Predicting the response to a bronchodilator in patients with airflow obstruction and lung cancer.

BACKGROUND: The aim of the present study was to clarify the predictors of the response of patients with resectable lung cancer and untreated airflow obstruction to tiotropium, an antimuscarinic bronchodilator.

METHODS: Tiotropium was administered to 29 preoperative patients with untreated airflow obstruction. The forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1 ) were measured before and after the introduction of tiotropium. The response to tiotropium was determined based on the percentage gain in the FEV1 . The volume of the total lung area (TLV) and the low-attenuation area (LAA) was measured by deep inspiratory computed tomography based on the predefined thresholds for attenuation values.

RESULTS: The introduction of tiotropium resulted in a 15% gain in the FEV1 (P < 0.001). A univariate regression analysis revealed that the FVC/TLV was the best predictor of the gain in FEV1 , followed by the FEV1 /FVC. Based on the results of a multiple regression analysis, a regression equation to predict a gain in the FEV1 was generated using the FVC, TLV, and LAA. A receiver operating characteristic curve analysis revealed that this equation led to the highest area under the curve for predicting a major response to tiotropium, followed by the FVC/TLV and FEV1 /FVC. Postoperatively, six of the 20 minor responders experienced a progression of dyspnea. In contrast, none of the major responders experienced a progression of dyspnea (P < 0.05).

CONCLUSIONS: We developed an equation for predicting the response to tiotropium using parameters obtained from spirometry and quantitative computed tomography. A large-scale study to validate the usefulness of this equation is warranted.