Table 2

Tumour regression grade (TRG), Dworak classification13

Grade 0No regression
Grade 1Dominant tumour mass with obvious fibrosis and/or vasculopathy
Grade 2Dominant fibrotic changes with few tumour cell groups (easy to find)
Grade 3Very few (difficult to find microscopically) tumour cells in fibrotic tissue with or without mucous substance
Grade 4No tumour cell, only fibrotic mass (total regression or response)