Molecularly Confirmed Female Donor-Transmitted Lobular Breast Cancer to Male following Renal Transplantation.

INTRODUCTION: Lobular breast cancer represents 10%-15% of breast cancers in women but is virtually nonexistent in men, related to the typical absence of the anatomic breast lobule structure in male breast tissue. We describe donor-transmitted metastatic lobular carcinoma to a male after kidney transplantation. Determining whether a post-transplant cancer is transplant associated, donor transmitted, or donor derived is significant for treatment, prognosis, and possibly management of other organ recipients. CASE REPORT: A 74-year-old Caucasian male presented to the emergency department with lower abdominal pain and macro-hematuria. Past medical history included two renal transplantations. Computed tomography identified a 4-5-cm space-occupying lesion in the native left kidney. A left native nephrectomy was performed. Histology pathologic examination demonstrated lobular (as opposed to ductal) breast carcinoma. Fluorescent in situ hybridization probes to identify X- and Y-chromosomes showed tumor cells with an XX genotype, whereas the surrounding host cells were of XY genotype. These findings confirmed the female-sex origin (donor) of the tumor within the XY native male (current patient) tissues. DISCUSSION/CONCLUSION: Due to discordance between the donor and recipient sex, fluorescent in situ hybridization as a molecular technique correctly identified the origin of an individual's cancer in the post-transplant setting. The metastatic breast cancer behaved more indolently than usually seen. Expanded criteria donors (ECD) are those who cannot donate under standard criteria for organ transplantation; expanded criteria widen the potential organ donor pool at the expense of increased risk for post-transplant complications (e.g., graft failure, the transmission of malignancy). The case provides a potential area of future research into considering allowing ECDs with a distant history of cancer with very low transmission risk when the biochemical environment of the recipient would, in the unlikely event of transmission, induce the tumor to pursue an indolent clinical course.

Targetable alterations in invasive pleomorphic lobular carcinoma of the breast.

BACKGROUND: Invasive pleomorphic lobular carcinoma (PLC) of the breast is a subtype of invasive lobular cancer which compromises approximately 1% of all epithelial breast malignancies and is characterized by higher nuclear pleomorphism and poorer prognosis than classic invasive lobular cancer (ILC). Since PLC is more aggressive than classical ILC, we examined the underlying molecular alterations in this subtype of breast cancer to understand the possible benefit from targeted therapies. METHODS: In this study, we investigate the clinical characteristics and molecular alterations in 16 PLC from our institution. Additionally, we examined the clinical and genomic features in 31 PLC from the Cancer Genome Atlas (TCGA). RESULTS: Overall, our analysis of PLC found that 28% had activating ERBB2 mutations, 21% had ERBB2 amplification, and 49% activating PIK3CA mutations. Among cases from our institution, we found 19% with activating ERBB2 mutations, 25% had ERBB2 amplification, and 38% with activating PIK3CA mutations. In data from TCGA, 32% had activating ERBB2 mutations, 19% had ERBB2 amplification, and 55% had activating PIK3CA mutations. While classic ILC in TCGA had similar percentages of PIK3CA alterations compared to PLC, activating ERBB2 alterations were exceedingly rare, with no activating ERBB2 mutations and only one case with ERBB2 amplification. Interestingly, in further examining TCGA data which included FGFR1 and PTEN, 94% of PLC had alterations in ERBB2, FGFR1, or the PI3K pathway. CONCLUSIONS: Our results show a high frequency of ERBB2 and PIK3CA alterations in PLC and suggest all PLC should be tested for potential therapeutic targeting.

Invasive lobular carcinoma of the breast: the increasing importance of this special subtype.

Invasive lobular carcinoma (ILC) is the most common of the breast cancer special types, accounting for up to 15% of all breast cancer cases. ILCs are noted for their lack of E-cadherin function, which underpins their characteristic discohesive growth pattern, with cells arranged in single file and dispersed throughout the stroma. Typically, tumours are luminal in molecular subtype, being oestrogen and progesterone receptor positive, and HER2 negative. Since last reviewing the lobular literature (McCart Reed et al., Breast Cancer Res 17:12, 2015), there has been a considerable increase in research output focused on this tumour type, including studies into the pathology and management of disease, a high-resolution definition of the genomic landscape of tumours as well as the evolution of several potential therapeutic avenues. There abounds a huge amount of new data, which we will review herein.

