Oncologic Efficacy of Anatomic Segmentectomy in Stage IA Lung Cancer Patients With T1a Tumors

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1 Oncologic Efficacy of Anatomic Segmentectomy in Stage IA Lung Cancer Patients With T1a Tumors James M. Donahue, MD, Christopher R. Morse, MD, Dennis A. Wigle, MD, PhD, Mark S. Allen, MD, Francis C. Nichols, MD, K. Robert Shen, MD, Claude Deschamps, MD, and Stephen D. Cassivi, MD, MS Divisions of General Thoracic Surgery and Biostatistics, Mayo Clinic, Rochester, Minnesota GENERAL THORACIC Background. Segmentectomy provides an anatomic, parenchymal-sparing strategy for patients with limited lung function. Recently, interest has been renewed in segmentectomy for the treatment of early stage lung cancer. Methods. We reviewed the medical records of all patients undergoing segmentectomy from January 1999 through December Survival curves were estimated using the Kaplan-Meier method. Results. There were 113 consecutive patients (58 men, 55 women); median age was 72.5 years (range, 30 to 94 years). Median forced expiratory volume in 1 second was 1.53 L (range, 0.5 L to 3.27 L). Median diffusion capacity of lung for carbon monoxide was 69% predicted (range, 23% to 129%). Significant comorbidities were present in 62 patients (55%). There was no perioperative mortality. Major morbidity occurred in 28 patients (25%). Mean tumor size was 2.1 cm. Resection margins were negative in all cases. Ninety-two patients (81%) were stage I. Overall 5-year survival was 79% for stage IA patients. Current smoking, diffusion capacity of lung for carbon monoxide less than 69%, tumor size greater than 2 cm, N2 disease, and advanced histology grade were associated with decreased survival by univariate analysis. In a multivariate model, only tumor size greater than 2 cm remained significant. Tumor recurrence was observed in 39 patients (35%): local in 17 patients (15%) and distant only in 22 (20%). For stage IA patients with T1a lesions, local recurrence was 5% and distant recurrence was 13%. Five-year recurrence-free survival of these patients was 69%. Conclusions. Pulmonary segmentectomy can be performed safely in selected patients with preoperative reduced lung function and comorbidities. For stage IA disease, survival approximates that seen after lobectomy, with similar local recurrence rates for patients with T1a tumors. (Ann Thorac Surg 2012;93:381 8) 2012 by The Society of Thoracic Surgeons Accepted for publication Oct 27, Presented at the Fifty-seventh Annual Meeting of the Southern Thoracic Surgical Association, Orlando, FL, Nov 3 6, Address correspondence to Dr Cassivi, William J. von Liebig Transplant Center, Division of General Thoracic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905; cassivi.stephen@mayo.edu. Pulmonary segmentectomy was initially introduced more than 70 years ago, primarily for the treatment of infectious pulmonary disorders [1]. During the 1970s reasonable survival results were reported with these sublobar, anatomic pulmonary resections in the management of small peripheral lung cancers in patients with limited lung function [2, 3]. A debate began regarding the best surgical treatment options for early non-small cell lung carcinoma (NSCLC), which was addressed by the Lung Cancer Study Group (LCSG) [4]. This report is the only prospective, randomized study to compare limited, sublobar resections (segmentectomy and wedge resections) to lobectomy for stage IA NSCLC. This study solidified lobectomy as the procedure of choice with the principal finding of an almost threefold increase in local recurrence (6.4% versus 17.2%) after sublobar resection. In this study, grouping of wedge resection and segmentectomy together precluded the analysis of the recurrence rate after segmentectomy alone. Interestingly, no statistically significant survival difference between lobectomy and limited resection could be demonstrated. Increased use of high-definition computed tomography (CT) scanning and lung cancer screening programs has led to the increased detection of small peripheral lung cancers. That has spurred a renewed interest in examining the use of limited resection for these small lesions. The role of segmentectomy in particular has recently been examined in numerous retrospective [5-8] and one prospective [9] study. This growing body of literature has demonstrated favorable results for segmentectomy for treating small, early stage NSCLC. Local recurrence rates in these more modern series are markedly reduced from those observed by the LCSG. The role of lobar and sublobar resection for peripheral NSCLC, less than 2 cm in diameter, is currently being reexamined in the ongoing CALGB trial. Until the results of this trial become available, modern data from large series are needed to help guide surgical decision making for small, peripheral lesions. The purpose of this report is to review our experience with pulmonary segmentectomy in the management of primary lung cancer, particularly in patients with limited 2012 by The Society of Thoracic Surgeons /$36.00 Published by Elsevier Inc doi: /j.athoracsur

