Using routinely collected national data to describe the surgical management and outcomes of patients with colorectal cancer liver metastases in the English National Health Service

Colorectal cancer (CRC) is the fourth most common cancer in the United Kingdom. Up to half of patients with CRC will develop liver metastases. For selected patients with liver metastases, liver resection can offer a chance of long-term cure. The aim of this thesis was to investigate the management and outcomes associated with the surgical treatment of patients with CRC liver metastases in England in an attempt to identify areas where care may be improved. Four separate studies were performed describing i) the impact of centralisation of hepatobiliary surgical services on liver resections rates for patients with CRC liver metastases and patient survival, ii) the effect of socioeconomic deprivation on rates of liver resection in patients with CRC liver metastases ,and the impact on survival, iii) the timing of liver resection in relation to CRC resection in patients with synchronous CRC liver metastases and iv) the impact of advancing age on outcomes following liver resection. These studies were conducted by linking three national databases: the National Bowel Cancer Audit, Hospital Episode Statistics data and Office for National Statistics mortality data. The results of these studies highlight that firstly, amongst patients with synchronous CRC liver metastases, those diagnosed at hospital sites with no on-site hepatobiliary services and those of higher socioeconomic deprivation have poorer survival than would be expected. This appears to relate to inequalities in provision of liver resection. Secondly, there is wide inter-hospital variation in the timing of liver resection in relation to CRC resection in England. Thirdly, although elderly patients are at increased risk of post-operative mortality following liver resection, cancer-specific and overall survival in patients between 65 and 74 years are comparable to younger patients. This thesis also discusses methodological issues associated with using national routine data for the analyses in this patient cohort.