Global analysis of shared T cell specificities in human non-small cell lung cancer enables HLA inference and antigen discovery.

To identify disease-relevant T cell receptors (TCRs) with shared antigen specificity, we analyzed 778,938 TCRß chain sequences from 178 non-small cell lung cancer patients using the GLIPH2 (grouping of lymphocyte interactions with paratope hotspots 2) algorithm. We identified over 66,000 shared specificity groups, of which 435 were clonally expanded and enriched in tumors compared to adjacent lung. The antigenic epitopes of one such tumor-enriched specificity group were identified using a yeast peptide-HLA A∗02:01 display library. These included a peptide from the epithelial protein TMEM161A, which is overexpressed in tumors and cross-reactive epitopes from Epstein-Barr virus and E. coli. Our findings suggest that this cross-reactivity may underlie the presence of virus-specific T cells in tumor infiltrates and that pathogen cross-reactivity may be a feature of multiple cancers. The approach and analytical pipelines generated in this work, as well as the specificity groups defined here, present a resource for understanding the T cell response in cancer.

Integrating genomic features for non-invasive early lung cancer detection.

Radiologic screening of high-risk adults reduces lung-cancer-related mortality1,2; however, a small minority of eligible individuals undergo such screening in the United States3,4. The availability of blood-based tests could increase screening uptake. Here we introduce improvements to cancer personalized profiling by deep sequencing (CAPP-Seq)5, a method for the analysis of circulating tumour DNA (ctDNA), to better facilitate screening applications. We show that, although levels are very low in early-stage lung cancers, ctDNA is present prior to treatment in most patients and its presence is strongly prognostic. We also find that the majority of somatic mutations in the cell-free DNA (cfDNA) of patients with lung cancer and of risk-matched controls reflect clonal haematopoiesis and are non-recurrent. Compared with tumour-derived mutations, clonal haematopoiesis mutations occur on longer cfDNA fragments and lack mutational signatures that are associated with tobacco smoking. Integrating these findings with other molecular features, we develop and prospectively validate a machine-learning method termed 'lung cancer likelihood in plasma' (Lung-CLiP), which can robustly discriminate early-stage lung cancer patients from risk-matched controls. This approach achieves performance similar to that of tumour-informed ctDNA detection and enables tuning of assay specificity in order to facilitate distinct clinical applications. Our findings establish the potential of cfDNA for lung cancer screening and highlight the importance of risk-matching cases and controls in cfDNA-based screening studies.

Complications of Outpatient Chest Tube Management for Prolonged Air Leaks After Pulmonary Surgery.

PURPOSE: Air leaks are common after pulmonary surgery. Prolonged air leaks (PALs) may persist through discharge and often are managed with one-way valve devices (OWD). We sought to determine the course and complications of patients discharged with OWDs, risk factors for complications, and to evaluate the utility of clamp trials before chest tube (CT) removal. METHODS: Single-institution, retrospective review of patients discharged with a OWD after pulmonary surgery between 2008 and 2022. Charts were examined for the presence of complications and CT duration. Differences in CT duration were compared by using the Wilcoxon rank-sum test. RESULT: Sixty-four of 1917 (3.3%) pulmonary surgeries resulted in OWD use. Twelve of 64 (19%) patients discharged with a OWD suffered a complication. Nine of 64 (14%) had a CT-related readmission, and seven of 64 (11%) required PAL intervention. Patients sustaining a complication demonstrated longer CT durations before complication compared with duration in patients without complications, with median days of 13 [IQR 6-21] vs. 7 [IQR 6-12], p = 0.04). Five (7.8%) OWD patients developed an empyema; only one (20%) occurred before a CT duration of 14 days. Sixteen of 64 (25%) patients underwent a clamp trial before CT removal. One of ten (10%) failed even with no air leak present, whereas one of six (17%) failed with a present/questionable air leak. CONCLUSIONS: One-way valve device use has a substantial complication rate, and chest tube duration is a risk factor. In-hospital interventions might benefit patients with larger leaks that likely require prolonged OWD use. Because clamp trials occasionally fail, we contend that a clamp trial is the safest course before CT removal.

Impact of Delaying Surgery After Chemoradiation on Outcomes for Locally Advanced Esophageal Squamous Cell Carcinoma.

