1. What do Women Know About Breast Density?
Results from a Population Survey of Virginia women
Thomas M. Guterbock, Ph.D.1; Deborah L. Rexrode, Ph.D. 1; Casey Eggleston, M.A. 1;
Wendy F. Cohn, Ph.D. 2; Wendy Novicoff, Ph.D. 2;William A. Knaus, M.D. 3; Jennifer Harvey, M.D. 4
UVa Center for Survey Research1; UVa Public Health Sciences2; NorthShore University Health System 3;UVa Department of Radiology 4
Results
Knowledge of risk factors
Summary: Breast density is an important and independent risk factor for breast cancer, yet women may not know or understand the implications of their personal breast density on cancer risk or detection. Women in at least 14 states are subject to ‘density notification laws,’ laws that require radiologists to inform women of their breast density. The Virginia “Dense Breast” notification law went into effect on July 1, Our study sought to explore what women in Virginia know about breast density and its risks for cancer detection, diagnosis and recommendations. Women in the study were asked about screening and their perceptions of their own risk as well as their familiarity with breast density and its impact on risk factors for breast cancer.
Seventy-five percent of respondents reported being either somewhat or very familiar with risk factors for breast cancer, but less than 1% proved able to list breast density as a risk factor. Being informed about breast density by a doctor was the strongest predictor of familiarity and accuracy of knowledge about breast density. Socio-economic factors like education and home ownership were positively associated with familiarity and accurate knowledge. Even with education controlled, African-American, Asian and Ashkenazi Jewish women have lower levels of familiarity.
In order to understand what women think about their own risk for breast cancer, respondents were asked to estimate their chance of getting breast cancer in the future. About half of the women said their risk of getting breast cancer is the same as any other woman. Only thirteen percent said they feel their risk is more than the average woman. When asked how familiar they are with the risk factors, 9 out of 10 said they were at least slightly familiar. However, breast density was listed as a risk factor by less than one percent.
Multivariate Analysis of Indicators of Breast Density Knowledge
Risk Factors for Breast Cancer (% mentioning)
Significant
Predictor Variables
Dependent Variables
Familiarity with Breast Density
(1 - 4 scale)
Heard of Relationship between Breast Density and Breast Cancer
Accuracy of Knowledge about Breast Density
(0 – 4 points)
Ashkenazi Jewish
-.418**
-.172**
-.555***
Asian
-.526*
.084
-.369
Black/African American
-.272*
-.108*
-.236
Education Level
.046*
.020**
.055*
Home Ownership
.202
.041
.265*
Informed About Breast Density by Doctor
1.090***
.291***
.840***
Perceived Relative Breast Cancer Risk
.107**
.032
.154**
R-squared
.354
.170
.244
N of cases
934
910
942
Background
Breast density reduces the sensitivity of mammography and is also a moderate independent breast cancer risk factor.
Virginia is one of fourteen states that currently requires providers to notify patients when they have dense breasts.
Little is know about what women in the general population know and understand about breast density.
This survey study assessed knowledge about breast density, its impact on mammography and its relationship to breast cancer risk.
Methods
Data Sources: 1,024 completed interviews conducted by the University of Virginia Center for Survey Research
Sample/Setting: RDD, Listed and Cell Phone Samples from the general population in the State of Virginia. Eligibility limited to women between the ages of 35 and 70 who had not been diagnosed with breast cancer.
Interviews: Interviews averaged 24 minutes in length and were conducted via telephone, in English and Spanish, by trained, female CSR interviewers
Field Period: June 12-October 24, 2013 with one pretest prior to production calling.
Response Rate: The response rates, calculated using AAPOR standard rate RR4, varied by sampling frame, with an overall response rate of 24.5 percent.
Analysis: The data file was weighted for analysis using the US Census’s American Community Survey to yield distributions of age, race, ethnicity, marital status, homeownership and education among Virginia women ages 35 – 70.
Margin of error: ± 4.1 %
Less than 1%
Being Informed of Breast Density
*p-value< **p-value< ***p-value<.001
Virginia law, passed in 2012, requires notification to women whose breasts are dense, but does not mandate any notice to women with low breast density. The survey suggests that women who receive notifications are taking due notice.
Conclusions
This survey of 1,024 Virginia women is the largest general-population study of awareness of breast density and its risks. The survey shows:
The mandatory notification law in effect in Virginia has been successful in increasing women’s familiarity with the term “breast density.”
However, women are not well informed about the implications of having dense breasts and very few are aware that high breast density is a risk factor for breast cancer.
Increased effort is needed to educate women about the health implications of breast density and to assist care providers in providing more complete information about breast density to health consumers.
Time of last mammogram
Less than 1 year ago
1-2 years ago
3-4 years ago
5 or more years ago
Never had a mammogram
All women
Percent ever informed by doctor about density of their breasts
51.8%
33.7%
25.7%
24.0%
13.0%
38.8%