Combined Proctectomy and Hepatectomy for Metastatic Rectal Cancer Should be Undertaken with Caution: Results of a National Cohort Study

Background: Simultaneous proctectomy and hepatic resection for stage IV rectal cancer remains controversial due to concerns for increased morbidity and mortality. While small series have described simultaneous rectal and hepatic resection, surgical outcomes in a large national cohort have not been described. Methods: Overall, 9012 patients with stage IV rectal adenocarcinoma with hepatic metastases were identified in the National Cancer Data Base (2010–2015). Associations between treatment selection, tumor and patient characteristics, 30- and 90-day mortality, and factors predictive of survival after surgery were examined. Logistic regression analyses were used to evaluate associations between tumor/patient characteristics, and selection of combined proctectomy and hepatectomy (C-PH). Kaplan–Meier analysis was used to identify median survival stratified by age and other patient-specific factors. Results: Among patients included for analysis, 1331 (14.8%) underwent C-PH. Factors associated with lower rates of C-PH included increasing age, Black/Hispanic race, increased Charlson comorbidity score, Medicare/Medicaid/uninsured status, and treatment at a community cancer program. Thirty- and 90-day mortality increased with age (Chi square 11.4, p < 0.005; and Chi square 23.9, p < 0.001, respectively). On multivariate analysis, poorer survival after C-PH was associated with age > 70 years (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.0–2.5, p < 0.001), perineural invasion (HR 1.5, 95% CI 1.2–1.9, p < 0.001), kras mutation (HR 1.5, 95% CI 1.1–2.1, p = 0.006), positive circumferential margin (HR 1.3, 95% CI 1.0–1.7, p = 0.03), and omission of postoperative chemotherapy (HR 1.4, 95% CI 1.1–1.7, p = 0.002). Conclusions: C-PH should be utilized with caution in frail, high-risk patients. Such patients may be better served by staged surgical management or nonsurgical therapy.