Table 2.

Classification of risk of recurrence after breast cancer surgery

Risk	Criterion
	Metastatic lymph nodes	ER/PR	Other conditions
Low risk	Negative	Positive	Simultaneously meet the following conditions a: pT ≤ 2 cm; histological grade I; LVI negative; HER2 negative; age ≥ 35 years; Ki67 ≤ 20% or laboratory median value
			Negative HER2; do not meet the above conditions, but polygenic testing result indicates low risk
Intermediate risk	Other situations that do not meet the definition of low or high risk
High risk	1–3 positive	Positive	Meet any of the following conditions b: histological grade III; pT > 5 cm; HER2 positive; polygenic testing result high-risk
		Negative	Any condition
	≥ 4 positive	Any condition	Any condition

^aPolygenic testing is unnecessary at this time (e.g., 21-gene or 70-gene).

^bAlthough Ki67 is one of the independent factors for breast cancer recurrence, the expert panel is still undecided whether pN1 with high Ki67 expressed is conclusively high-risk. Although pN₁ with high Ki67 is the classification criterion of high-risk luminal-HER2 negative breast cancer in certain clinical trials, this classification does not have universality.