Optimum diagnostic pathway and pathologic confirmation rate of early stage lung cancer: Results from the VIOLET randomised controlled trial

Background
Pathologic confirmation of lung cancer influences treatment selection for suspected early-stage lung cancer. High pre-treatment tissue confirmation rates are recommended. We sought to define management and outcomes of patients undergoing surgery for primary lung cancer in a UK multi-centre clinical trial.

Methods
VIOLET compared minimally invasive video-assisted thoracic surgery versus open surgery for known or suspected lung cancer. Diagnostic patient pathways were identified and methods of tissue confirmation were documented. The outcome of inappropriate lobectomy for benign disease or inappropriate wedge resection for primary lung cancer was compared with respect to the pathologic diagnosis.

Findings
From July 2015 to February 2019, 502 patients were randomised and underwent surgery; 262 (52%) had a pre-operative pathologic confirmed diagnosis of primary lung cancer, 205 did not have a pre-operative biopsy and 35 had a non-diagnostic pre-operative biopsy.

Of the 240 participants without pre-operative pathologic confirmation of primary lung cancer, intraoperative biopsy and frozen section analysis was undertaken in 144 (60%). The remaining 96 underwent direct surgical resection without tissue confirmation (19% of the entire cohort). Confirmation of histologic diagnosis before surgery was less costly than diagnosis in the operating theatre. The inappropriate surgery rate was 3.6% (18/502 participants, 7 lobectomy for benign disease, 11 wedge resection for lung cancer).

Interpretation
Low levels of inappropriate resection can be achieved at pre-operative tissue confirmation rates of 50% through a combination of intra-operative confirmatory biopsy and correct risk estimation of lung cancer. Practice needs to be monitored to ensure acceptable levels are consistently achieved.