The expression of FHIT, PCNA and EGFR in benign and malignant breast lesions

Immunohistochemical staining for FHIT and PCNA proteins was carried out in 451 breast lesions showing nonproliferative benign breast disease (BBD) (n=263), proliferative BBD without atypia (n=128), proliferative BBD with atypia (n=11), carcinoma in situ (n=15) or invasive carcinoma (n=34) and for EGFR protein in a subset of 71 of these cases. FHIT underexpression was not detected in nonproliferative lesions, but occurred in 2% of proliferative BBD without atypia, 10% proliferative BBD with atypia, 27% of carcinoma in situ and 41% of invasive carcinoma, which suggests that it could be useful in assessing those carcinoma in situ lesions (ductal, DCIS and lobular, LCIS) that are more likely to progress to malignancy. Preliminary microarray comparisons on DCIS and invasive carcinoma samples dissected from formalin-fixed paraffin sections showed a consistent downregulation of two previously identified FHIT-related genes, caspase 1 and BRCA1 in lesions underexpressing FHIT.     

Increased expression of fatty acid synthase and progesterone receptor in early steps of human mammary carcinogenesis

Progestins increase the risk of breast cancer in the hormone therapy of menopause, and progesterone receptor-induced fatty acid synthase (FAS) is a potential therapeutical target of breast cancer. In a first attempt to specify in which lesions at risk of breast cancer progestins might be acting, we have compared the progesterone receptor (PR) and FAS expression in preinvasive breast lesions and in adjacent "normal" mammary glands. We used archive paraffin-embedded tissues from 116 patients, with 164 lesions of increasing histological risk from nonproliferative "benign" breast disease (BBD) to in situ breast carcinomas. Immunostaining using our FAS antibody and a PR antibody from Dako was quantified as continuous variables by computer-assisted image analysis. FAS level increased (p < 10(-3) by the Kruskall-Wallis test) in all lesions, starting from nonproliferative BBD, and was maximal in in situ carcinoma. The % of PR-positive cells increased from nonproliferative BBD and was higher in proliferative atypia (p < 10(-3)). It was very low in high-grade DCIS corresponding to a likely different carcinogenesis pathway. There was a trend for a positive correlation between FAS and PR in normal glands. However, the 2 markers increased independently in BBD and were negatively correlated in in situ carcinomas. FAS and PR were positively correlated with Ki67 in BBD. The increased PR level in premalignant steps of mammary carcinogenesis suggests an early increased responsiveness to progestins. The increased FAS expression, in lesions parallel to their increased breast cancer risk, suggests further studies to develop new markers of high-risk lesions and to prevent breast cancer.     

Expression of caspases 3, 6 and 8 is increased in parallel with apoptosis and histological aggressiveness of the breast lesion

The aim of this investigation was to study the expression of caspases 3, 6 and 8 and their association to apoptosis in preneoplastic and neoplastic lesions of the breast. The material consisted of nine benign breast epithelial hyperplasias, 15 atypical hyperplasias, 74 in situ and 82 invasive carcinomas. The extent of apoptosis was assessed by the TUNEL method and caspase 3, 6 and 8 expression by immunohistochemistry with specific antibodies. Increased caspase 3 immunopositivity, as compared to staining of normal breast ductal epithelium, was seen in 22% of benign epithelial hyperplasias, 25% of atypical hyperplasias, 58% of in situ carcinomas and 90% of invasive carcinomas. The corresponding percentages for caspase 6 and 8 were 11%, 25%, 60%, 87% and 22%, 57%, 84%, 83% respectively. In high-grade in situ lesions there were significantly more cases with strong caspase 3, 6 and 8 immunoreactivity than in low- and intermediate-grade lesions (P = 0.0045, P = 0.049 and P = 0.0001 respectively). In invasive carcinomas, however, no association between a high tumour grade and caspase 3, 6 or 8 expression was found (P = 0.27, P = 0.26 and P = 0.69 respectively). The mean apoptotic index was 0.14 +/- 0.14% in benign epithelial hyperplasias, 0.17 +/- 0.12% in atypical hyperplasias, 0.61 +/- 0.88% in in situ carcinomas and 0.94 +/- 1.21% in invasive carcinomas. In all cases strong caspase 3, 6 and 8 positivity was significantly associated with the extent of apoptosis (P < 0.001, P = 0.015 and P = 0.050 respectively). The results show that synthesis of caspases 3, 6 and 8 is up-regulated in neoplastic breast epithelial cells in parallel to the increase in the apoptotic index and progression of the breast lesions.     

