Prognostic value of synaptophysin and chromogranin a expression in patients receiving palliative chemotherapy for advanced non-small-cell lung cancer

Background: Chemotherapy is the principal treatment method for patients with advanced non-small-cell lung cancer (NSCLC). Treatment with platinum-based and novel chemotherapeutic regimens, compared to monotherapy, slightly increases the response rates to 20-40%. The predictive and prognostic values of molecular factors are highly variable; however, data on clinical-demographic factors are still burdened by significant limitations. Objectives: The aim of this study was to assess the prognostic value of synaptophysin and chromogranin A protein expression in patients receiving palliative chemotherapy for advanced NSCLC. Methods: The study population consisted of 23 women and 116 men. The median age was 57.3 years. Expression of synaptophysin and chromogranin was assessed using a two-step model of immunohistochemical staining. Level 0 represented lack of activity, while level 1 represented its expression. Results: Expression of synaptophysin and chromogranin A was observed in 12 (8.6%) and 5 (3.6%) patients, respectively. The risk of death was significantly lower in patients with expression of synaptophysin (p = 0.008) and chromogranin A (p = 0.014). The 12- and 24-month survival rate of patients with synaptophysin expression was 64% (95% CI 0.35-0.93), while for patients without expression it was 46% (95% CI 0.36-0.56) and 16% (95% CI 0.07-0.25), respectively. The 12- and 24-month survival rate of patients with chromogranin expression was 80% (95% CI 0.44-1.00), while for chromogranin A-negative patients it was 47% (95% CI 0.37-0.57) and 19% (95% CI 0.10-0.28), respectively. We did not observe associations between expression of synaptophysin and chromogranin A and the other typical prognostic factors. Conclusions: Expression of synaptophysin and chromogranin A was associated with a longer median overall survival and might have prognostic value. These results should be confirmed in a prospective study.