BACKGROUND: Performing selective esophagectomy for locally advanced squamous cell carcinoma may spare patients morbidity, but delayed surgery may infer higher risks. This study evaluated the impact of length of time between chemoradiation and esophagectomy on perioperative outcomes and long-term survival. METHODS: The impact of surgical timing, stratified by surgery performed < 180 and ≥ 180 days from starting radiation, on perioperative outcomes and survival in patients treated with chemoradiation and esophagectomy for cT1N + M0 and cT2-4, any N, M0 squamous cell carcinoma of the mid-distal esophagus in the National Cancer Database (2006-2016) was evaluated with logistic regression, Kaplan-Meier curves, Cox proportional-hazards methods, and propensity-matched analysis. RESULTS: Median time between starting radiation and esophagectomy in 1641 patients was 93 (IQR 81-114) days. Most patients (96.8%, n = 1589) had surgery within 180 days of starting radiation, while 52 patients (3.2%) had delayed surgery. Black race and clinical T stage were associated with delayed surgery. Rates of pathologic upstaging, downstaging, complete response, and positive margins were not significantly different between the groups. Patients with delayed surgery had increased major morbidity as measured by a composite of length of hospital stay, readmission, and 30-day mortality [42.3% (22/52) vs 22.3% (355/1589), p = 0.001]. However, delayed surgery was not associated with a significant difference in survival in both univariate [5-year survival 32.8% (95% CI 21.1-50.7) vs 47.3% (44.7-50.1), p = 0.19] and multivariable analysis [hazard ratio (HR) 1.23 (0.85-1.78), p = 0.26]. CONCLUSIONS: Delaying surgery longer than 180 days after starting chemoradiation for esophageal squamous cell carcinoma is associated with worse perioperative outcomes but not long-term survival.

Characterization of Epidural Analgesia Interruption and Associated Outcomes After Esophagectomy.

INTRODUCTION: Interruption of thoracic epidural analgesia may impact the postoperative course following esophagectomy. This study investigates the incidence and causes of epidural interruption in esophagectomy patients along with associated postoperative outcomes. METHODS: This single-institution retrospective analysis examined patients undergoing esophagectomy who received a thoracic epidural catheter from 2016 to 2020. Patients were stratified according to whether epidural catheter infusion was interrupted or not postoperatively. Outcomes were compared between the two groups, and predictors of epidural interruption and postoperative complications were estimated using multivariable logistic regression. RESULTS: Of the 168 patients who received a thoracic epidural before esophagectomy, 60 (35.7%) required epidural interruption and 108 (64.3%) did not. Interruption commonly occurred on postoperative day 1 and was due to hypotension 80% of the time. Heart failure (10.0% versus 0.9%, P = 0.009), atrial fibrillation (20.0% versus 3.7%, P = 0.002), preoperative opioid use (30.0% versus 16.7%, P = 0.043), and higher American Society of Anesthesiology classification (88.4% versus 70.4%, P = 0.008) were more prevalent in the epidural interruption cohort. The female gender was associated with epidural interruption on multivariable logistic regression (adjusted odds ratio [AOR] 2.45, P = 0.039). Patients in the epidural interruption cohort had a higher incidence of delirium (30.5% versus 13.9%, P = 0.010), sepsis (13.6% versus 3.7%, P = 0.028), and severe anastomotic leak (18.3% versus 7.4%, P = 0.032). On adjusted analysis, heart disease (AOR 4.26, P = 0.027), BMI <18.5 (AOR 9.83, P = 0.031), and epidural interruption due to hypotension (AOR 3.51, P = 0.037) were associated with severe anastomotic leak. CONCLUSIONS: Early epidural interruption secondary to hypotension in esophagectomy patients may be a harbinger of postoperative complications such as sepsis and severe anastomotic leak. Patients requiring epidural interruption due to hypotension should have a low threshold for additional workup and early intervention.

Perioperative Outcomes After Combined Esophagectomy and Lung Resection.

