Conversion to Thoracotomy in Non-Small Cell Lung Cancer: Risk Factors and Perioperative Outcomes.

: We aimed to identify predictors of conversion to thoracotomy and test the hypothesis that conversion is associated with inferior perioperative outcomes in non-small cell lung cancer (NSCLC). : We queried the National Cancer Database for patients with stage I to III NSCLC undergoing minimally invasive surgery (MIS) during 2010 to 2016. We compared clinicopathologic factors between patients undergoing MIS with and without conversion. We fitted multivariable regression models to identify independent predictors of conversion and compare perioperative outcomes between the 2 groups. : A rising trend in the use of MIS was accompanied by a declining trend in the rate of conversion to thoracotomy. A total of 11.3% of the 83,219 cases were converted. Conversion was associated with a higher Charlson-Deyo score, squamous histology, nodal involvement, high tumor grade, tumor size ≥5 cm, and a higher T stage ( < 0.05). Successful MIS without conversion was predicted by advanced age, sublobar resection, robotic approach, and treatment at an academic high-volume facility ( < 0.05). Conversion was linked to longer hospital stays, higher 30-day and 90-day mortality, and unplanned readmission ( < 0.05), irrespective of the type of MIS approach. : Conversion rates for video-assisted and robot-assisted thoracoscopic surgery have seen a decline in recent years. Irrespective of the type of MIS approach, conversion was associated with inferior perioperative outcomes. The robotic approach and treatment at an academic high-volume facility were associated with a lower likelihood of conversion. Early recognition of the individual risk factors for conversion may help to counsel patients about the likelihood of, and detriments associated with, conversion and ultimately reduce conversion rates.