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Evolving characteristics of lung cancer: a surgical appraisal.

OBJECTIVE
Lung cancer management has changed due to emergence of new imaging techniques and of multimodal therapies. Our purpose was to analyse how lung cancer evolved in surgical practice.


METHODS
The records of patients who underwent surgical resection for lung cancer from 1983 to 2006 in two centres were reviewed. Data were split into four time periods of 6 years. We analysed and compared the epidemiological, pathological and prognostic characteristics of each period.


RESULTS
There were 832, 1148, 1493 and 1195 patients during the periods 1983-88, 1989-94, 1995-2000 and 2001-06, respectively. The main changed characteristics were increasing numbers of older patients, females, past history of another cancer and/or cardio-vascular disease, adenocarcinomas and undifferentiated large-cell carcinomas, smaller tumour size, T1-T2, N0 (47.2-61.2%) and neoadjuvant therapy (NAT) (3.8-24.9%). There were also a decreasing number of exploratory thoracotomies, pneumonectomies and adjuvant therapy (AT) (48.5-30%). The 5-year survival rates improved (34.5-46.3%, P < 10(-6)), mainly after lobectomy, and in the case of adenocarcinoma, N0 and N2 patients. Multivariate analysis confirmed that time trend was an independent factor of prognosis (P < 10(-6)), just as important as N involvement, complete resection (R0), tumour size, age, another cancer history and more significant than the type of resection, histology, NAT and AT.


CONCLUSIONS
During the last 25 years, the clinico-pathological features of operated patients have progressively changed and the results following surgery improved. Earlier stage diagnosis might explain overall survival improvement, and play a more major role than associated peri-operative treatments. Therefore, it is advisable to consider the time-related factor in future studies on lung cancer surgery.