Title: Considering the economic impact of a simultaneous versus staged approach to resection of colorectal cancer with synchronous liver metastases in a publicly funded healthcare model.

Simultaneous resection for colorectal cancer with synchronous liver metastases (SLM) is an established alternative to a staged approach in select patients. There is a paucity of literature comparing cost of these two surgical approaches. The aim of this study was to compare the simultaneous and staged approach with regard to economic parameters and short-term clinical outcomes in a publically funded healthcare model.
A retrospective chart review was conducted at a tertiary academic hospital between February 2005 and February 2016. The primary exposure was surgical approach: (1) simultaneous resection; and (2) staged resection. The primary outcome was cost per episode of care including total cost and cost breakdown by operating room, PACU, ward, laboratory, imaging and pharmacy costs. Secondary outcomes included postoperative complications as well as 30-day morbidity, mortality and readmission rate.
Fifty-four cases were identified. Twenty-Eight patients underwent a staged resection of their disease, while 26 patients underwent a simultaneous resection.  Patient demographics including age (p=0.49), sex (p=0.20), BMI (p=0.74), and ASA class (p=0.44) were comparable between groups. Tumor characteristics including pathologic T (0.66) and N (O.23) stage, and number (0.12) and size (0.50) of metastasis were also comparable. Total cost ($20297 vs $27522), OR ($6830 vs $10376), PACU ($675 vs $1182), ward ($7586 vs $11603) and pharmacy costs ($728 vs $1075) were significantly less for the simultaneous group (p<0.05). Total LOS was shorter in the simultaneous group (12 mean days [SD=8.3] vs 22 mean days [SD=6.9], p<0.01). The two groups were comparable with regard to Clavien-Dindo scores (p=0.96), as well as 30-day readmissions (p=0.44), morbidity (p=0.22) and mortality (p=1.00). 
Our study confirms equivalent short-term outcomes between a simultaneous and staged surgical approach. The simultaneous approach was associated with significantly lower total cost and a significantly shorter hospital stay. More studies are needed to validate these findings.

Considering the economic impact of a simultaneous versus staged approach to resection of colorectal cancer with synchronous liver metastases in a publicly funded healthcare model.