A. Hanna1, M. Chuong1, S. Bentzen1, N. Hanna1 1University Of Maryland,School Of Medicine,Baltimore, MD, USA
Introduction: Esophageal cancer represents a growing public health burden in the United States, with 5 year survival rates at 20 to 30%. Surgery is the mainstay of localized esophageal cancer and minimally invasive esophagectomy (MIE) presents as an alternative approach to open esophagectomy (OE). While no randomized control trial has clarified its utility, MIE has been shown in small series to be better in hospital stay parameters, and equivalent in postoperative morbidity and mortality as well as survival. The generalizability from these studies, however, is not clear as treatment selection bias becomes a significant problem in applying their results in clinical practice.
Methods: The National Cancer Database was used to identify stage I-III esophageal adenocarcinoma and squamous cell carcinoma cancer patients 18 – 90 years old who underwent either MIE or OE from 2010 to 2012. Several factors were identified that differed between those undergoing MIE vs OE such as insurance type, the rate of receiving chemotherapy and radiation, grade, stage and the type of surgical procedure (total vs partial esophagectomy). Propensity score analysis (PSA) with 1:1 ‘nearest neighbor’ matching based on all demographic and disease factors was therefore used to control for this treatment selection bias. The main outcomes analyzed were 30 day mortality, 30-day unplanned readmissions, 1 year mortality, and overall survival. All statistical analyses used either a logisitic or Cox regression.
Results: Out of a total of 8659 patients in the database who had surgery in 2010 or later, 1004 MIE and 3026 OE met inclusion criteria. After PSA matching, both groups contained 1004 patients and were balanced in all demographic and disease factors, including the propensity of having a MIE. The number of lymph nodes sampled and rate of negative margins were not statisitically different in both the original matched cohorts. After multivariate analysis, surgery type (MIE vs OE) was not a significant factor in 30-day mortality, 30-day unplanned readmissions, or 1 year mortality in both the unmatched and matched cohorts. While it was also not a significant predictor of overall survival in the unmatched cohort, the use of MIE showed improved overall survival in the matched cohort (HR = 0.85, P < 0.01). Other factors that predicted for improved survival in both the unmatched and matched group include treatment at an academic research program, private insurance, a younger patient with less comorbidities, smaller tumors, lower grade and stage of cancer, no lymphovascular invasion, fewer positive lymph nodes, negative margins, and the receipt of neoadjuvant chemoradiation.
Conclusion: In the surgical management of esophageal cancer in the United States, a minimally invasive approach confers neither a benefit nor a risk compared to an open approach in short term outcomes and may actually provide a small but not insignificant survival benefit long term.