Secondary Analysis of the Rate of Second Primary Lung Cancer From Cancer and Leukemia Group B 140503 (Alliance) Trial of Lobar Versus Sublobar Resection for T1aN0 Non-Small-Cell Lung Cancer

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Patients with early-stage non-small-cell lung cancer (NSCLC) who undergo curative surgical resection are at risk for developing second primary lung cancer (SPLC). Cancer and Leukemia Group B 140503 (Alliance) was a multicenter, international, randomized, phase III trial in patients with stage T1aN0 NSCLC (using the TNM staging system seventh edition) and demonstrated the noninferiority for disease-free survival between sublobar resection (SLR) and lobar resection (LR). After surgery, patients underwent computed tomography surveillance as defined by the protocol. The determination of a SPLC was done by the treating physician and recorded in the study database. We performed an analysis of the rate of SPLC (per patient per year) and the 5-year cumulative incidence in the study population and within the SLR and LR arms. Median follow-up was 7 years. The rate per patient per year in the study population, in the SLR arm, and in the LR arm was 3.4% (95% CI, 2.9 to 4.1), 3.8% (95% CI, 2.9 to 4.9), and 3.1% (95% CI, 2.4 to 4.1), respectively. The estimated 5-year cumulative incidence of SPLC in the study population, SLR arm, and LR arm was 15.9% (95% CI, 12.9 to 18.9), 17.2% (95% CI, 12.7 to 21.5), and 14.7% (95% CI, 10.6 to 18.7), respectively.

Wedge resection, segmentectomy, and lobectomy: oncologic outcomes based on extent of surgical resection for ≤2 cm stage IA non-small cell lung cancer

Background

Long-standing controversy has existed over whether sublobar resection is an adequate oncological procedure for clinical stage IA non-small cell lung cancer (NSCLC) ≤2 cm, despite the recent randomized trial reports of Japanese Clinical Oncology Group (JCOG) 0802 and Cancer and Leukemia Group B (CALGB) 140503 demonstrating non-inferior outcomes with sublobar resection compared to lobectomy. As practice patterns shift, we sought to compare oncologic outcomes in patients with these early-stage tumors after wedge resection, segmentectomy, or lobectomy in a contemporary, real-world, cohort.

Methods

A retrospective review of a prospectively maintained database from a single institution was conducted from 2011 to 2020 to identify all patients with clinically staged IA1 or IA2 NSCLC (tumors ≤2 cm with no nodal involvement). The primary outcomes of interest were overall survival (OS) and disease-free survival (DFS), with secondary outcomes of lung cancer-specific survival (LCSS), recurrence patterns, and perioperative morbidity and mortality.

Results

A total of 480 patients were identified; 93 (19.4%) patients underwent wedge resection, 90 (18.7%) received segmentectomy, and 297 (61.9%) underwent lobectomy. Patients who underwent wedge resection had worse Eastern Cooperative Oncology Group (ECOG) performance status (23.7% ECOG 1 or 2 vs. 5.6% among segmentectomy and 5.4% among lobectomy, P<0.05). Both wedge resection and segmentectomy patients had lower preoperative mean percentage of predicted forced expiratory volume in one second (%FEV1) compared to the lobectomy group (81.8% and 82.6% vs. 89.6%, P=0.002), a higher proportion of patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD), and a higher Charlson Comorbidity Index. There were no statistically significant differences in 5-year OS, DFS, or LCSS between groups: 90%, 61%, 78% for wedge resections compared with 85%, 75%, 86% for segmentectomy, and 87%, 77%, 87% for lobectomy, respectively. Recurrence was observed in 17 patients who underwent wedge resection (18.3%, 8 local, 9 distant), 12 patients who received segmentectomy (13.4%, 6 local, 6 distant), and 38 patients who underwent lobectomy (12.8%, 11 local, 27 distant), which was not significantly different (P=0.36).

Conclusions

Patients with inferior performance status or lower baseline pulmonary function are more likely to receive wedge resection for clinical stage IA NSCLC ≤2 cm in size. For these small tumors, lobectomy, segmentectomy, and wedge resection provide comparable oncologic outcomes.

The Emerging Role of Immunotherapy in Resectable Non-Small Cell Lung Cancer

BACKGROUND

Despite surgical resection, long-term survival of patients with resectable non-small cell lung cancer (NSCLC) remains poor. Adjuvant chemotherapy, the standard of care for locally advanced NSCLC, provides a marginal 5.4% benefit in survival. Immune checkpoint inhibitors (ICIs) have shown a significant survival benefit in some patients with advanced NSCLC and are being evaluated for perioperative use in resectable NSCLC.

METHODS

We conducted a literature search using the PubMed online database to identify clinical trials of immunotherapy in resectable NSCLC and studies analyzing biomarkers and immune priming strategies.

RESULTS

Building on previous phase I and II trials, randomized phase III trials have shown efficacy of neoadjuvant nivolumab, perioperative pembrolizumab, adjuvant atezolizumab, and adjuvant pembrolizumab in the treatment of NSCLC with improvement of event-free/disease-free survival of 24% to 42%, leading to United States Food and Drug Administration approval of these drugs in the treatment of resectable NSCLC. Three additional phase III trials have also recently reported the use of immunotherapy both before and after surgery, with pathologic complete response rates of 17% to 25%, significantly better than chemotherapy alone. Perioperative ICI therapy has comparable perioperative morbidity to chemotherapy alone and does not impair surgical outcomes.

CONCLUSIONS

Perioperative immunotherapy, in combination with chemotherapy, is safe and improves outcomes in patients with resectable NSCLC. Questions regarding patient selection, the need for adjuvant ICI therapy after neoadjuvant chemoimmunotherapy, and the duration of perioperative immunotherapy remain to be answered by future trials.

Lobectomy, segmentectomy, or wedge resection for peripheral clinical T1aN0 non-small cell lung cancer: A post hoc analysis of CALGB 140503 (Alliance)

BACKGROUND

We have recently reported the primary results of CALGB 140503 (Alliance), a randomized trial in patients with peripheral cT1aN0 non-small cell lung cancer (American Joint Committee on Cancer seventh) treated with either lobar resection (LR) or sublobar resection (SLR). Here we report differences in disease-free survival (DFS), overall survival (OS) and lung cancer-specific survival (LCSS) between LR, segmental resection (SR), and wedge resection (WR). We also report differences between WR and SR in terms of surgical margins, rate of locoregional recurrence (LRR), and expiratory flow rate at 6 months postoperatively.

