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

Recurrence in lobular carcinoma of the breast: A 14-year review

INTRODUCTION

The two most common types of breast cancer are invasive or infiltrating ductal carcinoma (IDC) and invasive or infiltrating lobular carcinoma (ILC) (Pestalozzi et al., J. Clin. Oncol., 26, 2008, 3006). Between 5% and 15% of invasive breast carcinomas are lobular carcinomas (Pestalozzi et al., J. Clin. Oncol., 26, 2008, 3006; Dossus and Benusiglio, Breast Cancer Res., 17, 2015, 37; Braunstein et al., Breast Cancer Res. Treat., 149, 2015, 555). The paucity of data relating to recurrence rates of lobular cancers prompted this study.

METHODS

A retrospective cohort study of all cases of lobular breast carcinoma reported to the Western Australia Cancer Registry with the clinical and pathological details between 2000 and 2014.

RESULTS

Overall, 2463 subjects with a total of 2526 events of invasive lobular carcinoma of the breast. 11/2463 (0.45%) subjects met criteria for local recurrence of invasive lobular breast cancer, with an incidence of 1 in 224.

CONCLUSION

There are clinical implications for the management and follow-up for patients with a diagnosis of lobular cancer of the breast. Due to the low recurrence rate, now, the standard practice in our institution does not offer magnetic resonance imaging (MRI) as part of the follow-up for ILC patients. Other centres should establish local recurrence rates to aid development of appropriate management protocols.

Ocular and Periocular Metastasis in Breast Cancer: Clinical Characteristics, Prognostic Factors and Treatment Outcome

BACKGROUND

Breast cancer remains a leading cause of cancer-related mortality and morbidity worldwide. Ocular and periocular metastasis present as a rare but clinically significant manifestation. This study aims to explore demographics and clinical aspects of ocular and periocular metastasis in breast cancer patients.

METHODS

A retrospective cohort study comprising 45 breast cancer patients with ocular or periocular metastasis treated between 2013 and 2023. Patient demographics, tumor characteristics, diagnostic methods, treatment modalities, visual outcomes, and survival data were analyzed.

RESULTS

Among 9902 breast cancer patients, 0.5% developed ocular or periocular metastasis, constituting 2.4% of metastatic cases. The median age was 50 years. Ocular metastasis timing varied: 5% before breast cancer, 24% concurrent, 22% within a year, and 49% after. The most common presentations included incidental MRI findings (42%) and vision decline (31%). Metastasis involved the orbit (47%), choroid (40%), optic nerve (11%), and iris (2%), with 44% having bilateral involvement. Predictive factors included invasive lobular carcinoma (ILC) (p < 0.0001) and brain metastasis (p < 0.0001), with ILC exhibiting a sixfold higher likelihood of ocular metastasis than invasive ductal carcinoma (IDC). Primary treatment was radiation therapy (89%), yielding a 55% maintenance of excellent vision (<0.5), with 93% developing dry eye disease. Patients with ocular metastasis faced an increased risk of disease-related mortality (p < 0.0001), with 71% succumbing within 10 months post-diagnosis.

CONCLUSIONS

Ocular metastasis in breast cancer is rare (0.5%) but signifies poor outcome. It is linked to ILC and concurrent brain metastasis. Primary treatment involves radiation therapy, with a favorable visual prognosis.

Metastatic Occult Primary Lobular Breast Cancer: A Case Report

Breast cancer is the most common malignancy diagnosed in women. Invasive lobular breast cancer (ILC) is the second most common histologic subtype after invasive ductal carcinoma. Metastatic occult primary breast cancer, although rare, is a well-known clinical entity that usually presents with axillary lymphadenopathy without a detectable breast tumour. A perimenopausal woman in her 50s presented with abdominal pain, fatigue, and weight loss. Imaging showed peritoneal carcinomatosis with ascites, ovarian masses, and a lesion in the ascending colon. Gastric and colon biopsies showed infiltration from lobular breast cancer. Diagnostic workup, including mammography, breast ultrasound, and breast MRI, showed no evidence of breast pathology or axillary lymphadenopathy. First-line treatment with goserelin, letrozole, and palbociclib commenced with clinical improvement and radiological response. This case illustrates the challenges faced by clinicians in the diagnosis and treatment of lobular breast cancer without an identifiable primary lesion or axillary lymphadenopathy.

Breast surgery after neoadjuvant chemotherapy in patients with lobular carcinoma: surgical and oncologic outcome

INTRODUCTION

Breast cancer patients with invasive lobular carcinoma (ILC) have an increased risk of positive margins after surgery and often show little response to neoadjuvant chemotherapy (NAC). We aimed to investigate surgical outcomes in patients with ILC treated with NAC.

