Table 1. Age-wise distribution of female patients with newly diagnosed breast cancer in 2018 in Korea.

Age (yr)	KBCS registry data	KCCR data
< 20	6 (< 0.1)	4 (< 0.1)
20–29	101 (0.8)	205 (0.7)
30–39	1.224 (9.8)	2.425 (8.6)
40–49	4.334 (35.2)	9.432 (33.6)
50–59	3.712 (30.2)	8.335 (29.7)
60–69	2.032 (16.5)	4.845 (17.3)
70–79	747 (6.1)	2.115 (7.5)
≥ 80	150 (1.3)	688 (2.5)
Total	12,306 (100.0)	28,049 (100.0)

Values are presented as number (%).

KBCS = Korean Breast Cancer Society; KCCR = Korea Central Cancer Registry.