Synchronous bilateral breast cancer: a nationwide study on histopathology and etiology.

PURPOSE: The aim of the present study was to describe histopathologic characteristics of synchronous bilateral breast cancer (SBBC), and by comparing SBBC to unilateral breast cancer (UBC), identify possible etiological mechanisms of SBBC. METHODS: Patients with primary SBBC (diagnosed within 4 months) and UBC diagnosed in Denmark between 1999 and 2015 were included. Detailed data on histopathology were retrieved from the Danish Breast Cancer Group database and the Danish Pathology Register. Associations between bilateral disease and the different histopathologic characteristics were evaluated by odds ratios and estimated by multinomial regression models. RESULTS: 1214 patients with SBBC and 59,221 with UBC were included. Patients with SBBC more often had invasive lobular carcinomas (OR 1.29; 95% CI 1.13-1.47), a clinically distinct subtype of breast cancer, than UBC patients. Further, they were older than UBC patients, more often had multifocal cancer (OR 1.13; 95% CI 1.01-1.26), and a less aggressive subtype than UBC patients. Invasive lobular carcinoma was associated with having multiple tumors in breast tissue-both in the form of bilateral disease and multifocal disease, and this association was independent of laterality. No similar pattern was observed for other tumor characteristics. CONCLUSION: We identified two etiological mechanisms that could explain some of the occurrence of SBBC. The high proportion of less aggressive carcinomas and higher age of SBBC compared to UBC patients suggests that many are diagnosed at a subclinical stage as slow-growing tumors have a higher probability of simultaneous diagnosis. The high proportion of invasive lobular carcinoma observed in bilateral and multifocal disease, being independent of laterality, suggests that these patients have an increased propensity to malignant tumor formation in breast tissue.

Heterogeneity in risk factors for ductal and lobular breast carcinomas: A case-control study.

Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) of the breast are the most common histological subtypes of breast cancer. However, the associations and heterogeneity between histological subtypes and their risk factors are not well established. This study aimed to investigate risk factors for IDC and ILC. This case-control study included 1,009 incident breast cancer cases and 1,009 hospital controls, frequency-matched by age. Data were obtained from the patients' medical files and an interview administered via a questionnaire. Multinomial logistic regression was used and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The heterogeneity of the associations was assessed using the Wald test. Family history of breast cancer was associated with IDC (OR 2.64, 95% CI: 1.97-3.55) but not ILC (OR 0.81, 95% CI: 0.42-1.57; p for heterogeneity <0.001). Conversely, a history of miscarriage was associated with ILC (OR 1.71, 95% CI: 1.17-2.51) but not IDC (OR 1.18, 95% CI: 0.95-1.46; p for heterogeneity = 0.04). Similarly, type 2 diabetes was associated with ILC but not IDC (p for heterogeneity = 0.02). Age at first delivery and breastfeeding were significantly associated with IDC but not ILC, though p values for heterogeneity did not reach the significance level. Deliberate weight loss and age at menarche were significantly associated with ILC but not IDC (p for heterogeneity ≥0.27). Smoking, history of benign breast disease and BMI were associated with both subtypes. The present study supports the hypothesis that IDC and ILC are etiologically distinct tumours.

Breast cancer and thyroid diseases: analysis of 867 consecutive cases.

