Are prognostic factors more favorable for breast cancer detected by organized screening than by opportunistic screening or clinical diagnosis? A study in Loire-Atlantique (France)

Purpose: Comparisons of breast cancer characteristics between organized and opportunistic screening have been limited. This study was designed to compare characteristics of cancers detected by either organized or opportunistic screening as well as clinically diagnosed cancers in Loire-Atlantique (a French administrative entity), from 2003 to 2007. Methods: This study is based on data from the population-based Loire-Atlantique Cancer Registry. Stage at diagnosis and prognostic characteristics of carcinomas detected by organized screening were compared, by age-adjusted logistic regressions, to those of cancers detected by opportunistic screening and diagnosed clinically. Analyses were restricted to women aged 50–74 years (the age group targeted by the organized screening program) for the 2003–2007 period. Results: Between 2003 and 2007, 2864 invasive and 400 in situ breast cancer cases were diagnosed in women aged 50–74 years in Loire-Atlantique. Compared to cancers diagnosed clinically, cancers detected by organized screening were more likely to be in situ (13.7% vs. 3.8%), diagnosed at an early stage (74.4% vs. 51.3%), have a low SBR grade (grade 1: 35.4% vs. 18.5%), and be positive for estrogen–progesterone receptors (68.3% vs. 59.0%). The distribution of stage at diagnosis and prognostic characteristics between organized and opportunistic screening were similar. Conclusion: These findings are consistent with the hypothesis that breast cancers are detected early by organized screening. Cancer characteristics were similar between the two screening modes. Estimating the impact of mammography screening on mortality in Loire-Atlantique should be the object of further investigations.     

Agreement of self-reported hormone receptor status with cancer registry data in young breast cancer patients

BackgroundThough breast cancer subtype is a key determinant of treatment choice and prognosis, few studies have assessed breast cancer patients’ knowledge of estrogen and progesterone receptor (ER/PR) status.MethodsWomen diagnosed with invasive breast cancer at age 18–64 years in 2007 were recruited from the Pennsylvania Cancer Registry, and mailed a questionnaire that asked respondents to identify their ER/PR status. There were 2191 respondents included in the analysis. Agreement between self-report and cancer registry ER/PR status was assessed using kappa statistic. Logistic regression was used to assess the association of demographic, socioeconomic, and tumor factors with inaccurate self-report of ER/PR status.ResultsFifty-nine percent of respondents reported ER/PR positive status, 15% reported ER/PR negative status, 17% responded ‘don’t know’, and 9% did not respond. Overall, there was 69% agreement between self-report and cancer registry data, and fair agreement as measured by kappa (0.36). After excluding women who did not know or did not report their ER/PR status, there was 93% agreement, and substantial agreement as measured by kappa (0.76). Women who were older, non-white, less educated, lower income, and had ER/PR negative disease were significantly more likely to inaccurately report their ER/PR status.ConclusionsThough a significant proportion of women do not know their hormone receptor status, women who reported their ER/PR status were accurate. Our results suggest room for improvement in patient knowledge of tumor subtypes, but also that self-reported ER/PR status may be a useful surrogate when medical record or cancer registry data is unavailable.     

Breast Cancer Incidence in Black and White Women Stratified by Estrogen and Progesterone Receptor Statuses

Background

There is increasing evidence that breast cancer is a heterogeneous disease presented by different phenotypes and that white women have a higher breast cancer incidence rate, whereas black women have a higher mortality rate. It is also well known that white women have lower incidence rates than black women until approximately age 40, when rate curves cross over and white women have higher rates. The goal of this study was to validate the risk of white and black women to breast cancer phenotypes, stratified by statuses of the estrogen (ER) and progesterone (PR) receptors.

