Utility of NSE, ProGRP and LDH in Diagnosis and Treatment in Patients with Small Cell Lung Cancer

Background and objective Small cell lung cancer (SCLC) is a rapidly growing tumor with characteristic of neuroendocrine cellular function. Neuron specific enolase (NSE), pro-gastrin-releasing peptide (ProGRP) and lactic dehydrogenase (LDH) are valuable in diagnosis and treatment of SCLC. By analyzing the variation of NSE, ProGRP and LDH before and after treatment, the aim of this study is to investigate the efficacy of tumor markers in diagnostic staging, therapeutic evaluation and prediction of disease relapsing. Methods Patients with SCLC who receiving the first line chemotherapy in Cancer Hospital, Chinese Academy of Medical Sciences were enrolled and retrospectively analyzed. Clinical characteristic (includes NSE, ProGRP and LDH level before and after 2 cycles chemotherapy), efficacy evaluation, progression-free survival (PFS) were analyzed. Results Before treatment, Serum NSE, ProGRP and LDH in patients with extensive disease (ED) were significantly higher than those with limited disease (LD)(all P4 cycles chemotherapy and with obvious decrease of ProGRP than those who accepted ≤4 cycles chemotherapy and with less obvious decrease of ProGRP in LD group; ED patients with no more than 2 distant metastasis, normal LDH level before treatment and obvious decrease of ProGRP after chemotherapy had lower short term relapse risk. In addition, the types of relapse (sensitive relapse, drug resistance relapse and refractory relapse) were negatively correlated with decrease of ProGRP (P=0.044). By multivariate analysis, numbers of chemotherapy cycle was independent prognostic factor for PFS in LD SCLC; numbers of distant metastasis and decrease of ProGRP were independent prognostic factors for PFS in ED SCLC. Conclusion Increase level of serum tumor markers is related to tumor burden. Decrease level of ProGRP after treatment may prognose efficacy and relapse risk.