Mammographic density and breast cancer risk: current understanding and future prospects

Breast Cancer Research

Table 4 Summary of studies of mammographic density and risk of second breast cancers

				Results
Authors, region (year)	Study population	Median follow-up	Measurement of MD	Events^b	Number	HR (95% CI)	Adjustments^a	Comments
Habel et al. [91], USA (2010)	935 patients with DCIS	8 years	Planimeter Highest versus lowest quintile of dense area	All Ips.	228 164	1.8 (1.2 to 2.9) 1.7 (1.0 to 2.9)	Age, BMI, treatment, and diagnosis year	Similar HR in subgroups of age, BMI, treatment, and menopausal status
				Cont.	59	3.0 (1.3 to 6.9)
Hwang et al. [93], USA (2007)	3,274 patients with DCIS	39 months	BI-RADS High (3 or 4) versus low (1 or 2)	All inv.	133	1.4 (0.9 to 2.1)	Age and radiation treatment	No interaction of density with radiation treatment
				Ips. inv.	83	1.0 (0.6 to 1.6)
				Cont. inv.	52	3.1 (1.6 to 6.1)
Habel et al. [90], USA (2004)	334 patients with DCIS	11 years	Planimetry >75% versus <25% PMD	All	112	2.8 (1.3 to 6.1)	Age, BMI, and radiation treatment	No interaction with radiation treatment or menopausal Status
				Ips.	80	3.0 (1.2 to 7.5)
				Cont.	28	3.4 (0.7 to 16.2)
Cil et al. [79], Canada (2009)	335 patients with invasive breast cancer	8 years	Wolfe score High versus low Wolfe score	Ips. inv.	34	5.7 (1.6 to 20.0)	Age, menopause, and radiation treatment	Association stronger in those who did not receive radiation treatment
				Dist. inv.	31	No association (HR not given)
Park et al. [92], USA (2008)	136 patients with invasive breast cancer	7.7 years	Computer- assisted >75% versus <25% PMD	Ips. inv.	19	3.4 (1.6 to 7.5)	BMI
				Cont./Dist. inv.	25	No association (HR not given)

^aFactors included in the analysis of mammographic density and risk of second breast cancer. ^bEvents include in situ and invasive cancer unless specified as invasive (inv.). All, all second breast cancers; BI-RADS, Breast Imaging-Reporting and Data System; BMI, body mass index; CI, confidence interval; Cont., second cancer in contralateral breast; DCIS, ductal carcinoma in situ; Dist, distant metastasis; HR, hazard ratio; Ips, second cancer in ipsilateral breast; MD, mammographic density; PMD, percent mammographic density.

ISSN: 1465-542X