2019 GI Cancers Symposium: Is Adjuvant HIPEC Effective in Reducing the Risk of Peritoneal Metastases in Patients With Colon Cancer?
Patients with advanced or perforated colon cancer may be at elevated risk of peritoneal metastases. Since many patients with peritoneal metastases are diagnosed at a late stage, researchers sought to study the effectiveness of hyperthermic intraperitoneal chemotherapy (HIPEC) in the adjuvant setting to reduce the risk of developing peritoneal metastases in a phase III trial. Study results were presented at the 2019 Gastrointestinal Cancers Symposium by Klaver et al (Abstract 482).
Study Background
Between April 2015 and January 2017, 204 patients were randomly assigned 1:1 to receive adjuvant HIPEC followed by routine adjuvant systemic chemotherapy (n = 100, 2 dropouts) or to adjuvant systemic chemotherapy alone (n = 102). Patients were diagnosed with either stage T4 (either cT4 or pT4, N0–2, M0) or perforated colon cancer and had undergone curative resection. Adjuvant HIPEC was either performed simultaneously (9%) or within 5–8 weeks (91%) after primary tumor resection.
The primary endpoint was peritoneal metastasis–free survival at 18 months. Patients without evidence of recurrent disease at 18 months based on computed tomography underwent diagnostic laparoscopy in both arms.
Study Findings
Surgical exploration at the start of HIPEC at 5 to 8 weeks postresection revealed metastases in 11 patients (peritoneal metastases in 9 of 11) in the experimental arm, and adjuvant HIPEC was not applied. Adjuvant systemic chemotherapy was administered in 89 of 100 eligible patients after a median of 6 weeks in the control arm and in 84 of 89 after 10 weeks in the experimental arm.
The rate of peritoneal metastases after completion of 18 months of follow-up was 22 of 102 patients in the HIPEC group and 18 of 100 patients in the control group. In the intention-to-treat analysis, no difference in peritoneal metastasis–free survival at 18 months was observed—77% among controls vs 81% in the experimental group (hazard ratio [HR] = .836). There were also no differences observed in 18-month disease-free survival (HR = 1.016) and overall survival (HR = 1.139). One patient developed encapsulating peritoneal sclerosis after HIPEC.
The study authors concluded, “Adjuvant HIPEC with oxaliplatin for patients with T4 or perforated colon cancer does not result in improved 18-month peritoneal metastasis–free survival. Long-term results have to be awaited to assess the role of HIPEC in the adjuvant setting.”
Disclosure: The study authors' full disclosures can be found at coi.asco.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