Methodology/Principal Findings

SEER17 data were fractioned by receptor status into [ER+, PR+], [ER−, PR−], [ER+, PR−], and [ER−, PR+] phenotypes. It was shown that in black women compared to white women, cumulative age-specific incidence rates are: (i) smaller for the [ER+, PR+] phenotype; (ii) larger for the [ER−, PR−] and [ER−, PR+] phenotypes; and (iii) almost equal for the [ER+, PR−] phenotype. Clemmesen''s Hook, an undulation unique to women''s breast cancer age-specific incidence rate curves, is shown here to exist in both races only for the [ER+, PR+] phenotype. It was also shown that for all phenotypes, rate curves have additional undulations and that age-specific incidence rates are nearly proportional in all age intervals.

Conclusions/Significance

For black and white women, risk for the [ER+, PR+], [ER−, PR−] and [ER−, PR+] phenotypes are race dependent, while risk for the [ER+, PR−] phenotype is almost independent of race. The processes of carcinogenesis in aging, leading to the development of each of the considered breast cancer phenotypes, are similar in these racial groups. Undulations exhibited on the curves of age-specific incidence rates of the considered breast cancer phenotypes point to the presence of several subtypes (to be determined) of each of these phenotypes.     

Mammographic density and hormone receptor expression in breast cancer: the Multiethnic Cohort Study

Background: It is unclear whether mammographic breast density, a strong risk factor for breast cancer, predicts subtypes of breast cancer defined by estrogen receptor (ER) and/or progesterone receptor (PR) expression. Methods: In a nested case–control study, we compared the breast density of 667 controls and 607 breast cancer cases among women of Caucasian, Japanese, and Native Hawaiian ancestry in the Hawaii component of the Multiethnic Cohort Study. A reader blinded to disease status performed computer assisted density assessment on prediagnostic mammograms. Receptor status was obtained from the statewide Hawaii Tumor Registry. Tumors were classified into ER+PR+ (n = 341), ER−PR− (n = 50), ER+PR−/ER−PR+ (n = 64), and unstaged/unknown (n = 152). Mean percent density values were computed for women with more than one mammogram. Polytomous logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) while adjusting for confounders. Results: Mean percent density was significantly greater for ER+PR+ but not for ER−PR− tumors compared to controls after adjusting for age: 37.3%, 28.9% versus 29.4%, respectively. The overall OR per 10% increase in percent density were similar for ER+PR+ and ER+PR−/ER−PR+ tumors: 1.26 (95% CI 1.17–1.36) and 1.23 (95% CI 1.07–1.42), respectively. However, percent density was not found to be a predictor for ER−PR− tumors (OR 1.00, 95% CI 0.84–1.18). The results did not differ by ethnicity, nor by menopausal status, parity, or HRT use. Conclusions: Our findings indicate that within a multiethnic population, women with higher breast density have an increased risk for ER+PR+ but not ER−PR− tumors.     

Expression of sex steroid receptors and IGF-1 mRNA in breast tissue--effects of hormonal treatment

The mechanisms behind increased breast tissue proliferation and a possibly increased breast cancer risk in women using hormonal contraception (HC) and hormonal replacement therapy (HRT) are incompletely understood. We analyzed breast tissue from 20 premenopausal and seven postmenopausal women undergoing reduction mammoplasties for estrogen receptor (ER) and progesterone receptor (PR) content as well as mRNA levels for ER, PR and insulin-like growth factor-1 (IGF-1). The receptor values were correlated to IGF-1 mRNA concentrations and levels of steroid and peptide hormones and SHBG. In women using HC, we found significantly lower ER values (p=0.02) but non-significantly lower ER mRNA levels compared to those in naturally cycling women. PR and PR mRNA were no different. Women on HC displayed a higher breast tissue proliferation (p=0.05) expressed as Ki-67, MIB-1 positivity, which was correlated with IGF-1 mRNA (r_s=0.82, p=0.04). Since the concentration of sex steroid receptors in breast tissue is comparatively low and steroid receptors are down-regulated during hormonal treatment, mechanisms other than direct sex steroid receptor action are likely to be present. Our results suggest a role for IGF-1 in the proliferative response of breast tissue during exogenous hormonal treatment.     

