Lymphopenia: Is it a prognostic factor in metastatic non-small cell lung cancer?

e18124 Background: Lymphopenia is frequent in advanced cancers and predicts the toxicity of chemotherapy. It is known as a poor prognostic marker in solid tumors such as metastatic breast cancer and sarcomas. However, its impact on relapse and survival in metastatic non small cell lung cancer is unknown. The aim of our study was to establish the correlation between lymphopenia and survival (disease-free survival (DFS) and overall survival (OS)) in metastatic non small cell lung cancer. Methods: We reviewed retrospectively 115 cases of metastatic non small cell lung carcinomas diagnosed between January 2007 to June 2011 at the Medical Oncology Department at Hassan II University Hospital. Complete blood counts were performed at the time of diagnosis and prior to treatment. Lymphopenia was defined as an absolute lymphocyte count (ALC) < 1000 /µL. We used the Kaplan-Meier method and Cox model to estimate OS and DFS. Results: Median age was 57 ± 10 years. 83.5% of patients were men. 81% of patients were treated with platinum based chemotherapy. Twelve patients (13%) had a low ALC at diagnosis with a mean of 854 (± 100)/µL. Lymphopenia was frequent in men patients (p=0.03) and non squamous cell carcinomas (p= 0.04). However, it was not correlated to age, performance status, body mass index, number of metastatic sites involved, pleural effusion, liver metastasis, hypercalcemia, anemia and hypoalbuminemia. The median duration of follow-up was 7.4 months (range: 1-99 months). In the univariate analysis, the medians of OS and DFS were shorter but not significantly different in lymphopenic patients (OS: 7.5 versus 9 months p= 0.07 and DFS: 5 versus 6 months p= 0.12). In multivariate analysis, lymphopenia was not significantly associated with OS and DFS. Conclusions: In this study, the association between lymphopenia and unfavorable OS and DFS was not clearly demonstrated in patients with metastatic non small cell lung carcinoma. Prospective clinical trials are needed to confirm or deny the prognostic role of lymphopenia in this cancer.