INTRODUCTION: The impact of concomitant lung resection during esophagectomy on short-term outcomes is not well characterized. This study tests the hypothesis that lung resection at the time of esophagectomy is not associated with increased perioperative morbidity or mortality. METHODS: Perioperative outcomes for esophageal cancer patients who underwent esophagectomy alone (EA) were compared to patients who had concurrent esophagectomy and lung resection (EL) using the NSQIP database between 2006-2017. Predictors of morbidity and mortality, including combined surgery, were evaluated using multivariable logistic regression. RESULTS: Among the 6,225 study patients, 6,068 (97.5%) underwent EA and 157 (2.5%) underwent EL. There were no differences in baseline characteristics between the two groups. Operating time for EL was longer than EA (median 416 versus 371 minutes, P < 0.01). Median length of stay was 10 d for both groups. Perioperative mortality was not significantly different between EL and EA patients (5.1% versus 2.8%, P = 0.08). EL patients had higher rates of postoperative pneumonia (22.3% versus 16.2%, P = 0.04) and sepsis (11.5% versus 7.1%, P = 0.03), however major complication rates overall were similar (40.8% versus 35.3%, P = 0.16). Combining lung resection with esophagectomy was not independently associated with increased postoperative morbidity (AOR 1.21 [95% CI 0.87-1.69]) or mortality (AOR 1.63 [95% CI 0.74-3.58]). CONCLUSIONS: Concurrent lung resection during esophagectomy is not associated with increased mortality or overall morbidity, but is associated with higher rates of pneumonia beyond esophagectomy alone. Surgeons considering combined lung resection with esophagectomy should carefully evaluate the patient's risk for pulmonary complications and pursue interventions preoperatively to optimize respiratory function.

Cancer diagnoses and survival rise as 65-year-olds become Medicare-eligible.

BACKGROUND: A Medicare effect has been described to account for increased health care utilization occurring at the age of 65 years. The existence of such an effect in cancer care, where it would be most likely to reduce mortality, has been unclear. METHODS: Patients aged 61 to 69 years who were diagnosed with lung, breast, colon, or prostate cancer from 2004 to 2016 were identified with the Surveillance, Epidemiology, and End Results database and were dichotomized on the basis of eligibility for Medicare (61-64 vs 65-69 years). With age-over-age (AoA) percent change calculations, trends in cancer diagnoses and staging were characterized. After matching, uninsured patients who were 61 to 64 years old (pre-Medicare group) were compared with insured patients who were 65 to 69 years old (post-Medicare group) with respect to cancer-specific mortality. RESULTS: In all, 134,991 patients were identified with lung cancer, 175,558 were identified with breast cancer, 62,721 were identified with colon cancer, and 238,823 were identified with prostate cancer. The AoA growth in the number of cancer diagnoses was highest at the age of 65 years in comparison with all other ages within the decade for all 4 cancers (P < .01, P < .001, P < .01, and P < .001, respectively). In a comparison of diagnoses at the age of 65 years with those in the 61- to 64-year-old cohort, the greatest difference for all 4 cancers was seen in stage I. In matched analyses, the 5-year cancer-specific mortality was worse for lung (86.3% vs 78.5%; P < .001), breast (32.7% vs 11.0%; P < .001), colon (57.1% vs 35.6%; P < .001), and prostate cancer (16.9% vs 4.8%; P < .001) in the uninsured pre-Medicare group than the insured post-Medicare group. CONCLUSIONS: The age threshold of 65 years for Medicare eligibility is associated with more cancer diagnoses (particularly stage I), and this results in lower long-term cancer-specific mortality for all cancers studied. LAY SUMMARY: Contributing to the current debate regarding Medicare for all, this study shows that the expansion of Medicare would improve cancer outcomes for the near elderly.

A National Analysis of Short-term Outcomes and Long-term Survival Following Thoracoscopic Versus Open Lobectomy for Clinical Stage II Non-Small-Cell Lung Cancer.

OBJECTIVE: To compare outcomes after open versus thoracoscopic (VATS) lobectomy for clinical stage II (cN1) non-small-cell lung cancer (NSCLC). BACKGROUND: There have been no published studies evaluating the impact of a VATS approach to lobectomy for N1 NSCLC on short-term outcomes and survival. METHODS: Outcomes of patients with clinical T1-2, N1, M0 NSCLC who underwent lobectomy without induction therapy in the National Cancer Data Base (2010-2012) were evaluated using multivariable Cox proportional hazards modeling and propensity score-matched analysis. RESULTS: Median follow-up of 1559 lobectomies (1204 open and 355 VATS) was 43.2 months. The VATS approach was associated with a shorter median hospitalization (5 vs 6 d, P < 0.001) than the open approach. There were no significant differences between the VATS and open approach with regard to nodal upstaging (12.0% vs 10.5%, P = 0.41), 30-day mortality (2.3% vs 3.1%, P = 0.31), and overall survival (5-yr survival: 48.6% vs 48.7%, P = 0.76; multivariable-adjusted HR for VATS approach: 1.08, 95% CI: 0.90-1.30, P = 0.39). A propensity score-matched analysis of 334 open and 334 VATS patients who were well matched by 14 common prognostic covariates, including tumor size, and comorbidities, continued to show no significant differences in nodal upstaging, 30-day mortality, and 5-year survival between the VATS and open groups. CONCLUSION: In this national analysis, VATS lobectomy was used in the minority of N1 NSCLC cases but was associated with shorter hospitalization and similar nodal upstaging rates, 30-day mortality, and long-term survival when compared to open lobectomy. These findings suggest thoracoscopic techniques are feasible for the treatment of stage II (cN1) NSCLC.

