Neoadjuvant and Adjuvant Treatments for Resectable and Borderline Resectable Pancreatic Ductal Adenocarcinoma: The Current Status of Pancreatic Ductal Adenocarcinoma Treatment in Japan.

Resection is the only curative treatment for pancreatic ductal adenocarcinoma (PDAC). Although the outcome of technically resectable PDAC has improved with advances in surgery and adjuvant therapy, the 5-year survival rate remains low at 20% to 40%. More effective therapy is needed. Almost 15 years ago, the National Comprehensive Cancer Network guidelines proposed a resectability classification of PDAC based on preoperative imaging. Since then, treatment strategies for PDAC have been devised based on resectability. The standard of care for resectable PDAC is adjuvant chemotherapy after R0 resection, as shown by the results of pivotal clinical trials. With regard to neoadjuvant treatment, several recent clinical trials comparing neoadjuvant treatment with upfront resection have been conducted on resectable PDAC and borderline resectable PDAC, and the benefits and efficacy of neoadjuvant treatment for pancreatic cancer has become clearer. The significance of neoadjuvant treatment for resectable PDAC remains controversial, but in borderline resectable PDAC the efficacy of neoadjuvant treatment has been further recognised, although the standard of care has not yet been established. Several promising clinical trials for PDAC are ongoing. This review presents previous and ongoing trials of perioperative treatment for resectable and borderline resectable PDAC, focusing on the difference between Asian and Western countries.