METHODS

Between June 2007 and March 2017, a total of 697 patients were randomized to LR (n = 357) or SLR (n = 340) stratified by clinical tumor size, histology, and smoking history. Ten patients were converted from SLR to LR, and 5 patients were converted from LR to SLR. Survival endpoints were estimated using the Kaplan-Maier estimator and tested by the stratified log-rank test. The Kruskal-Wallis test was used to compare margins and changes in forced expiratory volume in 1 second (FEV1) between groups, and the χ2 test was used to test the associations between recurrence and groups.

RESULTS

A total of 362 patients had LR, 131 had SR, and 204 had WR. Basic demographic and clinical and pathologic characteristics were similar in the 3 groups. Five-year DFS was 64.7% after LR (95% confidence interval [CI], 59.6%-70.1%), 63.8% after SR (95% CI, 55.6%-73.2%), and 62.5% after WR (95% CI, 55.8%-69.9%) (P = .888, log-rank test). Five-year OS was 78.7% after LR, 81.9% after SR, and 79.7% after WR (P = .873, log-rank test). Five-year LCSS was 86.8% after LR, 89.2% after SR, and 89.7% after WR (P = .903, log-rank test). LRR occurred in 12% after SR and in 14% after WR (P = .295). At 6 months postoperatively, the median reduction in % FEV1 was 5% after WR and 3% after SR (P = .930).

CONCLUSIONS

In this large randomized trial, LR, SR, and WR were associated with similar survival outcomes. Although LRR was numerically higher after WR compared to SR, the difference was not statistically significant. There was no significant difference in the reduction of FEV1 between the SR and WR groups.

Should Sampling of Three N2 Stations be a Quality Metric for Curative Resection of Stage I Lung Cancer?

OBJECTIVE

In 2022, ACS Commission on Cancer (CoC) issued standard 5.8 quality metric for curative lung cancer resections requiring nodal resection from 3 N2 stations. In this report we compare oncologic outcomes following resection of 3 N2 stations versus 2 N2 stations in stage I NSCLC.

METHODS

A retrospective review from a single institution database was conducted from 2011-2020 to identify patients with clinical stage I NSCLC. Patients with history of lung cancer, carcinoid tumors, ground glass lesions <50% solid component were excluded. Primary outcome was overall survival (OS). Secondary outcomes included disease-free survival (DFS), recurrence patterns, and nodal upstaging.

RESULTS

581 patients were identified and divided into two groups based on number of N2 stations examined; Group A had 2 N2 stations examined (364 patients) and group B had ≥3 N2 stations examined (217 patients). Baseline demographic and clinical characteristics were similar between groups. In Group A, N1 and N2 positive nodal stations were present in 8.2% (30/364) and 5.2% (19/364) of patients versus 7.4% (16/217) and 5.5% (12/217) respectively in Group B. 5- year OS and DFS were 89% and 74% in Group A versus 88% and 78% in Group B respectively. Recurrence occurred in 56 patients (15.4%) in Group A (6.6% local and 8.8% distant) and 29 patients (13.4%) in Group B (5.1% local and 8.3% distant; p = 0.73).

CONCLUSION

There was no significant difference in oncological outcomes in stage I NSCLC resections that included 2 N2 stations compared to at least 3 N2 stations examined.

A 20-year Follow-up of the International Early Lung Cancer Action Program (I-ELCAP)

Background The low-dose CT (≤3 mGy) screening report of 1000 Early Lung Cancer Action Program (ELCAP) participants in 1999 led to the International ELCAP (I-ELCAP) collaboration, which enrolled 31 567 participants in annual low-dose CT screening between 1992 and 2005. In 2006, I-ELCAP investigators reported the 10-year lung cancer-specific survival of 80% for 484 participants diagnosed with a first primary lung cancer through annual screening, with a high frequency of clinical stage I lung cancer (85%). Purpose To update the cure rate by determining the 20-year lung cancer-specific survival of participants diagnosed with first primary lung cancer through annual low-dose CT screening in the expanded I-ELCAP cohort. Materials and Methods For participants enrolled in the HIPAA-compliant prospective I-ELCAP cohort between 1992 and 2022 and observed until December 30, 2022, Kaplan-Meier survival analysis was used to determine the 10- and 20-year lung cancer-specific survival of participants diagnosed with first primary lung cancer through annual low-dose CT screening. Eligible participants were aged at least 40 years and had current or former cigarette use or had never smoked but had been exposed to secondhand tobacco smoke. Results Among 89 404 I-ELCAP participants, 1257 (1.4%) were diagnosed with a first primary lung cancer (684 male, 573 female; median age, 66 years; IQR, 61-72), with a median smoking history of 43.0 pack-years (IQR, 29.0-60.0). Median follow-up duration was 105 months (IQR, 41-182). The frequency of clinical stage I at pretreatment CT was 81% (1017 of 1257). The 10-year lung cancer-specific survival of 1257 participants was 81% (95% CI: 79, 84) and the 20-year lung cancer-specific survival was 81% (95% CI: 78, 83), and it was 95% (95% CI: 91, 98) for 181 participants with pathologic T1aN0M0 lung cancer. Conclusion The 10-year lung cancer-specific survival of 80% reported in 2006 for I-ELCAP participants enrolled in annual low-dose CT screening and diagnosed with a first primary lung cancer has persisted, as shown by the updated 20-year lung cancer-specific survival for the expanded I-ELCAP cohort. © RSNA, 2023 See also the editorials by Grenier and by Sequist and Olazagasti in this issue.

Comparison of SP263 and 22C3 immunohistochemistry PD-L1 assays for clinical efficacy of adjuvant atezolizumab in non-small cell lung cancer: results from the randomized phase III IMpower010 trial

BACKGROUND

Tumor samples from the phase III IMpower010 study were used to compare two programmed death-ligand 1 (PD-L1) immunohistochemistry assays (VENTANA SP263 and Dako 22C3) for identification of PD-L1 patient subgroups (negative, positive, low, and high expression) and their predictive value for adjuvant atezolizumab compared with best supportive care (BSC) in resectable early-stage non-small cell lung cancer (NSCLC).

METHODS

PD-L1 expression was assessed by the SP263 assay, which measured the percentage of tumor cells with any membranous PD-L1 staining, and the 22C3 assay, which scored the percentage of viable tumor cells showing partial or complete membranous PD-L1 staining.

RESULTS

When examining the concordance at the PD-L1-positive threshold (SP263: tumor cell (TC)≥1%; 22C3: tumor proportion score (TPS)≥1%), the results were concordant between assays for 83% of the samples. Similarly, at the PD-L1-high cut-off (SP263: TC≥50%; 22C3: TPS≥50%), the results were concordant between assays for 92% of samples. The disease-free survival benefit of atezolizumab over BSC was comparable between assays for PD-L1-positive (TC≥1% by SP263: HR, 0.58 (95% CI: 0.40 to 0.85) vs TPS≥1% by 22C3: HR, 0.65 (95% CI: 0.45 to 0.95)) and PD-L1-high (TC≥50% by SP263: HR, 0.27 (95% CI: 0.14 to 0.53) vs TPS≥50% by 22C3: HR, 0.31 (95% CI: 0.16 to 0.60)) subgroups.

