Preoperative downstaging of pancreatic cancer is associated with improved survival after multi-agent chemotherapy, but not after radiation

Abstract

BackgroundDownstaging has been associated with improved survival for many cancers. However, the implications of downstaging are unclear for pancreatic cancer in an era of effective neoadjuvant systemic chemotherapy. MethodsNCDB retrospective cohort study of resected pancreatic carcinoma treated with neoadjuvant therapy. ResultsThe study included 73,985 patients: 66,589 with no neoadjuvant therapy, 2,102 neoadjuvant radiation therapy (N-RT), 3,195 neoadjuvant multiagent chemotherapy (N-MAC) and 2.099 with both neoadjuvant radiation and multiagent chemotherapy. There was increased use of N-MAC over the period of this study. Patients selected for treatment with N-MAC had longer survival from surgery on univariate (23.1 vs. 18.7 months, p = < 0.01) and multivariate analyses HR 0.81 (0.76–0.87, p < 0.001) compared to those selected with N-RT. Downstaging was similar in N-RT and N-MAC groups (25.1 vs. 24.1%, p = 0.43). Downstaging following N-MAC was associated with a survival benefit, HR 0.85 (0.74–0.98). However, downstaging following N-RT was not associated with a survival advantage, HR 1.12 (0.99–0.99). ConclusionClinicians have rapidly adopted N-MAC for treatment of pancreatic cancer. Although the rates of downstaging are similar between treatment groups, response translates into increased survival only with N-MAC and not with N-RT.