Biomarker‐based treatment selection in early‐stage rectal cancer to promote organ preservation. BJS 2014; 101: 1299-1309.

Results

Methylation of the retinoic acid receptor β gene, RARB, and that of the checkpoint with forkhead and ring finger gene, CHFR, was associated with tumour stage (RARB: 51·9 per cent for T1–2 versus 33·9 per cent for T3–4, P < 0·001; CHFR: 5·5 per cent for T1–2 versus 12·6 per cent for T3–4, P = 0·005). Gene methylation associated with nodal metastasis included RARB (47·1 per cent for N− versus 31·7 per cent for N+; P = 0·008), chemokine ligand 12, CXCL12 (12·3 per cent for N− versus 8·9 per cent for N+; P = 0·021), and death‐associated protein kinase 1, DAPK1 (19·3 per cent for N− versus 12·3 per cent for N+; P = 0·022). RARB methylation was also associated with LVI (45·1 per cent for LVI− versus 31·7 per cent for LVI+; P = 0·038). Predictive models for nodal metastasis and LVI achieved sensitivities of 91·1 and 85·0 per cent, and specificities of 55·3 and 45·3 per cent, respectively.