The association between biological subtype and locoregional recurrence in newly diagnosed breast cancer

We investigated the association between the risk of locoregional recurrence (LRR) and biological subtypes defined by hormonal receptors (HR) and HER-2 status in women with invasive breast cancer (BC). A total of 618 newly diagnosed BC patients were identified from a cancer registry within a single institution with standardized methods of tumor assessment for estrogen receptor (ER), progesterone receptor (PR), and HER-2. Patients were stratified based on surgical treatment, breast-conserving therapy (BCT) versus modified radical mastectomy (MRM), as well as biological subtypes: HR+/HER-2− (ER-positive or PR-positive, HER-2-negative), HR+/HER-2+ (ER-positive or PR-positive, HER-2-positive), HR−/HER-2+ (ER-negative and PR-negative, HER-2-positive) and TN (ER-negative, PR-negative and HER-2-negative). The association between clinicopathological factors, biological subtype and LRR was evaluated with univariate and multivariate Cox analysis. With a median follow-up of 4.8 years, the rate of LRR was 7.5%. On multivariate analysis, TN, tumor size ≥2 cm and lymph node (LN) positivity were associated with increased risk of LRR (P = 0.023, P = 0.048, and P = 0.0034, respectively). In BCT group, HR−/HER-2+ and LN positivity were associated with increased risk of LRR (HR 11.13; 95% CI 2.78–44.53; P = 0.0007 and HR 5.40; 95% CI 1.67–17.43; P = 0.0048, respectively). In MRM group, TN subtype and LN positivity were associated with increased risk of LRR (HR 4.72; 95% CI 1.53–14.52; P = 0.0069 and HR 3.23; 95% CI 1.44–7.29; P = 0.0047, respectively). Compared to HR+/HER-2−, HR−/HER-2+ treated by BCT and TN treated by MRM showed a significant decrease of 5-year LRR free survival (P = 0.0002 and P = 0.002, respectively). Tumor profiling using ER, PR, and HER-2 biomarkers is a promising tool to identify patients at high risk of LRR based on surgical treatment. Our findings suggest a different follow-up and locoregional treatment for patients with HR−/HER-2+ and TN subtypes.     

Breast cancer subtype approximations and loco-regional recurrence after immediate breast reconstruction

Background

A small but significant proportion of patients with breast cancer (BC) will develop loco-regional recurrence (LRR) after immediate breast reconstruction (IBR). The LRR also varies according to breast cancer subtypes and clinicopathological features.

Methods

We studied 1742 consecutive BC patients with IBR between 1997 and 2006. According to St Gallen conference consensus 2011, its BC approximations were applied to classify BC into five subtypes: estrogen receptor (ER) and/or progesterone receptor (PgR) positive, HER2 negative, and low Ki67 (<14%) [luminal A]; ER and/or PgR positive, HER2 negative and high Ki67(≥14%) [luminal B/HER2 negative]; ER and/or PgR positive, any Ki67 and HER2 positive [luminal B/HER2 positive]; ER negative, PgR negative and HER2 positive [HER2 positive/nonluminal]; and ER negative, PgR negative and HER2 negative [triple negative]. Cumulative incidences of LRR were compared across different subgroups by means of the Gray test. Multivariable Cox regression models were applied.

Results

Median follow up time was 74 months (range 3–165). The cumulative incidence of LRR was 5.5% (121 events). The 5-year cumulative incidence of LRR was 2.5% for luminal A; 5.0% for luminal B/HER2 negative; 9.8% for luminal B/HER2 positive; 3.8% for HER2 non luminal; and 10.9% for triple negative. On multivariable analysis, tumor size (pT) >2 cm, body mass index (BMI) ≥25, triple negative and luminal B/HER2 positive subtypes were associated with increased risk of LRR.

Conclusion

Luminal B/HER2 positive, triple negative subtypes and BMI ≥25 are independent prognostic factors for risk of LRR after IBR.     

