51: Response to neoadjuvant chemotherapy in invasive intraductal papillary mucinous cystic neoplasm compared to de novo pancreatic ductal adenocarcinoma

Saturday, March 25, 2023

10:46 AM – 10:56 AM

Location: Ballroom A

Abstract Presenter(s)

Alessandro Fogliati, MD (he/him/his)

Research fellow
Mayo Clinic
Rochester, Minnesota, United States

Disclosure(s): No financial relationships to disclose

First Author(s)

Alessandro Fogliati, MD (he/him/his)

Research fellow
Mayo Clinic
Rochester, Minnesota, United States

Disclosure(s): No financial relationships to disclose

Author(s)

AZ

Andrea Zironda, MD

Research Fellow
Mayo Clinic, United States

Disclosure information not submitted.

Author(s)

GF

Guido Fiorentini, MD

HPB surgery Fellow
Mayo Clinic, United States

Disclosure information not submitted.
Amro M. Abdelrahman, MBBS MS (he/him/his)

Research Fellow
Mayo Clinic
Rochester, Minnesota, United States

Disclosure information not submitted.
Susanne G. Warner, MD

Assistant Professor of Surgery
Mayo Clinic

Disclosure information not submitted.
CT

Cornelius A. Thiels, DO, MBA

Assistant Professor
Division of Hepatobiliary and Pancreas Surgery, Mayo Clinic, United States

Disclosure information not submitted.
RS

Rory L. Smoot, MD

Associate Professor of Surgery, Associate Professor of Biochemistry and Molecular Biology
Mayo Clinic, Department of Surgery and Department of Biochemistry and Molecular Biology, United States

Disclosure information not submitted.
MK

Michael Kendrick, MD

Professor
Division of Hepatobiliary and Pancreas Surgery, Mayo Clinic, United States

Disclosure information not submitted.
SC

Sean Cleary, MD

Professor
Division of Hepatobiliary and Pancreas Surgery, Mayo Clinic, United States

Disclosure information not submitted.
Mark J. Truty, MD, MSc

Practice Chair
Mayo Clinic Rochester
Rochester, Minnesota, United States

Disclosure information not submitted.

Disclosure(s):

Alessandro Fogliati, MD: No financial relationships to disclose

Introduction: Invasive intraductal papillary mucinous cystic neoplasms (I-IPMN) are often considered equivalent to de-novo pancreatic ductal adenocarcinoma (PDAC), management of these neoplasms does not differ in terms of surgery and chemotherapy regimen. Whether oncological outcomes of I-IPMNs are superior to de novo cancers is source of debate. This study aims at understanding whether I-IPMNs have a different response to chemotherapy compared to PDAC.

Methods: All patients undergoing pancreatic resection for PDAC and I-IPMN from 2011 to 2021 in a high-volume center were retrospectively reviewed. PDAC and I-IPMN cohorts were compared and then a subset analysis of patients who received neoadjuvant therapy (NAT) was carried out assess NAT response in I-IPMN and PDAC. Association to recurrence of NAT, staging, perineural invasion, margins and I-IPMN pathology was assessed with a multivariate analysis. The primary outcome was pathological response to NAT. Secondary outcomes were PET response, CA19-9 response and radiological response.

Results:

The study includes 1152 patients, with 1047 PDAC and 105 I-IPMN. The I-IPMN group had higher mean age compared to PDAC (68 ± 9.3 vs. 65.3 ± 9.9, p 0.003), but preoperative CA19.9 (120.9 ± 336 vs. 157.2 ± 523.1, p 0.251) and staging (Ia/Ib 50% vs. 46%, IIa/IIb 39% vs. 38%, III 10% vs. 15%, IV 2% vs. 1%, p 0.458) were similar. With a median follow up of 30 months (IQR 13-76), I-IPMN showed a higher 5-year OS (52% vs. 28%, < 0.001) and DFS (60% vs. 30%, < 0.001) in Kaplan-Meier curves. Twenty-six I-IPMN and 678 PDAC underwent NAT (25% vs. 65%, p < 0.001). I-IPMN and PDAC showed similar NAT pathological response (marked response 19% vs. 29%, partial response 50% vs. 52%, no response 31% vs. 15%, p 0.107). PET response (71% vs. 61%, p 0.447), CA19-9 response (85% vs. 76%, p 0.290), and radiological response (32% vs. 37%, p 0.628) were also equivalent between I-IPMN and PDAC. After multivariate analysis, I-IPMN (OR 0.35, 0.22-0.57 p < 0.001) and NAT (OR 0.71, 0.53-0.95 p 0.019) resulted independently associated with a reduced risk of recurrence.

Conclusions: I-IPMN have a longer OS and DFS after surgical treatment when compared to PDAC. The more favorable oncologic outcome of I-IPMN does not seem to be related to early detection as I-IPMN histological subclass is independently associated to a lower risk of disease recurrence. Moreover, neoadjuvant effect on I-IPMN was comparable to PDAC in terms of pathological, CA19-9, PET and radiological response.

Learning Objectives:

explain to patients with invasive IPMN what to expect from neoadjuvant chemotherapy
Interpret the difference in survival and disease-free survival for different subtype of pancreatic adenocarcinoma
Identify which IPMN patient could benefit from neoadjuvant chemotherapy