Ano1/TMEM16A Overexpression Is Associated with Good Prognosis in PR-Positive or HER2-Negative Breast Cancer Patients following Tamoxifen Treatment

The calcium-activated chloride channel Ano1 (TMEM16A) is overexpressed in many tumors. Although Ano1 overexpression is found in breast cancer due to 11q13 amplification, it remains unclear whether signaling pathways are involved in Ano1 overexpression during breast cancer tumorigenesis in vivo. Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) have been known to contribute to breast cancer progression. It is unclear whether Ano1 is associated with clinical outcomes in breast cancer patients with different ER, PR and HER2 status. In the present study, we investigated the Ano1 expression in 431 patients with invasive ductal breast carcinoma and 46 patients with fibroadenoma, using immunohistochemistry, and analyzed the association between Ano1 expression and clinical characteristics and outcomes of breast cancer patients with different ER, PR, and HER2 status. Ano1 was overexpressed in breast cancer compared with fibroadenoma. Ano1 was significantly more associated with breast cancer with the lower clinical stage (stage I or II), or triple-negative status. Mostly importantly, Ano1 overexpression was associated with good prognosis in patients with the PR-positive or HER2-negative status, and in patients following tamoxifen treatment. Multivariate Cox regression analysis showed that Ano1 overexpression was a prognostic factor for longer overall survival in PR-positive or HER2-negative patients, and a predictive factor for longer overall survival in patients following tamoxifen treatment. Our findings suggest that Ano1 may be a potential marker for good prognosis in PR-positive or HER2-negative patients following tamoxifen treatment. The PR and HER2 status defines a subtype of breast cancer in which Ano1 overexpression is associated with good prognosis following tamoxifen treatment.     

Epidermal growth factor receptors in human breast and endometrial carcinomas

The incidence and levels of epidermal growth factor receptor (EGFR) were studied in 67 breast tumors and 22 endometrial carcinomas. Estrogen receptors (ER) were also measured in all samples and progesterone receptors (PR) were analyzed in 57 breast samples and 21 endometrial tumors. A high level of EGFR expression is found in both breast and endometrial carcinomas, although the incidence of EGFR content is greater in breast carcinomas. 36% of breast tumors had EGFR at levels 3-49.5 fmol/mg membrane protein, whereas this percentage of positivity was 27% for endometrial tumors. In 51% of breast carcinoma and 73% of endometrial tumors, there was a positive ER content, whereas 53% of breast tumors and 62% of endometrial carcinomas were positive. A clear inverse relationship between EGFR content and ER and PR status has been observed in breast tumors. Our data confirm the previously described inverse correlation between expression of EGFR and estrogen receptors in human breast cancer. We also show here that there is a similar inverse relationship between EGFR content and ER levels in endometrial tumors.     

Estradiol and progesterone receptor levels in human breast cancer in relation to cytosol and plasma estrogen level

Estradiol receptor (ER) and progesterone receptor (PR) content along with the cytosol and plasma estrone and estradiol levels in 15 premenopausal and 26 postmenopausal women with breast cancer in different clinical stages (T₁₂₃, N₀₁, M₀) were measured. ER-positive tumor frequency and the ER content tended to be higher in postmenopausal than in premenopausal patients. There was no evidence for a relationship between high cytosol estrogen levels and low receptor measurements. The estrogen concentration was higher in ER-positive tumor cytosols than in those of ER-negative tumors; the differences were significant in postmenopausal women, only, with P < 0.05 for estrone and P < 0.01 for estradiol values. Twelve pairs of tumor and normal tissue from the same breast, were also studied: seven of which contained ER-positive and five ER-negative tumors. The ER-positive tumors showed a clear trend to higher estradiol content as compared to the corresponding normal tissues. The circulating level of estradiol in postmenopausal women, was higher (P < 0.05) in ER-positive tumors than that in ER-negative tumors. Our results indicate that: (a) false negative ER assays are not likely to be due to the presence of endogenous estrogens, (b) higher amounts of estrone and estradiol are contained in ER-positive tumors than in negative ones.     

