Cao X, Ganti AK, Stinchcombe T, et al. - Utilizing individual patient data from existing cooperative group phase II/III trials of stages III/IV non-small cell lung cancer or extensive small-cell lung cancer, researchers tried to construct a model to predict severe neutropenia induced by chemotherapy in lung cancer. They randomly divided the dataset into a training set including 7,606 (67%) patients and testing set comprising 3,746 (33%) patients. Incorporating routinely available pretreatment variables, such as age (> 65 years), gender (male), weight (kg), BMI, insurance status (yes/unknown), stage (IIIB/IV/ESSCLC), number of metastatic sites (1, 2 or ≥ 3), individual drugs (gemcitabine, taxanes), number of chemotherapy agents (2 or ≥ 3), planned use of growth factors, associated radiation therapy, prior therapy (chemotherapy, radiation, surgery), duration of planned treatment, pleural effusion (yes/unknown), performance status (1, ≥ 2) and presence of symptoms (yes/unknown), a relatively simple model was built to predict for neutropenia. Independent prospective validation of this model is recommended.