2 GENERAL THORACIC 382 DONAHUE ET AL Ann Thorac Surg SEGMENTECTOMY FOR EARLY STAGE LUNG CANCER 2012;93:381 8 Table 1. Postoperative Morbidity Complication lung function and early stage disease. Overall and recurrence-free-survival were analyzed as were factors associated with decreased long-term survival. In addition, postoperative pulmonary function was analyzed in a smaller subset of patients. Material and Methods Number of Patients Atrial arrhythmias 16 Pneumonia 11 Prolonged air leak 7 Myocardial infarction 1 Empyema 1 From our prospectively maintained database, we identified and retrospectively reviewed all patients who underwent segmentectomy for primary lung cancer between 1999 and 2004 at the Mayo Clinic in Rochester, Minnesota. The Mayo Foundation Institutional Review Board granted approval for this study. The medical records were reviewed for age, sex, comorbidities, operative procedure, operative morbidity and mortality, length of hospitalization, histopathology, recurrence, adjuvant therapy, and long-term survival. All patients underwent CT imaging before the procedure. Pulmonary function tests were performed in the majority of patients as well as standard investigations for preoperative lung cancer staging such as positron emission tomography/ct fusion scans [10]. Patients were staged postsurgically according to the seventh edition of TNM staging system of the American Joint Committee on Cancer (AJCC). The indication for segmentectomy in this group of patients was poor pulmonary function, comorbidities, or surgeon judgment. Operative reports for all cases were reviewed. All segmental resections were performed by serratus anterior muscle-sparing posterolateral thoracotomy. The bronchovascular structures were identified, isolated, and divided; and the parenchymal margins of the segment resected with surgical staplers along the intersegmental plane. Simple wedge resections without anatomical dissection of the bronchovascular structures were specifically excluded. Mediastinal lymphadenectomy was a standard part of the procedure. Operative mortality included all deaths occurring within 30 days of the operative procedure and deaths that occurred later during the initial perioperative hospitalization. Survival data not available in the medical record were obtained from the Social Security Death Index. Deaths were attributed to lung cancer unless another cause was explicitly specified. Recurrence was defined as local if it occurred in the lobe in which the segmentectomy was performed or in the mediastinum. Patients whose recurrence was both local and distant were analyzed as having a local recurrence. Descriptive statistics for categorical variables are reported as frequency and percentage, and continuous variables are reported as mean (standard deviation) or median (range) as appropriate. Long-term survival was estimated using the Kaplan-Meier survival method, and 5-year estimates and 95% confidence intervals (CI) are reported [11]. The date of hospital discharge was the starting point in the survival estimation, and the date of death or last follow-up was the end point. The association of individual variables with survival was assessed using the log rank test for categorical variables and the Cox proportional hazards model for continuous variables and for the multivariate model [12, 13]. The multivariate model considered univariately significant variables (p 0.05) with model selection using the stepwise method (backward and forward methods resulted in the same model). Disease-free survival was analyzed with similar statistical methods. All statistical tests were two-sided with the p value set at 0.05 for statistical significance. Results One hundred thirteen consecutive patients underwent anatomic segmentectomy for the treatment of primary lung cancer during the study period. There were 58 men and 55 women with a median age of 72.5 years (range, 30 to 94 years). Significant comorbidities including emphysema, coronary artery disease, and diabetes were present in 62 patients (54.8%). Ninety-seven patients (85.8%) had a significant history of smoking. Twenty-seven patients Table 2. Pathologic Stage and Histology Stage n Squamous Adenocarcinoma BAC Carcinoid Other IA (T1a) IA (T1b) IB IIA IIB IIIA IIIB Totals Other histologies include small cell (n 3), large cell (n 2), spindle cell (n 1), and sarcomatoid (n 1). BAC bronchoalveolar cell carcinoma.

