Table 2.

Risk of ipsilateral breast tumors^a associated with race and ethnicity among women with unilateral ductal carcinoma in situ (DCIS) diagnosed between 1988 and 2009^b (n = 74,809)

	Person-years	Ipsilateral breast tumors			Ipsilateral DCIS			Ipsilateral invasive cancer
		Cases	RRc	95 % CIc	Cases	RRc	95 % CIc	Cases	RRc	95 % CIc
White	355,850	2,104	1.00	Referent	595	1.00	Referent	1,509	1.00	Referent
Black	39,822	3,30	1.46	1.29–1.65	98	1.48	1.18–1.86	232	1.45	1.25–1.67
Asian/PI	39,132	255	1.11	0.96–1.29	62	0.94	0.70–1.27	193	1.18	0.99–1.39
Hispanic	32,118	236	1.18	1.03–1.36	69	1.33	1.02–1.72	167	1.13	0.96–1.34
Pheterogeneity = 0.25

RR relative risk, 95 % CI 95 % confidence interval

^aIpsilateral breast tumors were defined as local recurrence of DCIS or invasive carcinoma in the ipsilateral breast that was diagnosed at least 6 months after the first DCIS

^bPatients who had been treated with mastectomy for their first DCIS (n = 27,680) were excluded

^cRelative risks were adjusted for age (20–39, 40–49, 50–59, 60–69, or 70–84 years) and year of the first DCIS diagnosis (1988–1989, 1990–1994, 1995–1999, 2000–2004, or 2005–2009), registry, treatment for the first DCIS (no surgical treatment, breast-conserving surgery alone, or breast-conserving surgery plus radiation therapy) and histopathological features including tumor size (<2 cm, 2–5 cm, ≥5 cm, or unknown), grade (well differentiated, moderately differentiated, poorly differentiated, or unknown), and histology (comedo, papillary, cribriform, solid, or NOS)