INTRODUCTION: The aim of this study was to evaluate the association of breast cancer with thyroid diseases. Many authors have already studied the possible relationship between these two diseases, but the results are nowadays conflicting. MATERIALS AND METHODS: Our study examining 867 patients with breast cancer (862 women and 5 men, average age = 61 years old) of whom 141 also had thyroid disease evaluated the recurrence of thyroid diseases and their association with different types of breast cancer. Statistical analyses were performed using SPSS software for Windows; we used nonparametric tests (Chi-square and Mann-Whitney), and the level of significance was set at p < 0.05. RESULTS: We found a significant association between breast cancer diagnosed after menopause and thyroid disease (p < 0.003). Moreover, we analyzed the role of thyroid autoimmunity identifying an association between chronic autoimmune thyroiditis and breast cancer diagnosed before menopause (p < 0.05). Regarding receptor profile of breast carcinoma, we have found an increased expression of estrogen receptors in patients with autoimmune thyroiditis compared to patients with any other thyroid diseases (p < 0.03). Contrariwise, we do not have found any difference between the group with every thyroid disease and the group without thyroid disease (p < 1.00). We did not find other statistically significant associations with breast cancer's parameters like family history, tumor size, lymph node metastasis, distant metastasis, cancer clinical and pathological stage, differentiation grade and expression of Ki67, p53 and Her2 in the two main groups with or without thyroid disease. Likewise, we did not found other statistically significant association between hypothyroidism or hyperthyroidism and breast cancer.

Lobular breast cancer: incidence and genetic and non-genetic risk factors.

While most invasive breast cancers consist of carcinomas of the ductal type, about 10% are invasive lobular carcinomas. Invasive lobular and ductal carcinomas differ with respect to risk factors. Invasive lobular carcinoma is more strongly associated with exposure to female hormones, and therefore its incidence is more subject to variation. This is illustrated by US figures during the 1987 to 2004 period: after 12 years of increases, breast cancer incidence declined steadily from 1999 to 2004, reflecting among other causes the decreasing use of menopausal hormone therapy, and these variations were stronger for invasive lobular than for invasive ductal carcinoma. Similarly, invasive lobular carcinoma is more strongly associated with early menarche, late menopause and late age at first birth. As for genetic risk factors, four high-penetrance genes are tested in clinical practice when genetic susceptibility to breast cancer is suspected, BRCA1, BRCA2, TP53 and CDH1. Germline mutations in BRCA1 and TP53 are predominantly associated with invasive ductal carcinoma, while BRCA2 mutations are associated with both ductal and lobular cancers. CDH1, the gene coding for the E-cadherin adhesion protein, is of special interest as mutations are associated with invasive lobular carcinoma, but never with ductal carcinoma. It was initially known as the main susceptibility gene for gastric cancer of the diffuse type, but the excess of breast cancers of the lobular type in CDH1 families led researchers to identify it also as a susceptibility gene for invasive lobular carcinoma. The risk of invasive lobular carcinoma is high in female mutation carriers, as about 50% are expected to develop the disease. Carriers must therefore undergo intensive breast cancer screening, with, for example, yearly magnetic resonance imaging and mammogram starting at age 30 years.

Lobular breast cancer: molecular basis, mouse and cellular models.

Infiltrating lobular breast cancer (ILC) is the most common special breast cancer subtype. With mutational or epigenetic inactivation of the cell adhesion molecule E-cadherin (CDH1) being confined almost exclusively to ILC, this tumor entity stands out from all other types of breast cancers. The molecular basis of ILC is linked to loss of E-cadherin, as evidenced by human CDH1 germline mutations and conditional knockout mouse models. A better understanding of ILC beyond the level of descriptive studies depends on physiologically relevant and functional tools. This review provides a detailed overview on ILC models, including well-characterized cell lines, xenograft tumors and genetically engineered mouse models. We consider advantages and limitations of these models and evaluate their representativeness for human ILC. The still incompletely defined mechanisms by which loss of E-cadherin drives malignant transformation are discussed based on recent findings in these models. Moreover, candidate genes and signaling pathways potentially involved in ILC development and progression as well as anticancer drug and endocrine resistance are highlighted.

Variation in Breast Cancer-Risk Factor Associations by Method of Detection: Results From a Series of Case-Control Studies.