METHODS

In this retrospective cohort study, all breast cancer patients with ILC treated with NAC who underwent surgery at the Netherlands Cancer Institute from 2010 to 2019 were selected. Patients with mixed type ILC in pre-NAC biopsies were excluded if the lobular component was not confirmed in the surgical specimen. Main outcomes were tumor-positive margins and re-excision rate. Associations between baseline characteristics and tumor-positive margins were assessed, as were complications, locoregional recurrence rate (LRR), recurrence-free survival (RFS), and overall survival (OS).

RESULTS

We included 191 patients. After NAC, 107 (56%) patients had breast conserving surgery (BCS) and 84 (44%) patients underwent mastectomy. Tumor-positive margins were observed in 67 (35%) patients. Fifty five (51%) had BCS and 12 (14%) underwent mastectomy (p value < 0.001). Re-excision was performed in 35 (33%) patients with BCS and in 4 (5%) patients with mastectomy. Definitive surgery was mastectomy in 107 (56%) patients and BCS in 84 (44%) patients. Tumor-positive margins were associated with cT ≥ 3 status (OR 4.62, 95% CI 1.26-16.98, p value 0.021) in the BCS group. Five-year LRR (4.7%), RFS (81%), and OS (93%) were not affected by type of surgery after NAC.

CONCLUSION

Although 33% of ILC breast cancer patients undergoing BCS after NAC required re-excision for positive resection margins, it is considered safe given that five-year RFS remained excellent and LRR and OS did not differ by extent of surgery.

Prevalence of targetable genomic alterations in young women with advanced breast cancer: a cross-sectional study

PURPOSE

Approximately 5% of breast cancers each year are diagnosed in young women < 40 years who tend to have worse clinical outcomes. We compared genomic alterations using comprehensive genomic profiling (CGP) of tumor tissue among very young women (< 30 years) and young women (30-39 years) compared to women ≥ 40 years at diagnosis.

METHODS

2049 advanced breast cancer cases were submitted to Foundation Medicine within a 22-month window for CGP. Hybrid-capture based CGP was performed to evaluate all classes of genomic alterations. Tumor mutational burden was determined on at least 0.8 Mbp of sequenced DNA and microsatellite instability was determined on at least 95 loci. Immunocyte PD-L1 expression was determined by immunohistochemistry.

RESULTS

Of the total cases, 28 (1.37%) were < 30 years, 159 (7.76%) were 30-39 years, and 1862 (90.87%) were ≥ 40 at time of diagnosis. Breast tumors were less likely to be estrogen receptor positive in younger women (54% of < 30 years, p > 0.05; 60% of 30-39 years, p < 0.001; 69.4% of ≥ 40 years) and more likely to be triple negative (43%, p = 0.05; 33%, p = 0.05; 26.1% respectively). Young women had higher rates of BRCA1 mutations (17.9% <30 years, p < 0.001; 10.1% 30-39 years, p < 0.001; 2.6% ≥40 years), but lower rates of CDH1 (7.1% <30 years, p > 0.05; 5.0% 30-39 years, p < 0.001; 15.4% ≥40 years) and PIK3CA mutations (17.9% <30 years, p = 0.02; 17.6% 30-39 years, p < 0.001; 40.0% ≥40 years).

CONCLUSION

Our findings contribute to the growing literature demonstrating unique genetic profiles among young women diagnosed with breast cancer, compared to older women.

The impact of histologic subtype on primary site surgery in the management of metastatic lobular versus ductal breast cancer: a population based study from the National Cancer Database (NCDB)

PURPOSE

Primary site surgery for metastatic breast cancer improves local control but does not impact overall survival. Whether histologic subtype influences patient selection for surgery is unknown. Given differences in surgical management between early-stage lobular versus ductal disease, we evaluated the impact of histology on primary site surgery in patients with metastatic breast cancer.

METHODS

The National Cancer Database (NCDB, 2010-2016) was queried for patients with stage IV HR-positive, HER2-negative invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC). We compared clinicopathologic features, primary site surgery rates, and outcomes by histologic subtype. Multivariable Cox proportional hazard models with and without propensity score matching were used for overall survival (OS) analyses.

RESULTS

In 25,294 patients, primary site surgery was slightly but significantly less common in the 6,123 patients with ILC compared to the 19,171 patients with IDC (26.9% versus 28.8%, p = 0.004). Those with ILC were less likely to receive chemotherapy (41.3% versus 47.4%, p < 0.0001) or radiotherapy (29.1% versus 37.9%, p < 0.0001), and had shorter OS. While mastectomy rates were similar, those with ILC who underwent lumpectomy had significantly higher positive margin rates (ILC 15.7% versus IDC 11.2%, p = 0.025). In both groups, the odds of undergoing surgery decreased over time, and were higher in younger patients with T2/T3 tumors and higher nodal burden.

