Adjuvant Hyperthermic Intraperitoneal Chemotherapy in Patients With Locally Advanced Colon Cancer (COLOPEC): 5-Year Results of a Randomized Multicenter Trial
Authors: Zwanenburg Emma Sophia , El Klaver Charlotte , Wisselink Daniel D. , Punt Cornelis J.A. , Snaebjornsson P. , Crezee Johannes , Aalbers Arend G.J. , Brandt-Kerkhof Alexandra R.M. , Bremers Andre J.A. , Burger Pim J.W.A. , Fabry Hans F.J. , Ferenschild Floris T.J. , Festen Sebastiaan , van Grevenstein Wilhemina M.U. , Hemmer Patrick H.J. , de Hingh Ignace H.J.T. , Kok Niels F.M. , Kusters M. , Musters G.D. , Schoonderwoerd Lotte , Tuynman J.B. , van de Ven Anthony W.H. , van Westreenen Henderik L. , Wiezer M.J. , Zimmerman David D.E. , van Zweeden Annette , Dijkgraaf Marcel G.W. , Tanis Pieter J. ,   on behalf of the COLOPEC Collaborators Group, Andeweg Caroline S. , Bastiaenen Vivian P. , Bemelman Willem A. , van der Bilt Jarmila D.W. , Bloemen Johanne , den Boer Frank C. , Boerma Djamila , Huinink Daan ten Bokkel , Brokelman Walter J.A. , Cense Huib A. , Consten Esther C.J. , Creemers Geert-Jan , Crolla Rogier , Dekker Jan-Willem T. , Demelinne Jennifer , van Det Marc J. , van Diepen Karin K. , Diepeveen Marjolein , van Duyn Eino B. , van den Ende Esther D. , Evers Pauline , van Geloven Anna A.W. , van der Harst Erwin , Heemskerk Jeroen , Heikens Joost T. , Hess Daniel A. , Inberg Bas , Jansen Jan , Kloppenberg Frank W.H. , Kootstra Thomas J.M. , Kortekaas R.T.J. , Los Maartje , Madsen Eva V.E. , van der Mijle H.C.J. , Mol Linda , Neijenhuis Peter A. , Nienhuijs Simon W. , van den Nieuwenhof Loes , Peeters Koen C.M.J. , Polle Sebastiaan W. , Pon Jolien , Poortman Pieter , Radema Sandra A. , van Ramshorst Bert , de Reuver Philip R. , Rovers Koen P. , Schmitz Roderick F. , Sluiter Nina , Sommeijer Dirkje W. , Sonneveld Eric , van Sprundel T.C. , Veltkamp Sanne C. , Vermaas Maarten , Verwaal Victor J. , Wassenaar Emma , Wegdam Johannes A. , de Wilt Johannes H.W. , Westerterp Marinke , Wit Fennie , Witkamp Arjen J. , van Woensdregt Karlijn , van der Zaag Edwin S. , Zournas Mandy 
Published: November 2023

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. Whether adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC) might prevent peritoneal metastases after curative surgery for high-risk colon cancer is an ongoing debate. This study aimed to determine 5-year oncologic outcomes of the randomized multicenter COLOPEC trial, which included patients with clinical or pathologic T4N0-2M0 or perforated colon cancer and randomly assigned (1:1) to either adjuvant systemic chemotherapy and HIPEC (n = 100) or adjuvant systemic chemotherapy alone (n = 102). HIPEC was performed using a one-time administration of oxaliplatin (460 mg/m2, 30 minutes, 42°C, concurrent fluorouracil/leucovorin intravenously), either simultaneously (9%) or within 5-8 weeks (91%) after primary tumor resection. Outcomes were analyzed according to the intention-to-treat principle. Long-term data were available of all 202 patients included in the COLOPEC trial, with a median follow-up of 59 months (IQR, 54.5-64.5). No significant difference was found in 5-year overall survival rate between patients assigned to adjuvant HIPEC followed by systemic chemotherapy or only adjuvant systemic chemotherapy (69.6% v 70.9%, log-rank; P = .692). Five-year peritoneal metastases-free survival rates were 63.9% and 63.2% ( P = .907) and 5-year disease-free survival was 55.7% and 52.3% (log-rank; P = .875), respectively. No differences in quality-of-life outcomes were found. Our findings implicate that adjuvant HIPEC should still be performed in trial setting only.