Chemotherapy-induced leukopenia as a prognostic factor in patients with metastatic non-small cell lung cancer treated with platinum-based chemotherapy

Platinum-based chemotherapy is the front-line treatment in patients with metastatic non-small cell lung cancer (NSCLC). Leukopenia is one of its common side effects. The aim of this study was to analyze the association between the grade of platinum-based chemotherapy induced leukopenia and the clinical outcome of NSCLC patients. Three hundred nine patients with metastatic NSCLC, treated with platinum-based chemotherapy, were retrospectively analyzed. Patients were divided into 3 groups according to the presented worst leukopenia grade: absent (grade 0), mild (grade I/II) and severe (grade III/IV). The associations between platinum-based chemotherapy induced leukopenia and time to tumor progression (TTP) and overall survival (OS) were evaluated and correlated to response rate (RR) and disease control rate (DCR). The results showed RR, DCR, TTP and OS were significantly better in patients developing any grade of leukopenia compared with those without leukopenia. The median TTPs were 2.0, 5.88, 7.44 months for absent, mild and severe leukopenia, respectively; the median OSs were 7.64, 14.69, 13.72 months for the same groups, respectively. Multivariate analysis revealed that mild chemotherapyinduced leukopenia was an independent factor associated with a better TTP and OS. In conclusion, platinum-based chemotherapy induced leukopenia was emerged as an independent prognostic factor. Our study suggests that chemotherapy-induced leukopenia can be regarded as a surrogate marker for optimal dosing of anticancer drugs.