P-P42 Neo-adjuvant Chemoradiation for Borderline Resectable Pancreatic Adenocarcinoma: A UK Tertiary Surgical Oncology Centre Series

Background Pancreatic ductal adenocarcinoma (PDAC) is associated with a historically poor long-term survival of 5-10%, despite surgical resection. Borderline resectable pancreatic ductal adenocarcinoma (BR-PDAC) is reported as potentially resectable disease with a degree of vascular involvement, increasing the risk of a positive surgical margin. This cohort of patients have the worst survival despite curative resection and adjuvant chemotherapy. Emerging evidence suggests that neo-adjuvant chemoradiation (NCR) improves R0 resection rates in BR-PDAC patients. We evaluated the R0 resection rate, disease free survival (DFS) and overall survival (OS) in our patients, who had undergone NCR for BR-PDAC at our institution. Methods Data was collected retrospectively for all patients undergoing NCR for BR-PDAC between Jan 2010 to Mar 2020 for this study. Surgical management was ratified by clinical assessment and cross-sectional imaging in a pancreatic multidisciplinary team meeting (MDM). Patients underwent NCR by a number of standardised regimens. Patients with proven regressive or stable disease on imaging underwent a pancreatic resection. All BR-PDAC patients underwent resection in the form of classical Whipple’s or pylorus preserving pancreaticoduodenectomy (PPPD) depending on intra-operative findings. Patient morbidity, R0 resection rate, histological parameters, DFS and OS were evaluated. Results 29 patients were included in the study (16 men and 13 women), with a median age of 65 years (range, 46-74 years). 17 patients received FOLFIRINOX and 12 patients received gemcitabine (GEM) based NCR regimens. All patients received chemoradiation at the end of chemotherapy (range 45-56Gy). 75% had an R0 resection, with a greater proportion in the FOLFIRINOX group. Whole cohort median DFS was 35 months, survival was superior in the FOLFIRINOX group (42 months). Median OS was 30 months for the whole group, with a greater median OS in the FOLFIRINOX versus the GEM cohort (42 versus 29 months). Conclusions We present a single centre retrospective study utilising NCR for BR-PDAC, we reiterate the strong association of an R0 resection with superior patient overall survival following surgery in this cohort. We show that in patients with BR-PDAC, NCR results in superior R0 resection rates with an associated increase in patient survival. Our results show that survival advantage is greatest in BR-PDAC patients who received neo-adjuvant FOLFIRINOX. Our findings affirm the advantage of NCR prior to surgery, particularly FOLFIRINOX based treatment, in this cohort of patients.

Evaluation of Treatment Outcome and Acute Toxicity in Patients Undergoing Adjuvant Therapy in Ductal Carcinoma Pancreas: A Prospective Observational Study

Ductal adenocarcinoma of the pancreas is one of the commonly diagnosed cancers and is a leading cause of cancer mortality in the population. The prognosis of patients even after undergoing a complete resection is generally poor, with a median survival of 13–20 months and a 3-year survival of 30%. Therefore, adjuvant therapies including adjuvant chemoradiation and adjuvant chemotherapy are given in an effort to improve survival. In the authors’ centre, all patients undergoing resection are given adjuvant chemoradiation followed by adjuvant chemotherapy. This study was conducted to evaluate the acute toxicity and treatment outcome (patterns of failure, overall and disease-free survival) of patients undergoing adjuvant therapy in resected carcinoma pancreas. Adjuvant chemoradiation was well tolerated by most patients with resected carcinoma pancreas and all patients completed chemoradiation. Adjuvant chemotherapy was associated with high haematological toxicity, similar to previously published literature. However, treatment interruptions were higher and only 77% patients completed adjuvant chemotherapy. The adjuvant gemcitabine, given on Days 1, 8, and 15, for a 4-weekly schedule was poorly tolerated by the authors’ patient population and there were only fewer interruptions in patients who were switched to the 3-weekly schedule. Inclusion of a greater number of patients and longer follow-up of this study is required to clearly assess the patterns of failure and survival outcomes.

