Adjuvant therapies for special types of breast cancer

Comparing core needle biopsy and surgical excision in breast cancer diagnosis: implications for clinical practice from a retrospective cohort study

BACKGROUND

Preoperative ultrasound-guided core needle biopsy (CNB) is currently the standard procedure for managing breast illnesses. However, the differences in outcomes between CNB and surgical excision (SE) have not been thoroughly assessed. This study aimed to explore the disparities in pathological outcomes between these two procedures, using a large sample dataset.

METHODS

This retrospective study consecutively included patients who underwent CNB and SE at Shenzhen People's Hospital from May 2016 to June 2023. Immunohistochemistry (IHC) was utilized to determine the status of estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor-2 (HER2), and Ki-67. Patients presenting with HER2 IHC 2+ underwent additional fluorescence in situ hybridization (FISH) examination. The cutoff value for high Ki-67 expression was established at 14%. Molecular subtypes were classified into four groups (Luminal A, Luminal B, Triple-negative, and HER2-positive) and five groups [Luminal A, Luminal B+ (HER2-positive), Luminal B- (HER2-negative), Triple-negative, and HER2-positive], based on different criteria.

RESULTS

A total of 4,209 patients were included in this study. Post-surgical confirmation revealed 2,410 cases as benign and 1,799 as malignant. Among the malignant cases, 334 were excluded due to either not having undergone direct surgery or having incomplete IHC results. The remaining 1,465 cases underwent IHC testing. CNB demonstrated a 97% concordance rate (CR) in diagnosing benign cases. The CRs for diagnosing invasive breast cancer (IBC) and carcinoma in situ (CIS) were 92% and 54%, respectively. ER, PgR, HER2, and Ki-67 exhibited CRs of 94%, 91%, 98%, and 84%, respectively. In the four-group classification, the overall diagnostic CR was 82%, with CRs for Luminal A, Luminal B, HER2-positive, and triple-negative breast cancer (TNBC) being 84%, 82%, 78%, and 85%, respectively. Under the five-group classification, the overall diagnostic CR was also 82%, with CRs for Luminal A, Luminal B+, Luminal B-, HER2-positive, and TNBC being 86%, 85%, 94%, 88%, and 92%, respectively.

CONCLUSIONS

This study demonstrates that CNB is highly accurate in differentiating benign from malignant breast lesions, particularly showing significant consistency in the diagnosis of molecular subtypes, providing a reliable reference for clinical diagnosis.

Clinicopathological Features and Outcomes Comparing Patients With Invasive Ductal and Lobular Breast Cancer

BACKGROUND

There is increasing interest in better understanding the biology and clinical presentation of invasive lobular cancer (ILC), which is the most common special histological subtype of breast cancer. Limited large contemporary data sets are available allowing comparison of clinicopathologic features between ILC and invasive ductal cancer (IDC).

METHODS

The Great Lakes Breast Cancer Consortium was formed to compare clinical behavior of ILC (n = 3617) and IDC (n = 30 045) from 33 662 patients treated between 1990 and 2017 at 3 large clinical centers. We used Kaplan-Meier analysis, Cox proportional hazards modeling, and propensity score matching to evaluate treatment differences and outcomes. All statistical testing used 2-sided P values.

RESULTS

Compared with IDC, patients with ILC were more frequently diagnosed at later stages and with more lymph node involvement (corrected P < .001). Estrogen receptor-positive ILCs were of lower grade (grade 1 and 2: 90% in ILC vs 72% in IDC) but larger in size (T3 and 4: 14.3% in ILC vs 3.4% in IDC) (corrected P < .001), and since 1990, the mean ILC size detected at diagnosis increased yearly. Patients with estrogen receptor (ER)-positive ILC underwent statistically significantly more mastectomies compared with ER-positive IDC (57% vs 46%). Using Kaplan-Meier analysis, patients with ER-positive ILC had statistically significantly worse disease-free survival and overall survival than ER-positive IDC although 6 times more IDCs were classified as high risk by OncotypeDx Breast Recurrence Score assay.

CONCLUSIONS

This large, retrospective, collaborative analysis with 3 clinical centers identified meaningful differences in clinicopathological features between ILC and IDC, providing further evidence that these are 2 different entities requiring different clinical management.

