Mammographic Breast Density in Infertile and Parous Women

Meggiorini Maria Letizia; Vestri Anna Rita; De Stefano Maria Grazia; Cipolla Valentina; Bellati Filippo; Maffucci Diana; Nusiner Maria Paola; Aragona Cesare; De Felice Carlo


BMC Womens Health. 2016;16(8) 

In This Article


Breast cancer is the most common malignancy in women and a leading cause of cancer-related death worldwide.[15,19] In the absence of a known preventable cause of breast cancer, the single most important factor in reducing mortality is early detection. Mammography and ultrasound are currently the techniques of choice for breast cancer evaluation. The sensitivity of mammography varies and is influenced by breast density. Dense fibroglandular tissue is the most important inherent limitation of mammography in the diagnosis of breast cancer,[12] and dense breast tissue is considered a risk factor in the subsequent development of breast cancer.[19]

Mammographic breast density is very often linked to cancer due to masking bias, as malignant lesions have the same x-ray attenuation properties as fibroglandular tissue.[19,20] In our previous study, we analysed a selected population of women with primary infertility and we found that 68 % of patients had dense breasts according to the BIRADS score.[17] The study in question presented some limitations: it lacked a control group and used only the BIRADS system, which was originally a morphological assessment.

This is the first study that has investigated breast density of infertile women referred to assisted conception services and compared the outcome with a group of premenopausal parous women aged ≥35. In this study, two methods were used to assess mammographic density, BIRADS and Boyd, and both confirmed previous results for the infertile women. The percentage of dense breasts in the group of women with primary infertility was higher using both BIRADS (66.9 % vs. 53.9 %, p < 0.05) and Boyd (53.6 % vs. 31.8 %, p < 0.05) compared to parous woman. One of the most important limitations of this study is the difference in the mean age between the two groups. Mean age of the control group was higher, because mammographic screening and other preventive measures before age 40 are not recommended except in women at high risk of breast cancer.[12] According to the FONCAM guidelines, the first diagnostic approach recommended before age 40 is clinical examination. If suspicious signs for malignancy are found, ultrasound is performed, followed by a mammogram if necessary.[12] Therefore, from the database of the Department of Radiology, we selected women who had undergone mammography examinations for various reasons. This caused a slight difference between the mean age in the two study groups. Sensitivity and specificity of mammographic evaluation is lower in younger women than in older women because younger woman more often have dense breast tissue.[21] Therefore, we used multivariate analysis to take into account potential confounding factors, such as age, BMI and family history. Nevertheless, dense breast tissue was more frequent in the case group as established according to the Boyd and BIRADS systems. The role of nulliparity as a risk factor for breast density has been discussed in several studies.[13,22] There might be a biological relationship between parity and the risk of breast cancer given that high breast density is present in most nulliparous women.[10,14,17] Furthermore, nulliparous women often present a large quantity of undifferentiated epithelial breast tissue, which is more susceptible to carcinogenetic stimuli such as endogenous and exogenous female hormones.[23]