Risk Factors Affecting Survival Following Oncologic Esophagectomy at Kenyatta National Hospital

Abstract

Background: Globally, oesophageal cancer (EC) is the 6th most common cause of death and ranks 8th in the most commonly diagnosed cancers. Esophagectomy is the gold standard treatment for patients with only locally advanced resectable EC with neoadjuvant chemotherapy and radiotherapy as important adjuncts. Oncologic esophagectomy has been documented to carry one of the highest perioperative mortality rates of up to 57.8% with 2-year survival rates of 26% - 80%. Although Kenyatta National Hospital is classified as a medium to high volume centre in performing oncological esophagectomy, no data exists about the operation’s overall survival. Objectives: To determine the two-year survival following oncologic oesophagostomy performed in Kenyatta National Hospital, and to establish the risk factors affecting poorer survival as well as to establish the Perioperative Mortality Rate. Methodology: This was a retrospective cohort study. The study cohort were all subjects that underwent oncologic esophagectomy during the ten-year period between 1st January 2011 and 31st December 2020. The main outcome variable was the observed 2-year overall survival of these patients. Exposure variables were the patient characteristics (age and sex), tumour characteristics (pathologic “T” stage, histological type, and location of tumour) and therapeutic approach (exposure to neoadjuvant or adjuvant therapy, surgical approach). Overall, two-year Survival was reported using Kaplan-Meir estimates. The log-rank test was used to evaluate significant differences in overall survival by different variables. The Perioperative Mortality Rate was calculated Results: 90 subjects were selected for this study. The overall two-year survival rate was 53% (95%CI: 43%-66%). Women [overall 2-year survival 35% (95%CI:22%-56%)] had poorer two-year survival when compared to men [overall 2-year survival 70% (95%CI:57%-85%)]. Subjects who had their operation at Stage III-IVA [40% (95%CI:25%-63%)] had poorer survival when compared to those that presented at “TNM” Stage I-II [61% (95%CI:49%-76%)]. There was no significant difference in the two year survival probability in with age 60 and older [overall 2 year survival 56% (95%CI: 40%-78%)], squamous Cell Carcinoma [overall 2 year survival 53% (95%CI:42-66)], poorly differentiated tumours [overall 2 year survival 51% (95%CI:35%-75%)] tumour located in the lower third of the oesophagus [overall 2 year survival 57% (95%CI:45%-72%)], exposure to neoadjuvant [overall 2 year survival 54% (95%CI:41%-71%)] or adjuvant therapy [overall 2 year survival 51% (95%CI:35%-85%)], and

McKeown’s approach [overall two year Survival of 51% (95%CI:36%-68%)]. Perioperative Mortality Rate was calculated to be 43.3% Conclusion: The two-year survival following oncological esophagectomy in Kenyatta National Hospital is comparable to other centres globally and above the two-year actuarial survival rate. Female sex and late presentation may be a risk factor affecting two-year survival following oncological esophagectomy. Age, histological subtype, tumour grade and location, exposure to neoadjuvant or adjuvant therapy, and surgical approach may not affect the two-year survival following oncological esophagectomy.