A18 Role of hormones in human breast development: The menopausal breast

Russo, José; Russo, I. H.

doi:10.1016/s0378-5122(97)80853-5

Cited by 3 publications

(5 citation statements)

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“…Furthermore, we expect that a broad mapping of gene expression of early parous women free of cancer in comparison with that of nulliparous and late parous women with cancer will allow us to identify the differences postulated here. Genomic mapping will significantly add to our observations of lower proliferative activity in the Lob 1 of the parous woman's breast, whereas cell proliferation is higher in the Lob 1 of the nulliparous woman's breast (40–42). We have also shown that during the fourth and fifth decades of life, there is a decrease in the number of Lob 2.…”

Section: Influence Of Age and Parity On Human Breast Developmentmentioning

confidence: 57%

“…The percentage of Ki67‐positive cells (Ki67 or proliferation index) decreases progressively as the lobules mature from Lob 1 to Lob 2 and these to Lob 3 and Lob 4 (30,40–42). These differences were not abrogated when the proliferation index was corrected for the phase of the menstrual cycle (41,42). We concluded that parity, in addition of exerting an important influence in the lobular composition of the breast, profoundly influences the proliferative activity of the breast.…”

Section: Cell Proliferation and Steroid Receptor Content In The Normamentioning

confidence: 87%

“…Further analysis led us to discover variations in the rate of cell proliferation among these categories. Cell proliferation, a cellular function essential for normal growth, also plays a crucial role in the development of cancer (30,40–42). Normal growth requires a net increase of cycling cells over two other cell populations, resting cells (arrested in G 0 ) and dying cells (cells lost through programmed cell death or apoptosis).…”

Section: Cell Proliferation and Steroid Receptor Content In The Normamentioning

confidence: 99%

“…The quantitation of proliferating cells, determined by immunocytochemical reaction of breast tissues of nulliparous and parous women with monoclonal antibody against Ki67 antigen, allowed us to determine that the proliferative activity of the mammary epithelium varies as a function of the degree of lobular differentiation. The percentage of Ki67‐positive cells (Ki67 or proliferation index) decreases progressively as the lobules mature from Lob 1 to Lob 2 and these to Lob 3 and Lob 4 (30,40–42). These differences were not abrogated when the proliferation index was corrected for the phase of the menstrual cycle (41,42).…”

Section: Cell Proliferation and Steroid Receptor Content In The Normamentioning

confidence: 99%

“…However, the mechanisms by which these molecules exert their mitogenic and differentiation effects have not been clearly established (45–53). We have measured the levels of steroid hormone receptors in normal breast tissue by identifying and quantitating individual cells expressing the traditional estrogen receptor (ER), now called ERα, and progesterone receptor (PgR) using monoclonal antibodies that specifically recognize these receptors (30,40–42). Our studies revealed that the percentage of cells expressing these receptors varies as a function of the degree of lobular development of the breast and therefore of the type of lobular structure analyzed.…”

Section: Cell Proliferation and Steroid Receptor Content In The Normamentioning

confidence: 99%

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Mammary Gland Architecture as a Determining Factor in the Susceptibility of the Human Breast to Cancer

2001

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The developmental pattern of the breast can be assessed by determining the composition of the breast in specific lobular structures, which are designated as lobules type 1 (Lob 1), lobules type 2 (Lob 2), and lobules type 3 (Lob 3), with Lob 1 being the less developed and Lob 3 being the most differentiated or with the highest number of ductules per lobular unit. In the present work, the patient population consisted of three groups of women who underwent surgical procedures: The first group included women who underwent reduction mammoplasty (RM) for cosmetic reasons. The second group included women who underwent prophylactic subcutaneous mastectomy after genetic counseling for either carrying the BRCA-1 gene or belonging to a pedigree with familial breast cancer (FAM), and the third group included women who underwent modified radical mastectomy (MRM) for the diagnosis of invasive carcinoma. The RM group consisted of 33 women, of whom 9 were nulliparous and 24 were parous. The FAM group consisted of 17 women, of whom 8 were nulliparous and 9 were parous. The MRM group consisted of 43 women, of whom 7 were nulliparous and 36 were parous. The analysis of the lobular composition of all of the samples from the RM group, which is considered the control group, revealed that Lob 1 represented 22%, Lob 2 represented 37%, and Lob 3 represented 38%, whereas the tissue examined from the FAM and MRM groups contained a preponderance of Lob 1 at 48% and 74%, respectively, over Lob 3, which was 10% and 3%, respectively. When the results of the analysis of breast tissue were separated according to the pregnancy history of the donor, it was found that in the control group or RM, there was a significant difference in lobular composition. Nulliparous women of the RM group showed a preponderance of Lob 1 (46%) over parous women, which contained only 17%, whereas the percentage of Lob 3 in the nulliparous group was significantly lower (7%) than the parous group (48%). In the breast tissues obtained from FAM and MRM, no significant differences in lobular composition were observed, as all of the samples contained a higher concentration of Lob 1, independent of the pregnancy history. The breast tissue of FAM and MRM of parous women had a developmental pattern that was similar to that of nulliparous women of the same group and that was less developed than the breast of parous women of the control group. An important difference between the Lob 1 of the FAM group versus the control (RM) and the MRM group was that most of these lobules had thin ductules with an increase in hyalinization of the intralobular stroma manifested in the whole-mount preparation as an alteration in the branching pattern. The data suggest that the breast tissue of women with invasive cancer, as well as those from a background of familial breast cancer, have an architectural pattern different from the control or normal tissues and that the BRCA-1 or related genes may have a functional role in the branching pattern of the breast during lobular development, mainly in th...

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Section: Influence Of Age and Parity On Human Breast Developmentmentioning

confidence: 57%

Section: Cell Proliferation and Steroid Receptor Content In The Normamentioning

confidence: 87%

Section: Cell Proliferation and Steroid Receptor Content In The Normamentioning

confidence: 99%

Section: Cell Proliferation and Steroid Receptor Content In The Normamentioning

confidence: 99%

Section: Cell Proliferation and Steroid Receptor Content In The Normamentioning

confidence: 99%

See 3 more Smart Citations