New reference equations for lung function can affect eligibility for lung cancer surgery.

INTRODUCTION: The standard treatment for early-stage non-small cell lung cancer is surgical resection. Assessment of operability includes evaluation of lung function. Current European guidelines are based on reference equations from the former European Community for Steel and Coal (ECSC). New reference equations from Global Lung Initiative (GLI) and Danish Lung Function Material (DALFUMAT) have been published for forced expiratory volume in the first second (FEV1) and Lung carbon monoxide diffusing capacity (DLCO). OBJECTIVE: To evaluate whether the use of GLI or DALFUMAT instead of ESCS reference equations result in a higher number of patients with predicted values for FEV1 and DLCO below 30% and 40. METHODS: This is a retrospective cohort study. Data were collected from medical records of 1400 patients. Percent of predicted values calculated using the ECSC reference equations were compared with those using the GLI and DALFUMAT reference equations. RESULTS: GLI reference equations did not result in a significant change in number of patients with FEV1 or DLCO percent of predicted below 30% or 40%.DALFUMAT reference equations made a significant change in the number of patients who had a FEV1 percent of predicted below 40% (n = 69 ~ 86%) and the number of females with DLCO percent of predicted below 40% (23~ - 37%). When using a threshold of 30%, there was an increase in number of females with DLCO over 30% (n = 17 ~ 155%), but this was not significant. CONCLUSION: Using national reference equations can affect the pre-operative assessment of patients with lung cancer.