Axillary lymph node status of operable breast cancers by combined steroid receptor and HER-2 status: triple positive tumours are more likely lymph node positive

Aims To examine the frequency of axillary lymph node (ALN) invasion of operable breast cancers by their combined oestrogen receptor (ER), progesterone receptor (PR) and HER-2 status. Methods 2227 recently operated cases in one centre were retrieved from the Multidisciplinary Breast Centre database and stratified according to their combined immunohistochemical (IHC) expression of ER/PR/HER-2 status. An equivocal HER-2 status was further analysed by Fluorescence in situ Hybridisation (FISH). The following 6 groups were considered: ER⁻PR⁻HER-2⁻ (NNN; triple negative), ER⁻PR⁻HER-2⁺ (NNP), ER⁺PR⁻HER-2⁻ (PNN), ER⁺PR⁻HER-2⁺ (PNP), ER⁺PR⁺HER-2⁻ (PPN), ER⁺PR⁺HER-2⁺ (PPP; triple positive). For ALN, the following variables were tested in uni- and multivariate models: age at diagnosis (years), tumour size (mm), tumour grade, ER, PR, HER-2 and the combined steroid receptor and HER-2 status. Likelihood ratio χ²-tests were used for univariate analysis and logistic regression for multivariate analysis. Results Triple positive tumours had a higher likelihood of being ALN positive than others (56.2% versus 35.7%; P < 0.0001). Univariate logistic regression also withheld age, size, grade and HER-2 as predictors of ALN involvement. Final multivariate logistic regression revealed age, size, grade and PPP versus non-PPP to be independent predictors of ALN involvement; the odds ratio (OR) and 95% CI for PPP versus non-PPP tumours was 2.169 (1.490–3.156). Conclusion Our data provide insight into the natural history of triple positive breast carcinomas. Such tumours are more likely ALN positive than those with another steroid receptor and HER-2 status. How these findings correlate with breast cancer prognosis remains to be investigated.     

Implications of constructed biologic subtype and its relationship to locoregional recurrence following mastectomy

Introduction

We examined the prognostic value of biologic subtype on locoregional recurrence (LRR) after mastectomy in a cohort of low risk women who did not receive adjuvant radiation therapy.

Methods

A total of 819 patients with invasive breast cancer underwent mastectomy from January 2000 through December 2005. No patient received preoperative chemotherapy. Estrogen receptor (ER) receptor, progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status were used to construct the following 4 subtypes: i) ER+ or PR+ and HER2- (HR+/HER2-), ii) ER+ or PR+ and HER2+ (HR+/HER2+), iii) ER- and PR- and HER2+ (HR-/HER2+)and iv) ER- and PR- and HER2- (HR-/HER2-). LRR-free survival was estimated by the Kaplan-Meier method. Cox proportional hazard models were used to evaluate the association between time-to-event outcomes and patient prognostic factors.

Results

At a median follow-up of 58 months, five-year cumulative incidence of LRR for the entire cohort was 2.5%. Subtype specific LRR rates were 1% for HR+/HER2-, 6.5% in HR+/HER2+, 2% for HR-/HER2+ and 10.9% for HR-/HER2- (P < 0.01). In HER-2+ patients (irrespective of ER/PR status), trastuzumab therapy was not associated with LRR-free survival. On multivariate analysis, one to three positive lymph nodes (HR 4.75 (confidence interval (CI) 1.75 to 12.88, P < 0.01), ?? 4 positive lymph nodes (HR23.4 (CI 4.64 to 117.94, P < 0.01), HR+/HER2+ (HR 4.26 (CI 1.05 to 17.33), P = 0.04), and HR-/HER2- phenotype (HR 13.87 (CI 4.96 to 38.80), P < 0.01) were associated with shorter LRR-free survival whereas age > 50 at diagnosis (HR 0.31 (CI 0.12 to 0.80), P = 0.02) was associated with improved LRR-free survival. Among the HR-/HER2- subtypes, five-year LRR incidence was 23.4% in patients with positive lymph nodes compared to 7.8% for lymph node negative patients (P = 0.01), although this association did not reach significance when the analysis was limited to HR-/HER2- women with only one to three positive lymph nodes (15.6% versus 7.8%, P = 0.11).