3 Ann Thorac Surg DONAHUE ET AL 2012;93:381 8 SEGMENTECTOMY FOR EARLY STAGE LUNG CANCER Table 3. Anatomic Segments Resected Segment Number of Patients Right upper lobe 30 Posterior 22 Anterior 4 Apical 4 Right lower lobe 23 Superior 16 Basilar 7 Left upper lobe 44 Apical-posterior 17 Anterior 14 Lingula 13 Left lower lobe 16 Superior 14 Basilar 2 (23.9%) were defined as current smokers as they were smoking at the time of diagnosis or within 30 days of surgery. Preoperative pulmonary function tests were available for review in 105 patients (92.9%). In these patients, the median preoperative forced expiratory volume of air in 1 second (FEV 1 ) was 1.53 L (range, 0.5 L to 3.27 L). The median preoperative percent of predicted FEV 1 was 61% (range, 20% to 112%). The median diffusion capacity of lung for carbon monoxide (DLCO) was 69% of predicted (range, 23% to 129%). Fourteen patients (12.4%) had a preoperative FEV 1 less than 1 L. All patients underwent preoperative CT scanning. Positron emission tomography scans were performed in 51 patients (45.1%). Percutaneous or transbronchial biopsies of the pulmonary lesion were attempted preoperatively in 31 patients (27.4%) and were positive for malignancy in 27 (87.1%). A previous thoracotomy had been performed in 24 patients (21.2%). Twenty-two (19.5%) of these patients had undergone a prior lobectomy for lung cancer. The lobectomy was performed a median of 45 months (range, to 228) before the segmentectomy. Previous stage designation was available for 17 patients (77.3%). Nine patients were stage IA, 4 were stage IB, 2 were stage IIA, 1 was stage IIB, and 1 was stage IIIA. There was no operative mortality. As detailed in Table 1, major postoperative morbidity occurred in 28 patients (24.8%), 7 of whom had multiple complications. The most common complication was development of an atrial arrhythmia, which occurred in 16 patients (14.2%). Eleven patients (9.7%) were diagnosed with pneumonia. Prolonged air leak occurred in 7 patients (6.2%). The median length of stay was 6 days (range, 3 to 30 days). Three patients required admission to the intensive care unit for respiratory insufficiency with a median duration of stay of 2 days (range, 1 to 20 days). Segmentectomy was performed through a serratus anterior muscle-sparing posterolateral thoracotomy in all patients. Concomitant procedures, most commonly an additional wedge resection, were performed in 21 patients (18.6%). Resection margins were negative in all cases. Tumor histology and pathologic staging are detailed in Table 2. Squamous cell histology, found in 43 patients (38.1%), was most common. Thirty-five patients (31.0%) had adenocarcinoma and 19 patients (16.8%) had bronchoalveolar cell carcinoma (BAC). Median tumor size was 2.2 cm (range, 0.4 cm to 8.0 cm). Sixty-nine patients (61.1%) had T1 tumors. Thirty-six patients (31.9%) had T2 tumors. Four patients (3.5%) had T3 tumors, 1 by virtue of chest wall invasion and 3 due to metastatic nodules within the same lobe. Four patients (3.5%) had T4 tumors due to the presence of metastatic nodules within a different, ipsilateral lobe. Twenty-two patients (19.5%) underwent mediastinoscopy; all were negative for nodal metastases. One hundred six patients (93.8%) underwent a mediastinal lymphadenectomy. Ninety-eight patients (86.7%) were N0, 9 patients (8.0%) were N1, and 6 patients (5.3%) were N2. Ninety-two patients (81.4%) were stage I, with 63 patients (55.8%) classified as stage IA and 29 (25.6%) classified as stage IB. GENERAL THORACIC Fig 1. Probability of overall survival (death from any cause) based on American Joint Committee on Cancer pathology stage after anatomic segmentectomy for primary lung cancer. Stages 2a and 2b and stages 3a and 3b are grouped together owing to small numbers of patients in these groups. Zero time represents hospital discharge date. Stage 1a (solid line) versus 1b (dashed line), p 0.005; stage 1a versus stage 2a/2b (dotted line), p 0.003; stage 1a versus stage 3a/3b (broken line), p