Concerns about breast cancer overdiagnosis have increased the need to understand how cancers detected through screening mammography differ from those first detected by a woman or her clinician. We investigated risk factor associations for invasive breast cancer by method of detection within a series of case-control studies (1992-2007) carried out in Wisconsin, Massachusetts, and New Hampshire (n=15,648 invasive breast cancer patients and 17,602 controls aged 40-79 years). Approximately half of case women reported that their cancer had been detected by mammographic screening and half that they or their clinician had detected it. In polytomous logistic regression models, parity and age at first birth were more strongly associated with risk of mammography-detected breast cancer than with risk of woman/clinician-detected breast cancer (P≤0.01; adjusted for mammography utilization). Among postmenopausal women, estrogen-progestin hormone use was predominantly associated with risk of woman/clinician-detected breast cancer (odds ratio (OR)=1.49, 95% confidence interval (CI): 1.29, 1.72), whereas obesity was predominantly associated with risk of mammography-detected breast cancer (OR=1.72, 95% CI: 1.54, 1.92). Among regularly screened premenopausal women, obesity was not associated with increased risk of mammography-detected breast cancer (OR=0.99, 95% CI: 0.83, 1.18), but it was associated with reduced risk of woman/clinician-detected breast cancer (OR=0.53, 95% CI: 0.43, 0.64). These findings indicate important differences in breast cancer risk factors according to method of detection.

The risk of breast cancer associated with specific patterns of migraine history.

PURPOSE: Studies have suggested that a history of migraines may be associated with a lower risk of some types of breast cancer, though biological mechanisms are unclear. Identifying specific characteristics of migraines which are most strongly associated with breast cancer risk could improve our understanding of this relationship. METHODS: We ascertained specific characteristics of women's migraine histories (severity, timing features, and presence of migraine aura). We used polytomous logistic regression to estimate the risk of ER+ ductal, ER- ductal, ER+ lobular, and ER+ ductal-lobular breast cancer associated with self-reported characteristics of migraine history. A total of 715 breast cancer cases (276 ER+ ductal, 46 ER- ductal, 191 ER+ lobular, and 202 ER+ ductal-lobular) and 376 controls ages 55-74 years were included in this population-based case-control study. RESULTS: Compared to women without a migraine history, women with a >30-year history of migraines had a 60 % (95 % CI 0.2-0.6) lower risk of ER+ ductal breast cancer; those who had their first migraine before age 20 had 50 % lower risks of ER+ ductal and ER+ lobular breast cancer (both 95 % CIs 0.3-0.9), and women who experienced migraine with aura had 30 % (95 % CI 0.5-0.98) and 40 % (95 % CI 0.4-0.9) lower risks of ER+ ductal and ER+ lobular breast cancer, respectively. CONCLUSION: The lower risk of ER+ breast cancer associated with migraine appears to be limited to those women with early onset or long duration of migraine history, or those who experienced migraine with aura. This expands our understanding of the relationship between migraine and breast cancer and provides additional insight into potential underlying biological mechanisms.

Is There a Special Role for Ovarian Hormones in the Pathogenesis of Lobular Carcinoma?

Lobular carcinoma represent the most common special histological subtype of breast cancer, with the majority classed as hormone receptor positive. Rates of invasive lobular carcinoma in postmenopausal women have been seen to increase globally, while other hormone receptor-positive breast cancers proportionally have not followed the same trend. This has been linked to exposure to exogenous ovarian hormones such as hormone replacement therapy. Reproductive factors resulting in increased lifetime exposure to endogenous ovarian hormones have also been linked to an increased risk of lobular breast cancer, and taken together, these data make a case for the role of ovarian hormones in the genesis and progression of the disease. In this review, we summarize current understanding of the epidemiological associations between ovarian hormones and lobular breast cancer and highlight mechanistic links that may underpin the etiology and biology.

Breast cancer in systemic lupus erythematosus.

