Comparison of CT and MRI-Based Gross Tumor Volume and Organ at Risk Delineation for Pancreatic Cancer Patients Undergoing Neoadjuvant Stereotactic Body Radiation Therapy

Abstract

Purpose/Objective(s): To determine the effects of adjuvant treatment on survival in patients 70 years and older compared to those less than 70 years of age with pancreatic cancer treated with surgery. Materials/Methods: An analysis of patients with upfront surgically resected pancreatic cancer treated at our institution between 2000 and 2012 was performed to compare outcomes of patient 70 versus <70 years. Survival curves were calculated according to the Kaplan-Meier method and log-rank analysis. Multivariate analysis (MVA) was performed by the Cox proportional hazard model. Results: We identified 245 patients who met inclusion criteria. Patients 70 years of age less frequently received adjuvant treatment (p<0.001); however there was no difference between the two age groups based on primary site, margin status, grade, histology, tumor stage, and post-op CA19-9. There was a trend to increased pancreatic leaks in the elderly group (pZ 0.053) but no difference in post-operative complications between the two groups with respect to gastric/ jejunum tube leaks, atrial fibrillation, pulmonary embolism, infections, wound complications, fistulas, or 30, 60, 90 day mortality. There was no difference in overall survival (OS) based on age. Median and 5-year OS was 23 months and 19% inpatients 70years versus 21months and25% in those<70 (pZ0.3).On univariate analysis (UVA) there was increased OS in patients with lower T stage (pZ0.02),N0status (p<0.001), post-operativeCA19-9<90 (p<0.001), anduse of chemoradiation therapy (pZ 0.002). MVA for all patients revealed that lower T stage, N0, post-operative CA 19-9 <90 and use of adjuvant therapy, both chemotherapy and chemoradiation therapy were prognostic for decreased mortality (all p<0.05). Age, sex, or positive margins were not prognostic on MVA. Conclusions: There is no difference in outcomes when comparing elderly patients with resected pancreatic cancer to those patients <70 years of age. There was an increase in OS in patients that were treated with either adjuvant chemotherapy or chemoradiation therapy. Author Disclosure: J. Freilich: None. T. Strom: None. G.M. Springett: None. S.E. Hoffe: None. L. Balducci: None. K.L. Meredith: None. M.P. Malafa: None. R. Shridhar: None.