4 GENERAL THORACIC 384 DONAHUE ET AL Ann Thorac Surg SEGMENTECTOMY FOR EARLY STAGE LUNG CANCER 2012;93:381 8 Table 4. Univariate Analysis of Overall Survival, Cox Proportional Hazard Model Variable HR 95% CI p Value Age, per 10 years Sex, male Smoking status Nonsmoker Previous smoker Current smoker FEV L 1.75 L DLCO 69% 69% Diabetes mellitus CAD Postoperative arrhythmia Postoperative pneumonia Any postoperative complication Stage IA IB IIA/B IIIA/B Grade 1or Tumor size 2 cm Tumor location RUL LLL LUL RLL Histology Adenocarcinoma Squamous cell BAC BAC bronchoalveolar cell carcinoma; CAD coronary artery disease; CI confidence interval; DLCO lung diffusion capacity for carbon monoxide; FEV 1 forced expiratory volume in 1 second; HR hazard ratio; LLL left lower lobe; LUL left upper lobe; referent; RLL right lower lobe; RUL right upper lobe. The frequency with which respective segments were resected is detailed in Table 3. The most commonly resected segments were the posterior segment of the right upper lobe in 22 patients (19.5%), apical-posterior segment of the left upper lobe in 17 patients (15.0%), and superior segment of the right lower lobe in 16 patients (14.2%). Follow-up was complete in all patients with a median of 2 years (range, 30 days to 6.2 years). Eight patients (7.1%) received adjuvant therapy because of positive nodal disease. Thirty-nine patients (34.5%) died during the follow-up period. Estimated overall estimated 5-year survival for the entire study population was 59.4% (95% CI, 49.8% to 70.8%), with a median survival of 6.2 years. As depicted in Figure 1, for patients with stage IA lung cancer, estimated 5-year survival was 79.0 % (95% CI, 68.0% to 91.8%). For patients with stage IB lung cancer, estimated overall 5-year survival was 45.9% (95% CI, 29.6% to 71.3%). As seen in Table 4, current smoking at the time of diagnosis (p 0.03), preoperative DLCO less than 69% (p 0.04), tumor size greater than 2 cm (p 0.01), advanced stage (p 0.001), and advanced histology grade (p 0.03) were associated with decreased survival by univariate analysis. Neither histology nor location of the resected segment was associated with decreased survival, although BAC histology very closely approached statistical significance. In a multivariate model evaluating current smoking at the time of diagnosis, preoperative DLCO less than 69%, and tumor size greater than 2 cm, only tumor size greater than 2 cm was associated with decreased long-term survival (p ). Postoperative pulmonary function testing was performed in 37 patients (35.2%) who had preoperative values for comparison. These studies were obtained at a median of 22 months (range, 2 to 61 months) from the date of the segmentectomy. Twenty-seven of these patients were stage IA (16 T1a and 11 T1b), 9 were stage IB, and 1 was stage IIB. In this cohort of 37 patients, the median postoperative FEV 1 was 1.32 L (range, 0.5 L to 2.43 L). The median decline in FEV 1 after segmentectomy was 0.20 L (range, 0.84 L to 0.50 L; p 0.006). Postoperative DLCO values were available for review in 27 patients (25.7%) who had preoperative values for comparison. The median postoperative DLCO in these patients was 56% of predicted (range, 26% to 82%). The median decline in DLCO after segmentectomy was 11% (range, 29% to 13%; p ). We analyzed recurrence separately. Thirty-nine patients (34.5%) had a recurrence. These were local only in 8 patients (7.1%), local and distant in 9 patients (7.9%), and distant only in 22 patients (19.5%). Median time to recurrence was 505 days (range, 30 to 1,887 days). For the entire cohort, estimated 5-year recurrence-free survival was 52.7% (95% CI, 40.4% to 68.8%), with a median recurrence-free survival of 5.1 years. Table 5 depicts recurrence data for stage I patients. Seventeen patients (27.0%) with stage IA disease recurred. Estimated 5-year recurrence-free survival for stage IA patients was 62.8% (95% CI, 47.5% to 82.9%) (Fig 2). For the subset of 40 patients whose tumors were 2.0 cm or less, and are now considered T1a, 7 patients (17.5%) had recurrences. Two of these were local (5.0%) and 5 were distant (12.5%). For the 23 patients whose tumors were between 2 cm and 3 Table 5. Location of Recurrence in Stage I Patients Stage n Recurrence Local (%) Distant (%) IA (12.7) 9 (14.3) T1a (5.0) 5 (12.5) T1b (26.1) 4 (17.4) IB (27.6) 6 (20.7)

5 Ann Thorac Surg DONAHUE ET AL 2012;93:381 8 SEGMENTECTOMY FOR EARLY STAGE LUNG CANCER 385 Fig 2. Probability of recurrence-free survival based on American Joint Committee on Cancer pathology stage after anatomic segmentectomy for primary lung cancer. Stages 2a and 2b and stages 3a and 3b are grouped together owing to small numbers of patients in these groups. Zero time represents hospital discharge date. Stage 1a (solid line) versus stage 1b (dotted line), p 0.002; stage 1a versus stage 2a/2b (dashed line), p 0.222; stage 1a versus stage 3a/3b (broken line), p GENERAL THORACIC cm and are now considered T1b, 10 patients (43.5%) had recurrences, 6 of which involved local recurrence (26.1%). Estimated 5-year recurrence-free survival for stage I patients with T1a tumors was 68.8% (95% CI, 48.2% to 98.0%), compared with 49.4% (95% CI, 29.0% to 84.3%) for patients with T1b