GRP and metastatic malignant neoplasm in the lymph nodes: Nevertheless, ProGRP and NSE serum levels were dramatically elevated In patients with extensive-stage SCLC, who had lymph node metastasis and a tumour diameter of at least 5 cm, vis-à-vis patients with limited-stage SCLC who had no lymph node metastasis and a tumour diameter less than 5 cm.