Pre-operative FOLFOX chemotherapy in advanced colon cancer: Pathology analysis of the FOxTROT trial

Background The phase III international FOxTROT trial assessed the effectiveness of pre-operative chemotherapy in locally advanced colon cancer. Patients were randomised across 85 centres to pre- and post-operative FOLFOX-based chemotherapy (pre-op) or to post-operative FOLFOX chemotherapy alone (post-op) in a 2:1 ratio. Methods Central pathological review was performed on scanned H&E stained slides in 904 out of 1,052 cases (86%) to include reassessment of the core pathology endpoints and an additional assessment of novel prognostic and immunological markers according to trial arm. Results The pre-op group showed a lower pT stage (pT0-pT2 rate 18% vs 8%, p Conclusions Pre-op chemotherapy in locally advanced colon cancer is associated with a significant reduction in many high-risk pathological features and potential mechanisms of metastatic spread. There is also a clear effect on tumour immunology. The association with 2 year DFS is currently being performed and will be presented at the meeting. Legal entity responsible for the study University of Birmingham. Funding Amgen. Disclosure All authors have declared no conflicts of interest.