The First Evaluation of Serum Levels of MGP, Gas6 and EGFR after First Dose of Chemotherapy in Lung Cancer

SIMPLE SUMMARY: Serum levels of MGP, Gas6, vitamin K(1), and EGFR were not significantly changed in response to the first cycle of chemotherapy. We found a strong correlation between MGP and VitK(1) serum values, and a moderate negative correlation between VitK(1) and EGFR in pre-treatment patients. The post-treatment value of EGFR is a strong independent factor that correlates positively with the Gas6 post-treatment values. ABSTRACT: Background: Vitamin K-dependent proteins (VKDPs) and the epidermal growth factor receptor (EGFR) are involved in lung cancer progression. Therefore, we aimed to study the serum concentration of Matrix Gla protein (MGP), Growth Arrest-specific 6 (Gas6), and EGFR before and after the first cycle of chemotherapy and to investigate how MGP, Gas6, and EGFR are modified after one cycle of chemotherapy. Methods: We performed an observational study on twenty patients diagnosed with lung cancer, by assessing the serum concentration of vitaminK(1) (VitK(1)), MGP, Gas6, and EGFR using the ELISA technique before and after three weeks of the first cycle of chemotherapy. Patients were evaluated using RECIST 1.1 criteria. Results: Serum levels of MGP, Gas6, EGFR, and VK(1) before and after treatment were not changed significantly. Regarding the pre-treatment correlation of the MGP values, we found a strong positive relationship between MGP and VK(1) pre-treatment values (r = 0.821, 95%CI 0.523; 0.954, p < 0.001). Furthermore, there was a moderately negative correlation between VK(1) and EGFR pre-treatment values, with the relationship between them being marginally significant (r = −0.430, 95%CI −0.772; 0.001, p = 0.058). Post-treatment, we found a strong positive relationship between MGP and VK(1) post-treatment values (r = 0.758, 95%CI 0.436; 0.900, p < 0.001). We also found a moderate positive relationship between Gas6 and EGFR post-treatment values, but the correlation was only marginally significant (r = 0.442, p = 0.051).