Strong for Surgery: Association Between Bundled Risk Factors and Outcomes After Major Elective Surgery in the VA Population.

BACKGROUND: Strong for Surgery (S4S) is a public health campaign focused on optimizing patient health prior to surgery by identifying evidence-based modifiable risk factors. The potential impact of S4S bundled risk factors on outcomes after major surgery has not been previously studied. This study tested the hypothesis that a higher number of S4S risk factors is associated with an escalating risk of complications and mortality after major elective surgery in the VA population. METHODS: The Veterans Affairs Surgical Quality Improvement Program (VASQIP) database was queried for patients who underwent major non-emergent general, thoracic, vascular, urologic, and orthopedic surgeries between the years 2008 and 2015. Patients with complete data pertaining to S4S risk factors, specifically preoperative smoking status, HbA1c level, and serum albumin level, were stratified by number of positive risk factors, and perioperative outcomes were compared. RESULTS: A total of 31,285 patients comprised the study group, with 16,630 (53.2%) patients having no S4S risk factors (S4S0), 12,323 (39.4%) having one (S4S1), 2,186 (7.0%) having two (S4S2), and 146 (0.5%) having three (S4S3). In the S4S1 group, 60.3% were actively smoking, 35.2% had HbA1c > 7, and 4.4% had serum albumin < 3. In the S4S2 group, 87.8% were smokers, 84.8% had HbA1c > 7, and 27.4% had albumin < 3. Major complications, reoperations, length of stay, and 30-day mortality increased progressively from S4S0 to S4S3 groups. S4S3 had the greatest adjusted mortality risk (adjusted odds radio [AOR] 2.56, p = 0.04) followed by S4S2 (AOR 1.58, p = 0.02) and S4S1 (AOR 1.34, p = 0.02). CONCLUSION: In the VA population, patients who had all three S4S risk factors, namely active smoking, suboptimal nutritional status, and poor glycemic control, had the greatest risk of postoperative mortality compared to patients with fewer S4S risk factors.

Cut it out! Thoracic surgeon's approach to pulmonary mucormycosis and the role of surgical resection in survival.

BACKGROUND: Mucormycosis portends a poor prognosis with mortality rates ranging from 50% to 70% in pulmonary mucormycosis (PM) and up to 95% in disseminated disease. However, detailed outcomes data have been lacking. It remains unknown how to identify patients who would benefit from surgical resection. OBJECTIVES: We present our experience with patients undergoing surgical resection for PM, including an analysis of factors affecting postoperative survival. We also describe a thoracic surgeon's approach through illustrative cases. PATIENTS/METHODS: We conducted a single-centre retrospective study of all adult patients with PM who received antifungal therapy and underwent surgical resection or who received antifungal therapy alone at Stanford between January 2004 and June 2018. RESULTS: Twelve patients received antifungal therapy and underwent surgical resection and 13 patients received antifungal therapy alone. From infection onset to death (or right-censoring if still alive), patients who underwent surgical resection had a median survival of 406 days (mean, 561.3; range, 22-2510), and patients who received antifungal therapy alone had a median survival of 28 days (mean, 66.7; range, 8-447). In patients who underwent surgical resection, median postoperative survival time was 154 days (range, 11-2495), in-hospital mortality was 16.7%, and 1-year mortality was 50.0%. Age, primary disease, ASA status, extrapulmonary dissemination, laterality, multilobar involvement, number of lesions, largest lesion size, platelet count, surgical approach, type of resection or extent of resection were not significantly associated with postoperative survival. CONCLUSIONS: Surgical resection significantly increases survival and should be strongly considered for selected patients with PM.

The Trajectory of Postoperative Pain Following Mastectomy with and without Paravertebral Block.

