Mammary Parenchyma: Definition, Genetics and Treatments of Breast Cancer

In Anatomical terms, the breast parenchyma is the tissue in the breast that lies just under the skin.

Sometimes fibroids and benign cysts can grow in this tissue, producing cells that affect the milk ducts and glands that produce milk.

Certain diseases, such as breast cancer , can change the characteristics of the breast parenchyma.

Stroma, is the scientific term for all breast tissue that is not part of the parenchyma.

This is the fatty, connective tissue that gives the breast volume, providing an essential blood supply for the parenchymal cells of the breast.

Much of the volume of the breast belongs to the tissue of the parenchyma that contains the lobes. These are the areas of the organs that produce milk to feed a baby, which are attached to the ducts that drain the milk.

The smaller milk ducts are small channels through which the milk moves to the main duct that is connected to the mouthpiece where babies receive their milk through the nipple.

The stroma provides the reserves of fat and supplies the blood to the cells of the breast. Although blood is essential for cells, this role is generalized to the rest of the body, and is not included in the definition of the parenchyma.

Changes in the mammary parenchyma, due to the important role it plays, can also be a sign of disease onset for physicians.

Medical technology has found that women have a normal range of density of their breast tissue.

When the tissues of the parenchyma are altered, they can change the density and this can be recognizable under imaging techniques such as mammography.

Some cases of breast cancer are identified through alterations in parenchymal density, which may be beneficial for the treatment of patients.

Are breast parenchyma patterns related to cancer risk?

Measuring breast tissue density by analyzing mammographic parenchyma patterns could help doctors better determine the risk of breast cancer in women, according to a new study published online .

It could also lead to better patient care by allowing more accurate density measurements.

Researchers at the University of Michigan developed a computerized mammographic parenchymal pattern (MPP) measure and explored the association between the patterns of fibroglandular mammary tissue texture in the retroareolar region and the risk of breast cancer.

Currently, the most common approach to determining a woman’s breast density is for the radiologist to visually evaluate the fibroglandular tissue photographed on mammography and assign it a BI-RADS category, according to lead author Jun Wei, PhD, and colleagues. However, this approach is subjective.

“A more accurate and reproducible measure than [BI-RADS] for breast density that does not depend on the subjective impression of human readers can further improve the reliability of mammary density estimates for risk prediction,” the authors wrote. .

Computerized quantitative measurements of breast density are still new in the clinical setting, but studies have shown that these techniques can improve reproducibility and intraobserver concordance of breast density measurements, they wrote.

For the current study, Wei and colleagues used computerized analyzes of mammary tissue distribution in mammograms, compared to mammographic density measurements (percent density or PD) in which density is measured as the percentage of dense area estimated from the breast segmented in mammograms.

The study population included women who had received mammographic screening in the University of Michigan Health System between 1993 and 2002.

Wei’s team collected mammograms of 382 women, acquired at least one year before diagnosis, in 136 cancer patients, as well as controlling the mammograms of 246 healthy women who had a cancer-free follow-up for at least five years.

The team used an automated method previously developed in their laboratory to estimate the percentage of fibroglandular tissue area relative to the total area of ​​the breast.

Wei’s group also designed a computerized mammographic parenchymal pattern algorithm to analyze the texture patterns of the fibroglandular tissue behind the nipple and areola.

The use of textural information in the mammary parenchyma is to improve risk prediction, the MPP descriptor needed to be able to characterize the spatial relationships of the mammary structures while having a low correlation with the density percentage measurements, wrote Wei and his colleagues.

The Pearson product-moment correlation coefficient between the MPP and the PD was 0.13, a low correlation, according to the authors, while the measurement of computerized MPP had a strong association (p <0.001) with the risk of cancer. of breast.

“The computerized MPP measure can provide useful information, in addition to PD, to predict the risk of breast cancer in an individual, so it can serve as an additional biomarker for breast cancer risk monitoring and patient management. “, They concluded.

Breast parenchyma and genetics

Women with a certain genetic mutation are among high-risk breast cancer patients. With magnetic resonance tomography (MRT), it is possible to detect tissue with a measurable active blood supply that indicates an increased risk of breast cancer.

Biologist and molecular radiologist Barbara Bennani-Baiti and radiologist Pascal Baltzer of the Radiology and Nuclear Medicine Clinic of MedUni Vienna are exploring whether tissue with visible active blood supply with MRT could indicate an increased risk in those patients without genetic mutation.

The result is the so-called ” bottom parenchymal improvement ” of the breast in these women is not associated with breast cancer.

Magnetic resonance tomography is the most sensitive procedure for the detection of breast cancer because, unlike conventional imaging procedures (mammography and ultrasound), it provides functional information about the blood circulation of the tissue.

