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PPS19. Appraising the role of laparoscopy for peritoneal surface malignancy assessment: a retrospective cohort study

Thursday, March 5, 2026
10:00 AM - 10:30 AM MST
Location: HUB Poster Park - West Hall 1-3
Introduction: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) can improve long term survival in selected patients with peritoneal surface malignancies. Due to tumor biology and potential surgical morbidity, patient selection is pivotal. The Peritoneal Cancer Index (PCI) combines tumor distribution and size scores to estimate burden of disease. A staging laparoscopy (SL) provides an opportunity for PCI assessment to guide eligibility for CRS/HIPEC. Here, PCI scores of patients during SL and subsequent CRS/HIPEC were evaluated.  


Methods:

A retrospective review from July 2017 to July 2025 of patients who underwent SL and CRS/HIPEC at our institution was performed. Outcomes of interest included PCI scores at both procedures  and overall survival (OS). 


Results:

A total of 152 patients were identified who underwent staging laparoscopy and exploration with intent of CRS/HIPEC. Of these, 118 patients had available data from both procedures and were included for analysis. The median age of the cohort was 58 years old and 50% of patients were male. Most patients had undergone prior abdominal operations (n=106) with more than half performed minimally invasively (69/106, 65%). 43% of patients had appendiceal cancer, 57% of these patients had low grade and 43% high grade disease. Of the remainder patients, 41% of patients had colon adenocarcinoma and 6% had either gastric cancer or mesothelioma . The median PCI at SL was 6 (IQR 3-12) and no adverse events were noted following the procedure. The median time to planned CRS/HIPEC was 43 days with a median PCI of 14 (IQR 7-23). Majority of patients experienced an increase in PCI (n=109, 90%) with a median change of 7 (IQR 3-11). The most commons anatomical sites with a PCI increase were the right flank and lower ileum (55%, 50%), by a median of 1 point increase. In patients with high grade appendiceal cancer or colon adenocarcinoma, a greater than the median change in PCI was not associated with worse survival (p=0.85, p=0.25).  In 15% of patients the CRS/HIPEC was aborted due to extensive disease (n=18).  Most commonly, small bowel disease was the limiting factor (n=11, 61%). There was a significant increase in overall survival in patients who completed CRS/HIPEC regardless of histology (p=0.03).


Conclusions:

SL underestimated PCI by a median of 7 points with the R flank and distal ileum as the most common sites increased after CRS/HIPEC. While underestimation of PCI at SL did not affect OS, these data are pivotal for preoperative planning and informed decision making with patients.

Learning Objectives:

  • Understand the utility of staging laparoscopy with peritoneal cancer index in guiding eligibility for CRS/HIPEC
  • Acknowledge the limitations of staging laparoscopy and the rate of upstaging of the peritoneal cancer index at subsequent CRS/HIPEC