Evidence to support the argument that general anesthesia (GA) with paravertebral block (PVB) provides better pain relief for mastectomy patients than GA alone is contradictory. The aim of this study was to explore pain and analgesia after mastectomy with or without PVB during acute inpatient recovery. A retrospective study was conducted in a single hospital providing specialist cancer services in metropolitan Melbourne, Australia. We explored pain and concomitant analgesic administration in 80 consecutive women recovering from mastectomy who underwent GA with (n = 40) or without (n = 40) PVB. A pain management index (PMI) was derived to illustrate the efficacy of management from day of surgery (DOS) to postoperative day (POD) 3. Patients who reported no pain progressively increased from DOS (n = 12, 15%) to POD 3 (n = 54, 67.5%). Most patients were administered analgesics as a combination of acetaminophen and a strong opioid on DOS (n = 53, 66.2%), POD 1 (n = 45, 56.2%), POD 2 (n = 33, 41.2%), and POD 3 (n = 21, 26.2%). Less than 6% of patients on any POD were administered multimodal anlagesics. PMI scores indicate some pain in the context of receiving weak and strong opioids for GA patients and more frequent use of nonopioid analgesics in PVB patients during recovery. These findings highlight the need for data describing patterns of analgesic administration in addition to reports of postoperative pain to determine the most effective means of avoiding postoperative pain in patients who require mastectomy.

Management of Paraesophageal Hernias.

Paraesophageal hernias are classified according to the altered anatomic relationships between the gastroesophageal junction or stomach and the diaphragmatic hiatus. Herniation of these structures into the mediastinum may produce common complaints such as reflux, chest pain, and dysphagia. The elective repair of these hernias is well tolerated and significantly improves quality of life among patients with symptomatic disease. The hallmarks of a quality repair include the circumferential mobilization of the esophagus to generate 3 cm of tension-free intra-abdominal length and the performance of a fundoplication.

The Impact of Immunotherapy Use in Stage IIIA (T1-2N2) NSCLC: A Nationwide Analysis.

Introduction: Multiple clinical trials have revealed the benefit of immunotherapy (IO) for NSCLC, including unresectable stage III disease. Our aim was to investigate the impact of IO use on treatment and outcomes of potentially resectable stage IIIA NSCLC in a broader nationwide patient cohort. Methods: We queried the National Cancer Database (2004-2019) for patients with stage IIIA (T1-2N2) NSCLC. Treatment and survival were evaluated with descriptive statistics, logistic regression, Kaplan-Meier analysis, and Cox proportional hazards modeling. Results: Overall, 5.5% (3777 of 68,335) of patients received IO. IO use was uncommon until 2017, but by 2019, it was given to 40.1% (1544 of 2308) of stage IIIA patients. The increased use of IO after 2017 was associated with increased definitive chemoradiation treatment (54.2% [6800 of 12,535] from years 2017 to 2019 versus 46.9% [26,251 of 55,914] from 2004 to 2016, p < 0.001) and less use of surgery (18.1% [2266 of 12,535] from years 2017 to 2019 versus 22.0% [12,300 of 55,914] from 2004 to 2016, p < 0.001). IO treatment was associated with significantly better 5-year survival in the entire cohort (36.9% versus 23.4%, p < 0.001) and the subsets of patients treated with chemoradiation (37.2% versus 22.7%, p < 0.001) and surgery (48.6% versus 44.3%, p < 0.001). Pneumonectomy use decreased with increased IO treatment (5.1% of surgical patients [116 of 2266] from years 2017 to 2019 versus 9.2% [1127 of 12,300] from 2004 to 2016, p < 0.001). Conclusions: Increased use of IO was associated with a change in treatment patterns and improved survival for patients with stage IIIA(N2) NSCLC.

Lepidic-Type Lung Adenocarcinomas: Is It Safe to Observe for Growth Before Treating?

BACKGROUND: Lepidic-type adenocarcinomas (LPAs) can be multifocal, and treatment is often deferred until growth is observed. This study investigated the potential downside of that strategy by evaluating the relationship of nodal involvement with tumor size and survival. METHODS: The impact of tumor size on lymph node involvement and survival was evaluated for National Cancer Database patients who underwent surgery without induction therapy as primary treatment for cT1-3 N0 M0 histologically confirmed LPA from 2006 to 2019 by using logistic regression, Kaplan-Meier, and Cox analyses. RESULTS: Positive nodes occurred in 442 of 8286 patients (5.3%). The incidence of having positive nodes approximately doubled with each 1-cm increment increase in size. Patients with positive nodes were more likely to have larger tumors (27 mm vs 20 mm, P < .001) and clinical ≥T2 disease (40.7% vs 26.8%, P < .001) compared with node-negative patients. However, tumor size was the only significant independent predictor of having positive nodal disease in logistic regression analysis, and this association grew stronger with each incremental centimeter increase in size. Patients with positive nodes were more likely to undergo adjuvant radiotherapy (23.5% vs 1.1%, P < .001) and chemotherapy (72.9% vs 7.9%, P < .001), and expectedly, had worse survival compared with the node-negative group in univariate (5-year overall survival, 50.9% vs 81.1%, P < .001) and multivariable (hazard ratio, 2.56; 95% CI, 2.14-3.05; P < .001) analyses. CONCLUSIONS: Nodal involvement is relatively uncommon in early-stage LPAs but steadily increases with tumor size and is associated with dramatically worse survival. These data can be used to inform treatment decisions when evaluating LPA patients.