In general, this test is applied annually in patients at high risk of breast cancer according to family history or a special mutation (eg, BRCA 1).

In the process, women are initially injected with a contrast medium, which makes the so-called “bottom parenchyma improvement” visible in the MRT.

It was already possible to demonstrate in these women that the improvement of the severe background parenchyma, indicating an increase in the blood supply and therefore, for example, a hormonally activated breast tissue.

In the context of the program for the early detection of breast cancer, routine mammography and possibly a complementary ultrasound examination are carried out for all other Austrian patients.

In the case of an unclear result, it is possible to perform an MRT in Austria for further clarification. Basic medical research tries to find biomarkers of tumors in order to preventively proceed against breast cancer in the future and be able to treat it at an early stage.

In this context, Barbara Bennani-Baiti and Pascal Baltzer of the Clinic of Radiology and Nuclear Medicine of MedUni Vienna (Mammary Image Manager: Thomas H. Helbich) together with Matthias Dietzel of the Erlangen University Clinic discussed the subject if the breast tissue with the increase of the bottom parenchyma improvement.

They were able to demonstrate that, ultimately, only age was decisive for the risk of breast cancer in this group of patients, who were not at increased risk of breast cancer due to family accumulation or known mutations.

The activity of the breast, as demonstrated in the MRT due to the improvement of the background parenchyma, is not important in this case. The study data also showed that very active breast tissue in patients without high risk points to a younger age and, therefore, to a lower risk of the disease.

Nor is it necessary for these women to undergo additional tests. However, with her work, Barbara Bennani-Baiti, Matthias Dietzel and Pascal Baltzer demonstrated the importance of knowing the improvement of the background parenchyma for high-risk patients for a risk assessment of breast cancer.

Their results indicate that the changed breast tissue of high-risk patients is more susceptible to degeneration compared to women without these risk factors.

If this susceptible tissue now becomes active, which is also reflected in a higher rate of cell division, cellular degenerations increase, most likely leading to cancer. On the contrary, this activation is not harmful in healthy patients, whose tissue presents repair mechanisms intact.

The tissue can automatically remedy possible defects before it turns into cancer.

Conclusion: The improvement of the high background parenchyma of the visible breast with MRT in high risk patients indicates mainly a young age; however, for high-risk patients, it indicates an evident increase in cancer risk according to current findings and should be considered in the decision-making process for any preventive measure.


Mammograms can be carried out in order to see if there is any growth in this tissue. Surgery is the primary treatment for breast cancer .

Objectives include complete resection of the primary tumor, with negative margins to reduce the risk of local recurrences, and pathological staging of the tumor and axillary lymph nodes to provide necessary prognostic information.

What are the types of breast cancer treatment?

Some treatments eliminate or destroy the disease within the breast and nearby tissues, such as the lymph nodes. These include:

  • Surgery:  to remove the entire breast (called a mastectomy), or to remove only the tumor and surrounding tissues, called lumpectomy or breast-conserving surgery. There are different types of mastectomies and lumpectomies.
  • Radiation therapy:  which uses high-energy waves to kill cancer cells.

Other treatments destroy or control cancer cells throughout the body:

Chemotherapy:  uses drugs to kill cancer cells. As these powerful medications fight the disease, they can also cause side effects, such as nausea, hair loss, early menopause, hot flashes and fatigue.

Hormone therapy:  uses drugs to prevent hormones, especially estrogens, from feeding the growth of breast cancer cells.

Medications include tamoxifen (Nolvadex, Soltamox) for women before and after menopause and aromatase inhibitors, which include anastrozole (Arimidex), exemestane (Aromasin) and letrozole (Femara) for postmenopausal women.

Side effects may include hot flashes and vaginal dryness. Some types of this therapy work by preventing the ovaries from producing hormones, either through surgery or medication.

Fulvestrant (Faslodex) is an injection that prevents estrogen from attaching to cancer cells.

Terapia dirigida: como lapatinib (Tykerb), pertuzumab (Perjeta) y trastuzumab (Herceptin).

These medications cause the body’s immune system to destroy the cancer. They target breast cancer cells that have high levels of a protein called HER2.

Palbociclib (Ibrance) and ribociclib (Kisqali) work by blocking a substance that promotes the growth of cancer.

Along with an aromatase inhibitor, palbociclib and ribociclib are for postmenopausal women with certain types of advanced cancer. Abemaciclib and palbociclib are sometimes used with fulvestrant hormone therapy (Faslodex).

You may receive chemotherapy, hormone therapy, or targeted therapy along with surgery or radiation. They can kill any cancer cells that have been left by other treatments.