Conclusions

Constructed subtype is a prognostic factor for LRR after mastectomy among low risk women not receiving adjuvant radiation therapy, although rates of LRR remain low across subtypes. Patients with node positive, HR-/HER2- type tumors were more likely to experience LRR following mastectomy alone. Prospective studies to further investigate the potential benefit of adjuvant radiation therapy in these women are warranted.     

αB-crystallin is a novel predictor of resistance to neoadjuvant chemotherapy in breast cancer

Aims αB-crystallin is an anti-apoptotic protein commonly expressed in poor prognosis basal-like breast tumors, which are largely triple (estrogen receptor (ER), progesterone receptor (PR), and HER2) negative. We examined whether αB-crystallin expression in breast cancer was associated with a poor response to neoadjuvant (preoperative) chemotherapy. Methods One hundred and twelve breast cancer patients who received neoadjuvant chemotherapy and who had post-chemotherapy tumor specimens available for analysis were included in the study. Forty-nine percent of patients were treated with doxorubicin and cyclophosphamide (AC), 37% received AC in combination with a taxane, and 14% received other regimens. Paired pre- and post-chemotherapy tumor specimens were available for 33 patients. αB-crystallin expression was determined by immunohistochemistry in tissue microarrays. Results Seventeen percent of tumors were αB-crystallin positive. αB-crystallin expression was identical in 32 of 33 cases for which both pre- and post-chemotherapy tumor tissue was available. αB-crystallin expression was associated with ER-negative (P = 0.0024) and triple negative status (P = 0.005). Overall response rates (ORR) defined as ≥50% reduction in tumor size after treatment were 53% (clinical ORR) and 61% (pathological ORR). Although tumor grade, size, ER, PR, HER2 or triple negative status was not associated with response, αB-crystallin-positive tumors had poorer overall response rates than αB-crystallin-negative tumors (clinical ORR, 21% vs. 59%, respectively, P = 0.0045; pathological ORR, 16% vs. 70%, respectively, P < 0.0001). Conclusion αB-crystallin is a novel biomarker expressed predominantly in triple negative breast tumors that identifies a subset of chemotherapy-resistant tumors, which may contribute to their poor prognosis.     

Reproductive history and risk of three breast cancer subtypes defined by three biomarkers

Breast cancer subtypes defined by estrogen receptor (ER), progesterone receptor (PR), and HER2 expression are biologically distinct and thus, may have distinct etiologies. In particular, it is plausible that risk factors operating through hormonal mechanisms are differentially related to risk of such tumor subtypes. Using data from the Breast Cancer Surveillance Consortium, we explored associations between reproductive history and three breast cancer subtypes. Data on parity and age at first birth were collected from 743,623 women, 10,896 of whom were subsequently diagnosed with breast cancer. Cases were classified into three subtypes based on tumor maker expression: (1) ER positive (ER+, N = 8,203), (2) ER negative/PR negative/HER2 positive (ER−/PR−/HER2+, N = 288), or (3) ER-, PR-, and HER2-negative (triple-negative, N = 645). Associations with reproductive history, evaluated using Cox regression, differed significantly across tumor subtypes. Nulliparity was most strongly associated with risk of ER+ breast cancer [hazard ratio (HR) = 1.31, 95% confidence interval (CI): 1.23–1.39]; late age at first birth was most strongly associated with risk of ER-/PR-/HER2+ disease (HR = 1.83, 95% CI: 1.31–2.56). Neither parity nor age at first birth was associated with triple-negative breast cancer. In contrast to ER+ and ER−/PR−/HER2+ subtypes, reproductive history does not appear to be a risk factor for triple-negative breast cancer.     

Incidence and prognostic significance of receptor discordance between primary breast cancer and paired bone metastases

