Victoria has outstanding survival rates nationally and internationally1, but regional inequalities persist. Notably, there is a 10% absolute difference in five-year survival for patients diagnosed between 2005 – 2009 in Metropolitan Melbourne compared to the Grampians region.
This comparative analysis aims to elucidate contributing factors that impact mortality.
Patients with early stage colorectal cancer (CRC) diagnosed from 2005 - 2009 at Ballarat Health Services (BHS), Victoria, and Austin Health, Melbourne, who did not receive adjuvant chemotherapy, were identified via the Victorian Cancer Registry (VCR). Demographic, tumour and treatment data were extracted from medical records.
VCR survival data was correlated with hospital records to identify cause of death. Cox regression and Kaplan-Meir method were used for survival analysis and survival curves.
303 patients were diagnosed with early stage colorectal cancer from 2005 -2009, with 185 (61.1%) treated at Austin Health and 118 (38.9%) at BHS. Mean age was 71.45 (95% CI 69.7684-73.1444) and 71.55 (95% CI 68.269-75.654) respectively.
No significant differences in mortality between cohorts were detected within one, five, eight or ten years of surgical intervention, irrespective of cause of death. Late age, poorer premorbid function and multiple comorbidities were associated with CRC-specific death and all-cause death at five, eight and ten years post surgery.
Emergency presentation was independently associated with poorer survival outcomes at one year (p = 0.002), five years (p = 0.018), eight years (p=0.008) and ten years (p=0.002). Distance to treating centre was not associated with survival.
Unsurprisingly, emergency presentation, concomitant illness, poor premorbid function and increasing age significantly impact survival.
There was no notable survival difference between treatment centres. This raises several possibilities including that the discrepancy could have arisen from a survival difference for metastatic CRC, or from poorer outcomes for patients in the Grampians region not treated locally at BHS.