Invasive cribriform carcinoma of the breast detected incidentally on computed tomography: A case report

Invasive cribriform carcinoma is a rare type of invasive breast carcinoma, and a few cases have been reported. Its features are a cribriform pattern resembling the histological structures of cribriform ductal carcinoma in situ and an excellent prognosis. However, the extent of progress for intraductal extension must be carefully evaluated.

Rare Breast Cancer Subtypes

PURPOSE OF REVIEW

Breast cancer is a collection of diseases including the more common invasive ductal and lobular carcinomas and rarer subtypes of breast cancer. This review summarizes the features of rare breast cancers.

RECENT FINDINGS

Each of the rare tumors has defined pathological and clinical features that impact treatment recommendations. In this review, we summarize these for each rare type of breast cancer and where available we include molecular features of each tumor. Rare subtypes of breast cancer each have unique features. In many cases, data is limited for the optimal treatment approaches.

Evaluation of efficacy of chemotherapy for mucinous carcinoma: a surveillance, epidemiology, and end results cohort study

Background

In this study, we investigated the impact of chemotherapy on breast cancer-specific survival (BCSS) in patients with mucinous carcinoma using the surveillance, epidemiology, and end results (SEER) database.

Methods

A large-scale SEER-based retrospective analysis was conducted; 13,329 patients with mucinous carcinoma from 1994 to 2014 were identified. Clinicopathological characteristics were compared using the chi-square test. BCSS curves were generated using the Kaplan-Meier method. The prognostic significance of all demographic and clinicopathological characteristics and treatment patterns were calculated using univariate and multivariate regression analyses.

Results

Mucinous carcinoma was demonstrated to be less aggressive than invasive ductal carcinoma and predicted a better prognosis in the Kaplan-Meier analysis (hazard ratios = 0.336, 95% confidence interval: 0.308-0.368, p < 0.001). Univariate and multivariate analyses revealed that chemotherapy did not provide any additional benefit for patients with mucinous carcinoma. Predictors for receiving chemotherapy were younger age, estrogen receptor-negative, progesterone receptor-negative, and human epidermal growth factor receptor 2-positive status, higher grade, larger tumor size, lymph node involvement, radiation reception, and mastectomy. Further subgroup analysis verified that regardless of the hormone receptor (HR) and lymph node (LN) status, patients did not benefit from chemotherapy.

Conclusion

Our study showed that patients with HR+/LN- mucinous carcinoma did not benefit from chemotherapy and that chemotherapy could not improve the survival of all subtypes of mucinous carcinoma based on large-scale SEER data. These results support that patients with mucinous carcinoma could be exempt from chemotherapy. Additional research is needed to further evaluate the impact of adjuvant treatments, particularly in patients with favorable histology.

Special subtypes with favorable prognosis in breast cancer: A registry-based cohort study and network meta-analysis

BACKGROUND

We aimed to explore whether cribriform and adenoid cystic carcinoma had comparable prognoses to mucinous, tubular and papillary carcinoma, which were long recognized as favorable histologies by NCCN guidelines.

METHODS

A retrospective analysis based on the Surveillance, Epidemiology, and End Results Study (SEER) database (1994-2014) was conducted. The prognostic significance of all clinicopathological factors was calculated using univariate and multivariate analyses. A systematic review based on PubMed and network meta-analysis was conducted.

RESULTS

From the SEER database, the histologic subtypes of breast cancer (tubular, cribriform, adenoid cystic, mucinous, and papillary) were sorted by overall survival (OS) (94.4%, 91.6%, 90.8%, 87.6%, and 84.2%, respectively) and tubular, cribriform, mucinous, papillary, and adenoid cystic carcinoma by breast cancer-specific survival (BCSS) (99.4%, 98.4%, 97.7%, 95.2%, and 94.9%, respectively). A network meta-analysis combining 11 studies (886,649 patients) was conducted, which demonstrated consistent outcomes. SEER-based analyses revealed that, among the favorable subtypes, systemic chemotherapy did not improve OS or BCSS in hormone receptor-positive, node-negative patients, validating that these subtypes are generally associated with excellent outcomes, for which systemic chemotherapy may not be warranted.

CONCLUSIONS

Our data are consistent with guidelines suggesting that the mucinous, tubular, and papillary subtypes of breast cancer have favorable histologies. SEER data and meta-analysis supports this favorable category to include adenoid cystic and cribriform carcinoma, whose OS and BCSS outcomes are comparable to the former three. These findings add to the body of data, suggesting that patients with these histologic subtypes confer excellent prognosis, which may guide optimal therapeutic management strategies.