tumors (p 0.07) (Fig 3). Furthermore, 14 of the 29 stage IB patients (48.3%) had recurrences, 8 of which involved local recurrence (27.6%). Estimated 5-year recurrence-free survival for stage IB patients was only 32.8% (95% CI, 17.2% to 68.5%). Comment The principal concerns regarding segmentectomy as an acceptable treatment option for primary lung cancer are twofold: technical difficulty as compared with lobectomy or wedge resection, and oncologic adequacy of resection. The issue of oncologic adequacy extends to the comparison of segmentectomy to wedge resection as well. The major advantage of segmentectomy over lobectomy is that it spares pulmonary parenchyma and therefore has correspondingly decreased perioperative morbidity and preserves long-term respiratory function as compared with larger resections such as lobectomy. There is a growing base of literature relating the increased experience with segmentectomy, attesting to its technical feasibility, both by open and video-assisted thoracoscopic approaches [14]. Nevertheless, the use of true anatomic segmentectomies remains limited, accounting for only 4.4% of all pulmonary resections for primary lung tumors in The Society of Thoracic Surgeons (STS) general thoracic surgery database [15] perhaps because a true anatomic segmentectomy, with dissection, isolation, and control of the individual segmental bronchovascular structures, is more technically demanding than its less formal sublobar correlate, the wedge resection. This particular issue is likely why both segmentectomy and wedge resection were grouped together in the Fig 3. Probability of recurrence-free survival comparing stage 1A patients with stage T1a tumors (solid line) versus T1b tumors (broken line) after anatomic segmentectomy for primary lung cancer. Zero time represents hospital discharge date.

6 GENERAL THORACIC 386 DONAHUE ET AL Ann Thorac Surg SEGMENTECTOMY FOR EARLY STAGE LUNG CANCER 2012;93:381 8 limited resection arm of the current CALGB trial. We have specifically included only true anatomic segmental resections in this study in an effort to analyze this distinct operation. In view of this, the technical feasibility appears, as with previous reports, to be once again validated. The operative mortality, nil in this series, along with the perioperative morbidity appear to be consistent with other reports. Given the nature of the patients included in this cohort, with a large proportion having major comorbidities and limited lung function, these results compare favorably with recent reports on outcomes after anatomic segmentectomy from the University of Pittsburgh and in the multicenter ACOSOG Z0030 trial [7, 16]. With regard to oncologic adequacy of this form of limited resection, there are an increasing number of recent reports showing favorable results for segmentectomy for treating small, early stage NSCLC. A retrospective review of 68 patients who underwent segmentectomy at Rush-Presbyterian-St. Luke s Medical Center documented a 22.7% local/regional recurrence rate compared with 4.9% for the 103 patients who underwent lobectomy [5]. One year later, the prospective, randomized LCSG trial reported a local recurrence rate of 17.2% in 122 patients after limited resection compared with 6.4% after lobectomy [4]. Importantly, despite these high rates of local recurrence, neither study demonstrated a statistically significant survival advantage for lobectomy over limited resection for T1 tumors. This finding prompted the continuation of limited resections in higher risk patients. More recent refinements focusing on tumor size and margin have helped to dramatically reduce local recurrence rates to approximately the 5% local recurrence rates seen after lobectomy. A multiinstitutional, prospective Japanese study evaluated 55 patients with peripheral tumors less than 2 cm who underwent segmentectomy [9]. All patients were candidates for lobectomy and were N0 on the basis of intraoperative frozen section analysis during mediastinal node dissection. A mean margin of 2.3 cm was obtained by transecting the lung beyond the involved segment. With all patients followed for at least 5 years, local recurrence was 1.8%. Similarly, in the recently reported series of 182 patients who underwent segmentectomy for stage I NSCLC at the University of Pittsburgh, the mean tumor size was 2.3 cm and the mean margin was 1.82 cm [7]. Local/regional recurrence was 7.7%. Notably, 89% of recurrences occurred when the margin was less than 2.0 cm. Additional work from this group analyzing both wedge resections and segmentectomies found that a margin of at least 1 cm was