OBJECTIVE: Evidence points to a decreased breast cancer risk in systemic lupus erythematosus (SLE). We analyzed data from a large multisite SLE cohort, linked to cancer registries. METHODS: Information on age, SLE duration, cancer date, and histology was available. We analyzed information on histological type and performed multivariate logistic regression analyses of histological types according to age, SLE duration, and calendar year. RESULTS: We studied 180 breast cancers in the SLE cohort. Of the 155 cases with histology information, 11 were referred to simply as 'carcinoma not otherwise specified'. In the remaining 144 breast cancers, the most common histological type was ductal carcinoma (n = 95; 66%) followed by lobular adenocarcinoma (n = 11; 8%), 15 cancers were of mixed histology, and the remaining ones were special types. In our regression analyses, the independent risk factors for lobular versus ductal carcinoma was age [odds ratio (OR) 1.07, 95% confidence interval (CI) 1.01-1.14] and for the 'special' subtypes it was age (OR 1.06, 95% CI 1.01-1.10) and SLE duration (OR 1.05, 95% CI 1.00-1.11). CONCLUSIONS: Generally, up to 80% of breast cancers are ductal carcinomas. Though our results are not definitive, in the breast cancers that occur in SLE, there may be a slight decrease in the ductal histological type. In our analyses, age and SLE duration were independent predictors of histological status.

Adherence to a western dietary pattern and risk of invasive ductal and lobular breast carcinomas: a case-control study.

Little is known about the role of diet in the risk of invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) of the breast, the most common histological subtypes of breast cancer (BC). This is because, the majority of studies on the association of diet and the risk of BC are focused on single food items, and studies considering the overall diet in terms of dietary patterns are limited. Also, the potential heterogeneity in the impact of Western diet (WD) on histological subtypes of BC is not established. This, the age-frequency-matched case-control study included 1009 incident BC cases and 1009 healthy controls. The required data was obtained from the patients' medical files and interviews using a previously validated researcher-designed questionnaire for collecting data on socio-economic and anthropometric statuses and a valid food frequency questionnaire (FFQ) to measure the participants' dietary intake. We used multinomial logistic regression, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. A positive and significant association was observed between higher adherence to a WD and risk of IDC (OR comparing highest with the lowest tertile: 2.45, 95% CI 1.88, 3.17; p-trend < 0.001), whereas no significant association was observed between adherence to the WD and the risk of ILC (OR comparing highest with the lowest tertile: 1.63, 95% CI 0.63, 3.25) (p for heterogeneity = 0.03). The results of an analysis stratified by menopausal status suggested a similar pattern. We provided evidence that adherence to a WD raises the risk of IDC, but not ILC, suggesting different etiological mechanisms for IDC and ILC.

Dietary Patterns and Risk of Invasive Ductal and Lobular Breast Carcinomas: A Systematic Review and Meta-analysis.

The histopathologic subtypes of breast cancer, including invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC), differ in terms of risk factors, progression, and response to treatment. The PubMed/Medline, Web of Science, and Scopus databases were searched up to February 2020 for published studies on the association between dietary patterns (Western diet [WD] or Mediterranean diet [WD]) and the risk of IDC/ILC of breast. Multivariable adjusted relative risk (RR) and 95% confidence intervals (CIs) comparing the highest and lowest categories of WD and MD patterns were combined by using the random-effects meta-analyses. After searching the databases, 10 eligible studies on the association of diet and IDC (7 articles) and ILC (3 articles) were included in the analysis. A statistically significant adverse association was observed between MD and IDC in case-control studies (RR = 0.47; 95% CI, 0.39-0.55; I2 = 85.1%; P < .001). However, the association was nonsignificant in cohort studies (RR = 0.98; 95% CI, 0.92-1.05; I2 = 88.8%; P = .003). The pooled analysis also suggested a significant and direct association between the WD and the risk of IDC (RR = 1.36; 95% CI, 1.18-1.53; I2 = 63.7%; P = .017). The risk of ILC for the highest compared to the lowest category of MD was highly protective (RR = 0.76; 95% CI, 0.64-0.87; I2 = 89.2%; P < .001), and a marginally significant association was found between the WD and risk of ILC (RR = 1.45; 95% CI, 1.04-1.86), with no heterogeneity (I2 = 0; P = .52). This meta-analysis provides supporting evidence for the association between MD decreased risk of IDC and ILC of the breast and the association between WD and increased risk of IDC and ILC. Further investigations are needed to better understand the reasons behind the etiologic mechanisms of how dietary patterns affect patients differently by common breast cancer subtypes, including IDC and ILC.

Simultaneous Effects of Viral Factors of Human Papilloma Virus and Epstein-Barr Virus on Progression of Breast and Thyroid Cancers: Application of Structural Equation Modeling.

