[Influence of chemiotherapeutic protocol and neuroendocrine differentiation on metastatic non-small cell lung cancer treatment results].

Background/aim: In 40-50% of patients with non-small cell lung cancer (NSCLC) at the time of making a diagnosis, the disease is yet at IIIb and IV stage. Standard in the treatment of these patient is the application of systemic chemiotherapy based on CIS/Carboplatin preparations. The aim of this study was to determine the influence of two different chemiotherapeutic protocols and neuroendocrine differentiation on treatment response and survival in patients with metastatic NSCLC.

Methods: We examined 85 patients with metastatic NSCLC, of which 51 with stage IIIb, and 34 with stage IV of the disease. The histologic diagnosis of NSCLC was determined by tissue assays using hematoxylin eosin method. Neuroendocrine differentiation was determined by immunohistochemical analysis of neuron-specific enolase (NSE), chromogranin A, and synapthophysin expression using monoclonal mouse anti-human bodies (DAKO, Denmark). According to chemiotherapeutic protocol, the patients were randomly assigned into combined Taxol + Cisplatin group (Tax + Cis, n = 35), and Cyclophosphamide + Etoposide + Carboplatin group (CEP, n = 50). The treatment was conducted within 4-6 chemiotherapeutic cycles. The efficacy was assessed after the therapy regimen and median survival time was assessed after the randomization.

Results: A total of 31 (36.47%) patients had a favourable therapeutic response, both partial and complete response (54.2% in the Tax + Cis group and 24% in CEP group of patients, respectively, p < 0.001). The median survival time in both groups was 13.1 months (15.3 months in the Tax + Cis group and 10.6 months in the CEP group, respectively, p < 0.001). A one-year follow-up survival period was confirmed in 40% of patients (60% only in the Tax + Cis group). A total of 23 (27.05%) patients with metastatic NSCLC had neuroendocrine differentiation. The disease progression or stable disease was noted only in patient with NSCLC without neuroendocrine differentiation (n = 42, 67.7%, p < 0.001). The median survival time in patients with NSCLC and neuroendocrine differentiation was 14.8 months, without neuroendocrine differentiation 10.7 months (p < 0.001). The patients with NSCLC and neuroendocrine differentiation in the CEP group had a longer one-year follow-up survival period than patients in Tax + Cis group (p < 0.001). In Tax-Cis group of patients, there was no significant difference in one-year follow-up survival period with neuroendocrine differentiation.

Conclusion: Better therapeutic response and longer median survival time in metastatic NSCLC was obtained using Tax + Cis as compared to CEP protocol. Similar effect was noted using CEP protocol in patients with NSCLC and neuroendocrine differentiation.