necessary to limit local recurrences [17]. Lending further support to the importance of a 1 cm margin, in a recent report from Germany of 49 patients undergoing segmentectomy for stage IA NSCLC, local recurrence was 16%. No local recurrences occurred in patients with a margin greater than 1 cm [8]. Although margin size was not specifically examined in our study, our results further validate and clarify the importance of tumor size when contemplating performance of segmentectomy. By multivariate analysis, tumor size above 2 cm was the only variable found to be associated with decreased long-term survival. For patients with T1aN0 lesions, local recurrence was 5%, and 5-year recurrence-free survival was 68.8%. By contrast, local recurrence for T1bN0 lesions was 26.1%, with 5-year recurrence-free survival of only 49.4%. Notably, as seen in Table 2, patients with BAC tumors made up 27.5% of all patients with T1aN0 and 26.1% of all patients with T1bN0 tumors. However, in terms of recurrences, patients with BAC histology accounted for 5 of the 7 recurrences (71.4%) in patients with T1aN0 lesions and 2 of the 10 recurrences (20%) in patients with T1bN0 lesions. Given the multifocal nature of BAC lesions, this finding might actually overrepresent the recurrence rate for T1aN0 lesions in this study. The question of the benefit in either local control or survival offered by a segmentectomy over a wedge resection is still a matter of debate. No randomized, direct comparison between wedge resection and segmentectomy has been undertaken. An early report from the Montreal Chest Hospital demonstrated similar 6-year survival rates for patients undergoing lobectomy (n 97) or wedge resection (n 100) for early stage NSCLC [18]. No recurrence data were provided in this report. In a retrospective, multiinstitutional report comparing wedge resection (n 102) versus lobectomy (n 117) in patients with pathologic stage 1 NSCLC, local recurrence ranged from 16% to 24% after wedge resection, compared with 9% after lobectomy [19]. In this study, there was a statistically significant survival advantage favoring lobectomy, although this was likely influenced by the increased number of noncancer-related deaths in the wedge resection group. Wedge resection was compared with segmentectomy in a retrospective Japanese study of 512 patients with pathologic stage 1 NSCLC. Five-year survival for patients with T1a tumors was 85.7% after wedge resection versus 96.7% after segmentectomy [20]. By contrast, for patients with T1b tumors, 5-year survival after wedge resection was 39.4% versus 84.6% for segmentectomy, a difference that was statistically significant and provides justification for performing segmentectomy over wedge resection. Presumably, the ability to attain an adequate surgical margin and better segmental lymph node dissection is enhanced after segmentectomy as compared with wedge resection. In addition to decreased mortality and morbidity, the other advantage of performing segmentectomy over lobectomy is the preservation of lung function. Although the indications for obtaining postoperative pulmonary function studies in our patients were variable, previous studies are in general agreement with our findings. In our study, the median decline in FEV 1 after segmentectomy was 0.20 L. Although that represented a statistically significant difference, it is unlikely to represent a noticeable clinical change. The LCSG found a statistically significant difference in the decline in FEV 1 when comparing segmentectomy and lobectomy. By 12 to 18 months after surgery, FEV 1 decreased by 5.2% predicted after segmentectomy as compared with 11.1% after lobectomy [4]. In the Pittsburgh experience, at 1 year from surgery, FEV 1 decreased by 3.1% after segmentectomy versus 8.4% after lobectomy [21]. By contrast, the median

7 Ann Thorac Surg DONAHUE ET AL 2012;93:381 8 SEGMENTECTOMY FOR EARLY STAGE LUNG CANCER decline in DLCO after segmentectomy in our study was 11%, representing a significant statistical, and likely clinical, difference as well. Similarly, in the Pittsburgh experience, DLCO decreased by 12.5% after segmentectomy. If segmentectomy is to be adopted on a larger scale for treatment of early stage lung cancer, more study of postoperative pulmonary function is warranted. The thoracic surgical community eagerly awaits the results of the CALGB trial revisiting lobectomy versus limited resection for T1aN0 NSCLC in patients with adequate lung function. Until that time, segmentectomy provides a feasible option for patients with small, anatomically appropriate lesions, who have limited lung function