Lymph node regression grading of locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Table 1 Examples for lymph node regression grading systems

Descriptive	Caricato et al[18]	Mirbagheri et al[28]	Beppu et al[32]	Lee et al[34]	Sun et al[35]	Cui et al[38]
Negative/normal	LRG1	LRG0	-	pLRG0	LRG0	LRG0
	Absence of histologically identifiable residual cancer and fibrosis extending through the different areas of the lymph node	Normal lymph nodes	-	LN-preserving normal nodal architecture without evidence of cancer cells or fibrosis was scored	Normal lymph node architecture without evidence of regression or cancer cells	Negative lymph node
Complete	LRG2	LRG1	LRG3	pLRG1	LRG1	LRG1
	Near complete pathologic response (pCR)	100% fibrosis, no residual cancer	Total regression. No cancer cells, single cells or small groups of cancer	LN with 100% fibrosis	100% fibrosis	Complete regression with no residual tumor cells
Subtotal	LRG3	LRG2	LRG2	pLRG2	LRG2	LRG2
	Presence of residual cancer cells with evident fibrosis	75%-100% fibrosis, 0-25% cancer	Good regression. Residual cancer outgrown by fibrosis	LN with < 25% cancer cells	< 25% remaining cancer cells	Rare residual tumor cells
Partial	LRG4	LRG3	LRG1	pLRG3	LRG3	LRG3
	Poor response	50%-75% fibrosis, 25%-50% cancer	Minor regression. Fibrosis outgrown by cancer or no fibrosis with extensive residual cancer	Scattered glandular elements with fibrosis	25%-50% scattered glandular elements with fibrosis	Fibrosis outgrown by residual tumor cells
No regression	LRG5	LRG4	-	pLRG4	LRG4	LRG4
	Nodal metastasis with absence of regressive changes	25%-50% fibrosis, 50%-75% cancer	-	LN with > 50% cancer cells	> 50% viable cancer cells	Residual tumor cell outgrown by fibrosis
		LRG5		pLRG5	LRG5	LRG5
		0-25% fibrosis, 75%-100% cancer	-	Complete replacement with cancer cells	Complete replacement with cancer cells	Absence of regression with no fibrosis

LRG: Lymph node regression grade; pCR: Complete pathologic response; LN: Lymph node.