Lung cancer staging: pathology issues

The previous, 6th, American Joint Committee on Cancer and International Union Against Cancer Staging Manual classification of lung cancer was largely unchanged from 5th edition. However, the most recent, 7th, edition has significantly updated the tumor, node, metastasis classification of lung cancer with regards to the inclusion of additional size criteria for T stages and revision of the staging for multiple tumor nodules, and represents the most dramatic change in 30 years. The recommendations for this most recent edition of tumor, node, metastasis classification are derived from a systematic retrospective review of data from a multi-international/institutional database of lung cancers and also incorporate expert opinion, to revise and clarify various staging factors. This review will primarily focus on the pathologically relevant aspects of 7th edition of American Joint Committee on Cancer/International Union Against Cancer classification of lung cancer as well as briefly reviewing the new staging guidelines.