or comorbidities such that the relative risks of lobectomy are concerning. The authors would like to acknowledge the expert assistance and statistical review by Kristine Thomsen and W. Scott Harmsen of the Mayo Clinic Department of Biostatistics. We also acknowledge the expertise and assistance of Lisa Halgren, RN, lead clinical nurse specialist from the Mayo Clinic General Thoracic Surgery Research Unit. erences 1. Churchill ED, Belsy R. Segmental pneumonectomy in bronchiectasis. Ann Surg 1939;109; Jensik RJ, Faber LP, Milloy FJ, Monson DO. Segmental resection for lung cancer: a fifteen-year experience. J Thorac Cardiovasc Surg 1973;66: Bennett WF, Smith RA. Segmental resection for bronchogenic carcinoma: a surgical alternative for the compromised patient. Ann Thorac Surg 1979;27: Ginsberg RJ, Rubinstein LV, for the Lung Cancer Study Group. Randomized trial of lobectomy versus limited resection for T1 N0 non-small cell lung cancer. Ann Thorac Surg 1995;60: Warren WH, Faber LP. Segmentectomy versus lobectomy in patients with stage I pulmonary carcinoma: five-year survival and patterns of intrathoracic recurrence. J Thorac Cardiovasc Surg 1994;107: Jones DR, Stiles BM, Denlinger CE, Antippa P, Daniel TM. Pulmonary segmentectomy: results and complications. Ann Thorac Surg 2003;76: Schuchert MJ, Pettiford BL, Keeley S, et al. Anatomic segmentectomy in the treatment of stage I non-small cell lung cancer. Ann Thorac Surg 2007;84: Sienel W, Stremmel C, Kirschnaum A, et al. Frequency of local recurrence following segmentectomy of stage 1A nonsmall cell lung cancer is influenced by segment localization and width of resection margins implication for patient selection for segmentectomy. Eur J Cardiothorac Surg 2007; 31: Yoshikawa K, Tsubota N, Kodama K, et al. Prospective study of extended segmentectomy for small lung tumors: the final report. Ann Thorac Surg 2002;73: Cassivi SD, Allen MS, Vanderwaerdt GD, et al. Patientcentered quality indicators for pulmonary resection. Ann Thorac Surg 2008;86: Kaplan E, Meier P. Nonparametric estimation from incomplete observations. J Am Stat Assoc 1958;53: Cox DR, Regression models and life tables (with discussion). J R Stat Soc Series B 1972;34: Peto R, Peto J. Asymptotically efficient rank invariant procedures (with discussion). J R Stat Soc Series A 1972;135: Shapiro M, Weiser TS, Wisnivesky JP, et al. Thoracoscopic segmentectomy compares favorably with thoracoscopic lobectomy for patients with small stage I lung cancer. J Thorac Cardiovasc Surg 2009;137: Boffa DJ, Allen MS, Grab JD, et al. Data from The Society of Thoracic Surgeons general thoracic surgery database: the surgical management of primary lung tumors. J Thorac Cardiovasc Surg 2008;135: Allen MS, Darling GE, Pechet TT, et al. Morbidity and mortality of major pulmonary resections in patients with early-stage lung cancer: initial results with randomized prospective ACOSOG Z0030 trial. Ann Thorac Surg 2006;81: El-Sharif A, Fernando HC, Santos R, et al. Margin and local recurrence after sublobar resection of non-small cell lung cancer. Ann Surg Oncol 2007;14: Errett LE, Wilson J, Chu-Jeng Chiu R, Munro DD. Wedge resection as an alternative procedure for peripheral bronchogenic carcinoma in poor-risk patients. J Thorac Cardiovasc Surg 1985;90: Landreneau RJ, Sugarbaker DJ, Mack MJ, et al. Wedge resection versus lobectomy for stage 1(T1 N0 M0) non-smallcell lung cancer. J Thorac Cardiovasc Surg 1997;113: Okada M, Nishio W, Sakamoto T, et al. Effect of tumor size on prognosis in patients with non-small cell lung cancer: the role of segmentectomy as a type of lesser resection. J Thorac Cardiovasc Surg 2005;129: Keenan RJ, Landreneau RJ, Maley RH, et al. Segmental resection spares pulmonary function in patients with stage 1 lung cancer. Ann Thorac Surg 2004;78: GENERAL THORACIC DISCUSSION DR BILL PUTNAM (Nashville, TN): Dr Donahue, I commend you and your coauthors for your efforts to identify those operations appropriate for patients with non-small cell lung cancer who may be at increased risk for resection. I agree that segmentectomy for high-risk T1a patients is preferred and can be recommended. However, I would be cautious about eliminating lung-sparing procedures for larger T status tumors as resection may have significant benefit over chemotherapy, radiation, or combinations of chemotherapy and radiation. Your retrospective review demonstrates the excellent local control and survival effectiveness of segmentectomy for T1a in patients carefully selected by their surgeon. This cohort reflects the patients undergoing segmentectomy over a 22-year period. How many patients had