Hypermethylation of 14-3-3 sigma (stratifin) is an early event in breast cancer.

We have identified 14-3-3 sigma (sigma) as a gene whose expression is lost in breast carcinomas, primarily by methylation-mediated silencing. In this report, we investigated the timing of loss of sigma gene expression during breast tumorigenesis in vivo. We analysed the methylation status of sigma in breast cancer precursor lesions using microdissection for selective tissue sampling. We found hypermethylation of sigma in 24 of 25 carcinomas (96%), 15 of 18 (83%) of ductal carcinoma in situ, and three of eight (38%) of atypical hyperplasias. None of the five hyperplasias without atypia showed sigma-hypermethylation. Unexpectedly, patients with breast cancer showed sigma hypermethylation in adjacent histologically normal breast epithelium, while this was never observed in individuals without evidence of breast cancer. Also, samples of periductal stromal breast tissue were consistently hypermethylated, underscoring the importance of selective tissue sampling for accurate assessment of 14-3-3-sigma methylation in breast epithelium. These results suggest that hypermethylation of 14-3-3-sigma occurs at an early stage in the progression to invasive breast cancer, and may occur in apparently normal epithelium adjacent to breast cancer. These results provide evidence that loss of expression of sigma is an early event in neoplastic transformation.     

Decreased expression of estrogen receptor beta protein in proliferative preinvasive mammary tumors

To understand the significance of estrogen receptor beta (ERbeta) in mammary carcinogenesis, we evaluated the expression of ERbeta in preinvasive mammary tumors. The percentage of ERbeta-positive epithelial or tumoral cells was assayed by quantitative immunohistochemistry using an image analyzer in 130 lesions of varying histological risk from 118 patients [71 with benign breast disease (BBD) and 59 with carcinoma in situ (CIS)] and compared with 118 adjacent histologically normal glands. Five groups of lesions with an increasing risk of invasive cancer, from BBD without hyperplasia to high-grade CIS, were studied. Results were compared with ERalpha and Ki67 immunostaining. The percentage of ERbeta-positive cells was high (median, 85%) in "normal" mammary glands and in nonproliferative BBD and decreased significantly (P < 0.0001) in proliferative BBD without atypia and in CIS, contrasting with an inverse progression for the ERalpha level. In normal mammary glands, the ERbeta level did not vary according to the nature of the lesion at the periphery and was significantly higher (P < 0.007) than in adjacent preinvasive lesions, except in nonproliferative BBD. The ERbeta level decreased in proliferative BBD, anticipating the ERalpha increase, which was significant in BBD with atypia. In high-grade ductal carcinoma in situ, both ER levels were low. The ratio between ERbeta and ERalpha was high in normal glands, and decreased significantly in proliferative lesions. ERbeta staining was inversely correlated with Ki67 (r = -0.333; P < 0.001), more particularly in high-grade ductal carcinoma in situ (r = -0.57; P < 0.02). The marked and early decreased level of ERbeta protein associated with other criteria of cell proliferation suggests a protective effect of ERbeta against the mitogenic activity of estrogens in mammary premalignant lesions. Knowledge of the ERbeta and ERalpha content in each preinvasive lesion should help to rationalize antiestrogen preventive therapy adapted to each individual patient.     

Reactivity of monoclonal antibody DF3 with a high molecular weight antigen expressed in human ovarian carcinomas

We have previously described the monoclonal antibody (MAb) DF3, prepared against a human breast carcinoma. MAb DF3 reacts with a high molecular weight glycoprotein detectable in human breast carcinomas and in human milk. Previous studies have demonstrated that DF3 antigen levels are elevated in the plasma of patients with breast and ovarian cancer. The present study has further examined the reactivity of MAb DF3 with human ovarian carcinomas. Immunoperoxidase staining demonstrated reactivity of MAb DF3 with 95% of benign, borderline, and malignant tumors (serous, mucinous, and endometrioid) of the ovary. Furthermore, malignant tumors contained cytoplasmic DF3 antigen while benign tumors expressed the antigen only on apical surfaces. Western blot analyses demonstrated that the MAb DF3 reactive ovarian antigen (DF3-O) was a glycoprotein with a heterogenous molecular weight ranging between 300,000 and 450,000. This antigen was detectable by immunofluorescence on the cell surface of five of six cultured human ovarian carcinoma cell lines. The extent of cell surface reactivity with MAb DF3 was equivalent to or greater than that obtained with MAb OC125, an antibody generated against coelomic epithelium and developmental amnion. Furthermore, uptake of 125I-labeled MAb DF3 by human ovarian carcinoma xenografts in athymic mice was 5.4- and 6.2-fold higher than the respective uptake noted in liver and control tumor (P = 0.031). These findings suggest that DF3-O antigen is similar if not identical to the antigen detected in human breast carcinomas by MAb DF3. Thus, MAb DF3 may be a useful reagent in immunodiagnostic evaluation of patients with ovarian cancer.     