SURG-09. SUCCESSFUL SAFETY AND EFFICACY OF GAMMATILE INTRACRANIAL BRACHYTHERAPY IMPLANTED DURING AWAKE CRANIOTOMY

INTRODUCTION GammaTile intracranial brachytherapy utilizing cesium-131 seeds has demonstrated encouraging safety and local control results in a single-arm precommercial study, and recently received Food and Drug Administration clearance. The authors report the first case of GammaTile intraoperative brachytherapy performed during an awake craniotomy. METHODS A 50-year-old man suffered a generalized tonic-clonic seizure while a vehicle passenger. MRI revealed a 2.8 cm left lateral frontal lesion nearing his Broca’s area. Open brain biopsy revealed IDH-wildtype MGMT unmethylated GBM. Unfortunately, despite several interventions (awake craniotomy, adjuvant chemoradiation with temozolomide, Avastin, tumor treating fields) he suffered tumor progression near the left parietal resection cavity. Due to the location of this tumor, re-resection was planned with awake craniotomy and language mapping. A preoperative planning session involving Radiation Oncology and Neurosurgery identified the area of the expected postoperative bed, and consequently five GammaTiles were ordered, each containing 4 cesium-131 3.5 U seeds. RESULTS During surgery, once the tumor was mapped, bipolar stimulation was performed while the patient spoke in complete sentences until going into speech arrest on the posterior edge of the gyrus, indicative of language cortex. Following this mapping, microsurgical maximal safe resection occurred, after which areas at risk for tumor residual/recurrence were determined in consultation with Radiation Oncology. Subsequently, Neurosurgery placed all five GammaTiles (20 cesium-131 seeds total) in customized forward fashion to optimally cover the dosimetric needs of these areas. Following GammaTile placement, closure was completed and radioactive surveys of the room remained within state statue. Postoperative dosimetry yielded excellent coverage, and speech function was maintained. CONCLUSIONS The first reported case of GammaTile intraoperative brachytherapy during awake craniotomy supports the safety and feasibility of this treatment strategy. This case indicates that for patients with tumors adjacent to eloquent cortex, awake craniotomy can allow for maximum safe resection and implantation of intraoperative brachytherapy.

Cost-utility of two minimally-invasive surgical techniques for operable oropharyngeal cancer: transoral robotic surgery versus transoral laser microsurgery

Background In the past few decades, a re-evaluation of treatment paradigms of head and neck cancers with a desire to spare patients the treatment-related toxicities of open surgery, has led to the development of new minimally invasive surgical techniques to improve outcomes. Besides Transoral Laser Microsurgery (TLM), a new robotic surgical technique namely Transoral Robotic Surgery (TORS) emerged for the first time as one of the two most prominent and widely used minimally invasive surgical approaches particularly for the treatment of oropharyngeal cancer, a sub-entity of head and neck cancers. Recent population-level data suggest equivalent tumor control, but different total costs, and need for adjuvant chemoradiation. A comparative analysis of these two techniques is therefore warranted from the cost-utility (C/U) point of view. Methods A cost-utility analysis for comparing TORS and TLM was performed using a decision-analytical model. The analyses adopted the perspective of a Swiss hospital. Two tertiary referral centers in Lausanne and Zurich provided data for model quantificantion. Results In the base case analysis TLM dominates TORS. This advantage remains robust, even if the costs for TORS reduce by up to 25%. TORS begins to dominate TLM, if less than 59,7% patients require adjuvant treatment, whereby in an interval between 55 and 62% cost effectiveness of TORS is sensitive to the prescription of adjuvant chemoradiation therapy (CRT). Exceeding 29% of TLM patients requiring a revision of surgical margins renders TORS more cost-effective. Conclusion Non-robotic endoscopic surgery (TLM) is more cost-effective than robotic endoscopic surgery (TORS) for the treatment of oropharyngeal cancers. However, this advantage is sensitive to various parameters, i.e.to the number of re-operations and adjuvant treatment.

Prognostic Factors and Effect of Adjuvant Chemoradiation Following Chemotherapy in Resected Pancreatic Cancer Patients With Lymph Node Metastasis or R1 Resection

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with a poor prognosis. In resectable PDAC, the recurrence rate is still high even when surgery and adjuvant chemotherapy (CT) are applied. Regional lymph node metastasis and positive margins are associated with higher recurrence risk and worse survival. Adjuvant radiotherapy has been explored, but its efficacy remains controversial. In recent years, some characteristics have been reported to stratify patients who may benefit from adjuvant chemoradiation (CRT), such as lymph node metastasis and margin status. Adjuvant chemotherapy followed by chemoradiation (CT-CRT) was also proposed. A total of 266 patients with resectable PDAC who have lymph node metastasis or R1 resection after surgery were enrolled. In multivariate Cox regression analyses, pancreatic body or tail tumor location (HR 0.433, p<0.0001, compared with pancreatic head) and adjuvant CT predicted a better survival, while there were no significant differences among the different CT regimens. Higher T stage indicated poor survival (stage I: reference; stage II: HR 2.178, p=0.014; stage III: HR 3.581, p=0.001). Propensity score matching was applied in 122 patients to explore the role of CRT. A cohort of 51 patients (31 and 20 patients in the CT and CT-CRT groups, respectively) was generated by matching. Further analyses revealed adjuvant CT-CRT was associated with prolonged survival compared with CT alone (HR 0.284, p=0.014) and less frequent local recurrences (56.5% vs. 21.4% in the CT and CT-CRT group, respectively). However, no significant differences in disease-free survival among these two groups were observed.