Putative tumor suppressor cytoglobin promotes aryl hydrocarbon receptor ligand–mediated triple negative breast cancer cell death

Nearly 40 000 women die annually from breast cancer in the United States. Clinically available targeted breast cancer therapy is largely ineffective in triple negative breast cancer (TNBC), characterized by tumors that lack expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her2). TNBC is associated with a poor prognosis. Previous reports show that aryl hydrocarbon receptor (AhR) partial agonist 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) selectively inhibits the growth of breast cancer cells, including those of the TNBC subtype. We previously demonstrated that 5F 203 induced the expression of putative tumor suppressor gene cytoglobin (CYGB) in breast cancer cells. In the current study, we determined that 5F 203 induces apoptosis and caspase-3 activation in MDA-MB-468 TNBC cells and in T47D ER⁺ PR ⁺ Her2 ⁻ breast cancer cells. We also show that caspases and CYGB promote 5F 203–mediated apoptosis in MDA-MB-468 cells. 5F 203 induced lysosomal membrane permeabilization (LMP) and cathepsin B release in MDA-MB-468 and T47D cells. In addition, silencing CYGB attenuated the ability of 5F 203 to induce caspase-3/-7 activation, proapoptotic gene expression, LMP, and cathepsin B release in MDA-MB-468 cells. Moreover, 5F 203 induced CYGB protein expression, proapoptotic protein expression, and caspase-3 cleavage in MDA-MB-468 cells and in MDA-MB-468 xenograft tumors grown orthotopically in athymic mice. These data provide a basis for the development of AhR ligands with the potential to restore CYGB expression as a novel strategy to treat TNBC.     

Quantitative image analysis of estrogen and progesterone receptors as a prognostic tool for selecting breast cancer patients for therapy

OBJECTIVE: To assess estrogen and progesterone receptor presence in human breast tumors using immunocytochemical analysis. STUDY DESIGN: For both estrogen (ER) and progesterone (PR) receptor assay, percent of stained cells and intensity of staining were estimated on a series of 251 consecutive breast cancer cases from the M. Ascoli Cancer Hospital Center in Palermo using the CAS 200 image analysis system. RESULTS: Cytochemical assay revealed a differential distribution of both ER and PR, by menopausal status of the patients; premenopause (PreM) was mostly ER negative (63%), and postmenopause (PostM) > 10 years was mostly ER and PR positive (64%). The percent of cells stained for ER was significantly different between PreM and PostM patients when they were considered as a whole. By contrast, no difference emerged for PR staining among menopausal groups. Overall, patients whose tumors were PR positive showed a significantly (P < .03) longer interval free of relapse. CONCLUSION: The present results suggest that PRs behave as better indicators than ERs of early relapse in breast cancer patients. Further studies, with longer follow-up, are needed, however, to validate this concept.     

Elevation of SIPL1 (SHARPIN) Increases Breast Cancer Risk

SIPL1 (Sharpin) or Sharpin plays a role in tumorigenesis. However, its involvement in breast cancer tumorigenesis remains largely unknown. To investigate this issue, we have systemically analyzed SIPL1 gene amplification and expression data available from Oncomine datasets, which were derived from 17 studies and contained approximately 20,000 genes, 3438 breast cancer cases, and 228 normal individuals. We found a SIPL1 gene amplification in invasive ductal breast cancers compared to normal breast tissues and a significant elevation of SIPL1 mRNA in breast cancers in comparison to non-tumor breast tissues. These results collectively reveal that increases in SIPL1 expression occur during breast cancer tumorigenesis. To further investigate this association, we observed increases in the SIPL1 gene and mRNA in the breast cancer subtypes of estrogen receptor (ER)+, progesterone receptor (PR)+, HER2+, or triple negative. Additionally, a gain of the SIPL1 gene correlated with breast cancer grade and the levels of SIPL1 mRNA associated with both breast cancer stages and grades. Elevation of SIPL1 gene copy and mRNA is linked to a decrease in patient survival, especially for those with PR+, ER+, or HER2- breast cancers. These results are supported by our analysis of SIPL1 protein expression using a tissue microarray containing 224 breast cancer cases, in which higher levels of SIPL1 relate to ER+ and PR+ tumors and AKT activation. Furthermore, we were able to show that progesterone significantly reduced SIPL1 mRNA and protein expression in MCF7 cells. As progesterone enhances breast cancer tumorigenesis in a context dependent manner, inhibition of SIPL1 expression may contribute to progesterone''s non-tumorigenic function which might be countered by SIPL1 upregulation. Taken together, we demonstrate a positive correlation of SIPL1 with BC tumorigenesis.     