The expression of Fhit protein is related inversely to disease progression in patients with breast carcinoma

BACKGROUND: The FHIT gene, located at human chromosome 3p14.2, frequently is deleted in a number of human tumors, including breast carcinoma. Its protein product (Fhit) is presumed to have tumor suppressor function. Loss of expression of a tumor suppressor gene is an important step in tumor progression from premalignant, to in situ, to invasive carcinoma. METHODS: In the current study, Fhit expression was examined in invasive carcinomas and in epithelial lesions representing stages of carcinoma progression in 50 mastectomy specimens using immunohistochemical methods. RESULTS: Normal ductal and lobular epithelium consistently and strongly expressed Fhit. A complete loss of or a significant reduction in Fhit expression was observed in 72% of breast carcinomas. A statistically significant, negative correlation in Fhit expression among the stages of disease progression in Fhit negative breast carcinomas was observed (normal epithelium > hyperplasia > atypical hyperplasia and carcinoma in situ > invasive carcinoma), whereas no loss of Fhit expression in precursor lesions was observed in Fhit positive tumors. CONCLUSIONS: These observations are consistent with the observed role of FHIT as a tumor suppressor gene in the pathogenesis of specific subsets of carcinomas.     

Mammary cancer antigen recognized by monoclonal antibody B72.3 in apocrine metaplasia of the human breast

Monoclonal antibody B72.3 recognizing a pan-associated carcinoma antigen expressed also in metastatic human breast cancer cells has been tested using the avidin-biotin peroxidase method applied to paraffin-embedded sections in 50 samples of mammary tissue showing apocrine metaplasia and in 58 cases of other mild or severe focal epithelial proliferative changes of the breast, including mostly in situ lobular or ductal carcinomas collateral to clinical cancer removed after radical mastectomy. The antigen detected by this antibody was present in the apocrine cells of 48 cases (96%). In the majority of these cases the reactivity was localized on the luminal border of the apocrine cells and in the luminal secretion. But ten cases showed positive staining also in the cell cytoplasm either focal or diffuse. The normal structures and mild focal hyperplastic changes collateral to clinical cancer were, in the majority of the cases (43 of 55), negative, and, when positive, displayed positivity only at the luminal border. By contrast, the independent foci of in situ carcinoma (17 of 31 examined), the intraduct papillomas (seven cases of 14), and the intraductal component of breast carcinoma (seven cases of 17) were positive, displaying a cytoplasmic focal or diffuse staining. In conclusion, mammary apocrine metaplasia, a metaplastic change of the normal epithelium that has been associated with increased breast cancer risk, shares antigens in common with breast cancer cells and/or with cells showing severe atypia. The possible clinical significance of the site of antigenic expression (cytoplasm or luminal border) needs further investigation.     

Immunohistochemical differentiation of atypical hyperplasia vs. carcinoma in situ of the breast.

The distinction between atypical hyperplasia and carcinoma in situ in breast lesions can be difficult. The identification of myoepithelial cell layers may be helpful in establishing a diagnosis of proliferative breast disease vs. intraepithelial neoplasia. We reviewed pathologic material on 20 cases of atypical hyperplasia and 29 cases of carcinoma in situ. Immunohistochemical stains were employed against muscle-specific actin, S-100 protein, and cytokeratin to identify myoepithelial cells and to recognize different staining patterns. In atypical hyperplasia, muscle-specific actin staining identified myoepithelial cells in fine branching fibrovascular layers or as scattered cells between other proliferating cells. This pattern was absent in carcinoma in situ. S-100 protein showed more positive staining in atypical hyperplasia than in carcinoma in situ with patterns distinct from muscle-specific actin. Immunostaining for cytokeratin demonstrated distinctly different patterns between the two lesions. This study suggests that muscle-specific actin, S-100 protein, and cytokeratin in combination may assist in distinguishing proliferative breast disease with atypia from carcinoma in situ.     