Long-Term Opioid Use in Post-Surgical Management of Patients With Head and Neck Cancer

Objective: This study aims to identify clinical and socioeconomic factors associated with long-term, post-surgical opioid use in the head and neck cancer population. Methods: A single center retrospective study was conducted including patients diagnosed with head and neck cancer between January 1, 2014 and July 1, 2019 who underwent primary surgical management. The primary outcome measure was continued opioid use 6 months after treatment completion. Both demographic and cancer-related variables were recorded to determine what factors were associated with prolonged opioid use. Univariate analysis was performed using chi-squared test for categorical variables and 2-sample t-test for continuous variables. Multivariate analysis was performed using logistic regression. Results: A total of 359 patients received primary surgical management. Forty-five patients (12.53%) continued to take opioids 6 months after treatment completion. Using univariate analysis, patients less than 65 years of age ( P = .0126), adjuvant chemoradiation (n = 25, P < .001), and overall length of hospital stay (8.60 ± 8.58 days, P = .0274) were significantly associated with long term opioid use. Multivariate logistic regression showed that adjuvant chemoradiation (OR = 3.446, 95% CI [1.742, 6.820], P = .0004) and overall length of hospital stay (OR = 0.949, 95% CI [0.903, 0.997], P = .0373) to be significantly associated with opioid use 6 months after head and neck cancer treatment. Conclusion: Long-term postoperative opioid use in head and neck cancer patients is significantly associated with adjuvant chemoradiation, and patients with longer length of hospital stay. Therefore, future research should focus on interventions to better manage opioid use during the acute treatment period to decrease long-term use.

Analysis of Post-operative Adjuvant Chemotherapy Versus Adjuvant Chemoradiation Therapy Outcomes in Non-metastatic Cholangiocarcinoma: an NCDB Review

Background Each year, approximately 8000 cases of cholangiocarcinoma are recorded in the USA. Surgical resection is considered to be the only curative option. Despite surgery as a curative approach, many patients will require adjuvant therapies in the form of chemotherapy (ChT) or chemoradiotherapy (CRT). As such, we sought to analyze outcomes in patients with non-metastatic cholangiocarcinoma receiving adjuvant ChT or CRT following surgical resection. Methods We queried the National Cancer Database (NCDB) for patients with a diagnosis of non-metastatic cholangiocarcinoma between the years 2010 and 2015 who underwent adjuvant ChT or CRT following surgery. Overall survival (OS) was calculated using Kaplan Meier method. Cox proportional hazard ratios were used to identify predictors of overall survival, and logistic regression was used to identify predictors of receiving each treatment. Results A total of 875 patients were identified who met the above eligibility criteria. Of these patients, 818 received adjuvant chemotherapy alone with 57 patients receiving adjuvant chemoradiation therapy. The median OS in patients receiving CRT was 19.8 months versus 11.9 months for ChT (p value < 0.0238). The 1- and 5-year survival rates between ChT and CRT were 50% vs 61% and 6% vs 13%, respectively (hazard ratio 0.7005; 95% CI 0.51–0.97; p value < 0.0294). Conclusion The results of this study suggest a potential benefit of chemoradiation therapy in the adjuvant setting, although the trends appear to show rare utilization. Given the limitations of our study, prospective corroboration is warranted.

The Effect of Treatment Facility, Race, and Chemoradiation on Survival for Signet Ring Cell Carcinoma of the Esophagus: An Analysis of the National Cancer Database

Background: Signet ring cell carcinoma of the esophagus (SRCCE) is an aggressive tumor that represents approximately 3.5-5.0% of all esophageal cancers. Prior studies have shown a strong correlation between treating facility and survival for different cancers, but this has not been studied in SRCCE. The goal of this study is to assess differences in survival based on the type of treatment facility. Methods: There were 2,021 patients with SRCCE identified using the histology 8490 and topography codes C15.0-C15.9 in the National Cancer Database (NCDB). Descriptive analysis, Kaplan-Meier curves, and a multivariable Cox hazard regression analysis were all utilized to determine the significance of treatment facility type and other variables. Results: The cohort mostly received treatment at academic centers (47.7%). As age increased, mortality also increased (HR=1.01; 95% CI:1.01-1.02, p<0.001). Africans Americans (HR=1.44; 95% CI:1.02-2.02, p=0.036) had an increased risk of mortality when compared to Non-Hispanic Caucasians. Patients at academic facilities demonstrated a decreased risk of mortality when compared to community programmes (HR=0.73; 95% CI:0.64-0.84, p<0.001) and integrated cancer programmes (HR=0.69; 95% CI:0.58-0.83, p=0.008). Neoadjuvant chemoradiation resulted decreased mortality when compared to adjuvant chemoradiation (HR=1.41; 95% CI:1.21-1.63, p<0.001) and no chemoradiation (HR=1.84; 95% CI:1.58- 2.14, p<0.001). Conclusion: For patients diagnosed with SRCCE, receiving treatment at academic centers resulted in better survival probabilities compared to nonacademic facilities. Older patients, African Americans, increasing tumor stage, no and adjuvant chemoradiation, and comorbidities with Charlson-Deyo scores of 1 and 2+ were all associated with an increased risk of mortality from SRCCE.