ER, PgR and HER-2 status are the cornerstones of choosing systemic therapy for breast cancer, but can change during the disease course. Guidelines recommended the biopsy of the metastatic tumor to reassess receptor status. Bone is the most frequent metastatic site of breast cancer but remained technically difficult to biopsy. Our study aimed to evaluate the incidence and prognostic significance of receptor discordance between primary breast cancer and paired bone metastases. One hundred and fifty-five breast cancer patients were diagnosed with pathology-confirmed bone metastasis at Fudan University Shanghai Cancer Center. Ninety-three patients with receptor status available on both primary tumor and bone metastases were included in our study. ER, PgR and HER-2 status converted from positive to negative in 10.8% (10/93), 28.0% (26/93) and 8.6% (8/93) of the patients, while ER, PgR and HER-2 status converted from negative to positive in 3.2% (3/93), 4.3% (4/93) and 1.1% (1/93) of the patients, respectively. 40.4% (17/42) of the HER2-0 tumors converted to HER2-low, which enabled them to receive the treatment of new antibody-drug conjugates (ADCs). Prior endocrine and anti-HER2 therapy were the independent risk factors for receptor conversion. Loss of HR expression in bone metastases was significantly associated with worse first-line PFS (adjusted hazard ratio = 3.271, P-value = .039) and OS (adjusted hazard ratio = 6.09, P-value = .011). In conclusion, our study confirmed that patients may experience receptor conversion between primary breast cancer and bone metastases, possibly influenced by prior treatments, which significantly influenced prognosis. The rebiopsy of bone metastases in patients with primary HER2-0 tumors may benefit from the new ADC drugs.     

Predictors of locoregional outcome in patients receiving neoadjuvant therapy and postmastectomy radiation

BACKGROUND:

The objective of this study was to identify predictors of locoregional recurrence (LRR) after neoadjuvant therapy (NAT) and postmastectomy radiation (PMRT) in a cohort of patients with stage II through III breast cancer and to determine whether omission of the supraclavicular field had an impact on the risk of LRR.

METHODS:

The authors reviewed records from 464 patients who received NAT and PMRT from January 1999 to December 2009.

RESULTS:

The median patient age was 50 years (range, 25‐81 years). Clinical disease stage was stage II in 29% of patients, stage III in 71%, and inflammatory in 14%. Receptor status was estrogen receptor (ER)‐positive in 54% of patients, progesterone receptor (PR)‐positive in 39%, human epidermal growth factor receptor 2 (HER2)‐positive in 24%, and negative for all 3 receptors (triple negative) in 32%. All patients received NAT and underwent mastectomy, and 19.6% had a complete pathologic response in the breast and axilla, 17.5% received radiation to the chest wall only, and 82.5% received radiation to the chest wall and the supraclavicular field; omission of the supraclavicular field was more common in patients with lower clinical and pathologic lymph node status. The median follow‐up was 50.5 months, and the 5‐year cumulative incidence of LRR was 6% (95% confidence interval, 3.9%‐8.6%). Predictors of LRR were clinical stage III (P = .038), higher clinical lymph node status (P = .025), higher pathologic lymph node status (P = .003), the combination of clinically and pathologically positive lymph nodes (P < .001), inflammatory presentation (P = .037), negative ER status (P = .006), negative PR status (P = .015), triple‐negative status (P < .001), and pathologic tumor size >2 cm (P = .045). On univariate analysis, omission of the supraclavicular field was not associated significantly with LRR (hazard ratio, 0.89; P = .833); however, on multivariate analyses, omission of the supraclavicular field was associated significantly with LRR (hazard ratio, 3.39; P = .024).

CONCLUSIONS:

Presenting stage, receptor status, pathologic response to neoadjuvant therapy, and omission the supraclavicular field were identified as risk factors for LRR after neoadjuvant therapy and PMRT. Cancer 2013. © 2012 American Cancer Society.     

Locoregional recurrence of triple‐negative breast cancer after breast‐conserving surgery and radiation

BACKGROUND:

The results of radiation on the local control of triple receptor‐negative breast cancer (negative estrogen [ER], progesterone [PR], and HER‐2/neu receptors) was studied.

METHODS:

Conservative surgery and radiation were used in 753 patients with T1‐T2 breast cancer. Three groups were defined by receptor status: Group 1: ER or PR (+); Group 2: ER and PR (?) but HER‐2 (+); and Group 3: triple‐negative (TN). Factors analyzed were age, menopausal status, race, stage, tumor size, lymph node status, presentation, grade, extensive in situ disease, margins, and systemic therapy. The primary endpoint was 5‐year locoregional recurrence (LRR) isolated or total with distant metastases.