Progression risk of columnar cell lesions of the breast diagnosed in core needle biopsies

Columnar cell lesions (CCLs) of the breast are recognized as putative precursor lesions of invasive carcinoma, but their management remains controversial. We therefore conducted a retrospective study on 311 CCLs, diagnosed in 4,164 14-gauge core needle biopsies (CNB): 221 CCLs without atypia (CCL), 69 with atypia (CCL-A), and 21 atypical ductal hyperplasias originating in CCL (ADH-CCL). Two groups were identified: "immediate treatment" group undergoing excision within four months after the CNB diagnosis of CCL (N = 52) and the "wait-and-see" group followed up to 8 years (median 3.5 years, N = 259). In 7 of 31 women (22.5%, 1 CCL, 4 CCL-A, 2 ADH-CCL) who underwent immediate surgical excision and were initially biopsied for microcalcifications, ductal carcinoma in situ (DCIS) was present and in 2/31 women (6.5%, 1 CCL, 1 CCL-A) invasive carcinoma. In 2/21 excisions (9.5%, 1 CCL, 1 CCL-A) initially biopsied for a density, DCIS was present and invasive carcinoma in 5/21 excisions (23.8%, 2 CCL, 3 CCL-A). In the wait-and-see group, 9/259 women (3.5%) developed invasive carcinoma, 6 ipsi, and 3 contralaterally. Progression risks of CCL-A and ADH-CCL were 18% and 22%,versus 2% for CCL without atypia (p < 0.001). In conclusion, CCL-A or ADH-CCL in a CNB were associated with a high risk of DCIS/invasive carcinoma in immediate surgical excision biopsies. The 8-years progression risks for CCL-A and ADH-CCL were around 20%. This illustrates that an atypical CCL in a CNB may signal the presence of concurrent lesions or development of advanced lesions in future and may justify ("mini") surgical excision.     

Proliferative, infiltrative, and metastatic activities in colorectal tumors assessed by MIB-1 antibody

MIB-1 antibody staining discriminates the cells in phases other than G0 of the cell cycle. The current study examined the proliferative activity assessed by MIB-1 antibody in colorectal adenoma, primary lesions of colorectal carcinoma (CRC) to investigate the relation between the histologic atypia, the proliferative, infiltrative, and metastatic activities. The MIB-1 antibody positive rate was immunohistologically determined in primary lesions in 311 patients, 22 having adenoma or carcinoma in situ, 207 invasive CRC without distant metastasis, and 82 invasive CRC with distant metastasis. The MIB-1 antibody positive rate was significantly higher in cases of adenoma with severe atypia and carcinoma in situ, showing a close relation between histologic atypia and proliferative activity. Among invasive CRC, the positive rate in poorly differentiated adenocarcinoma and mucinous carcinoma is significantly lower than in well differentiated and moderately differentiated adenocarcinomas. The positive rate was significantly lower in carcinomas with subserosa or deeper invasion than in carcinomas with submucosa or muscularis propria invasion, showing no distinct relation between the proliferative activity and the infiltrative activity. The positive rate of primary lesion was significantly lower in cases with metachronous liver or lung metastasis than in synchronous cases, indicating that metachronous hematogenous metastasis occurs even in cancers with low proliferative activity. The MIB-1 antibody positive rate showed a close relation between histologic atypia and proliferative activity in mucosal colorectal tumors although its relation with infiltrative activity was unclear in invasive CRC. It was apparent that metachronous hematogenous cancer metastasis might take place even in cases with low proliferative activity.     

