Clinical advances drive lung cancer staging, classification changes

The proposed revision would continue to group in the M1a category cases with pleural/pericardial effusions, contralateral/bilateral lung nodules, contralateral/bilateral pleural nodules, or a combination of multiple parameters. However, single metastatic lesions in a single distant organ would be reclassified as M1b, and multiple lesions in a single organ or multiple lesions in multiple organs would be reclassified as M1c.