RESULTS:

ER‐ and PR‐negative patients were statistically significantly more likely to be black, have T2 disease, have tumors detectable on both mammography and physical examination, have grade 3 tumors, and receive chemotherapy. There were no significant differences noted with regard to ER? and PR? patients by HER‐2 status. There was a significant difference noted in rates of first distant metastases (3%, 12%, and 7% for Groups 1, 2, and 3, respectively; P = .009). However, the isolated 5‐year LRR was not significantly different (2.3%, 4.6%, and 3.2%, respectively; P = .36) between the 3 groups.

CONCLUSIONS:

Patients with TN breast cancer do not appear to be at a significantly increased risk for isolated LRR at 5 years and therefore remain appropriate candidates for breast conservation. Cancer 2009. © 2009 American Cancer Society.     

Clinicopathologic features,patterns of recurrence,and survival among women with triple‐negative breast cancer in the National Comprehensive Cancer Network

BACKGROUND:

The objective of this study was to describe clinicopathologic features, patterns of recurrence, and survival according to breast cancer subtype with a focus on triple‐negative tumors.

METHODS:

In total, 15,204 women were evaluated who presented to National Comprehensive Cancer Network centers with stage I through III breast cancer between January 2000 and December 2006. Tumors were classified as positive for estrogen receptor (ER) and/or progesterone receptor (PR) (hormone receptor [HR]‐positive) and negative for human epidermal growth factor receptor 2 (HER2); positive for HER2 and any ER or PR status (HER2‐positive); or negative for ER, PR, and HER2 (triple‐negative).

RESULTS:

Subtype distribution was triple‐negative in 17% of women (n = 2569), HER2‐positive in 17% of women (n = 2602), and HR‐positive/HER2‐negative in 66% of women (n = 10,033). The triple‐negative subtype was more frequent in African Americans compared with Caucasians (adjusted odds ratio, 1.98; P < .0001). Premenopausal women, but not postmenopausal women, with high body mass index had an increased likelihood of having the triple‐negative subtype (P = .02). Women with triple‐negative cancers were less likely to present on the basis of an abnormal screening mammogram (29% vs 48%; P < .0001) and were more likely to present with higher tumor classification, but they were less likely to have lymph node involvement. Relative to HR‐positive/HER2‐negative tumors, triple‐negative tumors were associated with a greater risk of brain or lung metastases; and women with triple‐negative tumors had worse breast cancer‐specific and overall survival, even after adjusting for age, disease stage, race, tumor grade, and receipt of adjuvant chemotherapy (overall survival: adjusted hazard ratio, 2.72; 95% confidence interval, 2.39‐3.10; P < .0001). The difference in the risk of death by subtype was most dramatic within the first 2 years after diagnosis (overall survival for 0‐2 years: OR, 6.10; 95% confidence interval, 4.81‐7.74).

CONCLUSIONS:

Triple‐negative tumors were associated with unique risk factors and worse outcomes compared with HR‐positive/HER2‐negative tumors. Cancer 2012. © 2012 American Cancer Society.     

Triple negative breast cancer compared to hormone receptor negative/HER2 positive breast cancer

The aim of this study is to reveal likely demographic, clinical, and pathological differences among hormone receptor negative breast cancer patients according to their HER-2 status. The medical records of hormone receptor negative breast cancer patients with known HER-2 status between January 1999 and December 2006 were reviewed, retrospectively. A total of 91 cases were included in the study (68 HER-2 negative cases and 23 HER-2 positive cases). The results obtained showed that median age, menarche age, childbearing age, number of children, menopause age, and body-mass indexes were similar in both groups. The HER-2 negative patients had more family history of breast cancer than HER-2 positive patients (13.2% and 0%, respectively, P = 0.091). Eighty-three patients received neoadjuvant/adjuvant chemotherapy. Recurrence occurred in 41 (46.6%) patients. Neither recurrence nor disease-free survival of those patients was associated with HER-2 status. Tumor size (P = 0.042) and number of involved lymph nodes (P = 0.001) were found to be independent prognostic factors for disease-free survival. A tendency for more frequent cerebral metastasis was found in HER-2 positive advanced stage patients (P = 0.052). HER-2 positive patients were less responsive to taxanes (P = 0.071). The number of involved lymph nodes (P = 0.004) and HER-2 status (P = 0.043) were found to be prognostic factors for overall survival. HER-2 positive and negative patients should be followed and treated with different strategies. HER-2 positive patients are at least as resistant to systemic therapies as the HER-2 negative patients. Genetic counseling should be routinely provided to triple negative patients and their families. HER-2 positive patients may be candidates for prophylactic treatment strategies concerning cerebral metastasis.     