Quantitative analysis of disturbed cell maturation in dysplastic lesions of the respiratory tract epithelium

Autoradiographic patterns of [3H]thymidine incorporation, nuclear/cytoplasmic ratios (N/C), and the percentage of dark epithelial cells were analyzed in a group of epithelial lesions induced by 7,12-dimethylbenz[a]anthracene (DMBA) in rat tracheal transplants. It was found that similar lesions of different age exhibit the same labeling indices (LIs), therefore the lesions of different age were subsequently pooled in the following groups and studied by high resolution light microscopic autoradiography: squamous metaplasia without or with only mild atypia, squamous metaplasia with moderate atypia, squamous metaplasia with severe atypia, carcinoma in situ, and microinvasive carcinoma. Normal tracheal and esophageal epithelia were also analyzed. Whereas the normal tracheal basal layer exhibited an LI smaller than 1%, a clear difference between the carcinomas (in situ and invasive) on one hand (LI approximately 32%) and all the remaining epithelia on the other hand (LI approximately 18%) was detected. The LIs of the suprabasal cells exhibited a statistically significant difference between the squamous epithelia without atypia (LI approximately 2%) and the group comprising all the atypical lesions (LI approximately 9%). Gradients of increasing N/C (nucleus-cytoplasm ratios) values could be observed as the lesions increased in severity, especially in the middle and surface layers (e.g., in the surface layer regular metaplasia N/C = 0.08, squamous metaplasia with moderate atypia N/C = 0.26, and carcinoma in situ N/C = 0.50). Dark cells were absent in the normal esophageal epithelium, were present in moderate numbers in the basal layer of regular squamous metaplasia (18%), and increased markedly in the atypical epithelial lesions (approximately 50% in the atypical squamous metaplasias and 70% in carcinoma in situ). In the suprabasal layer dark cells increased from 3% in squamous metaplasia with moderate atypia to 28% in metaplasia with severe atypia and 56% in carcinoma in situ. The results confirm in a quantitative fashion that disturbances of cell maturation and cell proliferation are key features of dysplastic lesions induced by chemical carcinogens, and suggest the use of objective parameters for evaluation and classification of preneoplastic alterations.     

Clonal chromosome-aberrations in fibrocystic breast disease-associated with increased risk of cancer

Short-term cultures of 29 samples of fibrocystic breast disease were cytogenetically analyzed. Clonal chromosome aberrations were found in six specimens, whereas the remaining 23 had a normal karyotype. Three of the abnormal samples displayed karyotypic anomalies previously associated with breast cancer, i.e., gain of Iq, trisomy 18 and cytogenetic multiclonality. Furthermore, all cytogenetically aberrant specimens had either proliferative disease without atypia or atypical hyperplasia, features of fibrocystic disease considered risk factors for subsequent breast cancer development. The cytogenetic similarities between breast carcinomas and proliferative fibrocystic breast disease add further support for classifying certain types of fibrocystic disease as a premalignant condition. Whether cytogenetically abnormal fibrocystic lesions are the ones that subsequently progress to cancer remains to be elucidated.     

The ABO(H) cell surface antigens in carcinoma and benign lesions of the breast

The ABO(H) cell surface antigens of 13 breast carcinomas and 17 benign breast lesions were tested with a specific red cell adherence assay (SRCA). All 13 breat carcinomas, including 2 lobular carcinomas in situ and 1 noninfiltrating ductal carcinoma, had lost their ABO(H) surface antigens. Fourteen of 17 benign breast lesions had retained their ABO(H) surface antigens. The benign lesions losing their antigens were 1 case each of atypical intraductal hyperplasia, sclerosing adenosis, and intraductal papilloma. SRCA may be a predictor of which benign breast lesions are in fact premalignant.     

Immunohistochemical studies of early breast cancer evolution

Summary Despite modern therapy, one third to one half of patients who get breast cancer will eventually die from it. This disconcerting circumstance has focused attention on prevention, and preventing breast cancer will require a much better understanding of the biological abnormalities underlying its development and progression. Many studies into the mechanisms of invasive breast cancer evolution have evaluated presumed precursor lesions (e.g. proliferative disease without atypia, atypical ductal hyperplasia, and ductal carcinoma in-situ) for genetic alterations known to occur in fully developed invasive carcinomas. This approach has shed some light on events which may be important in early malignant transformation, including the observations that overexpression of the c-erbB-2 oncogene and mutations of the p53 tumor suppressor gene are present in significant subsets of DCIS, but not PDWA or ADH. Although this approach is limited by our incomplete knowledge of cancer genetics, there is still a great deal to learn about breast cancer evolution by evaluating cancer-associated genes in potential precursor lesions using established techniques such as immunohistochemistry and in situ hybridization.     

