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PSM

Plenary Session 2

68: Reliability of Recurrence-free Survival as an Efficacy Endpoint for Trials of Resected Colorectal Cancer Peritoneal Metastasis: Results from the PSOLARIS study group

Friday, March 22, 2024
3:06pm - 3:18pm ET
Location: Georgia Ballroom

    Abstract Presenter(s)

  • Muhammad Talha Waheed, MD

    Research Fellow
    Division of Surgical Oncology, City of Hope National Medical Center, Duarte, CA
    Duarte, California, United States

    • Submitter(s)

  • Muhammad Talha Waheed, MD

    Research Fellow
    Division of Surgical Oncology, City of Hope National Medical Center, Duarte, CA
    Duarte, California, United States

    • Author(s)

  • Muhammad Talha Waheed, MD

    Research Fellow
    Division of Surgical Oncology, City of Hope National Medical Center, Duarte, CA
    Duarte, California, United States

  • VK

    Vahan Kepenekian, MD

    Surgical Oncologist
    Department of Digestive Surgery, CHU Lyon Sud, Pierre-Benite, France, United States

  • IS

    Isabelle Sourrouille, MD

    Surgical Oncologist
    Department of Surgical Oncology, Institut Gustav Roussy, Paris, France, United States

  • FD

    Frédéric Dumont, MD, PhD

    Surgical Oncologist
    Department of Surgical Oncology, Institut du Cancer Ouest, Nantes, France, United States

  • MP

    Marc Pocard, MD, PhD

    Professor
    Department of Digestive Surgery, CHU Pitié Salpêtriere, Paris, France, United States

  • Anai Kothari, MD, MS

    Assistant Professor
    Medical College of Wisconsin
    Milwaukee, Wisconsin, United States

  • Charles A. Staley, MD

    Professor
    Division of Surgical Oncology, Emory University, Atlanta, GA, United States
    Atlanta, GA, United States

  • CE

    Clarisse Eveno, MD, PhD

    Professor
    Department of Digestive Surgery, CHU Claude Huriez, Lille, France, United States

  • Sameer H. Patel, MD, FSSO (he/him/his)

    Associate Professor
    Division of Surgical Oncology, University of Cincinnati, Cincinnati, OH, United States, United States

  • Jordan M. Cloyd, MD

    Surgical Oncologist
    Division of Surgical Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, United States
    Columbus, Ohio, United States

  • Laura A. Lambert, MD

    Professor
    Division of Surgical Oncology, University of Utah, Salt Lake City, UT, United States
    Salt Lake City, Utah, United States

  • MH

    Martin Hübner, MD

    Professor
    Department of Digestive Surgery, CHUV, Lausanne, Switzerland, United States

  • Fabian M. Johnston, MD, MHS

    Associate Professor of Surgery
    Division of Gastrointestinal Surgical Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
    Baltimore, Maryland, United States

  • PV

    Patrick R. Varley, MD, MS

    Assistant Professor
    Division of Surgical Oncology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, USA, United States

  • KF

    Keith F. Fournier, MD

    Associate Professor
    Division of Surgical Oncology, MD Anderson Cancer Center, Houston, TX, United States, United States

  • Sean Dineen, MD

    Assistant Professor
    Department of Gastrointestinal Oncology, Moffitt Cancer Center, Tampa, FL, United States
    Tampa, Florida, United States

  • Travis E. Grotz, MD

    Associate Professor
    Mayo Clinic, Rochester, MN, United States
    Rochester, Minnesota, United States

  • LB

    Lana Bijelic, MD

    Chief Peritoneal Surface Malignancies Unit
    Department of Surgical Oncology, CHU Moises Broggi, Barcelona, Spain, United States

  • Olivia Sgarbura, MD, PhD

    Surgical Oncologist
    Department of Surgical Oncology, Institut du Cancer Montpellier, Montpellier, France
    Montpellier, United States

  • Mustafa Raoof, MD, MS

    Assistant Professor
    Division of Surgical Oncology, City of Hope National Medical Center, Duarte, CA
    Duarte, California, United States

Disclosure(s):
Muhammad Talha Waheed, MD: No financial relationships to disclose
Sameer H. Patel, MD, FSSO: No financial relationships to disclose
Laura A. Lambert, MD: No financial relationships to disclose
Sean Dineen, MD: Oncoinvent: Consultant (Ongoing)
Introduction: Recurrence free survival (RFS) and peritoneal-RFS (P-RFS) have long been used as surrogate endpoints for overall survival (OS) in trials of resected colorectal cancer peritoneal metastases (CRC-PM). However, data supporting the use of these surrogate endpoints are lacking. We aimed to assess the correlation between RFS/P-RFS and OS in patients undergoing curative-intent cytoreduction to determine the adequacy of these surrogate endpoints.


Methods: In this retrospective study from the Peritoneal Surface Oncology Alliance for Research and Innovative Solutions (PSOLARIS) group, patients from 11 US and 8 European expert hyperthermic intraperitoneal chemotherapy (HIPEC) centers were included if they had undergone complete cytoreduction (completeness of cytoreduction score 0-1) for CRC-PM. Correlation of RFS and P-RFS was assessed with OS by using spearman’s rank correlation. We estimated median OS, RFS, P-RFS, survival after recurrence and survival after peritoneal recurrence using Kaplan-Meier method.


Results: A total of 2,269 patients (median age 59 years, 54% female, 51% left-sided colon primary) met inclusion criteria and had complete follow up data. Median follow-up time was 5.3 years (95% CI 5.1- 5.5). Most (80%) of the patients received neoadjuvant chemotherapy. Median PCI was 8 (IQR 4-13), and the majority (84%) of these patients underwent intra-op HIPEC. Subsequently, around 60% went on to receive adjuvant chemotherapy.  A total of 1642 (72%) recurrences were noted of which 1015 (61.8%) were peritoneal recurrences. Median OS was 3.7 years (95% CI 3.5- 3.9), median RFS was 1.1 years (95% CI 1.1- 1.2) and the median P-RFS was 1.8 years (95% CI 1.7- 2.0). Spearman correlation between RFS and OS was moderate for the whole cohort (rs 0.671, p-value < 0.001) and decreased slightly for patients with recurrence (rs 0.599, p-value < 0.001). In comparison to RFS, correlation for P-RFS and OS was higher for the whole cohort (rs 0.747, p < 0.001) and remained moderate for patients with peritoneal recurrence (rs 0.635, p-value < 0.001). Median time from peritoneal recurrence to death was 1.8 years (95% CI 1.7- 2.1). Expectedly, time-to-peritoneal-recurrence was strongly associated with overall survival after peritoneal recurrence with a threshold effect at 2 years (Figure1).


Conclusions:

This is the largest comparative analysis of RFS/P-RFS vs OS after curative-intent cytoreduction. Both RFS and P-RFS can be used as surrogate endpoints for OS in CRC-PM efficacy trials. Compared to RFS, P-RFS appears to be a better surrogate for OS.

Learning Objectives:

  • Upon completion, participant will be able to describe the reliability of recurrence free survival as a surrogate marker for overall survival in efficacy trials of resected colorectal peritoneal metastasis.
  • Upon completion, participant will be able to identify relevant surrogate endpoints of efficacy trials of resected colorectal peritoneal metastasis.
  • Upon completion, participant will be able to appraise the use of peritoneal recurrence free survival over recurrence free survival as an endpoint in efficacy trials of resected colorectal peritoneal metastasis.