CONCLUSIONS

The SP263 and 22C3 assays showed high concordance and a comparable clinical predictive value of atezolizumab at validated PD-L1 thresholds, suggesting that both assays can identify patients with early-stage NSCLC most likely to experience benefit from adjuvant atezolizumab.

TRIAL REGISTRATION NUMBER

NCT02486718.

Overall survival with adjuvant atezolizumab after chemotherapy in resected stage II-IIIA non-small-cell lung cancer (IMpower010): a randomised, multicentre, open-label, phase III trial

BACKGROUND

IMpower010 (NCT02486718) demonstrated significantly improved disease-free survival (DFS) with adjuvant atezolizumab versus best supportive care (BSC) following platinum-based chemotherapy in the programmed death-ligand 1 (PD-L1)-positive and all stage II-IIIA non-small-cell lung cancer (NSCLC) populations, at the DFS interim analysis. Results of the first interim analysis of overall survival (OS) are reported here.

PATIENT AND METHODS

The design, participants, and primary-endpoint DFS outcomes have been reported for this phase III, open-label, 1 : 1 randomised study of atezolizumab (1200 mg q3w; 16 cycles) versus BSC after adjuvant platinum-based chemotherapy (1-4 cycles) in adults with completely resected stage IB (≥4 cm)-IIIA NSCLC (per the Union Internationale Contre le Cancer and American Joint Committee on Cancer staging system, 7th edition). Key secondary endpoints included OS in the stage IB-IIIA intent-to-treat (ITT) population and safety in randomised treated patients. The first pre-specified interim analysis of OS was conducted after 251 deaths in the ITT population. Exploratory analyses included OS by baseline PD-L1 expression level (SP263 assay).

RESULTS

At a median of 45.3 months' follow-up on 18 April 2022, 127 of 507 patients (25%) in the atezolizumab arm and 124 of 498 (24.9%) in the BSC arm had died. The median OS in the ITT population was not estimable; the stratified hazard ratio (HR) was 0.995 [95% confidence interval (CI) 0.78-1.28]. The stratified OS HRs (95% CI) were 0.95 (0.74-1.24) in the stage II-IIIA (n = 882), 0.71 (0.49-1.03) in the stage II-IIIA PD-L1 tumour cell (TC) ≥1% (n = 476), and 0.43 (95% CI 0.24-0.78) in the stage II-IIIA PD-L1 TC ≥50% (n = 229) populations. Atezolizumab-related adverse event incidences remained unchanged since the previous analysis [grade 3/4 in 53 (10.7%) and grade 5 in 4 (0.8%) of 495 patients, respectively].

CONCLUSIONS

Although OS remains immature for the ITT population, these data indicate a positive trend favouring atezolizumab in PD-L1 subgroup analyses, primarily driven by the PD-L1 TC ≥50% stage II-IIIA subgroup. No new safety signals were observed after 13 months' additional follow-up. Together, these findings support the positive benefit-risk profile of adjuvant atezolizumab in this setting.

International Association for the Study of Lung Cancer Study of Reproducibility in Assessment of Pathologic Response in Resected Lung Cancers After Neoadjuvant Therapy

INTRODUCTION

Pathologic response has been proposed as an early clinical trial end point of survival after neoadjuvant treatment in clinical trials of NSCLC. The International Association for the Study of Lung Cancer (IASLC) published recommendations for pathologic evaluation of resected lung cancers after neoadjuvant therapy. The aim of this study was to assess pathologic response interobserver reproducibility using IASLC criteria.

METHODS

An international panel of 11 pulmonary pathologists reviewed hematoxylin and eosin-stained slides from the lung tumors of resected NSCLC from 84 patients who received neoadjuvant immune checkpoint inhibitors in six clinical trials. Pathologic response was assessed for percent viable tumor, necrosis, and stroma. For each slide, tumor bed area was measured microscopically, and pre-embedded formulas calculated unweighted and weighted major pathologic response (MPR) averages to reflect variable tumor bed proportion.

RESULTS

Unanimous agreement among pathologists for MPR was observed in 68 patients (81%), and inter-rater agreement (IRA) was 0.84 (95% confidence interval [CI]: 0.76-0.92) and 0.86 (95% CI: 0.79-0.93) for unweighted and weighted averages, respectively. Overall, unweighted and weighted methods did not reveal significant differences in the classification of MPR. The highest concordance by both methods was observed for cases with more than 95% viable tumor (IRA = 0.98, 95% CI: 0.96-1) and 0% viable tumor (IRA = 0.94, 95% CI: 0.89-0.98). The most common reasons for discrepancies included interpretations of tumor bed, presence of prominent stromal inflammation, distinction between reactive and neoplastic pneumocytes, and assessment of invasive mucinous adenocarcinoma.

CONCLUSIONS

Our study revealed excellent reliability in cases with no residual viable tumor and good reliability for MPR with the IASLC recommended less than or equal to 10% cutoff for viable tumor after neoadjuvant therapy.

Safety of adjuvant atezolizumab after pneumonectomy/bilobectomy in stage II-IIIA non-small cell lung cancer in the randomized phase III IMpower010 trial

OBJECTIVE

Adjuvant atezolizumab is a standard of care after chemotherapy in completely resected stage II-IIIA programmed death ligand-1 tumor cell 1% or greater non-small cell lung cancer based on results from the phase III IMpower010 study. We explored the safety and tolerability of adjuvant atezolizumab by surgery type in IMpower010.

METHODS

Patients had completely resected stage IB-IIIA non-small cell lung cancer (Union Internationale Contre le Cancer/American Joint Committee on Cancer, 7th Ed), received up to four 21-day cycles of cisplatin-based chemotherapy, and were randomized 1:1 to receive atezolizumab 1200 mg every 3 weeks (≤16 cycles or 1 year) or best supportive care. Adverse events and clinical characteristics were investigated by surgery type (pneumonectomy/bilobectomy or lobectomy/sleeve lobectomy) in the randomized stage II-IIIA population who received 1 or more atezolizumab dose or with 1 or more postbaseline assessment (safety evaluable) for best supportive care.