Characterization of breast precancerous lesions and myoepithelial hyperplasia in sclerosing adenosis with apocrine metaplasia

The identification as well as the molecular characterization of breast precancerous lesions in terms of increased risk of progression and/or recurrence is becoming a critical issue today as improved non‐surgical procedures are detecting cancer at an earlier stage. The strategy we have been pursuing to identify early apocrine breast lesions is based on the postulate that invasive apocrine carcinomas evolve from epithelial cells in terminal duct lobular units (TDLUs) in a stepwise manner that involves apocrine metaplasia of normal breast epithelia, hyperplasia, atypia, and apocrine carcinoma in situ. First, we identify specific protein biomarkers for benign apocrine metaplasia and thereafter we search for biomarkers that are highly overexpressed by pure invasive apocrine carcinomas. Here we present studies in which we have used antibodies against components of a benign apocrine signature that includes 15‐prostaglandin dehydrogenase (15‐PGDH), a protein that is expressed by all benign apocrine lesions, and markers that are highly overexpressed by pure invasive apocrine carcinomas such as MRP14 (S100A9), psoriasin (S100A7), and p53 to identify precancerous lesions in sclerosing adenosis (SA) with apocrine metaplasia. The latter is a benign proliferative lesion of the breast that exhibits an increase in the size of the TDLUs and characterized by retained two‐cell lining, and myoepithelial (ME) and stromal hyperplasia. SA with apocrine metaplasia, i.e. apocrine adenosis (AA), presents with a higher degree of atypical apocrine hyperplasia, and these lesions are believed to be precursors of apocrine carcinoma, in situ and invasive. Analysis of 24 selected SA samples with apocrine metaplasia revealed non‐obligate putative apocrine precancerous lesions that displayed some, or in same cases all the three markers associated with pure invasive apocrine carcinomas. These studies also revealed p53 positive, non‐apocrine putative precancerous lesions as well as novel phenotypes for ME and some luminal cells characterized by the expression of cytokeratin 15.     

Clinicopathological significance of stromal myofibroblasts in invasive ductal carcinoma of the breast.

The purpose of this study was to investigate the distribution of CD34-positive fibroblasts and alpha-smooth muscle actin (alpha-SMA)-reactive myofibroblasts in the stroma of benign and malignant breast lesions and, secondly, to determine whether the presence of stromal myofibroblasts is associated with some of the clinicopathological characteristics of patients with invasive ductal carcinoma. The presence of stromal CD34-positive fibroblasts and myofibroblasts was investigated (as defined immunohistochemically) in 8 normal breast tissue samples, 58 invasive ductal carcinomas, 9 ductal carcinomas in situ and 16 specimens with benign lesions of the breast (fibroadenomas, ductal hyperplasias). We further studied the correlations between the presence of stromal myofibroblasts with 7 clinicopathological parameters in 58 invasive ductal carcinomas. The results indicated that the stroma of normal breast tissues contained CD34-positive fibroblasts. All benign breast lesions exhibited stromal CD34-positive fibroblasts. In contrast, the stroma of ductal carcinomas showed a complete loss of CD34-positive fibroblasts. alpha-SMA expression in stromal fibroblasts (myofibroblasts) was not detected in normal tissue samples or benign lesions except in 1 case of fibroadenoma, whereas positive myofibroblasts were found in 44.4% of ductal carcinomas in situ and 56.9% of invasive breast carcinomas. Comparison of clinicopathological parameters between invasive ductal carcinomas with and without stromal myofibroblasts revealed significant differences in lymph node metastasis, high histological grade and high microvessel density. These results suggest that CD34 loss and the presence of myofibroblasts favor the diagnosis of breast carcinoma. In invasive ductal carcinoma, the presence of stromal myofibroblasts correlated significantly with pathological parameters associated with a poor prognosis.     

Endothelin-1, Endothelin-A- and Endothelin-B-receptor expression in preinvasive and invasive breast disease

