Effect of neoadjuvant chemoradiation therapy is independent of intratumoral vascularization in resectable pancreatic cancer

Abstract

Abstract Background Neoadjuvant chemoradiation therapy (NACRT) is a multidisciplinary treatment for pancreatic cancer (PC) in which the effect of anticancer drugs depends on intratumoral blood flow. Most PCs are hypovascular; however, the additional effects of radiation therapy on drug efficacy are unclear. We investigated the relationship between PC vascularity and the therapeutic effect of NACRT using contrast-enhanced harmonic EUS (CH-EUS).Methods Patients with resectable PC who underwent CH-EUS followed by NACRT were analyzed retrospectively. The CH-EUS enhancement pattern was evaluated in the vascular and perfusion phases, and classified according to vascularity: Group A, hypovascular in both phases; Group B, isovascular and hypovascular in the vascular and perfusion phases, respectively; Group C, isovascular in both phases. The relationship between CH-EUS vascular pattern and the histological effect of NACRT, recurrence-free survival (RFS), and overall survival (OS) were assessed.Results Of 48 enrolled patients, 31, 11, and 6 were classified into Groups A, B, and C, respectively. There was no significant difference in histopathological differentiation, efficacy of NACRT, median RFS or OS among the groups.Conclusions There was no significant difference in the histopathological efficacy of NACRT for resectable PC in terms of the enhancement pattern of CH-EUS. NACRT may provide additional therapeutic effect regardless of blood flow.