Clinical impact of EGFR and KRAS mutations in surgically treated unifocal and multifocal lung adenocarcinoma.

Background: Epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma (KRAS) are the two most common oncogenic drivers in lung adenocarcinoma, and their roles still need further exploration. Here we aimed to compare the clinical impact of EGFR and KRAS mutations on disease progression in resected unifocal and multifocal lung adenocarcinoma. Methods: Clinicopathologic and genomic data were collected for patients who underwent resection of lung adenocarcinoma from 2008 to 2022 at Stanford University Hospital. Retrospective review was performed in 241 patients whose tumors harbored EGFR (n=150, 62.2%) or KRAS (n=91, 37.8%) mutations. Clinical outcome was analyzed with special attention to the natural history of secondary nodules in multifocal cases wherein the dominant tumor had been resected. Results: We confirm that compared with EGFR mutations, patients with KRAS mutations had more smokers, larger tumor size, higher TNM stage, higher positron emission tomography (PET)/computed tomography (CT) standard uptake value max, higher tumor mutation burden, and worse disease-free survival and overall survival on univariate analysis. For patients with multifocal pulmonary nodules, the median follow-up of unresected secondary nodules was 55 months. Secondary nodule progression-free survival (SNPFS) was significantly worse for patients with KRAS mutations than those with EGFR mutations (mean 40.3±6.6 vs. 67.7±6.5 months, P=0.004). Univariate analysis showed tumor size, tumor morphology, pathologic TNM stage, and KRAS mutations were significantly associated with SNPFS, while multivariate analysis showed only KRAS mutations were independently associated with worse SNPFS (hazard ratio 1.752, 95% confidence interval: 1.017-3.018, P=0.043). Conclusions: Resected lung adenocarcinomas with KRAS mutations have more aggressive clinicopathological features and confer worse prognosis than those with EGFR mutations. Secondary pulmonary nodules in multifocal cases with dominant KRAS-mutant tumors have more rapid progression of the secondary nodules.

Impacts of Positive Margins and Surgical Extent on Outcomes After Early-Stage Lung Cancer Resection.

BACKGROUND: Sublobar resection of early-stage non-small cell lung cancer (NSCLC) is increasingly considered appropriate but may compromise margins compared with lobectomy. This study evaluated resection extent, margin status, and survival in patients with clinical stage I NSCLC. METHODS: Patients with clinical T1-2 N0 M0 NSCLC in the National Cancer Database (2006-2020) who were treated with primary surgery were compared stratified by margin status. The potential benefit of radiation was explored in subgroup analysis of patients who underwent sublobar resection with positive margins. RESULTS: Positive margins occurred in 5089 (2.8%) of 181,824 patients and were more common in sublobar resections compared with lobectomy (4.3% vs 2.4%; P < .001). Sublobar resection had the strongest association with positive margins in multivariable analysis (odds ratio, 2.06; 95% CI, 1.91-2.23; P < .001). Patients with positive margins were more likely to undergo both adjuvant chemotherapy (16% vs 13%; P < .001) and radiation (17% vs 1%; P < .001) but had worse survival in univariate analysis (44.0% 5-year overall survival vs 69.2%; P < .001) and multivariable Cox analysis (hazard ratio, 1.71; 95% CI, 1.63-1.78; P < .001) in the entire cohort, as well as in a univariate subset analysis of lobectomy (46.9% vs 70.4%; P < .001) and sublobar resection (37.5% vs 64.1%; P < .001). Postoperative radiation for patients who underwent sublobar resection with positive margins did not improve 5-year overall survival (36.3% for irradiated patients vs 38.3% for nonirradiated patients; P = .57), and patients who underwent sublobar resection with positive margins who were treated with radiation had survival inferior to that of patients who underwent lobectomy with negative margins. CONCLUSIONS: Positive margins occur more frequently after sublobar resection of clinical stage I NSCLC compared with lobectomy. Patients with positive margins have worse survival than patients who undergo complete resection and are not rescued by postoperative radiation.