Comparison of Patient Susceptibility Genes Across Breast Cancer: Implications for Prognosis and Therapeutic Outcomes

Hereditary breast cancer syndromes affect a small (10–15% of cases) but significant group of patients. BRCA1 and BRCA2 are the most familiar and well-studied genes associated with inherited breast cancer. However, mutations in the high-penetrance genes, TP53, PTEN, CDH1, MSH1, MLH1, MSH6, PMS2, PALB2, and STK11, and in the moderate-penetrance genes, CHEK2, ATM, and BRIP1, also correlate with high lifetime risks of breast cancer and other malignancies as well. Advances in breast cancer genetics have led to an improved perception of diagnosis and screening strategies. The specific considerations and challenges involved in treating this unique population have become a fertile ground for research. Indeed, these genes and downstream molecular pathways have now become potential therapeutic targets in breast cancer patients, including those with BRCA1 or BRCA2 mutations. This review describes the variety of hereditary breast cancer genes, from their molecular origins to the prognosis and multidisciplinary clinical decision-making processes. Key publications and other reported recent clinical trials and guidelines are provided.

Insights from a Long-Term Follow-Up Evaluation of Early Breast Cancer Outcomes by Tumor Subtype

INTRODUCTION

Our understanding of the granularity of breast cancer (BC) clinical outcomes by biologic subtype may be impaired by limited study follow-up times.

OBJECTIVE

We evaluated the impact of modern immunohistochemistry (IHC)-based BC subtypes on long-term mortality.

METHOD

We used a cohort of 200 women diagnosed with stage I-III BC in the period 1985-1990. Surgical samples underwent centralized pathology review. Multivariate models assessed associations of subtype with overall survival (OS) and BC-related survival (BCRS).

RESULT

42.0% women had luminal A-like, 32.5% luminal B-like/human epidermal growth factor receptor (HER)2-negative, 8.5% had HER2-positive, and 17.0% had triple-negative BC. 53.0% had tumor size (T) >2 cm and 47.5% had a positive nodal status (N). Over 18.7 years of median follow-up (range 0.3-32.0 years),140 deaths were recorded (75 BC-related). Median OS was longest for patients with luminal A-like tumors (21.2 years; 95% confidence interval [CI] 17.4-24.9]). The luminal B-like/HER2-negative subtype was significantly associated with worse BCRS (adjusted hazard ratio [HR] = 1.86; 95% CI 1.09-3.16). After multivariable analysis, T >2 cm (HR [vs. ≤2 cm] = 1.71 [95% CI 1.03-2.84]) and positive N (HR [vs. negative] = 2.19 [95% CI 1.03-4.65]) impacted BCRS.

CONCLUSION

IHC-defined subtype will continue informing treatment algorithms for BC, until more precise tools like molecular profiling become widely available. Although confirmation in larger and adequately powered studies is warranted, modern surrogate subtype definitions produced a valid long-term prognostic stratification in this mature cohort.

Multigene testing in breast cancer: What have we learned from the 21-gene recurrence score assay?

Most invasive breast cancers express hormone receptors (HR) and typically have a favorable prognosis following endocrine therapy. Patients at a higher risk of recurrence can be identified by multigene prognostic classifiers such as the 21-gene recurrence score (RS) assay, 70-gene prognostic signature, PAM-50, 12-gene molecular score, and others. The 21-gene RS assay (Oncotype Dx™, Genomic Health, Redwood City, CA) has level I clinical evidence and is the most widely used multigene assay in North America. The RS assay is based on reverse transcriptase polymerase chain reaction that can be performed on the RNA isolated from formalin-fixed paraffin-embedded tissue. It evaluates the expression of 16 cancer-related genes developed based on a multi-step approach. Due to its ability to assess recurrence risk and predict potential benefit from chemotherapy, the assay is recommended for patients with node-negative, HR-positive, and human epidermal growth factor receptor 2 (HER2)-negative breast cancer by the American Society of Clinical Oncology, National Comprehensive Cancer Network clinical practice guidelines in oncology, European Society for Medical Oncology clinical practice guidelines, and St. Gallen consensus panel guidelines. The RS assay has also been incorporated in the prognostic stage groups in the 8th edition of the American Joint Commission of Cancer staging manual in order to provide essential genomic information for optimal treatment decisions. This review will focus on the utility of the RS assay in HR-positive and HER2-negative breast cancer patients, including risk of distant and locoregional recurrence in node-negative and node-positive tumors, association with radiotherapy, special subtypes of breast cancer, practical issues related to selecting tumors for testing, and overview of the recently published TailorX (Trial Assigning IndividuaLized Options for treatment [Rx]) results.

