The intersection of age and tumor biology with postoperative outcomes in patients after cytoreductive surgery and HIPEC.

Abstract

184 Background: Patient age is often a significant factor in preoperative selection for major abdominal surgery. Its association with postoperative outcomes in patients undergoing cytoreductive surgery(CRS) and hyperthermic intraperitoneal chemotherapy(HIPEC) remains ill-defined. Methods: The US HIPEC Collaborative database(2000-2017) was reviewed for patients who underwent a CCR0/1 CRS/HIPEC. Age was categorized into < 65 or >65yrs. Primary outcomes were postoperative major complications, readmission, 30-day mortality, and non-home discharge(NHD). Analysis was stratified by disease histology: non-invasive(appendiceal LAMN/HAMN), and invasive(appendiceal/colorectal adenocarcinoma). Results: Of 1090pts identified, 22% were >65yrs(n = 240), 59% were female(n = 646), 25% had non-invasive(n = 276) and 51% had invasive(n = 555) histology. Median PCI was 13(IQR7-20). Patients >65yrs had a higher rate of major complications(37vs26%, p = 0.02), readmission(28vs22%,p = 0.05), 30-day mortality(3vs1%,p = 0.02), and NHD(12vs5%,p < 0.01) compared to those < 65yrs. On multivariable analysis accounting for extent of disease as measured by PCI, for non-invasive histology, age >65yrs was an independent predictor for NHD(OR:2.54,95%CI:1.08-5.99,p = 0.03), but not major complications. For invasive histology, even when accounting for PCI, age >65yrs was an independent predictor for both NHD(OR:2.54,95%CI:1.08-5.98,p = 0.03) and major complications(OR:2.04,95%CI:1.16-3.59,p = 0.05). Age was not associated with hospital readmission or 30-day mortality for any histology. Conclusions: Regardless of histology, patients >65yrs are nearly at three-fold increased risk for non-home discharge after CRS/HIPEC. For invasive histology, age >65yrs is also associated with increased major complication rates, but the procedure seems to be better tolerated when performed for indolent biology. These data inform preoperative counseling and risk stratification. Early planning for discharge disposition in this high-risk population can potentially translate to cost savings.