This study aimed to assess effects of the sets of EBV and HPV expressed proteins simultaneously on the sets of cellular/inflammatory factors in breast and thyroid cancers using structural equation modeling. In this multi-center case-control study, according to the inclusion and exclusion criteria, 83 breast and 57 thyroid specimens were collected from the eligible patients. In addition, 31 and 18 histopathological evaluated normal breast and thyroid samples were also examined as age-matched healthy controls. In addition, ELISA and Real-time PCR were used to measure the expression level of viral and cellular/inflammatory genes and proteins. Structural equation modeling was used to test the causal associations between the sets of EBV and HPV expressed proteins with inflammatory factors in breast and thyroid cancers development. Breast cancer patients had a higher incidence of HPV-positively and EBV-positively than healthy controls (OR=1.66, 95%CI=0.79-3.47, P-value=0.177), (OR=3.18, 95%CI=1.52-6.63, P-value=0.002), respectively. In addition, thyroid cancer patients had a significantly higher incidence of EBV-positivity than healthy controls (OR=3.72, 95% CI=1.65-8.36, P-value=0.001). After fitting the SEM model, HPV proteins factor has significant direct and total effects on the cellular/inflammatory factors in breast cancer (direct effect: ß=0.426, P-value=0.01; total effect: ß=0.549, P-value<0.001). However, EBV proteins factor has most significant total effect on the cellular/inflammatory factors in breast cancer (total effect: ß=0.804, P-value<0.001) than the cellular/inflammatory factors in thyroid cancer (total effect: ß=0.789, P-value<0.001). For the first time, a significant association between EBV and HPV -genes, anoikis resistance and the development of breast and thyroid cancers demonstrated by using SEM, Simultaneously.
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Menopausal hormone therapy and risk of clinical breast cancer subtypes.

BACKGROUND: Breast cancer is a heterogeneous disease with subtypes that may vary in their etiologies. Menopausal hormone therapy has been associated more strongly with lobular and tubular than ductal histologic types and with tumors that are smaller, hormone receptor-positive, and of lower grade. At the same time, correlations have been observed between histology and clinical characteristics. To identify those tumor subtypes most strongly associated with hormone therapy use, it is necessary to disentangle these interrelationships. METHODS: Based on 3,464 postmenopausal breast cancer cases and 6,657 controls from the population-based Mammary carcinoma Risk factor Investigation study, we used polytomous logistic regression to evaluate associations between hormone therapy use and risk of invasive breast cancer subtypes. We assessed variations in risk for selected tumor characteristics among histologic and hormone receptor subtypes, both overall and for specific hormone therapy regimens. RESULTS: Lobular and mixed types showed less variation by prognostic factors than did ductal tumors. Current hormone therapy use had the strongest associations with prognostic variables in estrogen receptor (ER)-positive and/or progesterone receptor (PR)-positive ductal tumors and in lobular tumors regardless of ER/PR status, with little effect on ER/PR-negative ductal tumors. The observed associations varied minimally by hormone therapy type or regimen. CONCLUSION: Current hormone therapy use was associated with more favorable breast cancer characteristics for ductal tumors but had less effect on prognostic characteristics in women with lobular tumors. Both histologic type and estrogen receptor/progesterone receptor status seem to be important in explaining the role of hormone therapy in the etiology of breast cancer subtypes.

Breast cancer risk factors in younger and older women.

Information is lacking regarding the interaction of established breast cancer risk factors and patient age. We attempted to study this interaction in high-risk women at the extremes of age in our population. The Women-At-Risk Registry was queried for women who were < or =35 and > or =70 years of age. Enrollment criteria included: strong family history of breast cancer (FHBC), and/or biopsy-proven history of atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), or lobular carcinoma in situ (LCIS). Descriptive analyses and Fisher's exact tests were used to analyze these factors and to assess their influence on breast cancer development. Our population included 1,412 high-risk women with median follow-up of 4 years. Of 195 women < or =35 years, 3 (1.5%) developed breast cancer. All three had strong FHBC and none had a prior high-risk lesion. Of 82 women > or =70 years, 6 (7.3%) developed breast cancer. Mean Gail score for women > or =70 years was 4.3, as compared with 4.7 in the subset of older women diagnosed with cancer. Fisher's tests demonstrated that ADH (p = 0.15), ALH (p = 1.0), LCIS (p = 1.0), and FHBC (p = 1.0) were not associated with breast cancer development in older women. We conclude that, for women < or =35 years, a significant FHBC may be a stronger predictor for breast cancer development than high-risk lesions. For women > or =70 years, FHBC and history of ADH, ALH, and LCIS were not predictors of breast cancer. This study emphasizes the importance of defining age-appropriate recommendations for breast cancer risk management, including surveillance and chemoprevention.

