Neutrophil-to-Lymphocyte Ratio Predicts Outcome in Limited Disease Small-cell Lung Cancer

Patients with limited disease small-cell lung cancer (SCLC) receive radiochemotherapy followed by prophylactic cranial irradiation. The prognosis of these patients remains poor with a median survival of 16-24 months. Systemic inflammation was suggested as an important prognostic factor for outcomes. This study investigated the impact of systemic inflammation measured with neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at first diagnosis in patients with limited disease SCLC for outcomes.

Data of 65 patients receiving radiochemotherapy for limited disease SCLC were analyzed. NLR and PLR were obtained from blood sample at first diagnosis of SCLC and 12 characteristics including gender, age, ECOG, T-category, N-category, pack years, smoking during radiotherapy, respiratory insufficiency, hemoglobin levels during radiotherapy, radiation dose (<56 vs. ≥56 Gy), concurrent radiochemotherapy, and prophylactic cranial irradiation (PCI) were evaluated for local control, metastasis-free survival, and overall survival.

Survival rates at 1, 2, and 3 years were 71, 45, and 28%, respectively. Median survival time was 20 months. Independent factors for improved survival were NLR < 4 (p = 0.03), ECOG 0-1 (p = 0.002), and PCI (p = 0.015). Lower T-category was an independent positive factor of local control (p = 0.035). Improved metastasis-free survival was associated with NLR < 4 (p = 0.011), ECOG 0-1 (p = 0.002), N-category 0-1 (p = 0.048), non-smoking during radiotherapy (p = 0.009), and PCI (p = 0.006).

NLR was found to be an independent prognostic factor for overall survival. The evaluation of NLR can help identify patients with poor prognosis and appears a useful prognostic marker in clinical practice. A prospective analysis is warranted to confirm these findings.