medigraphic Artemisaen línea REV INST NAL ENF RESP MEX VOLUMEN 20 - NÚMERO 1 CONFERENCIA MAGISTRAL ENERO-MARZO 2007 PÁGINAS: 21-32 Role of sublobar resection (segmentectomy and wedge resection) in the surgical management of non-small cell lung cancer BRIAN PETTIFORD* RODNEY J. LANDRENEAU* * Heart, Lung, and Esophageal Surgery Institute University of Pittsburgh Medical Center Pittsburgh, Pennsylvania Trabajo recibido: 13-XII-2006; aceptado: 23-I-2007 INTRODUCTION berculosis. Both of these pulmonary disease pro- cesses are commonly anatomically localized to Most thoracic surgeons regard pulmonary resec- discrete bronchopulmonary segments and the tion less than lobectomy as inadequate for the common bilateral involvement encourages the use management of lung cancers anatomically con- of parenchymal sparing resection techniques. 21 fined to a single lobe of the lung. Accordingly, The first reported use of segmentectomy for sublobar resection is considered by many sur- the management of bronchiectasis is credited to geons as a "compromise operation" that should Churchill and Belsey in 19391. Kent and Blades’ be only employed for the management of small advocacy of individual ligation of bronchial and peripheral lung cancers present in patients with vascular hilar structures coupled with Overholt significant impairment in cardiopulmonary re- and Langer’s 1947 description of the technique serve, who cannot withstand the physiologic rig- for resection of each bronchopulmonary segment ors of lobectomy. in the treatment of bronchiectasis established the High resolution computed tomography (CT) has use of anatomic segmentectomy for discrete sub- resulted in the increasingly common finding of new lobar pathology2,3. sub-centimeter malignant lesions. Surveillance CT Interestingly, total pneumonectomy was still chest scanning efforts have led many surgeons to regarded as the only appropriate surgical option reassess the need for total lobectomy in the man- for the treatment of primary lung cancer during agement of smaller peripheral non-small cell lung this period4. The dreadfully high mortality associ- cancers. Anatomic segmentectomy or extended ated with pneumonectomy (40%) at that time non-anatomic wedge resection has been consid- led to the use of lobectomy as the preferred ap- ered as an adequate surgical cure of early-stage proach to resection of peripheral lung cancers5. lung cancer. We review the clinical information The use of anatomic segmentectomy for the available today in formulating an opinion regard- management of peripheral lung cancers was ex- ing the appropriate use of sublobar resection for plored by some thoracic surgeons6-10, however, the small peripherally located NSCLC. the relative complexity of the operative approach edigraphic.comcompared to lobectomy and the increased mor- HISTORICAL PERSPECTIVE bidity related to prolonged air leak and local re- currence deterred the enthusiasm of most sur- Pulmonary segmentectomy was originally utilized geons for this approach to lung cancer11. The use for the resection of focal bronchiectasis and tu- of segmentectomy, and sublobar resection in REVISTA DEL INSTITUTO NACIONAL DE ENFERMEDADES R ESPIRATORIAS ISMAEL C OSÍO V ILLEGAS Enero-Marzo 2007, Segunda Época, Vol. 20 No 1 www.iner.gob.mx Brian Pettiford, et al. general, was relegated as a "compromise proce- of sublobar resection in the primary management dure" for the management of patients with sig- of non-small cell lung cancer. We must first clar- nificant impairment in cardiopulmonary reserve ify that we believe sublobar resection is inappro- having peripheral lung lesions confined within priate for the management of most clinical non- segmental anatomic boundaries10-15. small cell lung cancer beyond that of stage I An increasing body of evidence is emerging disease. For the most part, we favor the use of suggesting that sublobar resection with accurate segmentectomy without adjuvant local therapy nodal staging may be an adequate resection for for small stage IA disease without endobronchi- the small peripheral non-small cell lung cancer. al extension within anatomic segmental bound- Surgical marginal status following sublobar resec- aries that are less than 2 centimeters in diame- tion continues to be an important concern, and ter (Figure 1a-b). A surgical margin of at least 2 measures to enhance the marginal clearance con- centimeters should be readily achieved with le- tinue to be explored16-32. sions of this size. Larger lesions will necessarily be associated with anatomic margins of resection CONTROVERSIES REGARDING THE USE that are more likely to recur locally unless adju- OF SUBLOBAR RESECTION vant therapeutic measures to be discussed are considered (Figure 2a-b and Figure 3). The use of anatomic segmentectomy