Clinical Study of pathologic complete response after preoperative treatment in prancreas cancer associated with operative part analysis by molecular biology ; Étude clinique des patients très bons répondeurs au traitement néo adjuvant du cancer du pancréas associée à une analyse des pièces opératoires par biologie moléculaire

Introduction: a complete (ypT0) or major (ypT1) pathological response was sometimes observed after neoadjuvant treatment of pancreatic adenocarcinoma (ADK) borderline (BR) or locally advanced (LA), however recurrence was possible. The resectable ADK have their overall survival (OS) impacted by the presence of the Kras mutation on the surgical venous limits (LV). The purpose of this study was to analyze the long-term outcomes of very good responders and to evaluate the effect of the presence of the Kras mutation (Kras+) on healthy LV (R0). Method: from 2003 to 2017 at Bordeaux University Hospital, 29 BR or LA patients were identified with ypT0 or ypT1 responses after neoadjuvant treatment and pancreatic resection (R0). The search for the Kras mutation by digital PCR was performed on a 5mm3 sample of tumor tissue and healthy LV for 17 patients Results: the OS was 75.9% at 3 years and 62.1% at 4 years with a median of 59 months. 48.3% of patients recurred with a median delay of 17 months [4 - 55] including 10.34% at more than 4 years. 62.5% of ypT0 recurred in disseminated forms. The time between recurrence and death was 19 months [2 - 36]. No difference was found between ypT0 and ypT1 on OS and disease-free survival (DFS) (p>0.05). 52.9% of patients were Kras+ at the venous resection limits. The OS and DFS were comparable between the Kras+ and Kras- groups (p>0.05). Conclusion: the OS and DFS are high for ypT0 or ypT1. Recurrence is frequent, late, in disseminated forms and can be controlled for a long time by treatment. The presence of the Kras mutation on the limits of healthy venous resections had no impact on this small population. ; Introduction : une réponse histologique tumorale complète (ypT0) ou majeure (ypT1), était parfois observée après traitement néo adjuvant d’un adénocarcinome du pancréas (ADK) borderline (BR) ou localement avancés (LA), cependant la récidive était possible. Il est décrit que les ADK ré sécables d’emblée ont leur survie globale (SG) impactée par la présence de la mutation Kras ...