RESULTS

Overall, 871 patients comprised the safety-evaluable randomized stage II-IIIA population. In the atezolizumab arm, 23% (100/433) received pneumonectomy/bilobectomy and 77% (332/433) received lobectomy/sleeve lobectomy. Atezolizumab discontinuation occurred in 32% (n = 32) and 35% (n = 115) of the pneumonectomy/bilobectomy and lobectomy/sleeve lobectomy groups, respectively. Grade 3/4 adverse events were reported in 21% (n = 21) and 23% (n = 76) of patients in the atezolizumab arms in the pneumonectomy/bilobectomy and lobectomy/sleeve lobectomy groups, respectively. In the atezolizumab arms of the surgery groups, 13% (n = 13) and 17% (n = 55) had an adverse event leading to hospitalization. Atezolizumab-related adverse events leading to hospitalization occurred in 5% (n = 5) and 7% (n = 23) of the surgery groups.

CONCLUSIONS

These exploratory findings support use of adjuvant atezolizumab after platinum-based chemotherapy in patients with completely resected stage II-IIIA programmed death ligand-1 tumor cell 1% or more non-small cell lung cancer, regardless of surgery type.

Ten-Year Survival and Recurrence Patterns After Three-Field Lymph Node Dissection for Squamous Cell and Adenocarcinoma of the Esophagus

OBJECTIVE

The aim was to determine the prevalence of metastases to the cervical and recurrent laryngeal cervicothoracic (CT) nodes as well as survival and recurrence patterns after esophagectomy with three-field lymph node dissection (TFD) in patients with predominately adenocarcinoma (AC) of the esophagus.

BACKGROUND

Although esophagectomy with TFD is commonly practiced in Japan and Southeast Asia for squamous cell cancer (SCC) of the esophagus, there are only a handful of reports about its' utilization and survival benefit in North American patients.

METHODS

This is a retrospective case series of patients who had an esophagectomy with TFD. The primary outcomes of interest were the prevalence of nodal metastases to the CT nodes as well as overall survival (OS) and disease-free survival. Secondary outcomes included time to recurrence, recurrence patterns, operative morbidity as well as 30 and 90-day mortality.

RESULTS

Two hundred forty-two patients with esophageal cancer (AC: 67%) underwent esophagectomy with TFD. Metastases to the CT nodes were present in 56 patients (23%: AC 20% and SCC 30%). Positive CT nodes were present in 14% of pT1/T2 tumors and 30% of pT3 tumors. For the 56 patients with CT positive nodes, 5-year OS was 25% (AC:16%; SCC:39%). Fifteen of 56 (26.7%) patients with metastases to the CT nodes were alive and disease-free at a minimum of 5 years postoperatively. Ten-year OS was 43% for all patients with SCC and 28% for patients with AC.

CONCLUSIONS

Metastases to the CT nodes are common in both SCC and AC of the esophagus and may be present in at least 14% of early lesions. Five-year survival is encouraging particularly for patients with esophageal SCC cancer.

Sub-Lobar Resection: The New Standard of Care for Early-Stage Lung Cancer

The Lung Cancer Study Group previously established lobectomy as the standard of care for treatment of clinical T1N0 NSCLC. Advances in imaging technology and refinements in staging have prompted a re-investigation to determine the non-inferiority of sub-lobar resections to lobectomies. Two recent randomized studies, JCOG 0802 and CALGB 140503, are reviewed here in the context of LCSG 0821. The studies confirm non-inferiority for sub-lobar resection (wedge or segmentectomy) compared to lobectomy for peripheral T1N0 NSCLC less than or equal to 2 cm. Sub-lobar resection should therefore be considered the new standard of care in this sub-set of patients with NSCLC.

Improving outcomes in patients with oesophageal cancer

The care of patients with oesophageal cancer or of individuals who have an elevated risk of oesophageal cancer has changed dramatically. The epidemiology of squamous cell and adenocarcinoma of the oesophagus has diverged over the past several decades, with a marked increase in incidence only for oesophageal adenocarcinoma. Only in the past decade, however, have molecular features that distinguish these two forms of the disease been identified. This advance has the potential to improve screening for oesophageal cancers through the development of novel minimally invasive diagnostic technologies predicated on cancer-specific genomic or epigenetic alterations. Surgical techniques have also evolved towards less invasive approaches associated with less morbidity, without compromising oncological outcomes. With improvements in multidisciplinary care, advances in radiotherapy and new tools to detect minimal residual disease, certain patients may no longer even require surgical tumour resection. However, perhaps the most anticipated advance in the treatment of patients with oesophageal cancer is the advent of immune-checkpoint inhibitors, which harness and enhance the host immune response against cancer. In this Review, we discuss all these advances in the management of oesophageal cancer, representing only the beginning of a transformation in our quest to improve patient outcomes.

Surgical Treatment at an Academic Medical Center is Associated with Statistically Insignificant Lung Cancer Survival Outcome Differences Related to ZIP Code

BACKGROUND

Low socioeconomic status is a well-characterized adverse prognostic factor in large lung cancer databases. However, such characterizations may be confounded as patients of lower socioeconomic status are more often treated at low-volume, non-academic centers. We evaluated whether socioeconomic status, as defined by ZIP code median income, was associated with differences in lung cancer resection outcomes within a high-volume academic medical center.

METHODS

Consecutive patients undergoing resection for non-small cell lung cancer were identified from a prospectively maintained database (2011-18). Patients were assigned an income value based on the median income of their ZIP code as determined by census-based geographic data. We stratified the population into income quintiles representative of SES and compared demographics (chi-square), surgical outcomes, and survival (Kaplan-Meier).

RESULTS

We identified 1,693 patients, representing 516 ZIP codes. Income quintiles were Q1: $24,421-53,151; Q2:$53,152-73,982; Q3:$73,983-99,063; Q4:$99,064-123,842; and Q5:$123,843-250,001. Compared to Q5 patients, Q1 patients were younger (median 69 vs. 73, p < 0.001), more likely male (44 vs. 36%, p = 0.035), and more likely Asian, Black, or self-identified as other than white, Asian, or Black. (67 vs. 11%, p =  < 0.001). We found minor differences in surgical outcomes and no significant difference in 5-year survival between Q1 and Q5 patients (5-year: 86 vs. 85%, p = 0.886).

CONCLUSIONS

Surgical care patterns at a high-volume academic medical center are similar among patients from varying ZIP codes. Surgical treatment at such a center is associated with no survival differences based upon socioeconomic status as determined by ZIP code. Centralization of lung cancer surgical care to high-volume centers may reduce socioeconomic outcome disparities.

Abstract 3472: A tumor draining lymph node CD8 T cell memory response is pivotal for a decrease in recurrence after neoadjuvant anti PD-1 therapy for NSCLC

Background: Non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. Even at early stages, death rates remain disproportionately high due to metastatic recurrence. Recently, blockade of the PD-1/PD-L1 axis has shown impressive increases in recurrence-free survival in a subset of patients. While efforts to decrease relapse have focused on decreasing residual micrometastatic disease at the time of definitive treatment, PD-1 directed therapy may allow for an adaptive immune response and the establishment of anti-tumor immunosurveillance. Building on results from a clinically relevant murine model of metastatic relapse after tumor resection and robust assays on systematically characterized tumor, lymph node and blood samples of early-stage lung cancer patients, we posit that immunologic CD8 T cell memory may be a primary mechanism of metastatic protection.

