Adjuvant chemotherapy and outcomes in esophageal carcinoma

181 Background: Neoadjuvant chemoradiation (NCRT) and surgery is standard treatment for esophageal cancer (EC) in the U.S. The role of adjuvant chemotherapy (ACT) is unclear. Providers assign ACT inconsistently, and both its rationales and benefits have yet to be clearly defined. We sought to evaluate rationales and benefits for ACT in EC. Methods: This single institution retrospective review included 382 patients (pts) with EC who were treated at our tertiary referral center. All pts received NCRT and 46 received ACT. We reviewed medical records to obtain demographic and clinical information. Survival outcomes were analyzed with Kaplan-Meier method from date of death or last follow up and log-rank analysis. Case-control analysis was performed using a 2:1 nearest neighbor propensity score matching algorithm, and included 113 pts, 41 of which received ACT. Results: 46 of the 382 pts in our study who received NCRT and surgery for EC also underwent ACT; two pts had single agent paclitaxel, 9 had 5-F/U and leucovorin, 7 had 5-F/U and cisplatin, 5 had carboplatin and paclitaxel, 2 had carboplatin alone, and the remainder had other combinations. Pts who received ACT were younger (med. age = 60.2 v 63.8 yr, p = 0.047), more likely to have adenocarcinoma (91.3% v 85.1%, p = 0.034), and less likely to have positive LNs on pre-treatment EUS (60.1% v 77.4%, p = 0.018). Pts with pCR were less likely to receive further treatment (6.5% v 45.8%, p < 0.001), and pts with R1 resection were more likely to do so (15.2% v 4.2%, p = 0.007). With case-control analysis, no variables were significantly different between the two groups. The median follow-up times for the entire cohort and case-control analysis were 7.98 years and 8.89 years, respectively. There were no significant differences in overall (p = 0.975) or recurrence-free (p = 0.824) survival associated with ACT in either analysis. Conclusions: The role of CT following NCRT and surgical resection in pts with locally advanced ECis unclear. In the largest series to date, our single institution retrospective review found no significant difference in survival in pts who received ACT and those who did not. Prospective studies are needed to further identify the rationales for delivery of ACT, and to investigate any potential survival benefits

Can total psoas area predict toxicity after stereotactic body radiation therapy in borderline resectable and locally advanced pancreatic cancers?

455 Background: Total Psoas Area (TPA), a marker of sarcopenia, found clinical utility as an independent predictor of clinical outcomes in gastrointestinal cancers as a proxy for nutritional status. Our study evaluated the relationship of TPA and other proxies of nutrition like Body Mass Index (BMI) and Body Surface Area (BSA) with outcomes in Borderline Resectable Pancreatic Cancer (BRPC) and Locally Advanced Pancreatic Cancer (LAPC) patients receiving Stereotactic Body Radiation Therapy (SBRT). Methods: In retrospective analysis of an IRB approved database, 183 BRPC and LAPC patients treated with SBRT from 2009-2016 met our selection criteria. Patients underwent gemcitabine based or FOLFIRINOX chemotherapy for 3 months prior to SBRT. Eligible patients were those with pre-SBRT planning CT imaging on Pinnacle, a treatment planning system, and an identifiable L4 vertebra. Bilateral psoas muscles were manually contoured at the L4 vertebral level. This area was normalized by patient height (median = 876.505 mm2/m). ROC curves were created for TPA, BMI and BSA. Toxicities were evaluated by binomial logistic regression; survival functions were evaluated by Kaplan-Meier. Significance was set at p < 0.05. Results: Low TPA (OR = 1.903, p = 0.036) and BSA (OR = 1.836 p = 0.048) were predictive of acute toxicities but only TPA was predictive of Grade 3+ acute toxicities (OR = 10.24, p = 0.040). Both findings were independent of tumor resectability. No association was found between TPA/BMI/BSA and late toxicities, overall survival, local progression or local recurrence. However, BRPC patients survived longer (median = 21.98 months) than their LAPC (median = 16.2 months) counterparts (p = 0.002), independent of nutritional status. Conclusions: Pre-SBRT TPA measurement is readily available and more specific than BMI or BSA as a predictor of serious acute radiotoxic complications following SBRT in BRPC/LAPC patients. However, tumor resectability remains as the only predictor of overall survival in this cohort. Whether initial pre-chemo TPA may predict acute toxicity related to chemotherapy and guide individualization of systemic regimen warrants further investigation

Impact of duodenal invasion on outcomes in patients with pancreatic cancer treated with stereotactic body radiotherapy

408 Background: Clinical trials for pancreatic adenocarcinoma patients treated with a uniform SBRT tumor dose prescription exclude tumors invading the duodenum due to potential for increased GI mucosal complications. We analyzed our non-trial patients to determine the impact of SBRT in the setting of known duodenal invasion. Methods: An IRB-approved institutional database was queried identifying all 220 localized borderline resectable or locally advanced pancreatic cancer patients treated with SBRT from 2009 to 2015. Eligibility included patients with head tumors, a minimum of 6 months of follow up, and duodenal invasion on pretreatment endoscopic ultrasound (EUS). Dose painted SBRT delivered 25-30 Gy to tumor abutting the duodenum and up to 50 Gy to focal tumor/vessel abutment. Analysis evaluated whether patients with duodenal invasion had increased incidence of grade ≥ 3 (G3+) toxicity, GI ulceration or bleeding, or worsened overall survival (OS). Fisher’s Exact Test (2-tailed) compared patient characteristics and binary outcomes. Survival estimates by Kaplan-Meier were compared using log-rank test. Results: The study population included 126 patients (median F/U 14.1 months). Of 23 patients with duodenal invasion, 14 (61%) underwent resection, 3 (13%) developed G3+ toxicity and 1 (4%) had acute pre-op G3 GI bleeding that was controlled endoscopically prior to surgery. Of 103 without duodenal invasion, 48 (47%) underwent resection, 9 (9%) suffered G3+ toxicity and 7 (7%) had any GI bleed or ulceration. None of the 7 patients with GI bleeding or ulceration underwent pancreatectomy, and 3 had bleeding from tumor progression into the duodenum. There was no association between duodenal invasion and the incidence of G3+ toxicity (p = 0.76) or GI ulceration/bleeding (p = 1.0). There was no worsened OS (p = 0.17) or G3+ toxicity (p = 0.22) for patients with duodenal invasion on EUS. Patients with a GI bleeding or ulceration event had decreased OS (p = .014). Conclusions: Duodenal invasion on EUS prior to SBRT did not worsen GI bleeding risk or survival. Our data suggests that excluding pancreatic adenocarcinoma patients with duodenal invasion from SBRT when using a dose-painted approach is unnecessary