27 - Freie Mitteilung
15. Mai 2019, 15:30 - 17:00, Bellavista 2, 6. OG
Tumor biology determines recurrence patterns after radical surgery for peritoneal metastasis: Same but different
E. Breuer1, M. A. Schneider1, L. Roth1, J. Eden2, B. Pache3, T. Steffen2, M. Hübner3, A. Gupta1, V. Kepenekian4, G. Passot4, P. Gertsch1, O. Glehen4, K. Lehmann1, Presenter: E. Breuer1 (1Zurich, 2St. Gallen, 3Lausanne, 4Lyon/FR)
Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC) improve survival in selected patients with peritoneal metastasis (PM) from colorectal cancer. Disease recurrence is, however, frequent and can occur in the peritoneum or hematogenous (lung, liver). Currently, no data is available about factors predicting the localization of recurrent disease and its impact on survival.
The present study is a multicentric retrospective cohort analysis from four European tertiary centers and includes patients with colorectal PM between 2005 – 2017. Patients received standard perioperative chemotherapy. HIPEC was indicated after radical cytoreduction (CC-score 0) and performed at 42°C for 90 minutes with mitomycin C/doxorubicin (≥15 mg/m2) or 43°C for 30 minutes with oxaliplatin (300-400 mg/m2). Statistical analyses were performed with IBM SPSS (version 25, Chicago, IL). The study was approved by the responsible ethics committee.
A cohort of n=433 patients with colorectal PM was analyzed after CRS/HIPEC with curative intent (CC-score 0). Median peritoneal cancer index (PCI) was 6 (IQR 3-11) and 75% of patients had preoperative chemotherapy. Median overall and disease-free survival of the cohort was 46 months (CI 39.5-52.49) and 12 months (CI 11.04-12.96). After a median follow-up time of 22 months, disease recurrence was detected in n=304 (70.2%) patients, presenting as solitary hematogenous recurrence in n=103 (38.0%), isolated peritoneal recurrence in n=109 (40.2%) and mixed recurrence in n=59 (21.8%) patients. Recurrence involving the peritoneum was associated with a worse outcome compared to patients with recurrence to the liver or lung (35 vs. 43 months, HR 1.50, p=0.029). On multivariate regression analysis, PCI >7 (OR 2.44, p=0.028), positive nodal stage of the primary (OR 4.10, p=0.009) and RAS mutational status (OR 3.60, p=0.002) were identified as predictive factors for recurrence in the peritoneum. Hepatic recurrence was associated with the localization of the primary tumor in the right colon.
Recurrence rates after CRS/HIPEC for PM are high and disease recurrence to the peritoneum impairs survival outcomes. Together with the disease load (PCI), tumor biology (primary nodal status, RAS mutational status) has a major impact on the localization of recurrent disease.