Table 3.

Five-year survival/failure rates and hazard ratios by age group for the 2492 Asian breast cancer patients treated with breast-conserving therapy (1989–2012)

Clinical outcomes	No. of events/no. of patients	5-year rate [% (95% CI)]	Log-rank, P value	Hazard ratio (95% CI)	Cox model P value
Overall survival
All patients	162/2492	95.7 (94.6–96.6)
≤ 40 years at diagnosis	40/447	94.1 (90.6–96.4)		1.27 (0.88–1.82)
> 40 years at diagnosis	122/2045	96.1 (94.9–97.0)	0.198	1.00	0.209
Breast cancer-specific survival
All patients	77/2492	98.0 (97.1–98.6)
≤ 40 years at diagnosis	26/447	96.7 (93.7–98.3)		2.00 (1.23–3.23)
> 40 years at diagnosis	51/2045	98.3 (97.4–98.9)	0.004	1.00	0.007
Breast cancer-free interval
All patients	277/2492	10.5 (9.0–12.1)
≤ 40 years at diagnosis	85/447	15.3 (11.6–20.1)		1.92 (1.49–2.50)
> 40 years at diagnosis	192/2045	9.4 (7.9–11.1)	< 0.001	1.00	< 0.001
Local recurrence
All patients	89/2492	3.4 (2.6–4.4)
≤ 40 years at diagnosis	31/447	5.2 (3.1–8.5)		2.33 (1.49–3.57)
> 40 years at diagnosis	58/2045	3.0 (2.2–4.1)	< 0.001	1.00	< 0.001

Proportional hazards assumption was violated for overall survival