Establishment of two basal-like breast cancer cell lines with extremely low tumorigenicity from Taiwanese premenopausal women

The research of carcinogenetic mechanisms of breast cancer in different ethnic backgrounds is an interesting field, as clinical features of breast cancers vary among races. High premenopausal incidence is distinctive in East-Asian breast cancer. However, human cell lines derived from Asian primary breast tumor are rare. To provide alternative cell line models with a relevant genetic background, we aimed to establish breast cancer cell lines from Taiwanese patients of Han-Chinese ethnicity. Fresh tissue from mammary tumors were digested into organoids, plated and grown in basal serum-free medium of human mammary epithelial cells (HuMEC) with supplements. Cells were further enriched by positive selection with CD326 (epithelial cell adhesion molecule; EpCAM)-coated micro-magnetic beads. Two breast cancer cell lines derived from premenopausal women were successfully established by this method, and named Chang-Gung Breast Cancer 01 (CGBC 01) and 02 (CGBC 02). These two cell lines had a similar phenotype with weak expression of estrogen receptor (ER), progesterone receptor (PR), and without amplification of receptor tyrosine protein kinase erbB-2 (HER2/neu). Genome-wide Single Nucleotide Polymorphism (SNP) array showed multiple copy number alterations in both cell lines. Based on gene expression profiles, CGBC 01 and 02 were clustered into basal-like subtype with reference to the breast cancer cell line gene expression database. The tumorigenicity of both cell lines was extremely low in both anchorage-independence assay and transplantation into the mammary fat pads of nude mice. CGBC 01 and CGBC 02 are low tumorigenic breast cancer cell lines, established from Han-Chinese premenopausal breast cancer patients, which serve as in vitro models in studying the biological features of Asian breast cancer.     

Receptor-Defined Subtypes of Breast Cancer in Indigenous Populations in Africa: A Systematic Review and Meta-Analysis

Background

Breast cancer is the most common female cancer in Africa. Receptor-defined subtypes are a major determinant of treatment options and disease outcomes but there is considerable uncertainty regarding the frequency of poor prognosis estrogen receptor (ER) negative subtypes in Africa. We systematically reviewed publications reporting on the frequency of breast cancer receptor-defined subtypes in indigenous populations in Africa.

Methods and Findings

Medline, Embase, and Global Health were searched for studies published between 1st January 1980 and 15th April 2014. Reported proportions of ER positive (ER+), progesterone receptor positive (PR+), and human epidermal growth factor receptor-2 positive (HER2+) disease were extracted and 95% CI calculated. Random effects meta-analyses were used to pool estimates. Fifty-four studies from North Africa (n = 12,284 women with breast cancer) and 26 from sub-Saharan Africa (n = 4,737) were eligible. There was marked between-study heterogeneity in the ER+ estimates in both regions (I²>90%), with the majority reporting proportions between 0.40 and 0.80 in North Africa and between 0.20 and 0.70 in sub-Saharan Africa. Similarly, large between-study heterogeneity was observed for PR+ and HER2+ estimates (I²>80%, in all instances). Meta-regression analyses showed that the proportion of ER+ disease was 10% (4%–17%) lower for studies based on archived tumor blocks rather than prospectively collected specimens, and 9% (2%–17%) lower for those with ≥40% versus those with <40% grade 3 tumors. For prospectively collected samples, the pooled proportions for ER+ and triple negative tumors were 0.59 (0.56–0.62) and 0.21 (0.17–0.25), respectively, regardless of region. Limitations of the study include the lack of standardized procedures across the various studies; the low methodological quality of many studies in terms of the representativeness of their case series and the quality of the procedures for collection, fixation, and receptor testing; and the possibility that women with breast cancer may have contributed to more than one study.

