This study received ethics approval from the South Western Sydney Local Health District (SWSLHD) Human Research Ethics Committee (reference number HREC/12/LPOOL/102). Specifically, the research was conducted under the Protocol numbers X01-0138 and X03-0291 for the IHC assessment in paraffin embedded rectal cancer tissues and retrospective survival analyses. The ethics committee waived the need for direct consent for patients as samples and clinical data were all de-identified before access.