Ross, Helen J.

e15567 Background: Esophageal adenocarcinoma (EAC) prognosis is poor and there is a need to identify patients that benefit most from neoadjuvant therapy. To examine the association of various biomarkers with clinical outcomes in neoadjuvant treatment of EAC, we retrospectively evaluated the biomarker expression (TS, ERCC1, TOPO1, PD-L1, PD-1) in patient matched formalin-fixed paraffin-embedded (FFPE) tumor samples. Methods: Immunohistochemistry of TS (TS106/4H4B1) , ERCC1 (Ab. 8F1), TOPO1 (1D6), PD-L1 (both 22c3 and SP142), PD-1 (NAT105), and chromogenic in-situ hybridization (CISH) of Her2 were performed on FFPE samples from 35 patients across 2 institutions at time of EAC diagnosis and after treatment when available. Retrospective clinical data and survival (5/2006-1/2016) was analyzed with a mean follow up of 110 months (range 22-306). Results: Overexpression (pre/post-treatment) of TS (60%/54%), ERCC1 (69%/16%), TOPO1 (74%/50%), PD-1 (54%/63%), PD-L1 (SP142) (2.9%/4%), PD-L1 (22c3) (0%/4%) and amplification of Her2 (18%/23%) were observed. Pretreatment observed PD-L1 levels were lower in our study (3%) when compared to other studies in EAC specimens (35%). Immunohistochemistry and changes observed after chemoradiation are reviewed in Table. No markers had significant correlation with prognosis however TS negative expression showed a non-significant (p=0.15) trend towards improved survival. Conclusions: Analyzing biomarkers in our neoadjuvant EAC cohort demonstrated a lower than expected PD-L1 positivity. In the largest cohort, to our knowledge, of patient matched FFPE tumor samples, we did not observe a statistically significant association between TS, ERCC1, TOPO1, PD-L1, or PD-1 with improved clinical outcomes. [Table: see text]

e15563 Background: Expression of thymidylate synthase (TS), a target of fluoropyrimidine-based (5-FU) chemotherapy, has prognostic value in colorectal adenocarcinoma. Its value as a biomarker in treatment of esophageal adenocarcinoma (EAC) is unknown. With widespread adoption of CROSS trial protocol for treatment of EAC, 5-FU is frequently omitted from regimens. We retrospectively analyzed the association between TS protein expression and clinical outcomes in EAC. Methods: TS expression levels were measured by immunohistochemistry in formalin-fixed paraffin-embedded specimens from 35 primary EAC patients from 2 institutions (range 5/2006-1/2016); at time of diagnosis and surgical resection (33 neoadjuvant chemoradiation and 2 surgery alone). TS expression higher than 1+, 5% was read as positive. Mean follow up was 1323 days (range 263-3677). TS expression correlated with treatment response and survival in patients treated with and without 5-FU therapy (log-rank test, Kaplan-Meier method). Results: In the cohort of 35 patients, 21 patients (60%) had pretreatment positive TS expression. Overall survival (OS) for TS negative patients was 1216 days versus 974 days for TS positive (p = 0.15). In the 23 patients treated with 5-FU, TS-negative patients had a trend towards longer overall survival compared to TS-positive patients, mean OS (1272 days versus 743 days, p = 0.08). In the group of 12 patients not treated with 5-FU, 2 patients showed negative TS staining. Neoadjuvant chemoradiation was performed in 33/35 patients. Downstaging was observed in 69% (9/13) of patients with negative pre-treatment TS levels versus 55% (11/20) in pre-treatment TS positive patients (p = 0.48). In 23 patients treated with 5FU, 9/12 (75%) were downstaged in the TS-negative cohort versus 6/11 (45%) in the TS-positive cohort (p = 0.21). In the 5FU treatment group, complete response was seen in 2 patients with negative TS staining. Conclusions: Low TS expression in EAC patients trended towards improved survival and tumor downstaging, particularly in patients treated with neoadjuvant 5-FU and platinum based therapy. Prospective data and greater patient numbers may be necessary to demonstrate statistical significance.

