Predictors of Resectability in Locally Advanced Pancreatic Cancer and Effect on Outcome

Abstract

Pancreatic cancer remains a highly aggressive malignancy with surgery being the only curative option. Unfortunately, only 15-20% of patients are operative candidates at the time of diagnosis due to the disease’s typically late presentation. Patients with locally advanced disease are often initially deemed unresectable due to local invasion of surrounding vasculature; however, a subset of these patients will eventually go on to receive surgical intervention. We used the National Cancer Database (NCDB) to examine predictors of resection in locally advanced pancreatic cancer patients, and effect on outcome. We queried the NCDB from 2004-2014 for patients with T4N0-1M0 adenocarcinoma of the pancreas treated in a non-palliative manner with at least 3 months of follow-up. Multivariable logistic regression was done to identify predictors of surgical resection. Propensity score was calculated and matching was completed to generate a Kaplan-Meier curve comparing outcomes between surgical and non-surgical groups. We identified 14,390 patients meeting above eligibility criteria, of which 1,008 (7%) underwent surgical resection. Median age was 66 (40-90). Median follow up for the entire cohort was 12 months (3-151). Predictors of surgical treatment included chemoradiation, younger age, lower grade, higher education level, private insurance, white race, and more recent year of treatment. Multivariable cox regression predictors of improved survival included chemoradiation, younger age, lower comorbidity score, treatment at an academic facility, lower grade, higher income, N0 disease, surgical treatment, and more recent year of treatment. On propensity matched Kaplan-Meier analysis, survival was improved with surgical resection, with a median survival of 23 months compared to 13.8 months, p<0.0001. Surgery remains the biggest driver of survival in locally advanced pancreatic cancer. Based on the results of this analysis for younger patients with good performance, consideration should be given to combined neoadjuvant therapy to increase likelihood of surgery.