Prognostic Factors and Survival According to Tumor Subtype in Women With Breast Cancer Brain Metastases

Breast cancer (BC) is the second most cause of central nervous system (CNS) metastases. Studies report that almost one third of patients (pts) with triple-negative, one-third with human epidermal growth factor receptor 2 (HER2)-positive and 15% of those with hormone receptor-positive, HER2-negative metastatic breast cancer will develop brain metastases. It is known that the development of symptomatic brain metastases in women with advanced breast cancer is associated with poor prognosis, irrespective of local and systemic treatments. In the present study, we aim to determine the association between BC subtypes and CNS metastases occurrence and prognosis. Retrospective analysis of 309 BC patients with CNS metastases, confirmed by pathological and/or radiological methods, treated in a Cancer Center between 2003 and 2021, was obtained to identify clinicopathologic factors associated with early onset of brain metastases and survival outcomes. For analysis purposes, 3 BC subtypes were considered according to hormone receptor status and HER-2 expression: ER and/or PR positive, HER-2 positive and triple negative. The median time between diagnosis of BC and detection of CNS metastases was 43 months, and it was significantly shorter in triple negative group (8 months). Twenty-one patients (6,8%) had CNS metastases at BC diagnosis, with CNS being the first site of recurrence in 35,3%, mainly in HER2 positive. Most of the patients had parenchymal metastases (n = 245) and 37 (12%) had leptomeningeal (LM) disease, with predominance in ER and/or PR positive subtype (70,3%). In patients submitted to CNS surgery, the concordance between primary tumor and metastases subtype was higher in triple negative (76,9%) compared to 63,2% in HER-2 positive and 38,9% in ER and/or PR positive group (P < 0.05). After CNS involvement, 25,4% (n = 34) of patients with triple negative disease did not receive any systemic therapy, compared to 30,6% (n = 41) in HER-2 positive and 44% (n = 59) in ER and/or PR positive groups (P = 0.05). Median survival after CNS metastases was 9 months, but significantly longer in HER-2 positive group (16 months) and in patients submitted to surgical resection of CNS metastases, irrespectively of subtype (22 months vs 5 months in other treatment modalities). In multivariate Cox regression analysis, having HER-2 positive tumor was an independent prognostic factor for increasing survival after CNS metastases (HR 0.60, 95% CI: 0.41-0.87, P = 0.007), regardless the therapeutic strategy. Clinical behavior and prognosis of CNS metastases varies according to BC subtype. The association between LM disease and ER and/or PR positive tumors should be explored in upcoming studies. Also, these patients’ prognosis depends on the availability of specific treatment options, therefore, innovative and effective therapeutic approaches are needed, in order to improve survival and quality of life of these patients.     

Alternations of ER,PR, HER-2/neu,and P53 protein expression in ductal breast carcinomas and clinical implications

The aim of the study is to investigate the alterations in expression of estrogen receptor alpha (ER), progesterone receptor (PgR), c-erbB2 gene (HER-2/neu), and P53 protein in the progression from ductal carcinoma in situ (DCIS) to invasive ductal carcinomas (IDC), and the association between their expression and clinicopathologic findings. The mastectomy specimens of 520 cases containing both DCIS and IDC were examined. The expression of ER, PgR, HER-2/neu, and P53 proteins were examined by immunohistochemistry. Linear regression was used to investigate the correlation among ER, PgR, HER-2/neu, P53 protein expression, and the clinicopathologic factors. There was a significant decrease of ER and PgR expression in IDC compared to DCIS (32.81 vs. 21.05%, χ² = 4.45, P = 0.035; 26.56 vs. 15.57%, χ² = 4.82, P = 0.028, respectively). In contrast, there was a significant increase of HER-2/neu expression in IDC compared to DCIS (10.94 vs. 21.27%, χ² = 3.88, P = 0.049). However, there was no significant difference in expression of p53 between DCIS and IDC. In both DCIS and IDC, a significant positive correlation was observed between ER and PgR receptor expression (r = 0.67, P = 0.00; r = 0.56, P = 0.00, respectively). In conclusion, these findings substantiate the notion that breast cancer progression is often associated with alterations in expressions of ER, PgR, and HER-2/neu. The underlying mechanisms of these alterations need further investigation.     

