7. Tumor response grade (TRG).

Grade	Level of regression	Degree description
TRG score is limited to primary tumor lesions; tumor cells refer to active tumor cells, excluding degenerative and necrotic tumor cells; cell-free mucus lake after radiotherapy/chemotherapy is not considered as residue tumors.
Level 0	Complete response	No residual cancer cells
Level 1	Moderate response	Only small clusters or single cancer cells remaining
Level 2	Minimal response	Residual cancer cells, but with predominant fibrosis
Level 3	Poor response	Extensive residual cancer cells, minimal or no tumor cell necrosis