Abstract Checkpoint inhibitors targeted at programmed cell death-1 receptor (PD-1) and its ligand (PD-L1) can result in significant benefit to a small proportion of patients with cancer, including those with tumors of the stomach and gastroesophageal junction. These drugs are now approved for several solid tumors, including the recent accelerated approval of pembrolizumab for gastroesophageal adenocarcinomas in the third-line setting and beyond based on the KEYNOTE-059 phase II trial. Data are lacking on the efficacy of chemotherapy after progression on PD-1 blockade in metastatic gastroesophageal adenocarcinoma. This report describes the exceptional response of two patients who received ramucirumab plus paclitaxel after progressive disease on pembrolizumab. This early clinical observation suggests that the sequence of administration of PD-1 blockade and chemotherapy may be important in this disease.

165 Background: Distant metastases are common in primary esophageal cancer, but data conflict regarding the rates of brain metastases (BM) ranging from 0% to 13%. We sought to investigate whether the incidence of BM from esophageal malignancies is increasing in the modern era. Methods: After IRB approval, a single institution retrospective review identified 583 patients (pts) treated between 1/1997 and 1/2016 for stage I-IV cancer of the esophagus/esophagogastric junction with at least 3 months follow-up. Data collected included demographic information, primary diagnosis date and staging, histologic subtype, treatment regimens for primary and BM, date of BM diagnosis, status of neurologic symptoms and extracranial disease at BM diagnosis, and date of death. Data were analyzed by Fischer’s exact test and Kaplan-Meier analysis. Results: The overall cohort was comprised of 495 pts (85%) with adenocarcinoma and 82 pts (14%) with squamous cell carcinoma. 492 pts (84%) were male; the median age was 68 years (range 26-90). BM were identified in 22 pts (3.8%) with a median latency of 11 months from the primary diagnosis. Of the pts with BM, the primary histology was adenocarcinoma in 21 pts and squamous cell carcinoma in 1 pt ( P = 0.3). BM developed in 12 pts who were initially treated for locally advanced disease and in 10 pts who presented with distant metastases. Diagnosis of BM was at the time of initial presentation in 4 of these 10 stage IV pts. A solitary BM was identified in 9 pts. Initial treatments of BM were surgical resection followed by stereotactic radiosurgery (SRS; n = 5); surgical resection followed by whole brain radiotherapy (WBRT; n = 1); WBRT alone (n = 13); SRS alone (n = 3). Overall survival (OS) following diagnosis of BM was 18% at 1 year with a median of 4 months. OS was superior for pts who had surgical resection as initial treatment of BM compared to pts treated with WBRT or SRS alone (1-year OS 67 vs. 0%; median OS 13.5 vs. 3 months; P = 0.003). Conclusions: The incidence of BM is low in esophageal cancer with no statistically significant increased rate of BM developing in patients with adenocarcinoma compared with squamous cell carcinoma. Outcomes were poor overall for pts who developed BM, but pts who were appropriate for neurosurgical resection had improved survival.

134 Background: Brain metastasis (BM) is an uncommon site of failure in patients (pts) with esophageal cancer (EC) with reported rates between 1-6%. EC pts are living longer with the wider adoption of trimodality therapy and, as with other malignancies, this may change the patterns of failure. We evaluated the incidence and outcomes of BM in EC at Mayo Clinic in Arizona. Methods: A retrospective review identified pts who developed BM from cancer of the esophagus or gastroesophageal junction. A total of 321 patients treated for stage I-IV EC (adenocarcinoma, n = 273; squamous, n = 46; small cell, n = 2) were identified between 1997 and 2012. Fisher’s exact test was used for comparisons. Actuarial survival was calculated using Kaplan-Meier analysis. Results: BM developed in 13 pts (4%), all of whom had adenocarcinoma. Nine pts initially presented with T3 and/or node-positive disease. Four pts presented with metastatic disease to other sites, but only 1 of this group was diagnosed with BM at initial presentation. The median time from initial diagnosis to BM detection was 12 months (range 0-40). All pts were symptomatic at diagnosis. BM was solitary in 6 pts, multiple in 6 pts, and unknown in 1 pt. The posterior fossa was involved in 9 pts. The brain represented the first site of failure in 9 pts. Treatment included surgical resection (n = 5), stereotactic radiosurgery (n = 4), and whole brain radiotherapy (n = 9). Median overall survival was 24 months from initial diagnosis and 5 months from BM detection. Among pts with adenocarcinoma, 3/119 (2.5%) were diagnosed between 1997-2006 compared to 10/154 (6.5%) between 2007-2012 (P = 0.1). Conclusions: The brain remains an uncommon site of failure among pts with EC. A recent series reported an incidence of BM in 13% of pts, raising the possibility of a changing failure pattern. In our series, BM was detected in only 4% of pts. Our study is suggestive of a trend towards increased incidence of BM in more recent years, although it did not reach statistical significance and could be a consequence of the retrospective nature of the study. Both series found BM limited only to pts with adenocarcinoma, and a possible association has been reported between HER-2 overexpression and BM in EC. Therefore, BM in EC may be an interesting area for future study.

