In addition, elevated NSE did not have significant prognostic value of OS for SCLC patients part of whom received surgical resection before chemotherapy and radiotherapy in 2 studies [32, 34] with combined HR of 2.16 (95% CI 0.82–5.69, p = 0.12; I2 = 75%), while the combined HR of the remaining 13 studies indicated that elevated NSE may predict worse OS (HR 1.90, 95% CI 1.63–2.20, p < 0.001; I2 = 48%, p = 0.03) in SCLC patients who received chemotherapy with or without radiotherapy. This evidence concerns the gene ENO2 and small cell lung carcinoma.