Comparison of tumor regression grading systems for locally advanced gastric adenocarcinoma after neoadjuvant chemotherapy

Table 1 Criteria of five tumor regression grading systems

TRG system	Description
JGCA/JGCA2017-TRG
0	No response
1a	67%-99% residual tumor/tumor bed
1b	34%-66% residual tumor/tumor bed
2/2a	10%-33% residual tumor/tumor bed
/2b	< 10% residual tumor/tumor bed
3	Complete response
Becker-TRG
1a	Complete response
1b	< 10% residual tumor/tumor bed
2	10%-50% residual tumor/tumor bed
3	> 50% residual tumor/tumor bed
AJCC/CAP-TRG
0	No residual tumor
1	Single cells or rare small groups of cancer cells
2	More than single cells or rare small groups of cancer cells with evident tumor regression
3	Extensive residual tumor or no response
Mandard-TRG
1	No residual tumor
2	Rare residual tumor
3	Fibrosis outgrowing residual tumor
4	Residual tumor outgrowing fibrosis
5	No response

TRG: Tumor regression grade; JGCA: Japanese Gastric Cancer Association; AJCC: American Joint Committee on Cancer; CAP: College of American Pathologists.