Relationship between menopausal hormone therapy and risk of ductal, lobular, and ductal-lobular breast carcinomas.

Combined estrogen and progestin hormone therapy (CHT) increases breast cancer risk, but this risk varies by breast cancer type. Several studies indicate that CHT is more strongly related to lobular carcinoma risk than to ductal carcinoma risk, but these studies have been limited in their assessments of recency and duration of use, and none included a centralized pathology review. We conducted a population-based case-control study consisting of 324 lobular, 196 ductal-lobular, and 524 ductal cases diagnosed from 2000 to 2004 and 469 controls ages 55 to 74 years old. Tissue specimens were centrally reviewed for 83% of cases. Associations between hormone use and breast cancer risk were evaluated using polytomous logistic regression. Current CHT users had 2.7-fold [95% confidence interval (95% CI), 1.7-4.2] and 3.3-fold (95% CI, 2.0-5.7) elevated risks of lobular and ductal-lobular carcinomas, respectively, regardless of tumor stage, size, or nodal status. Elevations in risk were observed only among users of CHT for > or =3 years. Among ductal-lobular cases, CHT increased risk of tumors that were > or =50% lobular (odds ratio, 4.8; 95% CI, 2.1-11.1) but not tumors that were <50% lobular (odds ratio, 1.9; 95% CI, 0.9-4.1). Current CHT users for > or =3 years have a substantially increased risk of lobular carcinomas. Although lobular carcinomas are less common than ductal carcinomas ( approximately 16% versus 70% of all invasive breast cancers in the United States), this duration is shorter than the 5 years of use widely cited to be needed to confer an increased risk of breast cancer overall. Further studies focusing on the etiology of lobular carcinomas are needed.

Carcinoma originating from aberrant breast tissue. A case report and review of the literature.

Carcinoma arising from ectopic breast tissue, either supernumerary breast or aberrant breast tissue, is extremely rare. Carcinoma occurs more frequently in the ectopic breast tissue of the axilla than in extra-axillary ectopic breast tissue. Here we report a case of an invasive lobular carcinoma arising from extra-axillary ectopic breast tissue and presenting as a subcutaneous nodule.

Relationships between Reproductive Risk Factors for Breast Cancer and Tumor Molecular Subtypes

Background: Due to wide clinical differences in the various pathological types of breast cancer and also close associations between disease prognosis and molecular subtypes, relationships of the latter with traditional risk factors have been suggested. Hence, the present study aimed to assess any associations. Methods: This bi-center cross-sectional study was performed on 800 consecutive women with known breast cancer referred to two Comprehensive Cancer Centers in Tehran between 2006 and 2016. Baseline information related to reproductive risk profiles as well as pathological tumor diagnosis and molecular subtypes determined using immunohistochemical analysis by immune-staining for ER, PR, and HER2 molecules were collected by reviewing hospital records. Results: Of 800 samples included for immunohistochemical analysis, 314 (39.3%) were diagnosed as of Luminal A subtype, 107 (13.4%) as Luminal B subtype, 153 (19.1%) as HER-2 over-expressing, and 226 (28.3%) as triple negative. Among all reproductive risk factors initially assessed, young age was associated with HER-2 over-expression, greater tumor size and a history of abortion with the luminal B subtype, lower age at pregnancy with the luminal A subtype, and lower gravidity and a shorter duration of breastfeeding with the triple negative subtype. Conclusion: Each molecular subtype of breast cancer in our population may be associated with specific reproductive risk factors.