Background
Colorectal cancer is the third most diagnosed cancer in Australia and the second leading cause of cancer death(1). SWSLHD is one of the largest health districts in NSW serving a population of almost 1 million people. The patterns of colon cancer (CC) presentation in this diverse population including changes over time may have implications for health service provision and public health campaigns.
Methods
A retrospective review of patients who underwent primary tumour resection (PTR) and histopathology review for CC in SWSLHD from 2006-2015 with clinicopathological data were included. Basic demographics, site and stage of presentation, systemic therapy used, and recurrent/ survival data were collected in addition to tumour pathology data. Patients were analysed in two separate 5-year cohorts between 2006-2010 and 2011-2015 and chi-square tests were performed for categorical variables.
Results
907 patients were identified between 2006-2015 (329 between 2006-2010 and 578 between 2011-2015). Median age of diagnosis was 70 in both 5-year cohorts, predominantly male (51%) and of Caucasian (87%) or Asian ethnicity (12%. In this cohort receiving PTR, for the 2006-2010 cohort, 55% presented with early stage (1,2) CC and 45% late stage (3,4) CC and between 2011-2015, 52% and 48% had early and late stages respectively, with no statistically significant difference in stage over time (p= 0.28). There was a statistically significant difference in colon cancer sidedness of presentation with more patients diagnosed with right (71%) rather then left sided (29%) cancer between 2011 -2015 compared to 2006 - 2010 (64% right and 36% left) (p value <0.028).
Conclusion
There was no statistical significance difference in age of diagnosis, gender, ethnicity or stages of presentation between the two 5-year cohorts. In the 2011-2015 cohort, more patients presented with right-sided CC compared to 2006-2010. These results require further exploration including correlation with molecular pathology and clinical outcomes and may inform future screening and treatment strategies.