Other clinical characteristics such as sex, smoking history, tumor location, gene mutations and levels of tumor markers such as carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA-125), carbohydrate antigen 72-4 (CA72-4), squamous cell carcinoma antigen (SCC), pro-gastrin releasing peptide (ProGRP), and cytokeratin 19 fragment (Cyfra21-1), did not exhibit statistically significant differences in either group. Here, GRP is linked to neoplasm.