Endothelin-1 (ET-1) is overexpressed in breast carcinomas and influences via its receptors (ETAR and ETBR) transformation, differentiation and growth processes in the human breast, but little is known about the ET expression in breast cancer precursors. On this basis we evaluated the expression of ET-1, ETAR and ETBR in a series of breast carcinomas, ductal (DCIS) and lobular carcinoma in situ (LCIS) and normal breast tissue by immunohistochemical (IH) methods. IH staining of ET-1, ETAR and ETBR was performed in 88 invasive breast carcinomas, with adjacent carcinoma in situ and concomitant normal breast tissue. Moderate or strong cytoplasmic immunostaining was observed for ET-1 in 33.3%, for ETAR in 45.3% and for ETBR in 55.7% of invasive breast carcinomas. Comparative analysis of invasive cancer (CA), concomitant carcinoma in situ (CIS) and normal breast epithelium (NBE) revealed a stepwise increase of ET-1 and ETAR expression in the sequence NBE < CIS < CA. ETBR expression tended to be slightly higher in CIS than in CA (NBE versus CIS and NBE versus CA, for ETAR and ETBR, p<0.001, respectively; NBE versus CA for ET-1, p=0.035). Our data suggest that the expression of ET-1, ETAR and ETBR correlates with the acquisition of malignant potential and may be used as a prognostic indicator of aggressive behaviour and invasive potential of premalignant breast lesions.     

17-beta-hydroxysteroid dehydrogenase in human breast and endometrial carcinoma. A new development in intracrinology

Intratumoral metabolism and synthesis of estrogens are considered to play very important roles in the pathogenesis and development of various sex steroid-dependent neoplasms including breast and endometrial carcinoma. 17 beta-Hydroxysteroid dehydrogenase (17 beta-HSD) isozymes catalyze the interconversion of estradiol (E(2)) and estrone (E(1)), and thereby serve to modulate the tissue levels of bioactive E(2). 17 beta-HSD type 1 primarily catalyzes the reduction of E(1) to E(2), whereas 17 beta-HSD type 2 primarily catalyzes the oxidation of E(2) to E(1). In the human breast and its disorders, 17 beta-HSD type 1 is expressed in proliferative diseases without atypia, atypical ductal hyperplasia, ductal carcinoma in situ and invasive ductal carcinoma. 17 beta-HSD type 2 is not detected in any of the lesions. In addition, 17 beta-HSD type 1 coexpression is significantly correlated with estrogen receptor status in invasive ductal carcinoma cases. These results indicate that breast carcinoma can effectively convert E(1), produced as a result of in situ aromatization, to E(2), a biologically potent estrogen, and exerts estrogenic actions on tumor cells through the estrogen receptor. On the other hand, in the human endometrium, 17 beta-HSD type 2 is expressed, but not 17 beta-HSD type 1. 17 beta-HSD type 2 is expressed in the secretory phase but not in any proliferative phase in the endometrial mucosa. The enzyme is expressed in 75% of endometrial hyperplasias and 37% of carcinoma cases. In endometrial carcinoma cases, a significant inverse correlation has been detected between 17 beta-HSD type 2 immunoreactivity and age (p < 0.02). These results indicate that oxidation of E(2) to E(1) is dominant in endometrial carcinoma, 17 beta-HSD types 1 and 2 play an important role in the regulation of in situ estrogen production in breast and endometrial carcinoma.     

Biopsy confirmed benign breast disease, postmenopausal use of exogenous female hormones, and breast carcinoma risk

BACKGROUND: A history of proliferative benign breast disease has been shown to increase the risk of developing breast carcinoma, but, to the authors' knowledge, how postmenopausal exogenous female hormone use, in general, has affected breast carcinoma risk among women with a history of proliferative breast disease with or without atypia has not been well established. METHODS: In the current case-control study, nested within the Nurses' Health Study, benign breast biopsy slides of 133 postmenopausal breast carcinoma cases and 610 controls with a history of benign breast disease, were reviewed. Reviewers had no knowledge of case status. RESULTS: Women with proliferative disease without atypia had a relative risk for postmenopausal breast carcinoma of 1.8 (95%, confidence interval [CI]: 1.1 to 2.8), and women with atypical hyperplasia had a relative risk of 3.6 (95%, CI: 2.0 to 6.4) compared with women who had nonproliferative benign histology. Neither current postmenopausal use of exogenous female hormones nor long term use for 5 or more years further increased the risk of breast carcinoma in the study population beyond that already associated with their benign histology. CONCLUSIONS: Women who had proliferative benign breast disease, with or without atypia, were at moderately to substantially increased risk of developing postmenopausal breast carcinoma compared with women who had nonproliferative benign conditions. In the current study, postmenopausal exogenous female hormone use in general did not further increase the breast carcinoma risk for women with proliferative benign breast disease. However, the analysis did not exclude the possibility of increased risk with a particular hormone combination or dosage.