Hindawi Publishing Corporation
Radiology Research and Practice
Volume 2012, Article ID 127485, 7 pages
MammographicBreast Density Patterns in
AnaLauraCalder´ on-Garcidue˜ nas,1M´ onicaSanabria-Mondrag´ on,2
Lourdes Hern´ andez-Beltr´ an,3No´ e L´ opez-Amador,1andRicardo M. Cerda-Flores4
1Instituto de Medicina Forense, Universidad Veracruzana, 94294 Boca del R´ ıo, VER, Mexico
2Unidad de Medicina Familiar No. 2, Instituto Mexicano del Seguro Social, 43612 Tulancingo, HGO, Mexico
3Centro Medico Nacional del Noreste, Instituto Mexicano del Seguro Social, UMAE 25, 64180 Monterrey, NL, Mexico
4Facultad de Enfermeria, Universidad Autonoma de Nuevo Leon, 64460 Monterrey, NL, Mexico
Correspondence should be addressed to Ana Laura Calder´ on-Garcidue˜ nas, firstname.lastname@example.org
Received 28 September 2012; Revised 28 November 2012; Accepted 12 December 2012
Academic Editor: Philippe Soyer
Copyright © 2012 Ana Laura Calder´ on-Garcidue˜ nas et al. This is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
Breast density (BD) is a risk factor for breast cancer. Aims. To describe BD patterns in asymptomatic Mexican women and the
pathological mammographic findings. Methods and Material. Prospective, descriptive, and comparative study. Women answered
a questionnaire and their mammograms were analyzed according to BI-RADS. Univariate (χ2) and conditional logistic regression
analyses were performed. Results. In 300 women studied the BD patterns were fat 56.7% (170), fibroglandular 29% (87),
were observed in 25.6% (30/117) of women ≤50 years and 7.1% (13/183) of women >50. Asymmetry in BD was observed in 22%
(66/300). Compression cone ruled out underlying disease in 56 cases. In the remaining 10, biopsy revealed one fibroadenoma,
one complex cyst, and 6 invasive and 2 intraductal carcinomas. 2.6% (8/300) of patients had non-palpable carcinomas. Benign
lesions were observed in 63.3% (190/300) of cases, vascular calcification in 150 cases (78.9%), and fat necrosis in 38 cases (20%).
Conclusions. Mexican women have a low percentage of high-density patterns.
Breast cancer (BC) is a world health problem. Since 2006,
it is the first neoplasm mortality cause in adult women in
Mexico . In 1990, 6000 new cases were registered and by
2020, 16,500 are expected. At present, most of these cases
are detected by self-exam and only 10% are identified in
stage I [1, 2]. An essential tool in early detection of BC
is mammography. The advance of technology has refined
the images with increased accuracy for detecting non-pal-
pable lesions . In Mexico, there is a limited number of
mammography machines (4 per million population), below
the OECD (Organisation for Economic Cooperation and
Development) indicators (19.9 per million population) and
far from developed countries (France, 42.2/million) .
Incidence of BC increases with age. In Mexico, 46% of
BC cases occur before age 50 and the age group most affected
is that between 40 and 49 years . This contrasts with the
United States, where the average age of presentation is 61
years  and with European countries where the incidence
is higher in postmenopausal women [6–8]. Mexico’s first
voluntary mammography screening program was organized
by the Mexican Foundation for Education in Prevention and
Opportune Detection of Breast Cancer (FUCAM) and the
Mexico City Government. It targeted women over 40. More
than 96,000 mammograms were performed in mobile units
for residents in Mexico City’s Federal District over a 22-
month period ending in December 2006. Out of 949 women
with abnormal mammograms, 208 had breast cancer, a rate
of 2.1%. Most were in situ, stage I (29.4%) or stage II
2 Radiology Research and Practice
(42.2%). One percent were in BI-RADS 0, 4, or 5. Of the
women diagnosed with cancer, 68.5% were younger than 60,
with an average age of 53.5 . Thirty-eight percent of the
cancers occurred in women aged 49 or younger .
The screening programs are regulated by the Mexican
Official Standard (NOM-041-SSA2-2002) . The NOM
provides detection through self-examination, clinical exami-
nation, and mammography, the latter every one or two years
in women 40 to 49 years with two or more risk factors, and
annually for all women 50 years, whenever there is a resort
Actually, the program currently covers 19% of the female
population aged 40 or more .
