Authors: Yoshihisa Shimada Hisashi Saji Masatoshi Kakihana Hidetoshi Honda Jitsuo Usuda Naohiro Kajiwara Tatsuo Ohira Norihiko Ikeda
Publish Date: 2012/09/05
Volume: 36, Issue: 12, Pages: 2865-2871
Abstract
The tumor location was right upper lobe RUL in 79 middle lobe in 12 right lower lobe RLL in 40 left upper division LUD in 41 lingular division in 11 and left lower lobe LLL in 24 Both RUL and LUD tumors showed a higher incidence of upper mediastinal UM involvement 96 and 100 respectively and a lower incidence of subcarinal involvement 15 and 10 respectively than lower lobe tumors UM RLL 60 LLL 42 subcarinal RLL 60 LLL 46 respectively Among the patients with 24 right UMpositive RLL and 10 left UMpositive LLL tumors 2 showed negative hilar subcarinal and lower mediastinal involvement and cT1 suggesting that UM dissection may be unnecessary in lower lobe tumors with no metastasis to hilar subcarinal and lower mediastinal nodes on frozen sections according to the preoperative T status Among the patients with 12 subcarinalpositive RUL and 4 subcarinalpositive LUD tumors one showed negative hilar or UM involvement suggesting that subcarinal dissection may be unnecessary in RUL or LUD tumors with no metastasis to hilar and UM nodes on frozen sectionsLobectomy with systematic mediastinal lymph node dissection LND has been considered the standard of care for resectable nonsmall cell lung cancer NSCLC Lymph node dissection was first reported by Cahan in 1960 1 and is known to enhance staging accuracy by increasing lymph node harvesting and improving the identification of occult N2 disease In contrast other investigators claim that LND can potentially increased postoperative morbidity or may require longer operative time 2 3 4 5 Some randomized controlled trials addressing the survival benefit of LND and mediastinal lymph node sampling showed no difference in survival outcome between patients undergoing LND and those undergoing lymph node sampling 3 6 7 Whether or not patient outcome is improved by LND remains controversialAt present early lung cancers are more frequently encountered because of the widespread use of highresolution computed tomography CT in routine practice and cancer screening 8 9 Therefore the extent of LND should be tailored to each patient Selective lymph node dissection SLND based on the tumor locationspecific lymphatic pathway should be undertaken especially for patients with no apparent lymph node metastasis or with impaired pulmonary function or for elderly patients In the present study we retrospectively reviewed the prevalence of lymph node involvement in each mediastinal region in patients with N2 NSCLC according to the location of the primary tumor and we attempted to evaluate the possible indications for SLNDFrom January 1990 to December 2007 a total of 2195 patients underwent radical surgical resection of at least a lobectomy and systematic LND for NSCLC at our hospital Of these 2195 patients we retrospectively analyzed lymph node spread patterns and outcome in 207 patients with NSCLC of less than 5 cm with N2 involvement We excluded patients who had received preoperative treatment including chemotherapy or chemoradiotherapy those who had undergone only biopsy and SLND and those who had lowgrade malignant tumors We also excluded patients with tumors spreading across lobar fissures and invading multiple lobesPreoperative evaluation included physical examination chest radiography computed tomography CT of the chest and abdomen magnetic resonance imaging of the brain bone scintigraphy and blood examination We determined that a large lymph node over 10 mm in the shortest axis was positive for metastasis on CT scans Positronemission tomography PET scan recently integrated PETCT scan was not routinely used for staging resectable tumors during the study period In recent years endobronchial ultrasoundguided transbronchial needle aspiration EBUSTBNA was sometimes performed for the patients having suspected multiple N2 lymph node metastases but it was not routinely used Similarly mediastinoscopic biopsy was not routinely performed Patients with N2 lymph node positively diagnosed by EBUSTBNA or mediastinoscopic biopsy were excluded from the group of operative indication candidates
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