LBA8003 Background: PemC and PCB are regimens used for first-line treatment of advanced NS-NSCLC. The primary objective was to compare progression-free survival without Grade 4 toxicity (G4PFS) between two vs three drug regimen arms. Methods: Patients ≥18 years, Stage IV NS NSCLC, AJCC (v7.0), and ECOG PS 0/1 were enrolled. Patients were randomized (1:1); received 4 cycles of induction (PemC: Pem, 500 mg/m2 and C, AUC = 6; PCB: P, 200 mg/m2, C, AUC = 6, and B, 15 mg/kg) followed by Pem (PemC Arm) or B (PCB Arm) maintenance therapy in the absence of progressive disease or discontinuation. Secondary endpoints were PFS, overall survival (OS), overall response rate (ORR), and disease control rate (DCR). The study was powered for G4PFS; assuming hazard ratio (HR) of 0.75; there was 80% power to detect superiority of PemC over PCB with a 2-sided type I error of 0.10. Efficacy data were analyzed by intent-to-treat principle using the log-rank test for time-to-event variables, and an exact test for ORR and DCR. Safety data were evaluated using CTCAE v3 for patients who received ≥1 dose of study treatment. Results: Patients were randomized to PemC (N = 182) or PCB (N = 179). Baseline factors were balanced between arms: median age 66/66 years; % female 42/42; % PS=0, 47/47; % stage IV M1a 29/30; for PemC vs PCB, median G4PFS (months) was 3.91/2.86 (HR = 0.85, 90% CI 0.7, 1.04, p = 0.176); PFS and OS had HR = 1.06 (95% CI 0.84, 1.35), p = 0.610, and HR = 1.07 (95% CI 0.83, 1.36), p = 0.616, respectively. The ORR (%) 23.6/ 27.4 and DCR (%) 59.9/57.0 were for PemC vs PCB, respectively. Significantly more drug-related grade 3/4 anemia (18.7% vs 5.4%), and thrombocytopenia (24.0% vs 9.6%) were seen on PemC; significantly more grade 3/4 neutropenia (48.8% vs 24.6%) and grade 1/2 alopecia (28.3 % vs 8.2%) were seen on PCB. Conclusions: PemC was not superior to PCB in G4PFS; no difference in PFS or OS was observed for the two- vs three-drug regimens. There were no unexpected toxicities; the toxicity profiles demonstrated distinctions by arm, and both regimens demonstrated tolerability. Clinical trial information: NCT00948675.

