The aim of the present study was to evaluate whether serum levels of leptin, CEA, CA19-9, CA15-3, CA125, CA72-4, CYFRA21-1, NSE and SCC have prognostic indications in patients with lung adenocarcinoma who are treated with cisplatin/pemetrexed chemotherapy in the first-line setting. Here, CEACAM5 is linked to lung adenocarcinoma.