Methods: We utilized a syngeneic murine model of metastatic lung adenocarcinoma (344SQ) after resection of tumor, tumor draining lymph node (tdLN) and non-draining lymph nodes (ndLN). Using bioluminescent imaging (BLI) and flow cytometric analysis we monitored T cell kinetics and anti-tumor activity after administration of anti-PD-1 antibody and/or KD033, a fusion antibody combining a high affinity anti-PD-L1 IgG1 antibody with an IL-15Rα sushi binding domain. Tumor/tdLN and ndLN T cells were characterized for PD-1/TCF-1/CD62L/CD44/CXCR5 memory phenotypes. In parallel, we analyzed resected tumor, tdLN and ndLN from early-stage NSCLC patients.

Results: tdLN from murine models and early-stage patients maintain robust PD-1+ CXCR5+ CD8 T cell memory phenotypes not significantly found in the primary tumor, ndLN and peripheral blood. Neoadjuvant treatment with PD-1 blockade alone had a heterogenous response, with robust proliferation of T cell central and stem cell memory populations (CM & SCM) at the tdLN in responders compared to non-responders (p&lt;0.05). Combination therapy with IL-15Rα agonist (KD033) potentiated diverse PD-1+ CXCR5+ CD8 stem cell like memory subsets in the tdLN and subsequent response at the primary tumor (100%) as well as displayed superior protection against metastatic recurrence up to 200 days compared to PD-1 inhibition or KD033 alone (median survival undetermined vs. 120d, 161d respectively p&lt;0.05). Removal of tdLN or blockade of lymph node migration with FTY720 prior to therapy decreased a population of SCM and CM CD8 T cells found in the primary tumor, decreased primary tumor response and altered systemic memory subpopulations in the ndLN (p&lt;0.05).

Conclusions: Our data strongly points to a T cell memory response within the tumor draining lymph node as a possible driver of protection from systemic cancer recurrence, laying the groundwork for a new therapeutic strategy aimed at establishing CD8 immunosurveillance for protection from cancer recurrence.

Citation Format: Tatiana Delgado Cruz, Geoffrey J. Markowitz, Mitchell Martin, Arshdeep Singh, Shelley Yang Bai, Nasser Altorki, Timothy McGraw, Vivek Mittal, Jonathan Villena-Vargas. A tumor draining lymph node CD8 T cell memory response is pivotal for a decrease in recurrence after neoadjuvant anti PD-1 therapy for NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3472.

Lobar or Sublobar Resection for Peripheral Stage IA Non-Small-Cell Lung Cancer

BACKGROUND

The increased detection of small-sized peripheral non-small-cell lung cancer (NSCLC) has renewed interest in sublobar resection in lieu of lobectomy.

METHODS

We conducted a multicenter, noninferiority, phase 3 trial in which patients with NSCLC clinically staged as T1aN0 (tumor size, ≤2 cm) were randomly assigned to undergo sublobar resection or lobar resection after intraoperative confirmation of node-negative disease. The primary end point was disease-free survival, defined as the time between randomization and disease recurrence or death from any cause. Secondary end points were overall survival, locoregional and systemic recurrence, and pulmonary functions.

RESULTS

From June 2007 through March 2017, a total of 697 patients were assigned to undergo sublobar resection (340 patients) or lobar resection (357 patients). After a median follow-up of 7 years, sublobar resection was noninferior to lobar resection for disease-free survival (hazard ratio for disease recurrence or death, 1.01; 90% confidence interval [CI], 0.83 to 1.24). In addition, overall survival after sublobar resection was similar to that after lobar resection (hazard ratio for death, 0.95; 95% CI, 0.72 to 1.26). The 5-year disease-free survival was 63.6% (95% CI, 57.9 to 68.8) after sublobar resection and 64.1% (95% CI, 58.5 to 69.0) after lobar resection. The 5-year overall survival was 80.3% (95% CI, 75.5 to 84.3) after sublobar resection and 78.9% (95% CI, 74.1 to 82.9) after lobar resection. No substantial difference was seen between the two groups in the incidence of locoregional or distant recurrence. At 6 months postoperatively, a between-group difference of 2 percentage points was measured in the median percentage of predicted forced expiratory volume in 1 second, favoring the sublobar-resection group.

CONCLUSIONS

In patients with peripheral NSCLC with a tumor size of 2 cm or less and pathologically confirmed node-negative disease in the hilar and mediastinal lymph nodes, sublobar resection was not inferior to lobectomy with respect to disease-free survival. Overall survival was similar with the two procedures. (Funded by the National Cancer Institute and others; CALGB 140503 ClinicalTrials.gov number, NCT00499330.).

Integration of New Systemic Adjuvant Therapies for Non-Small Cell Lung Cancer: Role of the Surgeon

BACKGROUND

This review describes a new therapeutic landscape in the adjuvant treatment of resectable non-small cell lung cancer (NSCLC) and discusses the role of the surgeon in ensuring best outcomes within this treatment paradigm.

METHODS

We conducted a narrative literature review using the search terms "non-small cell lung cancer" AND "adjuvant" to identify randomized Phase III trials of systemic adjuvant therapy for NSCLC through Mar 17, 2022. We also searched ClinicalTrials.gov to identify ongoing trials of adjuvant immunotherapies and targeted therapies for NSCLC.

RESULTS

Three recent randomized Phase III trials reported significant improvements in disease-free survival with adjuvant immune checkpoint inhibitors or targeted therapy in patients with resectable NSCLC: IMpower010 (atezolizumab versus best supportive care; NCT02486718), KEYNOTE-091 (pembrolizumab versus placebo; NCT02504372), and ADAURA (osimertinib versus placebo; NCT02511106). Numerous other Phase III trials evaluating adjuvant immune checkpoint inhibitors and targeted therapies are currently underway, many of which demonstrate an evolution of trial design and endpoints for adjuvant therapy trials. This rapidly changing treatment landscape requires a shift in the role of the surgeon to facilitate appropriate biomarker screening for planning of the perioperative period and molecular testing of the surgical specimen to guide adjuvant therapy.

CONCLUSIONS

After decades of stagnation in the management of NSCLC, recent results with immune checkpoint inhibitors and targeted therapies are ushering in a new era of precision medicine in the adjuvant treatment of early-stage NSCLC. Surgeons have an important role in facilitating multidisciplinary care in this rapidly evolving landscape.

