70: Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy (CRS-HIPEC) of Extraperitoneal Abdominal Disease, Is it Appropriate?

Introduction: Potential CRS-HIPEC candidates often have extraperitoneal abdominal disease.  Current expert PSM guidelines recommend that the presence of extraperitoneal disease is a contraindication to CRS-HIPEC.


Methods: A retrospective review of our institutional CRS-HIEPC registries.  Two study cohorts, one involving a cytoreduction with extraperitoneal abdominal disease the other with cytoreductions limited to peritoneal structures alone.  Extraperitoneal cytoreductions included pancreatectomies, nephrectomies, adrenalectomies, and umbilectomies.  The primary study outcome was survival measured by overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS).


Results:

864 CRS-HIPEC cases evaluated of which 578 were appendiceal primaries and the remaining 286 cases were colorectal cancers.  The extraperitoneal cytoreduction cohort included 101 patients with 763 patients in the non-extraperitoneal group.  Median follow up time for all patients was 13.18 years with median times of 11.61 and 13.26 years for the extraperitoneal and non-extraperitoneal groups respectively.  Analysis revealed no significant difference in any survival times.  OS times were nearly identical with mean and median survival times of 5.87 and 4.43 years compared to 5.90 and 4.76 years for extraperitoneal and non-extraperitoneal cytoreductions respectively (P=0.955).  Similarly the 5-year OS rates did not significantly differ at 49.1% vs 49.5% (OR=1.036, 95%CI 0.671-1.597, P=0.874).  For DFS the mean and median survival times were 4.40 and 1.93 years vs 5.44 and 3.05 years for extraperitoneal and non-extraperitoneal cases respectively (P=0.210).  The 5-year DFS rates also showed no difference (OR=0.894, 95%CI 0.476-1.681, P=0.728).  Lastly, no significant difference in PFS times (P=0.061) was present.  On multivariate Cox regression analysis performance of an extraperitoneal CRS was not an independent predictor of survival for OS (HR=1.281, 95%CI 0.885-1.854, P=0.190), DFS (HR=1.087, 95%CI 0.694-1.701, P=0.716), and DFS (HR=0.650, 95%CI 0.243-1.738).  The Kalpan-Meier curves correlated with those findings as illustrated in Figure 1. 



Conclusions: This is the largest analysis to date exclusively evaluating the effect of extraperitoneal abdominal cytoreductions.  The study results found no significant difference in nearly all survival outcome for those undergoing CRS-HIPEC with extraperitoneal disease.  We propose that the presence of extraperitoneal abdominal disease is not a contraindication to proceeding with CRS-HIPEC.