Factors affecting surgical mortality of oral squamous cell carcinoma resection

Abstract

Survival rates for oral cancer showed minimal improvement in six decades, improving surgical outcomes could be an avenue to reduce mortality. This thesis seeks to identify the causes of surgical mortalities, evaluate the factors involved and determine if there are any modifiable risks that could be targeted to reduce the mortality in the post-operative period. The systematic review found that there is a paucity of existing knowledge on the factors affecting surgical mortality of oral squamous cell carcinoma. While there were two studies included, only one had detailed characteristics on the patients who died after the operation. A population level study illustrated that factors such as advanced age, an increased Charlson Comorbidity Index score, T classification had statistical significance in increasing the risk of surgical mortality, and the risk increases if these factors were combined. Analysis of data from the Australian and New Zealand Audit of Surgical Mortality (ANZASM) found that many of the preventable deaths were related to poor patient selection. The surgeons and assessors felt that these patients had very high pre-operative risk due to various factors such as advanced age, co-existing systemic illnesses such are cardiac and respiratory conditions and advanced malignancy. Changes could be made to ANZASM to improve the results for analysis. Further population analysis and establishment of an externally validated model to assess risk stratification will allow surgeons to make better decisions around patient selection and reduce avoidable surgical mortalities.