Micro-metastases and non-small cell lung cancer

Introduction Non-small cell lung cancer has a poor prognosis, including those with operable, apparently localised, disease. Preoperative staging investigations and histo-pathological analysis are poor at detecting small clusters of turnout cells, particularly in lymph nodes. State of art New methods based on immunohistochemistry, or molecular biology, have been developed to detect these so-called micro-metastases. We present a ten-year review of the literature published on this topic. Perspectives These publications primarily reported on the detection of micro-metastases within mediastinal lymph nodes removed at operation in order to identify patients at risk of recurrence, for whom adjuvant therapy might be offered. Conclusions Lymph node micro-metastases have been demonstrated to be an independent prognostic factor for survival, especially in stage 1 patients. On the other hand, the presence of bone marrow micro-metastases did not appear to be of significant prognostic value in non-small-cell lung cancer. Finally, the clinical relevance of circulating tumour cells is still debatable, although recent published studies show interesting results.