Abstract 2378: Methylmalonic acid is elevated in non-small cell lung cancer and promotes drug resistance

Lung cancer is the leading cause of cancer-related deaths in the United States. Identifying new factors that promote drug resistance is critical to restoring drug sensitivity and improving patient outcomes. Methylmalonic acid (MMA) is a dicarboxylic acid by-product of propionate metabolism. MMA levels rise in the serum with age and are associated with cancer-related mortality (the higher the MMA, the worse the mortality). We recently asked whether this metabolite had a functional impact and showed that treating non-small cell lung cancer (NSCLC) cells with MMA in vitro promotes drug resistance through triggering epithelial-to-mesenchymal transition (EMT). However, whether MMA is elevated in lung cancer is not known, and how MMA levels are regulated is poorly understood.

To determine if MMA is elevated in NSCLC, we performed targeted metabolomics on 20 resected lung adenocarcinomas and squamous cell carcinomas with matched normal lung tissue. We found that MMA was 2.5 fold elevated in tumors compared to controls (p&lt;0.001, paired t-test). To our knowledge, this is the first report of MMA being elevated in any cancer. MMAB is one of the key MMA regulatory genes. When MMAB is inactivated or underexpressed, MMA cannot be metabolized and its intracellular levels increase. We hypothesized that loss of MMAB expression may explain elevated MMA levels in lung cancer. To test this, we analyzed publicly available mRNA expression data sets and found that MMAB is underexpressed in NSCLC (suggesting high levels of MMA). Moreover, MMAB expression correlates with survival. The lower the MMAB expression (suggesting higher MMA), the worse the survival (Hazard Ratio 0.36, p&lt;0.001). We thus asked if suppressing MMAB expression had a functional impact on cell lines. Using shRNA constructs, we knocked down MMAB in the A549 and H1975 NSCLC cell lines. Targeted metabolomics confirmed that knockdown of MMAB increased MMA levels. Moreover, knockdown of MMAB decreased cellular proliferation and increased resistance to carboplatin, pemetrexed, and osimertinib. RNA-seq analysis showed that suppressing MMAB induced EMT and senescence expression signatures. Furthermore, we found that hypoxia and nutrient stress downregulate MMAB expression at the mRNA and protein level. Collectively, our data suggest that loss of MMAB expression through hypoxia or nutrient stress can increase MMA levels, triggering EMT and resistance to chemotherapy and targeted therapy in NSCLC. Our results indicate that dysregulation of MMA plays an important role in lung cancer.

Citation Format: Bobak Parang, Zhongchi Li, Vivien Low, Jennifer Endress, Murtaza Malbari, Ashish Saxena, Nasser Altorki, John Blenis. Methylmalonic acid is elevated in non-small cell lung cancer and promotes drug resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2378.

Expression of the mono-ADP-ribosyltransferase ART1 by tumor cells mediates immune resistance in non-small cell lung cancer

Most patients with non-small cell lung cancer (NSCLC) do not achieve durable clinical responses from immune checkpoint inhibitors, suggesting the existence of additional resistance mechanisms. Nicotinamide adenine dinucleotide (NAD)-induced cell death (NICD) of P2X7 receptor (P2X7R)-expressing T cells regulates immune homeostasis in inflamed tissues. This process is mediated by mono-adenosine 5'-diphosphate (ADP)-ribosyltransferases (ARTs). We found an association between membranous expression of ART1 on tumor cells and reduced CD8 T cell infiltration. Specifically, we observed a reduction in the P2X7R⁺ CD8 T cell subset in human lung adenocarcinomas. In vitro, P2X7R⁺ CD8 T cells were susceptible to ART1-mediated ADP-ribosylation and NICD, which was exacerbated upon blockade of the NAD⁺-degrading ADP-ribosyl cyclase CD38. Last, in murine NSCLC and melanoma models, we demonstrate that genetic and antibody-mediated ART1 inhibition slowed tumor growth in a CD8 T cell-dependent manner. This was associated with increased infiltration of activated P2X7R⁺CD8 T cells into tumors. In conclusion, we describe ART1-mediated NICD as a mechanism of immune resistance in NSCLC and provide preclinical evidence that antibody-mediated targeting of ART1 can improve tumor control, supporting pursuit of this approach in clinical studies.

Extent of Resection Influences Survival in Early-Stage Lung Cancer with Occult Nodal Disease

BACKGROUND

Minimal literature exists evaluating the impact of the extent of resection on survival in patients with small, early-stage non-small cell lung cancer (NSCLC) found to have occult nodal disease (OND). We hypothesized that sublobar resection has comparable overall survival to patients undergoing lobectomy for clinical Stage IA NSCLC that harbors OND.

METHODS

The National Cancer Database was reviewed for identification of patients with clinical Stage IA NSCLC who underwent wedge resection, segmentectomy or lobectomy and were found to have OND. Overall survival was compared between groups and a multivariate Cox-Regression model identified factors associated with worse survival.

RESULTS

OND occurred in 6.1% of all patients with clinical Stage IA disease undergoing resection. Patients undergoing wedge resection and segmentectomy found to have OND were older (67.6 ± 9.6 vs. 66.1 ± 9.3 vs. 65.6 ± 9.5, p=0.004), and had more advanced pathologic stage (pStage III: 68.7% vs. 50.5% vs. 41.5%, p<0.001) than those receiving lobectomy. There was no difference in the median overall survival between segmentectomy and lobectomy (68.5 months vs. 57.6, p=0.200.) However, wedge resection was independently associated with worse overall survival when controlling for other preoperative variables, hazard ratio: 1.23 (1.01 - 1.51), p=0.042.

CONCLUSIONS

Review of the National Cancer Database suggests that there is no improvement in overall survival in patients undergoing lobectomy versus segmentectomy in carefully selected patients with clinical Stage IA NSCLC harboring occult nodal disease. However, those undergoing wedge resection may have worse overall survival than those undergoing both lobectomy and segmentectomy.

Adjuvant atezolizumab after adjuvant chemotherapy in resected stage IB-IIIA non-small-cell lung cancer (IMpower010): a randomised, multicentre, open-label, phase 3 trial

BACKGROUND

Novel adjuvant strategies are needed to optimise outcomes after complete surgical resection in patients with early-stage non-small-cell lung cancer (NSCLC). We aimed to evaluate adjuvant atezolizumab versus best supportive care after adjuvant platinum-based chemotherapy in these patients.

