Prognostic significance of gamma-glutamyl transferase in patients with metastatic non-small cell lung cancer

Background: The prognostic significance of serum gamma-glutamyl transferase (GGT) level at diagnosis in patients with metastatic non-small lung cancer (NSCLC) is not clear. We aimed to assess the relationship between serum GGT level and overall survival (OS) and progression-free survival (PFS) in this patient population. Methods: Data of patients with metastatic NSCLC who were admitted to the medical oncology clinic of our hospital during April 2013-December 2017 were retrospectively analyzed. Patients were divided into two groups based on GGT levels, normal and high (as defined by normal reference levels), and then compared. Results: Significant differences between the high and normal GGT level groups were found regarding female sex, Eastern Cooperative Oncology Group performance score, weight loss at the time of diagnosis, and lactate dehydrogenase level (p < 0.05). The high GGT group had a shorter median OS (11.5 vs. 3.4 months, p < 0.001) and PFS (7.8 vs. 3.0 months, p = 0.001). High GGT level is an independent risk factor for OS (hazard ratio [HR] 2.270; 95% confidence interval [CI], 1.398-3.686; p < 0.001) and PFS (HR 2.489; 95% CI, 1.323-4.684; p = 0.005). Conclusions: High serum GGT level is an independent prognostic factor for OS and PFS in metastatic NSCLC patients.