Small cell lung cancer (SCLC) is a rapidly progressive malignancy with no improvement in survival outcome or change in the standard of care over the past thirty years. In this review, we examine molecular tissue markers, serum/ plasma markers, laboratory data and clinical markers that have been reported to have prognostic influence in SCLC. We discovered that the following held a poor prognosis in limited (LD) and extensive-stage (ED) SCLC: Autocrine growth loop activity via C-kit, gastrin-releasing peptide, or pro-gastrin releasing peptide, high pre-treatment beta fibroblast growth factor, increased cathepsin B or D expression, reduced intracellular fragile histidine triad protein expression, her-2/neu over-expression, high matrix metalloproteinase-11 or -14 activity, loss of function of Rb, elevated serum levels of ALT, CEA, CRP, LDH, or VEGF, hyponatremia, elevated lymphatic/vascular endothelial progenitor, disease extent, male gender, weight loss, anemia, neutrophilia, thrombocytopenia, prolonged PT or aPTT, and superior vena cava syndrome as part of an initial presentation of disease. Hypourecemia, elevated neuron-specific enolase, and age over 70 years conveyed a poorer prognosis in LD and elevated creatinine, higher performance status (>2), and liver, bone, or brain metastases conveyed a poorer prognosis in ED SCLC. The following conveyed a favorable prognosis in LD and ED SCLC: E-cadherin expression, increased cytoplasmic levels of inhibitor of DNA binding/differentiation-2, increased numbers of tumor-infiltrating lymphocytes, high MAPK activity, normal to elevated albumin levels, female gender, performance status <2, and smoking cessation at time of diagnosis. Age <70 and the absence of a pleural effusion were associated with a better prognosis in LD only. The data supporting many of these prognostic factors are somewhat weak and reflect that lack of translational research in this disease.
Keywords: Prognostic factors, Small Cell Lung Cancer, Survival.