METHODS

IMpower010 was a randomised, multicentre, open-label, phase 3 study done at 227 sites in 22 countries and regions. Eligible patients were 18 years or older with completely resected stage IB (tumours ≥4 cm) to IIIA NSCLC per the Union Internationale Contre le Cancer and American Joint Committee on Cancer staging system (7th edition). Patients were randomly assigned (1:1) by a permuted-block method (block size of four) to receive adjuvant atezolizumab (1200 mg every 21 days; for 16 cycles or 1 year) or best supportive care (observation and regular scans for disease recurrence) after adjuvant platinum-based chemotherapy (one to four cycles). The primary endpoint, investigator-assessed disease-free survival, was tested hierarchically first in the stage II-IIIA population subgroup whose tumours expressed PD-L1 on 1% or more of tumour cells (SP263), then all patients in the stage II-IIIA population, and finally the intention-to-treat (ITT) population (stage IB-IIIA). Safety was evaluated in all patients who were randomly assigned and received atezolizumab or best supportive care. IMpower010 is registered with ClinicalTrials.gov, NCT02486718 (active, not recruiting).

FINDINGS

Between Oct 7, 2015, and Sept 19, 2018, 1280 patients were enrolled after complete resection. 1269 received adjuvant chemotherapy, of whom 1005 patients were eligible for randomisation to atezolizumab (n=507) or best supportive care (n=498); 495 in each group received treatment. After a median follow-up of 32·2 months (IQR 27·4-38·3) in the stage II-IIIA population, atezolizumab treatment improved disease-free survival compared with best supportive care in patients in the stage II-IIIA population whose tumours expressed PD-L1 on 1% or more of tumour cells (HR 0·66; 95% CI 0·50-0·88; p=0·0039) and in all patients in the stage II-IIIA population (0·79; 0·64-0·96; p=0·020). In the ITT population, HR for disease-free survival was 0·81 (0·67-0·99; p=0·040). Atezolizumab-related grade 3 and 4 adverse events occurred in 53 (11%) of 495 patients and grade 5 events in four patients (1%).

INTERPRETATION

IMpower010 showed a disease-free survival benefit with atezolizumab versus best supportive care after adjuvant chemotherapy in patients with resected stage II-IIIA NSCLC, with pronounced benefit in the subgroup whose tumours expressed PD-L1 on 1% or more of tumour cells, and no new safety signals. Atezolizumab after adjuvant chemotherapy offers a promising treatment option for patients with resected early-stage NSCLC.

FUNDING

F Hoffmann-La Roche and Genentech.

Lung Cancer Stage Shift as a Result of COVID-19 Lockdowns in New York City, a Brief Report

Introduction

The COVID-19 pandemic reached New York City in early March 2020 resulting in an 11-week lockdown period to mitigate further spread. It has been well documented that cancer care was drastically affected as a result. Given New York City's early involvement, we attempted to identify any stage shift that may have occurred in the diagnoses of non-small cell lung cancer (NSCLC) at our institution as a result of these lockdowns.

Patients and Methods

We conducted a retrospective review of a prospective database of lung cancer patients at our institution from July 1, 2019 until March 31, 2021. Patients were grouped by calendar year quarter in which they received care. Basic demographics and clinical staging were compared across quarters.

Results

Five hundred and fifty four patients were identified that underwent treatment during the time period of interest. During the lockdown period, there was a 50% reduction in the mean number of patients seen (15 ± 3 vs. 28 ± 7, P = .004). In the quarter following easing of restrictions, there was a significant trend towards earlier stage (cStage I/II) disease. In comparison to quarters preceding the pandemic lockdown, there was a significant increase in the proportion of patients with Stage IV disease in the quarters following phased reopening (P = .026).

Conclusion

After a transient but significant increase in Stage I/II disease with easing of restrictions there was a significant increase in patients with Stage IV disease. Extended longitudinal studies must be conducted to determine whether COVID-19 lockdowns will lead to further increases in the proportion of patients with advanced NSCLC.

Treatment of cT3N1M0/IIIA non-small cell lung cancer and the risk of underuse of surgery

OBJECTIVE

Surgery may be underused for stage IIIA non-small cell lung cancer. Although an argument can be made for definitive chemoradiation for N2/3 mediastinal nodal disease, the role of a nonsurgical strategy is less clear in patients with cT3N1M0 stage IIIA given a lack of randomized data. We sought to determine the outcomes of patients with cT3N1M0 by treatment type from the National Cancer Database.

METHODS

The National Cancer Database (2004-2014) was queried for patients with cT3N1M0 non-small cell lung cancer, known treatment modalities, and sequence. Comparisons between groups were performed using Mann-Whitney and chi-square tests. Cox regression was performed to identify predictors of overall survival. Propensity score matching analysis was performed to compare overall survival in surgery versus definitive chemoradiation.

RESULTS

We identified 1937 patients undergoing surgery (1518 up-front and 419 after neoadjuvant treatment) and 1844 patients undergoing definitive chemoradiation. Among patients undergoing surgery without prior treatment, 19% were overstaged and were found to have pN0, whereas 9.6% had pN2/3. Median overall survival was 33.1 months in the surgery group (± adjuvant/neoadjuvant) versus 18 months in definitive chemoradiation. To compare outcomes in balanced groups, we propensity matched 1081 pairs of patients. Median overall survival was 31.1 months in the surgery group compared with 19.1 months in the definitive chemoradiation group (P < .001). By multivariable analysis, surgery (hazard ratio, 0.65; confidence interval, 0.59-0.73), female sex (hazard ratio, 0.88; confidence interval, 0.79-0.98), age (hazard ratio, 1.02; confidence interval, 1.01-1.03), squamous histology (hazard ratio, 1.22; confidence interval, 1.07-1.38), and Charlson score of 2 (hazard ratio, 1.31; confidence interval, 1.11-1.54) were predictors of survival.

CONCLUSIONS

In the National Cancer Database, approximately half of patients with clinical T3N1M0 were treated with definitive chemoradiation rather than surgery. This practice should be avoided in operable patients, because surgical resection is associated with better survival.

Lung Cancer Surveillance After Definitive Curative-Intent Therapy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations to practicing clinicians on radiographic imaging and biomarker surveillance strategies after definitive curative-intent therapy in patients with stage I-III non-small-cell lung cancer (NSCLC) and SCLC.

METHODS

ASCO convened an Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, radiology, primary care, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2019. Outcomes of interest included survival, disease-free or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 14 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Patients should undergo surveillance imaging for recurrence every 6 months for 2 years and then annually for detection of new primary lung cancers. Chest computed tomography imaging is the optimal imaging modality for surveillance. Fluorodeoxyglucose positron emission tomography/computed tomography imaging should not be used as a surveillance tool. Surveillance imaging may not be offered to patients who are clinically unsuitable for or unwilling to accept further treatment. Age should not preclude surveillance imaging. Circulating biomarkers should not be used as a surveillance strategy for detection of recurrence. Brain magnetic resonance imaging should not be used for routine surveillance in stage I-III NSCLC but may be used every 3 months for the first year and every 6 months for the second year in patients with stage I-III small-cell lung cancer who have undergone curative-intent treatment.