Microcephalin is a new novel prognostic indicator in breast cancer associated with BRCA1 inactivation

The authors have investigated the expression of the microcephalin (MCPH1) protein to evaluate its prognostic importance in breast cancer. Microcephalin is a damage response protein involved in the regulation of BRCA1 and BRCA2. BRCA1 mutations are often associated with basal-like breast cancer, which are also often negative for oestrogen receptor (ER), progesterone receptor (PR) and HER2. MCPH1 immunohistochemistry was performed on 319 breast cancers prepared as tissue microarray and correlated with pathology, survival, ER, PR, HER2, EGFR, CK5/6, CK14 and BRCA1 expression. After performing continuous data analysis, mean microcephalin expression decreased with increasing grade (P < 0.006). Mean microcephalin expression was lower in ER/PR negative (P < 0.001) and triple negative cancers (P < 0.004). Conversely, an association with HER2-positive cancers was also identified (P < 0.034). Reduced microcephalin also correlated with reduced nuclear BRCA1 staining (P < 0.001). No association was identified with basal markers. After dichotomising the data into low and high microcephalin expression, reduced expression was identified in 29% (93/319) of breast cancers. An association with low expression was identified in invasive ductal carcinomas with breast cancer-specific survival (BCSS) (P = 0.052). Multivariate analysis of ductal carcinomas showed that microcephalin, together with lymph node involvement and tumour size were independent predictors of BCSS (P = 0.037). Microcephalin expression is reduced in 29% of breast cancers, particularly in higher grade tumours and BRCA1-negative cases. Microcephalin is an independent predictor of BCSS in invasive ductal breast cancer patients and may prove to be a useful biomarker for the identification of aggressive breast cancers.     

Pathological characteristics of BRCA-associated breast cancers in Hispanics

The immunophenotype of BRCA-associated breast cancer has been studied in predominantly non-Hispanic whites (NHW). We evaluated the pathological characteristics of BRCA-associated invasive breast cancer in Hispanics. A case–control study was conducted on breast cancers from Hispanic and NHW women who enrolled in an IRB-approved registry and underwent BRCA gene analysis. BRCA negative controls (41 Hispanic, 39 NHW) were matched on age and ethnicity to BRCA positive cases (39 Hispanic, 35 NHW). A tissue array was constructed to characterize the expression of estrogen receptor (ER), progesterone receptor (PR), HER2, Ki-67 and p53 by immunohistochemistry. Mean age at diagnosis was 37.1 years (range 24–59) for Hispanics (80% with Mexican ancestry) and 40.1 years (range 21–63) for NHW (P = 0.03). Hispanic BRCA1 cases were more likely than BRCA negative controls to have tumors that were ER-negative (P < 0.001) and PR-negative (P = 0.001), had higher levels of Ki-67 (P = 0.001) and p53 expression, and lower levels of HER2 overexpression. When stratified by genes, there were no significant differences in expression of ER, Ki-67, HER2, and p53 by ethnicity among mutation carriers. However, a significantly higher proportion of BRCA-positive Hispanics had PR-negative tumors compared to BRCA-positive NHW (80 vs. 57%, OR = 2.9, 95% CI 1.0–8.1, P = 0.04). Hispanic BRCA-associated breast cancers were found to have the unique immunophenotype associated with BRCA mutations; however, there was a trend toward a difference in PR expression among Hispanic BRCA1 and BRCA2 cases. Additional research on the molecular mechanisms involved in the loss of PR in this population is warranted as it could have important implications for the treatment and prevention of breast cancer in Hispanics.