is general- ly accepted for the management of benign dis- Patient survival with sublobar resection ease processes and metastatic carcinoma to the lung confined to an anatomic segment. The use The argument of use of sublobar resection for of sublobar resection and segmentectomy in par- stage I non-small cell lung cancer attracted inter- ticular has been accepted as a reasonable ap- national attention with the initiation of the ran- 22 proach for resection of patients with significant domized trial of sublobar resection versus lobec- impairment in cardiopulmonary reserve. The pri- tomy for good risk patients with stage IA disease mary controversy over the years among thoracic conducted by the now defunct North American surgeons has been with the use of segmentec- "Lung Cancer Study Group" during the late 1980’s tomySUSTRAÍDODE-M.E.D.I.G.R.A.P.H.I.C as primary management of peripheral pri- and early 1990’s11. This study was inspired by the mary non-small cell lung cancer for patients who survival results seen among women undergoing are:ROP physiologically ODAROBALE fit toFDP undergo lobectomy. less than total mastectomy for small primary We will review representative pertinent clini- breast cancers and Erret’s 1986 reporting of calVC investigations ED AS, CIDEMIHPARG addressing the appropriateness equivalent survival results among stage I Non- ARAP ACIDÉMOIB ARUTARETIL :CIHPARGIDEM edigraphic.com A B Figure 1. Computed tomographic roentgenographic images of small peripheral T1 lesions ideal for sublo- bar resection. R EV I NST N AL ENF RESP MEX Enero-Marzo 2007, Segunda Época, Vol. 20 No 1 www.iner.gob.mx Role of sublobar resection in the surgical management of non-small cell lung cancer AB Figure 2. Computed tomographic roentgenographic images of lesion for which adjuvant brachytherapy should be used if sublobar resection is being considered. (T2 lesion confined to anatomic boundaries of the pulmonary segment). an aside observation, they also stated that they found no difference in the loss of pulmonary func- tionality between lobectomy and sublobar re- section patients when assessed one year follow- ing surgery. This important conclusion regarding postoperative functionality certainly caught the at- 23 tention of many thoracic surgeons already con- vinced that lobectomy was the superior operation for even small stage I non-small cell lung can- cers. Interestingly, this conclusion regarding post- operative physiologic equivalency between resec- tion approaches was made despite the fact that over one third of the patients in the study were not available for pulmonary function testing at the one year postoperative mark. Subsequent analy- ses of the late effects of relative pulmonary func- Figure 3. Lesion for which lobectomy is required tional preservation with segmentectomy compared due to central lobar location limiting marginal clear- to lobectomy have countered the conclusions of ance of the tumor. this study18,19. Furthermore, the survival and local recurrence differences were based on a one-tailed analysis designed to demonstrate a statistically sig- small cell lung cancer patients with impaired cardio- nificant difference at a higher p-value threshold. pulmonary reserve undergoing sublobar resection Lastly, one-third of the sublobar resection pa- compared to physiologically fit stage I patients tients underwent wedge resection, which is not undergoing lobectomy33,34. an anatomical resection and has well-document- The results of the Lung Cancer Study Group’s ed local recurrence rates. Regardless of these find- efforts were reported in 1995. Primary findingsedigraphic.com of ings, many thoracic surgeons continue to regard this study were that survival between sublobar lobectomy as the gold standard treatment for ear- resection and lobectomy were not significantly ly-stage non-small cell lung cancer. different but local recurrence was three times In Japan, large computed tomographic (CT) greater when sublobar resection was utilized. As radiologic screening programs in place for well R EV INST NAL E NF R ESP MEX Enero-Marzo 2007, Segunda Época, Vol. 20 No 1 www.iner.gob.mx Brian Pettiford, et al. over a decade have exposed an increased num- ered as primary therapy for tumors 20 mm or less ber of small, peripheral, early stage lung can- in size. cers.35 Programs utilizing "fast" CT scanners El-sherif et al, evaluated a 13-year experience screening high-risk populations (older patients in the management of resectable stage I non- with significant smoking history and impairment in small cell lung cancer at their institution25. The re- pulmonary function) are underway now in North currence patterns and survival of 784 patients (577 America and Europe36. Renewed interests in sub- lobectomies, 207 sublobar resections