Association between serum biomarkers CEA and LDH and response in advanced non‐small cell lung cancer patients treated with platinum‐based chemotherapy

BACKGROUND: In addition to radiological evaluation, biomarkers may be useful in providing early information on the response to treatment, and supporting clinical decision‐making. The objective of this study was to investigate carcinoembryonic antigen (CEA) and lactate dehydrogenase (LDH) as biomarkers for early assessment of response in patients with advanced non‐small cell lung cancer (NSCLC) treated with platinum‐based chemotherapy. METHODS: A retrospective follow‐up study was conducted from 2012 to 2017 among 593 consecutive patients with advanced NSCLC treated with first‐line platinum‐based chemotherapy in a large teaching hospital in the Netherlands. Pretreatment biomarker levels and changes from pretreatment levels were studied for association with radiologic response (partial response [PR] or complete response [CR], according to RECIST 1.1) using multivariate logistic regression, and with overall survival using COX proportional hazard modeling. Patient and disease characteristics such as age and disease stage were taken into account as potential confounding factors. RESULTS: Decreases in CEA and LDH (≥ 20%), particularly early in treatment, were significantly associated with better radiological response. Increases in these biomarkers (≥ 20%) and high pretreatment LDH levels (≥ 247 U/L) were significantly associated with lower overall survival. CONCLUSIONS: Our results support determination of CEA and LDH levels for earlier assessment of response to platinum‐based chemotherapy in patients with advanced NSCLC. Hence, routine determination and evaluation of CEA and LDH levels, prior to each cycle of platinum‐based chemotherapy in advanced NSCLC, should be considered as part of daily clinical practice. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: Serum biomarkers in monitoring of treatment in advanced NSCLC would be useful. CEA and LDH decrease (≥ 20%) is favorable for achieving radiological response. High LDH levels and CEA/LDH increase (≥ 20%) is associated with reduced survival. WHAT THIS STUDY ADDS: Monitoring of CEA seems to be particularly relevant in early stage of treatment. CEA and LDH determination should be considered as part of daily clinical practice.