Table 2. Univariate analysis of prognostic factors for locoregional recurrence-free survival.

Characteristic	Entire cohort			Without PMRT
	HR	95% CI	P	HR	95% CI	P
Age, years (< 40 vs. ≥ 40)	0.553	0.343-0.891	0.015	0.44	0.272-0.71	0.001
LNR (≤0.2 vs. >0.2)	2.387	1.367-4.167	0.002	2.519	1.44-4.405	0.001
Positive lymph nodes N(1-2 vs. 3)	1.39	0.869-2.226	0.170	1.65	1.023-2.666	0.040
Tumor size (T1 vs. T2)	1.167	0.564-2.417	0.677	1.23	0.593-2.549	0.588
Lymphatic invasion(negative vs. positive)	0.813	0.375-1.763	0.600	0.803	0.37-1.744	0.580
Menopausal status (Pre vs. Post)	1.5	0.792-2.838	0.213	1.198	0.632-2.274	0.580
Molecule classification
(luminal B vs. luminal A)	1.382	0.592-3.225	0.454	1.415	0.606-3.307	0.422
(her2-enriched vs. luminal A)	2.089	1.573-2.773	0.001	2.065	1.543-2,764	0.001
(triple negative vs. luminal A)	1.152	0.946-1.403	0.159	1.154	0.947-1.406	0.156
PMRT (yes vs. no)	0.155	0.038-0.629	0.009

PMRT, postmastectomy radiotherapy; LNR, lymph node ratio; HR, hazard ratio; CI, confidence interval.