cancer and 76 breast cancer patients were retrospectively collected and analyzed to identify the relationship between the Jab1/COPS5 level and the clinical progression and outcome of these patients. Lung cancer patients with increased Jab1/COPS5 level tend to be non-responsive to chemotherapy. Relapsed breast cancer patients had an increased Jab1/COPS5 level and breast cancer patients with increased Jab1/COPS5 level had significantly shorter disease-free survival and overall survival. In a multivariate survival analysis, histological type and Jab1/COPS5 were associated with disease-free survival and overall survival. The Jab1/COPS5 level was found to be a possible biomarker for clinical response to chemotherapy in lung cancer patients and for postoperative relapse in breast cancer patients who received adjuvant chemotherapy. In conclusion, this study identified Jab1/COPS5 as novel prognostic markers for lung cancer and breast cancer.