Last update:
25-Mar-2014

Small cell lung cancer (SCLC) accounts for approximately 13% of all newly diagnosed cases of lung cancer. It is characterized by rapid growth, early distant metastases and good response to chemotherapy. This is a topical review of the literature on the role of soluble tumor markers in the diagnosis and treatment of SCLC. PubMed was searched for relevant papers, using the key words "soluble tumor markers in SCLC". Most of the references found concerned pro-gastrin releasing peptide (pro-GRP) and neuron specific enolase (NSE) which are the markers most specific for the diagnosis of SCLC. The sensitivity and specificity of pro-GRP for the diagnosis of SCLC are 72% and 93%, respectively, slightly higher than those of NSE. Pro-GRP distinguishes with a higher accuracy between complete and partial response to treatment and diagnoses earlier relapse of the disease. On the other hand, NSE is a better predictor of survival, a role that is also provided by other tumor markers that are less specific to SCLC, such as carcinoembryonic antigen and chromogranin A. A few studies have demonstrated that measurement of tumor markers in bronchoalveolar lavage (BAL) and pleural fluid, in combination with traditional diagnostic methods such as bronchoscopy, may be useful for the diagnosis of SCLC. In conclusion, although soluble tumor markers appear to play an important role in the management of patients with SCLC after administration of chemotherapy, the sole use of tumor markers cannot establish the diagnosis with a high degree of confidence.

Key words: Gastrin releasing peptide, Neuron specific enolase, Small cell lung cancer, Tumor markers.