Conclusions

The published data from the more appropriate prospectively measured specimens are consistent with the majority of breast cancers in Africa being ER+. As no single subtype dominates in the continent availability of receptor testing should be a priority, especially for young women with early stage disease where appropriate receptor-specific treatment modalities offer the greatest potential for reducing years of life lost. Please see later in the article for the Editors'' Summary     

Pretreatment serum concentrations of 25-hydroxyvitamin D and breast cancer prognostic characteristics: a case-control and a case-series study

Background

Results from epidemiologic studies on the relationship between vitamin D and breast cancer risk are inconclusive. It is possible that vitamin D may be effective in reducing risk only of specific subtypes due to disease heterogeneity.

Methods and Findings

In case-control and case-series analyses, we examined serum concentrations of 25-hydroxyvitamin D (25OHD) in relation to breast cancer prognostic characteristics, including histologic grade, estrogen receptor (ER), and molecular subtypes defined by ER, progesterone receptor (PR) and HER2, among 579 women with incident breast cancer and 574 controls matched on age and time of blood draw enrolled in the Roswell Park Cancer Institute from 2003 to 2008. We found that breast cancer cases had significantly lower 25OHD concentrations than controls (adjusted mean, 22.8 versus 26.2 ng/mL, p<0.001). Among premenopausal women, 25OHD concentrations were lower in those with high- versus low-grade tumors, and ER negative versus ER positive tumors (p≤0.03). Levels were lowest among women with triple-negative cancer (17.5 ng/mL), significantly different from those with luminal A cancer (24.5 ng/mL, p = 0.002). In case-control analyses, premenopausal women with 25OHD concentrations above the median had significantly lower odds of having triple-negative cancer (OR = 0.21, 95% CI = 0.08–0.53) than those with levels below the median; and every 10 ng/mL increase in serum 25OHD concentrations was associated with a 64% lower odds of having triple-negative cancer (OR = 0.36, 95% CI = 0.22–0.56). The differential associations by tumor subtypes among premenopausal women were confirmed in case-series analyses.

Conclusion

In our analyses, higher serum levels of 25OHD were associated with reduced risk of breast cancer, with associations strongest for high grade, ER negative or triple negative cancers in premenopausal women. With further confirmation in large prospective studies, these findings could warrant vitamin D supplementation for reducing breast cancer risk, particularly those with poor prognostic characteristics among premenopausal women.     

Membrane progesterone receptor alpha as a potential prognostic biomarker for breast cancer survival: a retrospective study

Classically, the actions of progesterone (P4) are attributed to the binding of nuclear progesterone receptor (PR) and subsequent activation of its downstream target genes. These mechanisms, however, are not applicable to PR- or basal phenotype breast cancer (BPBC) due to lack of PR in these cancers. Recently, the function of membrane progesterone receptor alpha (mPRα) in human BPBC cell lines was studied in our lab. We proposed that the signaling cascades of P4→mPRα pathway may play an essential role in controlling cell proliferation and epithelial mesenchymal transition (EMT) of breast cancer. Using human breast cancer tissue microarrays, we found in this study that the average intensity of mPRα expression, but not percentage of breast cancer with high level of mPRα expression (mPRα-HiEx), was significantly lower in the TNM stage 4 patients compared to those with TNM 1-3 patients; and both average intensities of mPRα expression and mPRα-HiEx rates were significantly higher in cancers negative for ER, as compared with those cancers with ER+. However, after adjusting for age at diagnosis and/or TNM stage, only average intensities of mPRα expression were associated with ER status. In addition, we found that the rates of mPRα-HiEx were significantly higher in cancers with epithelial growth factor receptor-1 (EGFR+) and high level of Ki67 expression, indicating positive correlation between mPRα over expression and EGFR or Ki67. Further analysis indicated that both mPRα-HiEx rate and average intensity of mPRα expression were significantly higher in HER2+ subtype cancers (i.e. HER2+ER-PR-) as compared to ER+ subtype cancers. These data support our hypothesis that P4 modulates the activities of the PI3K and cell proliferation pathways through the caveolar membrane bound growth factor receptors such as mPRα and growth factor receptors. Future large longitudinal studies with larger sample size and survival outcomes are necessary to confirm our findings.     

