MINNEAPOLIS – Sublobar resection and lobectomy resulted in equivalent lung cancer survival and overall recurrence rates in a screen-detected cohort of 348 stage IA non–small-cell lung cancer patients.
In all, 7% of patients (4/54) who underwent sublobar resection and 10% of those (29/294) who underwent lobectomy died of lung cancer after a median follow-up of 73 months (P = .64).
All-cause mortality was also statistically similar at 17% and 22%, said Dr. Nasser Altorki, professor of cardiothoracic surgery and director of thoracic surgery at New York Presbyterian–Weill Cornell Medical Center in New York.
Although lobectomy has been the standard of care for resection of early-stage non–small-cell lung cancer since 1994, several studies support sublobar resection in patients with small peripheral tumors and the elderly with compromised pulmonary reserve.
The best surgical treatment for younger patients with adequate cardiopulmonary function remains controversial, with two large, ongoing trials in the U.S. and Japan evaluating lobar vs. sublobar resection in this setting. A recent best evidence paper (Interact. CardioVasc. Thorac. Surg. 2012;14:816-20) concluded that lobectomy is still the best surgical option for these patients, citing evidence of lower survival and higher recurrence rates with wedge resections than with anatomic segmentectomies. The two sublobar techniques are often lumped together in comparisons with lobectomy, but are not technically or oncologically the same.
Wedge resection in the current study seemed to be associated with a higher rate of recurrence than segmentectomy, Dr. Altorki said at the annual meeting of the American Association for Thoracic Surgery.
Recurrence occurred in 32 patients after lobectomy and 8 after sublobar resection (11% vs. 15%; P = .40), with all of the sublobar resection recurrences occurring after wedge resection (8/38 or 21% vs. 0%).
"I don’t want to say this is a practice-changing study; however, it is a study that calls for more technical equipoise in our approach to the [surgical] treatment of lung cancer," he said during a discussion of the results. "Clearly, we can apply this operation to patients who would be candidates for both lobectomy and sublobar resection, but it does not extend to those patients, for example, that would have been poor candidates for any surgical resection."
The 348 patients had c1A non–small-cell lung cancer that presented as a solid nodule on computed tomography screening and underwent surgery as part of the International Early Lung Cancer Action Program from 1993 to 2011. Comorbidities were similar among the lobectomy and sublobar patients including cardiac disease (6% vs. 11%), chronic obstructive pulmonary disease (15% vs. 26%) and diabetes (9% vs. 7%). Their median age was 63 vs. 65 years, and the median number of pack-years of smoking was 48 vs. 49, respectively.
The lobectomy group had significantly larger tumors (13 mm vs. 11 mm), more frequent sampling of mediastinal nodes (78% vs. 56%) and more resected lymph nodes (mean 8 vs. 5).
The overall rate of hospital mortality in the multicenter study was low at 0.9% (3/348) and "represents what is achievable in screening centers of excellence," Dr. Altorki said.
Ten-year survival was 88% with lobectomy and 90% with sublobar resection (log rank P = .64). There was no difference in patients with tumors less than 2 cm (88% vs. 89%), who represented the majority or 86% of the cohort.
Cox regression analysis, adjusted for the above potential confounders, showed that only age (hazard ratio, 2.9; P less than .0001) and severe emphysema (HR, 4.2; P = .005) significantly predicted survival, whereas sublobar resection did not (HR, 0.8; P = .60), he said.
Invited discussant Dr. Joseph S. Friedberg, chief of thoracic surgery at the University of Pennsylvania Health System-Presbyterian in Philadelphia, expressed surprise that despite undergoing surgery by highly qualified general thoracic surgeons, 70% of sublobar resections were performed as wedge and not segmentectomies, and that more than 40% of sublobar resection patients and nearly a quarter of lobectomy patients did not have one mediastinal node biopsied.
"One would expect, based on the Lung Cancer Study Group analysis and common sense, that some of these patients, especially sublobar resection patients, were understaged and/or undertreated and yet the results are as good as anything in the literature," he said. "How do you reconcile that?"
Dr. Altorki said assessment of the mediastinal field was disappointing and that further education is needed on the prognostic and therapeutic benefits of such assessment, but that the rate far exceeds what is in the published literature. He also speculated that most of the patients were done by video-assisted thoracic surgery and that mediastinal node assessment may not be as straightforward with VATS as it is with open surgery.