Surgical management of lung cancer with multiple lesions: implication of the new recommendations of the 8^th edition of the TNM classification for lung cancer

The 8^th tumour, node and metastasis (TNM) revision of the staging classification for lung cancer has attempted to clarify the different properties of four distinct clinical presentations: synchronous multiple primary lung cancers; primary tumour with intrapulmonary metastases; pneumonic-type adenocarcinoma and multiple ground glass/lepidic lesions. The respective biological profiles determine different surgical strategies for each category. Accurate preoperative histological confirmation is required to identify synchronous primary tumours which should then be managed as two separate episodes within the confines of patient characteristics. Equally important is the confirmation of intrapulmonary metastasis which indicates a more conservative resection of the smaller lesion. In contrast, pneumonic-type adenocarcinoma may require larger parenchymal resection to achieve anatomical clearance but also symptom relief. Multiple subsolid lesions require a carefully planned strategy of parenchymal sparing and possible observation of less malignant abnormalities. In all the above situations careful clinical, radiological and pathological assessment is imperative to avoid one embarking on inappropriate invasive management. Either when the widespread nature of the disease renders extensive surgery futile or the relative benign or pre-malignant nature of the multiple lesions imply that the risks of surgery outweigh the prognostic benefits.