University of Massachusetts Medical School Faculty Publications

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Department of Radiation Oncology; Division of Thoracic Surgery; Department of Medical Oncology, University of Massachusetts Medical Center; Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine; Department of Orthopedics and Rehabilitation; Department of Radiology

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Diagnosis | Disease Modeling | Neoplasms | Oncology | Radiology | Respiratory Tract Diseases | Surgery | Surgical Procedures, Operative | Therapeutics


Purpose: To identify the incidence, preoperative risk factors, and prognosis associated with pathologically positive lymph node (pN+) in patients undergoing a sub-lobar resection (SLR).

Methods: This is a retrospective study using the National Cancer Database (NCDB) from 2004 to 2014 analyzing SLR excluding those with any preoperative chemotherapy and/or radiation, follow-up < 3 months, stage IV disease, or > 1 tumor nodule. Multivariable modeling (MVA) was used to determine factors associated with overall survival (OS). Propensity score matching (PSM) was used to determine preoperative risk factors for pN+ in patients having at least one node examined to assess radiation's effect on OS in those patients with pN+ and to determine whether SLR was associated with inferior OS as compared to lobectomy for each nodal stage.

Results: A total of 40,202 patients underwent SLR, but only 58.3% had one lymph node examined. Then, 2,615 individuals had pN+ which decreased progressively from 15.1% in 2004 to 8.9% in 2014 (N1, from 6.3 to 3.0%, and N2, from 8.4 to 5.9%). A lower risk of pN+ was noted for squamous cell carcinomas, bronchioloalveolar adenocarcinoma (BAC), adenocarcinomas, and right upper lobe locations. In the pN+ group, OS was worse without chemotherapy or radiation. Radiation was associated with a strong trend for OS in the entire pN+ group (p = 0.0647) which was largely due to the effects on those having N2 disease (p = 0.009) or R1 resections (p = 0.03), but not N1 involvement (p = 0.87). PSM noted that SLR was associated with an inferior OS as compared to lobectomy by nodal stage in the overall patient population and even for those with tumors < 2 cm.

Conclusion: pN+ incidence in SLRs has decreased over time. SLR was associated with inferior OS as compared to lobectomy by nodal stage. Radiation appears to improve the OS in patients undergoing SLR with pN+, especially in those with N2 nodal involvement and/or positive margins.


incidence, lung cancer, node positive, radiation, sub-lobar resection (SLR)

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Copyright © 2020 Varlotto, Emmerick, Voland, DeCamp, Flickinger, Maddox, Herbert, Griffin, Rava, Fitzgerald, Oliveira, Baima, Sood, Walsh, McIntosh, Lou, Maxfield, Rassaei and Uy. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

DOI of Published Version



Varlotto JM, Emmerick I, Voland R, DeCamp MM, Flickinger JC, Maddox DJ, Herbert C, Griffin M, Rava P, Fitzgerald TJ, Oliveira P, Baima J, Sood R, Walsh W, McIntosh LJ, Lou F, Maxfield M, Rassaei N, Uy K. The Incidence of Node-Positive Non-small-Cell Lung Cancer Undergoing Sublobar Resection and the Role of Radiation in Its Management. Front Oncol. 2020 May 26;10:417. doi: 10.3389/fonc.2020.00417. PMID: 32528866; PMCID: PMC7264374. Link to article on publisher's site


Full author list omitted for brevity. For the full list of authors, see article.

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Frontiers in oncology

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Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.