Body Mass Index and Breast Cancer Defined by Biological Receptor Status in Pre-Menopausal and Post-Menopausal Women: A Multicenter Study in China

Background

Few studies have investigated the association between body mass index (BMI) and breast cancer with consideration to estrogen/progesterone/human epidermal growth factor type 2 receptor status (ER/PR/HER2) in the breast tissue among Chinese pre- and post-menopausal women.

Methods

Four thousand two hundred and eleven breast cancer patients were selected randomly from seven geographic regions of China from 1999 to 2008. Demographic data, risk factors, pathologic features, and biological receptor status of cases were collected from the medical charts. Chi-square test, fisher exact test, rank-correlation analysis, and multivariate logistic regression model were adopted to explore whether BMI differed according to biological receptor status in pre- and post-menopausal women.

Results

Three thousand two hundred and eighty one eligible cases with BMI data were included. No statistically significant differences in demographic characteristics were found between the cases with BMI data and those without. In the rank-correlation analysis, the rates of PR+ and HER2+ were positively correlated with increasing BMI among post-menopausal women (r_{s BMI, PR+} = 0.867, P = 0.001; r_{s BMI, HER2+} = 0.636, P = 0.048), but the ER+ rates did not vary by increasing BMI. Controlling for confounding factors, multivariate logistic regression models with BMI<24 kg/m² as the reference group were performed and found that BMI≥24 kg/m² was only positively correlated with PR+ status among post-menopausal breast cancer cases (adjusted OR = 1.420, 95% CI: 1.116–1.808, Wald = 8.116, P = 0.004).

Conclusions

Post-menopausal women with high BMI (≥24 kg/m²) have a higher proportion of PR+ breast cancer. In addition to effects mediated via the estrogen metabolism pathway, high BMI might increase the risk of breast cancer by other routes, which should be examined further in future etiological mechanism studies.     

Promoter Hypermethylation in Tumor Suppressing Genes p16 and FHIT and Their Relationship with Estrogen Receptor and Progesterone Receptor Status in Breast Cancer Patients from Northern India

BACKGROUND: Aberrant DNA methylation has been recognized in human breast carcinogenesis as a common molecular alteration associated with the loss of expression of a number of key regulatory genes. The present study was undertaken to determine whether methylation and expression of p16 and FHIT genes would correlate with the estrogen receptor (ER) and progesterone receptor (PR) status. METHODS: Methylation-specific polymerase chain reaction, messenger RNA (mRNA) expression analysis, immunohistochemistry, and Western blot analysis were performed to study the methylation of p16 and FHIT genes in 351 pairs of malignant/normal breast tissues. We examined the expression of ER and PR in those specimens by immunohistochemistry. Mutations of p16 and FHIT genes in tumors were detected by direct sequencing. RESULTS: The frequency of hypermethylation was 31.9% and 36.8% in p16 and FHIT genes, respectively, and showed significant harmony in concordant hypermethylation (P < .0001). In postmenopausal patients, methylation frequency in both genes is significantly higher in poorly and moderately differentiated tumors. Loss of protein expression of p16 and FHIT in 77 and 74 tumors, respectively, is associated with their methylation status in premenopausal women. CONCLUSION: We did not find any significant differences in tumor-related gene methylation patterns relevant to both ER and PR status of breast tumors.