Rare epithelial breast cancer: surgery and adjuvant therapy

Breast cancer is a heterogenous disease, exhibiting a wide range of morphological phenotypes shaping its prognosis and clinical course. However, optimal management of rarer breast cancer subtypes is often undefined and controversial in literature due to the lack of large studies and randomised trials. This review aims to discuss the treatment of 13 rare epithelial subtypes, focussing on surgery and adjuvant therapies.

Tumor Heterogeneity in Breast Cancer

Breast cancer is a heterogeneous disease and differs greatly among different patients (intertumor heterogeneity) and even within each individual tumor (intratumor heterogeneity). Clinical and morphologic intertumor heterogeneity is reflected by staging systems and histopathologic classification of breast cancer. Heterogeneity in the expression of established prognostic and predictive biomarkers, hormone receptors, and human epidermal growth factor receptor 2 oncoprotein is the basis for targeted treatment. Molecular classifications are indicators of genetic tumor heterogeneity, which is probed with multigene assays and can lead to improved stratification into low- and high-risk groups for personalized therapy. Intratumor heterogeneity occurs at the morphologic, genomic, transcriptomic, and proteomic levels, creating diagnostic and therapeutic challenges. Understanding the molecular and cellular mechanisms of tumor heterogeneity that are relevant to the development of treatment resistance is a major area of research. Despite the improved knowledge of the complex genetic and phenotypic features underpinning tumor heterogeneity, there has been only limited advancement in diagnostic, prognostic, or predictive strategies for breast cancer. The current guidelines for reporting of biomarkers aim to maximize patient eligibility for targeted therapy, but do not take into account intratumor heterogeneity. The molecular classification of breast cancer is not implemented in routine clinical practice. Additional studies and in-depth analysis are required to understand the clinical significance of rapidly accumulating data. This review highlights inter- and intratumor heterogeneity of breast carcinoma with special emphasis on pathologic findings, and provides insights into the clinical significance of molecular and cellular mechanisms of heterogeneity.

The 21-gene recurrence score in special histologic subtypes of breast cancer with favorable prognosis

BACKGROUND/PURPOSE

The 21-gene recurrence score (RS) assay predicts the likelihood of distant recurrence and chemotherapy benefit in early-stage, estrogen receptor (ER)-positive, HER2-negative breast cancer. Data on the RS of special histologic subtypes of invasive breast carcinoma with favorable prognosis are limited.

METHODS

We reviewed our institutional database to identify patients with special histologic subtypes of breast cancer associated with favorable prognosis and available RS results. Our cohort consists of fifty-seven women: thirty-three patients with pure mucinous carcinoma (MC), ten with tubular carcinoma (TC), nine with encapsulated papillary carcinoma (EPC), and five with solid papillary carcinoma (SPC).

RESULTS

Most (44/57, 77.2%) carcinomas had low RS (≤17), and none had high RS (≥31). All EPCs had low RS, but other subtypes had RS 18-30. Higher RS was associated with lower progesterone receptor (PR) expression by immunohistochemistry and lower PR mRNA scores (P ≤ 0.007). No morphologic feature (tumor grade, biopsy site changes, cellular stroma, inflammatory cells) was associated with RS ≥ 18. At a median follow-up of 40 months, the distant recurrence-free survival was 100%. One patient with SPC developed locoregional recurrence at 22 months.

CONCLUSIONS

As the largest series to date, our study raises the question of whether the RS assay is necessary for breast cancers with favorable histology. Reflex testing of node-negative, ER+/HER2- breast cancers may be deferred for these special histologic subtypes, emphasizing the need for multidisciplinary discussions between breast pathologists and other members of the breast cancer team.

Outcomes of special histotypes of breast cancer after adjuvant endocrine therapy with letrozole or tamoxifen in the monotherapy cohort of the BIG 1-98 trial

BACKGROUND

We investigated the outcomes of postmenopausal women with hormone receptor-positive, early breast cancer with special histotypes (mucinous, tubular, or cribriform) enrolled in the monotherapy cohort of the BIG 1-98 trial.