20 Background: Esophageal adenocarcinoma (EAC) incidence is rising and prognosis is uniformly poor, even with early stage disease. Barrett esophagus (BE) serves as a premalignant marker for EAC, with an estimated progression of 0.5% per year. Low-grade (LGD) and high-grade dysplasia (HGD) confer a higher risk of progression, providing an opportunity for intervention and surveillance. Aims: To evaluate a large cohort of patients undergoing endoscopic evaluation of BE and thereby better understand the natural history of BE and dysplasia. Methods: A retrospective review of endoscopic databases was conducted for all patients with the diagnosis of BE undergoing upper endoscopy at a tertiary academic medical center from 1991-2010. All endoscopy and accompanying pathology reports were reviewed. Only those patients with 2 biopsies documenting specialized intestinal metaplasia were analyzed. Results: 848 patients underwent upper endoscopy for evaluation of BE. Of these, 674 patients met inclusion criteria, at a mean follow up of 66.6 months. Table 1 depicts the distribution of patients according to their histology at presentation. 22 (3.2%) patients presented with established EAC, while EAC developed in 51 (7.6%). Of patients with HGD, LGD, or no dysplasia (ND) at presentation, EAC ultimately developed in 30.6%, 6.6%, and 2.7%, respectively. EAC developed in 4 patients despite RFA treatment for ND (2) or LGD (2). HGD developed in 6 such patients after treatment for ND (3) and LGD (3). Only 1 patient in each RFA-treated cohort required esophagectomy, while the others cleared dysplasia or EAC with continuous treatment. Conclusions: In this large cohort of patients with Barrett’s esophagus, higher grade of dysplasia at first endoscopy was associated with development of EAC. Continuous surveillance during and after endoscopic treatment is necessary and often results in clearance of dysplasia and EAC. [Table: see text]

110 Background: Anastomotic leaks can occur after esophagectomy and optimal management after minimally invasive esophagectomy (MIE) is not well defined. We reviewed endoscopic management of leaks after MIE in patients undergoing trimodality therapy at Mayo Clinic Arizona. Methods: Records of patients undergoing MIE from November, 2006 to February, 2015 were reviewed after appropriate IRB approval. Results: 148 patients underwent MIE including 136 (91.8%) thoracic and 12 (8.1%) cervical anastomoses. Clinically significant anastomotic leaks were observed in 13 (8.8%) patients with 2 (16%) cervical and 11 (8%) thoracic anastomosis at a median of 6.1 days (0-14). 11 (11%) patients treated with neoadjuvant chemoradiotherapy experienced esophageal leak and 2 who did not receive chemoradiotherapy (4%). For treatment of anastomotic leaks, 10 patients underwent VATS with pleural space irrigation and chest tube replacement, and 11 patients underwent stent deployment at the anastomosis for repair. Stents were placed such that the fistula/leak was in the fully covered portion with the greater portion of the stent residing in the esophageal remnant. Stents were removed at a mean of 54 days (28-114). In 2 patients, overgrowth into the stent body required stent-in-stent placement (fully covered) with removal of both stents. Stents were successful at sealing all leaks. Conclusions: Leaks after MIE represent a small, but significant, morbidity in MIE. The majority can be managed by endoscopic stent placement. Stenting is an effective management tool for postoperative leaks in locally advanced esophageal malignancies.

158 Background: Esophageal cancer patients (pts) require multidisciplinary management involving thoracic and general surgeons, medical and radiation oncologists, gastroenterologists and psychiatrists. Pts navigate complex medical discussions and endure challenges to nutrition, body image, swallowing mechanics, energy level and weight, mood, and performance status. Coordination of care is complicated by multiple sites of pt entry, complex scheduling requirements, and incomplete information at multidisciplinary consultation. A nurse navigator to coordinate the patient experience may optimize treatment and improve outcomes, quality of life and patient satisfaction. Methods: The nurse navigator evaluates all pt records prior to initial appointment and coordinates scheduling, records acquisition, testing and specialty appointments. The nurse navigator serves as a liaison with pts throughout the course of care and provides a patient navigation book (PNB) as a central source for patient-directed information and record keeping. Benchmarks compared before and after creation of the nurse navigator position include: (1) time from appointment request to multidisciplinary evaluation and start of treatment; (2) completeness of medical records and data (scans, pathology slides); (3) patient awareness of support services for themselves and caregivers; (4) utilization of the PNB; (5) number and frequency of interim hospitalizations and emergency room visits; (6) patient, caregiver, and physician satisfaction. Results: From January to July 2012, 27 gastroesophageal cancer pts have been followed by the nurse navigator. Most of these patients remain on active treatment, hence benchmark analysis is ongoing. Metrics thus far suggest improvement in time to treatment start and awareness of patient resources, use of the PNB and patient satisfaction. Conclusions: Esophageal cancer pts undergo complex and toxic multimodality therapy with curative intent. A dedicated nurse navigator may improve the patient experience, optimize adherence to guideline based therapy and appropriate timeframes and provide continuity to pts undergoing multidisciplinary treatment.