Mammography is considered the most sensitive tool for
detecting early neoplasia. A particular parameter analyzed
in mammography is breast density. Mammographic density
reflects variations in adipose, stromal, and epithelial tissues
, associated with advancing age and hormonal changes
experienced by the woman. Hence, it is an important para-
meter to evaluate and in fact, a risk factor for BC . In
the mammary gland, the older the woman, the higher fat
content to be found. However, patterns at high risk of cancer
Breast density has the potential to be an important adjunct
to risk estimation and to monitor interventions for breast
cancer prevention with hormone replacement therapy and
by change in life style behaviours .
Therefore, the aim of this study is to determine the breast
density (BD) patterns in a sample of asymptomatic Mexican
The hospital is a referral center for cancer patients and is
a training center for radiologists in mammography. The
hospital supports some primary care clinics with mammo-
grams (medical and educational purposes). Women from
these clinics were recruited for the study. Upon approval by
the Research and Ethics Committees, all consecutive women
clinically asymptomatic in relation to breast disease who
attended the Department of Radiology and Image (July 2009
to July 2010) as part of the program of Screening for Cancer
were included in the study. The selection criteria were 40
years of age or older, clinically asymptomatic in relation to
not had previous malignant breast disease. Exclusion criteria
included the refusal to sign the consent form, no time to
answer the questionnaire, prior history of breast malignancy,
or breast resection surgery.
The patients signed informed consent, underwent mam-
mography, and gave the required clinical information based
on a questionnaire that was conducted in the visit for mam-
mography. Mammography studies were analyzed according
to the criteria of BI-RADS .
Because of the age difference in presentation of breast
cancer in Mexico in relation to other countries, we evaluated
two groups, women 50 years or younger and women older
than 50 years (> and <50 years) .
Figure 1: Breast density patterns according to percentage of
glandular component: (a) fat (up 25%), (b) fibroglandular (25–
50%), (c) heterogeneously dense (50–75%), and (d) dense (over
The BD was classified according to the percentage of
glandular component (Figure 1): fat (up 25%), fibrogland-
ular (25–50%), heterogeneously dense (50–75%), and dense
landular density patterns were considered “low density,”
whereas heterogeneously dense and dense patterns were
considered “high density.”
The technical quality of mammography was assessed at
the time of the study  and mammary ultrasound (US)
was performed if required. US was used as an adjunct to
mammography, when the tissue was very dense, or because
in the presence of a nodule, it was required to know whether
the content was liquid or solid, also in cases of focal or
global asymmetry, to rule out an underlying lesion not
visible by mammography. Mammographic findings were
assessed by two radiologists. In cases where classification
and/or diagnosis were discordant, another radiologist eval-
uated independently the case and afterwards, the study
was reviewed together to reach an agreement and a final
Radiology Research and Practice3
Table 1: Body mass index (BMI) in 300 Mexican women.
Grade 1 (30–34.9)
Grade 2 (35–39.9)
Grade 3 (≥40kg/m2)
described. We used a General Electric digital mammography,
Senographe Model 2002, and two ultrasound machines
Brand General Electric (model LOGIC 5, 2002, LOGIC
7.2003). The ultrasound machines were equipped with
7MHz linear transducers and 3.5MHz convex transducer.
19 variables were studied; 15 corresponded to the ques-
tionnaire: degree of obesity (according to Body Mass Index),
age of menarche and menopause, tobacco (at least one
cigarette per day) and alcohol consumption (at least one
drink per week), contraceptive use (type and duration of
use), hormone replacement therapy, number of pregnancies,
cesarean sections and abortions, age and duration of the first
and family history of breast cancer, and 4 mammographic
features (BD, BI-RADS and pathological findings, benign
and malignant). Measurements of weight, height, waist, and
hip were made in each patient.
We performed univariate analysis (Chi-square tables)
and multivariate (conditional logistic regression) using SPSS
17. Breast density was studied (1 high and 0 low) as well as
were compared in women younger and older than 50 years.
Of the 362 patients studied, 62 of them were excluded
or there was a prior history of breast resection surgery (4/62,
6.4%). The study group was 300 women with age ranging
from 40 to 77 years. Significant differences between the two
groups were not observed in obesity degree (Tables 1 and 2),
age of menarche (≤50: 12.68 ± 1.61; >50: 13.12 ± 1.64, t-
student −2.305, P = 0.022) tobacco and alcohol consump-
tion, history of oral contraceptive use, history of pregnancies
and abortions, lactation history, and familial history of BC
(Table 2). No woman in the study was classified with abuse
problem or alcohol dependency. Less than 20% of women
were smoking, with an average of 5 cigarettes per day, ±2.