PATIENTS AND METHODS

The intention-to-treat BIG 1-98 monotherapy cohort (5 years of therapy with tamoxifen or letrozole) included 4922 women, of whom 4091 had central pathology review. Histotype groups were defined as: mucinous (N = 100), tubular/cribriform (N = 83), ductal (N = 3257), and other (N = 651). Of 183 women with either mucinous or tubular/cribriform tumors, 96 were randomly assigned to letrozole and 87 to tamoxifen. Outcomes assessed were disease-free survival (DFS), overall survival (OS), breast cancer-free interval (BCFI), and distant recurrence-free interval (DRFI). Median follow-up in the analytic cohort was 8.1 years.

RESULTS

Women with tubular/cribriform breast cancer had the best outcomes for all end points compared with the other three histotypes, and had less breast cancer recurrence (97.5% 5-year BCFI) than those with mucinous (93.5%), ductal (88.9%), or other (89.9%) histotypes. Patients with mucinous or tubular/cribriform carcinoma had better DRFI (5-year rates 97.8% and 98.8%, respectively) than those with ductal (90.9%) or other (92.1%) carcinomas. Within the subgroup of women with special histotypes, we observed a nonsignificant increase in the hazard of breast cancer recurrence with letrozole [hazard (letrozole versus tamoxifen): 3.31, 95% confidence interval 0.94-11.7; P = 0.06].

CONCLUSIONS

Women with mucinous or tubular/cribriform breast cancer have better outcomes than those with other histotypes, although the observation is based on a limited number of events. In postmenopausal women with these histotypes, the magnitude of the letrozole advantage compared with tamoxifen may not be as large in patients with mucinous or tubular/cribriform disease.

CLINICALTRIALSGOV

NCT00004205.

Clinicopathological Characteristics and Survival Outcomes of Invasive Cribriform Carcinoma of Breast: A SEER Population-Based Study

Invasive cribriform carcinoma (ICC) is a rare histologic subtype of breast cancer. We aimed to investigate the clinicopathological characteristics and survival outcomes of ICC.Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 233,337 female patients diagnosed with ICC (n = 618) or infiltrating ductal carcinoma (IDC) (n = 232,719). Univariate and multivariate survival analyses were utilized to calculate and compare disease-specific survival (DSS) and overall survival (OS). A 1:1 paired match was carried out on age, tumor stage, tumor grade, estrogen receptor (ER) status, and progesterone receptor (PR) status. Baseline characteristics and survival outcomes were also analyzed in ER-positive tumors. Subgroup analyses summarized the hazard ratio (HR) of IDC versus ICC using a forest plot.ICCs presented smaller size, lower grade, higher ER and PR positive rate, less nodal metastasis, and were less likely to be treated with mastectomy compared to IDCs. Five-year DSS rates were significantly better for patients with ICC than for patients with IDC (98.8% vs. 93%, P < 0.001). Five-year OS rates were 95.3% versus 90.1% (P < 0.001). After adjustment for common clinicopathological factors in the multivariate analysis, patients with ICC showed limited DSS advantage over the IDC group (HR = 0.75, 95% CI: 0.38-1.51, P = 0.421). No significant difference in DSS nor OS was observed in matched groups between ICC and IDC. Analysis among ER-positive patients revealed similar prognostic factors as among all patients. Survival analysis in different tumor grade subgroups showed no significant difference between ICC and IDC.ICCs have unique clinicopathological characteristics, higher rates of breast-conserving surgery, and more favorable prognosis compared to the overall IDC population. Difference in tumor grade between the 2 groups may partially explain the different outcome. Improved clinical and biological understanding of ICC might lead to more individualized and tailored therapy for breast cancer patients.

Co-delivery of chemosensitizing siRNA and an anticancer agent via multiple monocomplexation-induced hydrophobic association