lobectomy, wedge resection, or some other type of therapy for similar staged lung cancer during this period? The Japanese have examined the role of segmental lymph node dissection in patients having segmentectomy. Positive N1 lymph node patients went on to lobectomy. For my second question, was a segmental lymph node dissection of any type performed in these patients and should this be recommended for those of us doing segmentectomy going forward? And given the excellent local control for these small lesions, the low 5% incidence of positive N2 disease, and a morbidity of 25%, our radiation oncology colleagues would have us believe that surgery is not needed. So why should these patients have an operation at all? Why not stereotactic radi-

8 GENERAL THORACIC 388 DONAHUE ET AL Ann Thorac Surg SEGMENTECTOMY FOR EARLY STAGE LUNG CANCER 2012;93:381 8 ation therapy? I enjoyed the presentation. Thank you very much. DR DONAHUE: Thank you very much, Dr Putnam. We would estimate that during the study period, 1,250 patients would have had a lobectomy for lung cancer, compared with 113 patients who had a segmentectomy. The overall wedge resection numbers are probably similar to the lobectomies, but I don t have the data on how many of those were for lung cancer. In terms of performing a segmental lymph node dissection with frozen section analysis, I think that is the certainly the ideal, and an approach we would advocate. This was not performed routinely during the segementectomies reported in this retrospective series. Finally, regarding the very important question that is looming about whether these patients need surgery at all, I think the data are still indicating that the gold standard would be surgery for these patients. As we heard this morning, the most current data from the RTOG study shows a 3-year survival of about 50% with SBRT for stage 1 patients. This falls short of our results with surgery, although it is fertile ground for cooperative group studies. Requirements for Maintenance of Certification in 2012 Diplomates of the American Board of Thoracic Surgery (ABTS) who plan to participate in the 2012 Maintenance of Certification (MOC) process as Certified-Active must hold an unrestricted medical license in the locale of their practice and privileges in a hospital accredited by the JCAHO (or other organization recognized by the ABTS). In addition, a valid ABTS certificate is an absolute requirement for entrance into the MOC process. If your certificate has expired, the only pathway for renewal of a certificate is to take and pass the Part I (written) and the Part II (oral) certifying examinations. The CME requirements are 150 Category I credits earned since January 1, At least half of these CME hours need to be in the broad area of thoracic surgery. Category II credits are not allowed. Interested individuals should refer to the Board s website ( for a complete description of acceptable CME credits. Diplomates will be required to take and pass a secured exam after their application has been approved. Taking SESATS in lieu of the secured exam is not an option. The secured exam will be given from September 10 to September 22, 2012, at Pearson Vue Testing Centers, which are located nationwide. Diplomates will have the opportunity to select the day and location of their exam. Diplomates who wish to maintain a Certified-Active status will be required to submit a summary of cases and will be required to participate in an outcomes database. For more details about this requirement, please visit the Board s website. Diplomates may apply for MOC in the year their certificate expires or, if they wish to do so, they may apply up to two years before it expires. However, the new certificate will be dated 10 years from the date of expiration of their original certificate or most recent MOC certificate. In other words, going through the MOC process early does not alter the 10-year validation. Diplomates certified prior to 1976 (the year that time-limited certificates were initiated) are also required to participate in MOC if they wish to maintain valid certificates. The deadline for submitting an application for MOC is March 1, 2012; however, the Board will accept late applications until April 15, A brochure outlining the rules and requirements for MOC in thoracic surgery is available on the Board s website. For additional information, please contact the American Board of Thoracic Surgery, 633 N St. Clair St, Ste 2320, Chicago, IL 60611; telephone (312) ; fax (312) ; info@abts.org by The Society of Thoracic Surgeons Ann Thorac Surg 2012;93: /$36.00 Published by Elsevier Inc