Changing patterns of lung cancer; (3/4 in.) 1.9 cm; still a safe length for bronchial resection margin?

Background: Surgical resection is the best treatment modality in non-small cell lung cancer (NSCLC). As a guideline, it is suggested that at least a b ronchial resection margin of 1.9 cm from the macroscopic tumor might provid e a tumor-free margin in lung cancer. In some recent reports, there is grea t emphasis on the changing histopathological patterns of lung cancer, but n o concern for the proximal extension of lung cancer. The aim of this study was to determine the validity of this guideline in the current time. Method s: Surgically resected specimens of NSCLC cases (n = 70) were examined. The bronchial tree including tumor was dissected and beginning from the edge o f the visible tumor, the bronchus were cut into serials in its transverse p lane, 5 mm apart from each other. Cut sections were examined for proximal e xtension of tumor at different levels. Results: Microscopic proximal extens ion was observed in 24.2% (n = 17/70) of all the cases. Peribronchial exten sion (n = 9/17) (52.9%) was more predominant compared with bronchial extens ion (n=8/17) (47.0%). Squamous cell carcinoma (n=11/38) (28.9%) showed prox imal extension more than adenocarcinoma (n = 5/23) (21.7%). Adenocarcinoma showed more peribronchial extension (n = 4/5) (80.0%) whereas squamous cell carcinoma (n = 7/11) (63.6%) showed more bronchial extension. The farthest extension was 3.0 cm for adenocarcinoma and 2.0 cm for squamous cell carci noma. Excluding tumor positive specimens beyond 1.5 cm level to the bronchi al resection margin, all tumors accounted for 96% of the whole series. Conc lusions: Microscopic proximal extension of lung cancer occurs in 24.2% of N SCLC cases. Squamous cell carcinoma extends more proximally compared with a denocarcinoma in ratio whereas adenocarcinoma extends more in length. A bro nchial resection of 1.5 cm in length from the macroscopic tumor will provid e clear margins in 93% of NSCLC cases. (C) 2000 Elsevier Science Ireland Lt d. All rights reserved.