The Prognostic Value of Pre-Treatment Leukocytosis in Patients with Previously Treated, Stage IIIB/IV Non-Small Cell Lung Cancer Treated with the IGF-1R Pathway Modulator AXL1717 or Docetaxel; a Retrospective Analysis of a Phase II Trial

Background: The aim of the present study was to investigate any prognostic value of pre-treatment anemia, leukocytosis and thrombocytosis in patients with advanced pretreated NSCLC. Methods: A randomized, multicenter phase II study comparing the IGF-1R modulator AXL with standard docetaxel in the treatment of previously treated stage IIIB or IV NSCLC patients was conducted in 2011-2013. Clinical and laboratory data were collected, including serum values for hemoglobin (Hgb), white blood cells (WBC) and platelets (Plt) at baseline. These hematological parameters were studied in relation to overall survival using Kaplan–Meier product-limit estimates and multivariate Cox proportional hazards regression models. Results: The median overall survival for all patients was 8.9 months. Patients with leukocytosis (WBC > 9 x 109/L) had a significantly shorter median overall survival (4.2 months) as compared with those with a WBC ≤ 9 x 109/L at baseline (12.3 months) with a corresponding of HR 2.10 (95% CI: 1.29-3.43). Patients with anemia (Hgb < 110 g/L) had a non-significant (p = 0.097) shorter median overall survival (6.1 months) as compared with their counterparts with Hgb ≥ 110 g/L at baseline (9.4 months). As for thrombocytosis (Plt > 350 x 109/L), there was no statistically significant impact on overall survival. Leukocytosis retained its prognostic significance in a multivariate model where other clinical factors such as age, sex and WHO performance status were taken into consideration (HR: 1.83, 95% CI: 1.06-3.13, p = 0.029). Conclusion: Pre-treatment leukocytosis is a strong and independent prognostic marker for shorter overall survival in previously treated stage IIIB or IV NSCLC patients receiving docetaxel or AXL1717. Combined use of pre-treatment leukocytosis assessments together with established prognostic factors such as performance status could be of help when making treatment decisions in this clinical setting.