A22: Q&A

Saturday, March 12, 2022

8:59 AM – 9:01 AM CST

Location: Coronado

Abstract Presenter(s)

Eliza W. Beal, MD, MS

Surgical Oncology Fellow
The Ohio State University Wexner Medical Center/The James Cancer Hospital
Columbus, Ohio, United States

Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.

Participants should be aware of the following financial/non-financial relationships:

Eliza W. Beal, MD, MS: I do not have any relevant financial / non-financial relationships with any proprietary interests.

Introduction: The long-term prognosis of patients who undergo cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal surface malignancies (PSM) varies considerably based on histological and operative factors. While overall survival (OS) estimates are used to inform adjuvant and surveillance strategies, conditional survival (CS) may provide more clinically relevant estimates of prognosis by accounting for disease-free time elapsed.

Methods: All patients from 12 academic institutions who underwent CRS+/-HIPEC for PSM between 2000-2017 were retrospectively analyzed. OS and disease-free survival (DFS) rates were calculated using the Kaplan-Meier method while conditional overall (COS) and conditional disease-free survival (CDFS) rates were calculated at 1, 2 or 3 years from surgery for different tumor histologies.

Results: Overall, 1,610 patients underwent CRS+/-HIPEC. Among patients with benign appendiceal mucinous tumors (N=460), 5-year OS and COS at 3-years were 92.2% and 96.4% (Δ 4.2%, Figure 1A). For patients with low-grade appendiceal cancers (N=490), 5-year OS (Figure 1B) and COS at 3-years were 72.1% and 88.2% (Δ 16.1%). For patients with colorectal/high grade appendiceal cancers (N=540), 5-year OS (Figure 1C) and COS at 3-years were 33.2% and 65.0% (Δ 31.8%). For patients with peritoneal mesothelioma (N=130), 5-year OS (Figure 1D) and COS at 3-years were 67.7% and 89.5% (Δ 21.8%). Similar trends were observed for DFS and CDFS.

Conclusions: The conditional survival of patients undergoing CRS+/-HIPEC for PSM depends on tumor histology. COS and CDFS provide a more accurate, dynamic estimate of survival than OS and DFS, especially for patients with more aggressive histologies.

Learning Objectives:

Describe the advantages and disadvantages of using conditional survival estimations.
Describe the use of conditional survival in evaluating survival and disease-free survival for patients with peritoneal surface malignancies after cytoreduction and hyperthermic intraperitoneal chemotherapy.
Describe potential future applications of conditional survival estimations including adjusting imaging surveillance protocols.