Synergistic combination of gene targeting and chemotherapy by co-delivering siRNA and anticancer drugs has widely been investigated to develop siRNA-based therapeutics for cancer treatment. Despite clinical potential of this approach, big challenges still remain such as delivery efficiency or stability/biocompatibility of the siRNA delivery system. Here we report a simple and biocompatible co-delivering formulation based on a unique complexation method, i.e., multiple monocomplexation-induced hydrophobic association between Bcl-2 targeting siRNA and a monocationic anticancer agent (benzethonium chloride, BZT). A colloidal formulation of the hydrophobically associated multiple monocomplex (HMplex) composed of siRNA, BZT and Pluronic F-68 was spontaneously constructed by physical mixing of the ternary constituents. In vitro and in vivo studies revealed that the ternary HMplex with a low charge ratio (N/P=4) possesses a tightly complexed stable nanostructure with Pluronic surface and small colloidal size less than 10nm, which allowed for 1) suitable protection of siRNA in serum-rich physiological environment, 2) efficient intracellular transfection into the cytoplasm, and 3) successful peritumoral co-delivery into the tumor tissue with dense interstitial matrix. Compared to non-targeting HMplexes between scrambled siRNA and BZT, Bcl-2 targeting HMplexes enhanced significantly both mRNA down-regulation by siRNA and apoptosis induction by BZT, and thus greatly suppressed the tumor volume when administered to highly aggressive and resistant human breast cancer xenografts (MDA-MB-231) in mice. These results elucidate that the co-complexed siRNA and BZT were liberated by intracellular decomplexation to trigger a synergistically combined therapeutic action. The successful siRNA/chemodrug co-delivery in vivo via peritumoral route and the greatly promoted therapeutic efficacy thereby represent the clinical potential of HMplexes for adjuvant locoregional cancer treatment by gene-targeted combination therapy.

Invasive cribriform carcinoma of the breast: A report of nine cases and a review of the literature

Nine cases of infiltrating cribriform carcinoma (ICC) of the breast are reported and the clinicopathological features, particularly the imaging findings, are analyzed in the present study. Sonograms revealed that all masses exhibited a hypoechoic internal echo texture (9/9) and that a number of masses presented with an irregular shape (8/9), obscure boundary (5/9), partially microlobulated (5/9) or well-circumscribed (4/9) margins, and an inhomogeneous echo (8/9). Mammographic imaging revealed increased radiological density masses (6/8), and sand-like calcification was not observed in all patients. In two patients, the tumors were mammographically occult. Magnetic resonance imaging performed on one patient revealed a slightly high signal intensity on fat-saturated T1- and T2-weighted images. Following contrast enhancement, a homogeneous early enhancement was revealed with a quick ascent and quick descent time-density curve. Immunohistochemistry revealed that all ICCs expressed estrogen receptor and progesterone receptor, but that none were positive for human epidermal growth factor receptor 2. The Ki-67 labeling index was 3.75% (range, 2–5%) in the tumor tissue. Four patients were treated with mastectomy and the others with breast-conserving surgery. Six clinically node-negative patients underwent sentinel lymph node biopsy; three then received axillary lymph node dissection. Following surgery, three patients received adjuvant chemotherapy, radiotherapy and hormonal therapy, respectively. With a median follow-up time of 38 months (range, 4–70 months), one patient developed local recurrence following breast-conserving surgery; axillary lymph nodes and distant metastases were not observed. This study confirms that this type of carcinoma has unique biological characteristics and a favorable prognosis, but that it remains possible to experience local recurrence.

Breast cancer susceptibility risk associations and heterogeneity by E-cadherin tumor tissue expression

E-cadherin is involved in cell-cell adhesion and epithelial-to-mesenchymal transitions. In cancers, loss or inactivation of E-cadherin is associated with epithelial cell proliferation and invasion. Here, we sought to determine, if risk associations for 18 breast cancer susceptibility single nucleotide polymorphisms (SNPs) differed by E-cadherin tumor tissue expression in the Polish Breast Cancer Study (PBCS), using data on 1,347 invasive breast cancer cases and 2,366 controls. E-cadherin expression (low/high) was assessed using immunohistochemical staining of tumor tissue microarrays. Replication data on 2,006 cases and 6,714 controls from the Study of Epidemiology and Risk Factors in Cancer Heredity was used to follow-up promising findings from PBCS. In PBCS, we found the rs11249433 SNP at the 1p11.2 locus to be more strongly associated with risk of E-cadherin low tumors (OR = 1.30, 95 % CI = 1.08-1.56) than with E-cadherin high tumors [OR = 1.06, 95 % CI = 0.95-1.18; case-only p-heterogeneity (p-het) = 0.05]. Findings in PBCS for rs11249433 were replicated in SEARCH. Combined analyses of the two datasets for SNP rs11249433 revealed significant heterogeneity by E-cadherin expression (combined case-only p-het = 0.004). Further, among carriers of rs11249433, the highest risk was seen for E-cadherin low tumors that were ER-positive and of lobular histology. Our results in two independent data sets suggest that rs11249433, which is located between the NOTCH2 and FCGR1B genes within the 1p11.2 locus, is more strongly associated with risk of breast tumors with low or absent E-cadherin expression, and suggest that evaluation of E-cadherin tumor tissue expression may be useful in clarifying breast cancer risk factor associations.