Sternal Reconstruction Using Customized 3D-Printed Titanium Implants

In this report, we describe the use of custom-designed 3D-printed titanium implants to reconstruct the anterior chest wall, including the sternum and adjacent ribs, in two patients. These cases are the first to be reported in the United States, and they are among a handful performed around the world.

Reintervention and Survival After Limited Lung Resection for Lung Cancer Treatment in Australia

BACKGROUND

To investigate the risk and predictors of reintervention (surgery or radiotherapy) after limited resection for lung cancer.

METHODS

A population-based, all-inclusive study using linked data from the New South Wales Admitted Patient Data Collection and Death Register included all patients undergoing limited resection for lung cancer between July 1, 2002, and March 31, 2014. Univariate and adjusted competing risk analyses were used to estimate the effect of potential factors for risk of reintervention within 6 months and 24 months of the initial surgery.

RESULTS

The overall 5-year survival for lung cancer patients undergoing limited lung resection was 52% (49% to 54%); for patients aged 70 years or more, the survival rate was 44% (40% to 47%). Reintervention occurred in 6.2% by 6 months and 11.3% by 24 months after the surgery. Younger age, surgery in private hospitals, and fewer comorbidities were independently associated with increased risk of reintervention. Patients who had the surgery performed in high surgical volume hospitals had 49% lower risk of reintervention within the first 6 months (95% confidence interval: 0.30 to 0.85). The effect of hospital surgical volume was attenuated by 24 months (hazard ratio 0.87, 95% confidence interval: 0.60 to 1.28). Patients undergoing reintervention within 6 months or 24 months had a twofold (1.52 to 2.57) and 2.3-fold (1.89 to 2.83) increased risk of death, respectively.

CONCLUSIONS

The reintervention rate within 6 or 24 months of initial limited lung cancer resection was modest, but there was considerable variation among hospitals. Reintervention was not a benign event and was associated with lower survival in an Australian population.

Consequences of Refusing Surgery for Esophageal Cancer: A National Cancer Database Analysis

BACKGROUND

Given the potential morbidity of esophagectomy, patients may pursue other treatments. We sought to determine predictors and outcomes of esophageal cancer patients who refused esophagectomy.

METHODS

The National Cancer Database (2004 to 2014) was queried for locally advanced esophageal cancer patients. A unique field allows identification of patients recommended to have surgery but who refused. Comparisons between the entire cohort and between propensity matched groups were performed using analysis of variance and χ² tests. Survival was compared using Kaplan-Meier curves. Logistic regression was performed to identify predictors of refusing surgery.

RESULTS

We identified 18,459 patients with esophageal cancer meeting criteria, including 708 (3.8) who were recommended but refused surgery. By multivariate analysis, elderly, female, nonwhite race, squamous histology, early year of diagnosis, absence of insurance, treatment at nonacademic centers, lower income, and clinical stage I/II predicted refusal of surgery. Median survival was worse for patients who refused surgery compared with patients undergoing surgery. Among propensity matched groups (n = 525 each), median survival was better for patients undergoing surgery versus patients who refused (32 versus 21 months, p < 0.001).

CONCLUSIONS

Although patients may be reluctant to undergo esophagectomy for esophageal cancer, refusal of surgery when offered comes at the expense of decreased survival. These data allow for a discussion of alternative outcomes with those patients in the context of shared decision making.

Abstract 3247: Genome-wide cell-free DNA mutation integration for sensitive cancer detection

Solid malignancies are often diagnosed at a late stage with dismal prognosis. Even after cancer is diagnosed, we lack sensitive tools to guide difficult therapeutic decisions such as adjuvant therapy. Sensitive cancer detection by blood biopsy can therefore transform care by enabling early detection and residual disease monitoring.

Cell free DNA mutation detection has shown significant promise in its ability to survey the somatic genome and enable detection of cancer mutations in the peripheral blood. However, the combination of low tumor fraction and limiting number of DNA fragments in a typical plasma sample, restrict the probability of detecting early stage cancer in cfDNA through current deep targeted sequencing methods.

Focusing on non-small cell lung cancer (NSCLC), we reasoned that we would need to supplant depth of sequencing with breadth of sequencing to overcome the fundamental limitation of low input of cfDNA. To do so, we apply whole genome sequencing (WGS) that allows us to base sensitive detection on the cumulative signal provided by 10,000-30,000 somatic mutations observed in a substantial proportion of NSCLC. We developed an analytic method that integrates genome-wide mutation signal to obtain a tumor fraction (TF) estimate, and thus allow sensitive detection of residual disease and quantitative dynamic monitoring of disease burden. Benchmarking on artificial plasma showed TF detection sensitivity as low as 1:100,000, two orders of magnitude more sensitive than currently available methods.

To test this method, we performed WGS on resected NSCLC and matched germline samples of 8 NSCLC patients, as well as on matched pre- and post-surgery cfDNA. Patient-specific somatic mutations were identified in the tumor/normal pairs and used for the estimation of TF in the matched plasma samples. We detect pre-surgery circulating tumor DNA (ctDNA) in all of the early-stage pre-operative samples and in ~40% post-operative patients, correlated with post-operative disease progression.

In early cancer detection, tumor DNA is not available, requiring de-novo mutation detection in cfDNA. To do so, we first trained a convolutional neuronal network to distinguish between cancer altered sequencing reads and reads affected by sequencing errors. This was followed by genome-wide pattern matching to a specific genomic signature that mark lung cancer mutations (Tobacco signature) indicating the presence of ctDNA in the patient plasma. Applying this method to the pre-operative early stage lung cancer samples and plasma samples from 5 patients with benign nodules (CT-detected) showed an accurate discrimination between malignant and benign nodules, suggesting a potential role in improving the positive predictive value of lung cancer screening in at-risk populations.

These results show that genome-wide mutation integration is a promising novel approach for ultra-sensitive early detection and residual disease monitoring.

Citation Format: Asaf Zviran, Steven T. Hill, Rafael Schulman, Minita Shah, Sunil Deochand, Gavin Ha, Sarah Reed, Denisse Rotem, Greg Gydush, Justin Rhoades, Kevin Huang, Will Liao, Dillon Maloney, Nathan Omans, Murtaza Malbari, Cathy F. Spinelli, Selena Kazancioglu, Nicolas Robine, Viktor Adalsteinsson, Brian Houck-Loomis, Nasser Altorki, Dan A. Landau. Genome-wide cell-free DNA mutation integration for sensitive cancer detection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3247.