In these women aged 40 years or older, the present study
was the first to be performed in 40% of cases. The average
age of the first mammogram was 49.9 years, ranging from 40
to 71 years. The decision to seek mammography performed
was the idea of the patient at 7% of cases and it was indicated
by the physician or a nurse as part of the breast cancer
screening program in 93%. There was no difference between
the two groups in relation to family history of breast cancer
in general, or in first-degree relatives (mother and sisters).
As expected, menopause was present in less than 50% of
Women in the north of the country have the highest rate of
been detected since several years ago.
Table 3 shows the distribution of BD patterns according
to age. The general distribution of mammographic density
in these women according to BI-RADS classification showed
a fat pattern in 56.7% of cases, 29% with fibroglandular
pattern, 5.7% with heterogeneous pattern, and 8.6% with
high density pattern.
Table 4 shows BD and its relationship to women older
and younger than 50 years. Mammographic density was
strongly influenced by the age of the patient, with significant
difference in younger and older than 50 years. Thus, the
distribution of the four patterns, fat, fibroglandular, hetero-
geneous dense, and dense was 37.6, 36.7, 9.4, and 16.2%,
respectively, for women under age 50 and 68.8, 24, 3.3 and
3.8% for women over 50 years.
66 women (22%) showed asymmetry in mammographic
density. The compression cone ruled out the underlying
pathology in 56 cases. In the remaining 10 women, lesions
were detected that were confirmed by biopsy. These lesions
were diagnosed as fibroadenoma (1 case), complex cyst (1
case), and cancer (8 patients). Of the cancers found, 6
were invasive ductal carcinomas and 2 were intraductal neo-
plasms. All carcinomas were non-palpable lesions. Cancer
was detected in 2.6% of patients in this study. 50% (N = 4)
of cancers were found in patients 50 years or younger.
Of the total sample, 190 women (63.3%) had benign
lesions that corresponded to vascular calcifications (150
patients), fat necrosis (38 patients), and hamartomas (2
patients). 246 cases (82%) only needed the mammography
for diagnosis, whereas in 54 patients (18%) it was necessary
to supplement the study with ultrasound.
Mammography identified BI-RADS 1 in 78 patients
(26%) of which only one required an additional ultrasono-
graphy (US) to define the diagnosis (0.3%); BI-RADS 2 was
diagnosed in 190 patients (63.3%) of which the mammo-
graphy was supplemented with US in 33 patients (11%).
BI-RADS 3 was found in 16 patients, 2 hamartomas and
2 fibroadenomas, the remaining 12 patients needed to
complement with US, detecting 5 simple cysts, 6 complex
cysts and 1 cancer, BI-RADS 4 were 8 cases, and all requir-
ed US complement; findings included 1 complex cyst, 1
fibroadenoma, and 6 neoplastic tumors.
Cancers detected by both mammography and US were
later corroborated by biopsy. Of these, one was BIRAD 3,
six had BI-RADS 4, and one was BI-RADS 5. Neoplastic
cases were associated with fibroglandular density pattern in
3 cases, 3 had heterogeneous, and 2 high-density patterns.
5 carcinomas were found in 43 patients with high-density
pattern (heterogeneous + dense) and 3 neoplasms were
detected in 3/257 patients with low-density patterns (fat &
fibroglandular) (Table 5). Table 5 shows the BI-RADS diag-
nosis according to BD patterns. Only dense density pattern
in this sample was associated to BI-RADS 0. Also, it had the
4 Radiology Research and Practice
Table 2: Distribution of characteristics according to age.
