Table 6.

Tumor regression grade (TRG) system according to (6).

Tumor Regression Grade	Histopathological findings
Grade 0:	No regression.
Grade 1:	Minor regression, residual tumor outgrowing fibrosis.
Grade 2:	Moderate regression, low tumor cell fibrosis in 26% to 50% of the tumor mass.
Grade 3:	Major regression, very few tumor cells in fibrotic tissue with or without mucous substance.
Grade 4:	Total regression, no viable tumor cells, only fibrotic mass.

Tumor regression grade (TRG) system according to Dworak et al.