Rare breast tumors: Review of the literature

Breast cancer tumors have different morphological phenotypes and specific histopathological types with particular prognostic and clinical characteristics. The treatment of rare malignant lesions is frequently controversial due to the absence of trials to determine the optimal managements. This review describes the spectrum of rare breast tumors indicating the clinical, epidemiological and treatment characteristics.

Invasive lobular carcinoma of the breast: patient response to systemic endocrine therapy and hormone response in model systems

Invasive lobular carcinoma of the breast (ILC) represents 10-15% of all newly diagnosed breast cancers, affecting ∼30,000 women annually in the United States. However, ILC is critically understudied as a breast cancer subtype. Though the vast majority of ILC are estrogen receptor-positive and present with overall favorable biomarkers, ILC patients do not benefit from improved outcomes versus other breast cancer patients. Patient outcomes, in particular in response to endocrine therapies, are not well understood in ILC, due in large part to the lack of prospective identification in large clinical trials. Further, there is a lack of laboratory models to study cell signaling, hormone response, and endocrine resistance in ILC. In this review, we provide an overview of clinicopathological features of ILC tumors, discuss issues with clinical management, and highlight the disconnect between ILC biomarkers and patient outcomes. We review currently available data on ILC patient outcomes, with a focus on response to endocrine therapy. Additionally, we describe currently available laboratory models for understanding hormone response in ILC cells, and review current data on these model systems. The promise for new insight into ILC, based on extensive representation of the disease in recent large scale genomic studies, is also discussed. Increasing understanding of endocrine response in ILC represents a critical area for future research to improve patient outcomes for this understudied breast cancer subtype.

A pure invasive cribriform carcinoma of the breast with bone metastasis if untreated for thirteen years: a case report and literature review

We report a case of pure invasive cribriform carcinoma of the breast, which had been untreated for thirteen years, being found with bone metastasis at initial presentation, because distant metastasis is rarely found in this tumor. A fifty-nine-year-old postmenopausal woman presented with a large left breast mass. Although she had noticed a lump in a left breast thirteen years ago, she had not sought treatment. The tumor had enlarged gradually since from one year before and become ulcerated. The two enlarged axillary lymph nodes were also palpable. After two cycles of neoadjuvant chemotherapy, she underwent left radial mastectomy with a free skin graft. Emission computed tomography result has confirmed bone metastasis. The histological diagnosis of the tumor revealed the pure invasive cribriform carcinoma, since over than ninety percent of invasive tumor components showed a characteristic cribriform growth, and the remainder was tubular carcinoma. She has been well without evidence of tumor recurrence for seven years after surgery and several routine postoperative therapies. Although with favorable prognosis, pure invasive cribriform carcinoma is still possible to develop into the advanced (Stage four) breast cancer if untreated for a long time. However, the survival of this patient for free disease after several locoregional and systemic therapies maybe provide a supplement for invasive cribriform carcinoma’s excellent prognosis.

Strategies for subtypes--dealing with the diversity of breast cancer: highlights of the St. Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2011

The 12th St Gallen International Breast Cancer Conference (2011) Expert Panel adopted a new approach to the classification of patients for therapeutic purposes based on the recognition of intrinsic biological subtypes within the breast cancer spectrum. For practical purposes, these subtypes may be approximated using clinicopathological rather than gene expression array criteria. In general, systemic therapy recommendations follow the subtype classification. Thus, 'Luminal A' disease generally requires only endocrine therapy, which also forms part of the treatment of the 'Luminal B' subtype. Chemotherapy is considered indicated for most patients with 'Luminal B', 'Human Epidermal growth factor Receptor 2 (HER2) positive', and 'Triple negative (ductal)' disease, with the addition of trastuzumab in 'HER2 positive' disease. Progress was also noted in defining better tolerated local therapies in selected cases without loss of efficacy, such as accelerated radiation therapy and the omission of axillary dissection under defined circumstances. Broad treatment recommendations are presented, recognizing that detailed treatment decisions need to consider disease extent, host factors, patient preferences, and social and economic constraints.