Normal weight25 (13.7)
Overweight-obesity99 (84.6) 158 (86.3)
No 60 (51.3)13 (7.1)
Yes 57 (48.7) 170 (92.9)
No98 (83.8) 151 (82.5)
Yes 19 (16.2)32 (17.5)
No 93 (79.5)144 (78.7)
Yes 24 (20.5) 39 (21.3)
History of oral contraceptives
No 73 (62.4) 144 (66.7)
Yes 24 (37.6)39 (33.3)
No10 (8.5)12 (6.6)
Yes 107 (91.5)171 (93.4)
No 65 (55.6)123 (67.2)
Yes52 (44.4) 60 (32.7)
No 90 (76.9) 122 (66.7)
Yes 27 (23.1)61 (33.3)
History of lactation
No 21 (17.9)27 (14.8)
Yes 96 (82.1) 156 (85.2)
No44 (37.6)76 (41.5)
Yes 73 (62.4) 107 (58.5)
Mammography required by:
Physician 83 (70.9) 133 (72.7)
Nurse (early detection program) 24 (20.5)39 (21.3)
Women10 (8.5)11 (6.0)
Breast cancer in the family
No 86 (73.5) 150 (82.0)
Yes 31 (26.5)33 (18.0)
Mother with BC
No 112 (95.7) 179 (97.8)
Yes5 (4.3) 4 (2.2)
Sister with BC
No 107 (91.5) 175 (95.6)
Yes 10 (8.5)8 (4.4)
Radiology Research and Practice5
Table 3: Breast density, and age distribution.
Table 4: Breast density in women younger and older than 50 years.
Mammographic density patterns
χ2= 35.5, P = 0.0001, gl = 9.
highest proportion of BI-RADS 3 and 4. The cancer cases
were associated to high density in 5 cases (62.5%).
Breast cancer is a major cause of morbidity and mortality
in our country. On the other hand, we have the growing
problem of obesity . Obesity is generally associated with
an increased risk of developing breast cancer, which is most
evident in women with morbid obesity . Only 14% of
the women studied were in normal weight and 17% were
obese grades III and IV. Age and obesity in women in our
population were correlated with low-density radiographic
of these women had glandular pattern, 5.7% heterogeneous
dense pattern, and 8.6% dense pattern. It is this latter group
of patients in whom the risk of BC is higher. There was
a significant difference in the patterns of breast density in
women under age 50 as compared with older ones. The
fat pattern increased from 38.5% in women under 50 years
to 65.4% in the group of 56–60 years and reached 82% in
women aged 61–65 years. However, even in old age it is
possible to observe high BD, as the patients in the age group
of 71–77 years. Breast high density is a risk factor for cancer.
It is known that the incidence of breast cancer increases with
age. In Mexico, 46% of BC cases occur before age 50 and the
age group most affected is that between 40 and 49 years .
This contrasts with the United States, where the average age
where the incidence is higher in postmenopausal women [7,
8]. Health authorities in Mexico recommend mammography
from age 40 if there are at least two risk factors.
When compared with other studies, the findings in
density (percent dense area) was 60% or more in 8.3% of
of dense mammogram (heterogeneously dense and dense
patterns) was 78.3% for women 40−44 years old, 61.1%
for (45−49) group, and 30.1% in (50−54) age range. In
Indian population alow prevalenceofdensemammographic
patterns (16.3% in noncancer controls and 26.7% in breast
cancer cases) has been reported . In Western women
figures were 47.2% (40−44 years), 44.8% (45−49), and
44.4% (50−54) . Mexican women had these frequencies
of high density, 30.7% (40–45), 21.5% (46–50), and 3.7%
(51–55). Therefore, the percentage of mammary glands with
high density was lower than in other countries.
The presence of asymmetry in mammographic density
requires to rule out underlying breast pathology. Besides
additional projections, maximum compression, and lateral
magnification cone to 90 degrees, the use of ultrasonography
in our study was very useful to complement the character-
ization of lesions of the mammary gland . US helped
to define diagnosis specially in BI-RADS 3 and 4 in patients
simple and complex cysts, fibroadenomas, and cancer. All
patients with a final diagnosis of cancer by mammography
and ultrasound underwent biopsy to corroborate diagnosis.
Coarse calcifications and fat necrosis were the most
frequent benign lesions in this sample of Mexican women.
6 Radiology Research and Practice
Table 5: Distribution of mammographic diagnostics (BI-RADS) according to breast densities patterns.
4 (2.4%)1 (5.8%)6 (23%)16
170 (56.6%) 87 (29%)26 (8.7%) 300
∗Number of carcinomas.
The patients were referred for routine mammography. This
finding is similar to the percentage found in the review of
96,000 mammograms in Mexico . Carcinomas in this
small sample were observed in 11.6% of women with high-
density patterns, and in 1.1% of patients with low-density
breast pattern, which supports the claim that high breast
density is a risk factor for carcinoma.
In general, Mexican women over 40 years of age have a breast
density profile different from Asian and European women.
25.6% of women under 50 years of age and 7.1% of older
women have high breast density. It would be interesting
to compare the BD distribution patterns with other Latin
American populations and determine if they are similar,
especially due to risk of carcinoma in high breast density
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