CONCLUSION

Lobular histology is associated with less primary site surgery, higher positive margin rates, less radiotherapy and chemotherapy, and shorter OS compared to those with HR-positive HER2-negative IDC. These findings support the need for ILC-specific data and treatment approaches in the setting of metastatic disease.

Deep learning and transfer learning identify breast cancer survival subtypes from single-cell imaging data

BACKGROUND

Single-cell multiplex imaging data have provided new insights into disease subtypes and prognoses recently. However, quantitative models that explicitly capture single-cell resolution cell-cell interaction features to predict patient survival at a population scale are currently missing.

METHODS

We quantified hundreds of single-cell resolution cell-cell interaction features through neighborhood calculation, in addition to cellular phenotypes. We applied these features to a neural-network-based Cox-nnet survival model to identify survival-associated features. We used non-negative matrix factorization (NMF) to identify patient survival subtypes. We identified atypical subpopulations of triple-negative breast cancer (TNBC) patients with moderate prognosis and Luminal A patients with poor prognosis and validated these subpopulations by label transferring using the UNION-COM method.

RESULTS

The neural-network-based Cox-nnet survival model using all cellular phenotype and cell-cell interaction features is highly predictive of patient survival in the test data (Concordance Index > 0.8). We identify seven survival subtypes using the top survival features, presenting distinct profiles of epithelial, immune, and fibroblast cells and their interactions. We reveal atypical subpopulations of TNBC patients with moderate prognosis (marked by GATA3 over-expression) and Luminal A patients with poor prognosis (marked by KRT6 and ACTA2 over-expression and CDH1 under-expression). These atypical subpopulations are validated in TCGA-BRCA and METABRIC datasets.

CONCLUSIONS

This work provides an approach to bridge single-cell level information toward population-level survival prediction.

Inhibiting KLRB1 expression is associated with impairing cancer immunity and leading to cancer progression and poor prognosis in breast invasive carcinoma patients

BACKGROUND

The association between Killer cell lectin like receptor B1 (KLRB1) and cancer has been reported, but the roles of KLRB1 in breast invasive carcinoma (BRCA) has not been fully revealed.

METHODS

Our study utilized the Cancer Genome Atlas (TCGA), Kaplan-Meier (K-M) Plotter, and TIMER databases to investigate the expression and clinical relevance of KLRB1 in BRCA and to explore its roles and mechanism in BRCA progression using gene set enrichment analysis, CCK-8, migration, apoptosis, and western blotting. We examined the relationship between KLRB1 expression and the BRCA immune microenvironment, using data from TCGA, and Gene Expression Profiling Interactive Analysis (GEPIA) databases and validated these findings in K-M Plotter databases.

RESULTS

A significant decrease of KLRB1 expression was observed in BRCA patients. BRCA patients with low KLRB1 levels were associated with older age, advanced disease stage, HER2-positivity, poor prognosis, and a decreased survival probability compared to the high-expression group. Increased KLRB1 expression levels were correlated with inhibition of breast cancer cell proliferation, migration, and invasion, as well as promotion of cell apoptosis, possible through regulation of the NF-κB, PI3K/AKT, and TNF signaling pathways. Moreover, the study also indicated that decreased KLRB1 expression correlated with tumor purity, immune score, and immune cell infiltration (B cells, CD8+ T cells, CD4+ T cells, neutrophils, dendritic cells, among others), cell markers, and immunotherapy.

CONCLUSION

Decreased KLRB1 expression in BRCA is associated with poor prognosis and immune microenvironment. This study also highlights KLRB1 as a potential molecular marker for poor prognosis in BRCA patients, and therefore, it may provide clinical implications for the management of patients with BRCA.

PATHOLOGICAL SIGNIFICANCE OF CDH1/E-CADHERIN GERMLINE SEQUENCE VARIANTS IN BREAST CANCER PATIENTS

BACKGROUND

Germline alterations of the CDH1 (E-cadherin) tumor suppressor gene have been reported in several epithelial malignancies like hereditary diffuse gastric cancer and lobular breast cancer. E-cadherin plays a central role in proliferation, maintenance of cell-to-cell adhesion, polarity, and epithelial-mesenchymal transition of tissue cells. It is necessary to analyze the impact of the CDH1 germline sequence variants on protein and predict its clinical significance in breast cancer (BC) progression. The aim of the current study was to evaluate the impact and association of CDH1 gene potentially pathogenic variants/likely pathogenic variants (PVs/LPVs) with the initiation and progression of BC.

MATERIALS AND METHODS

In this study, the clinical data of 200 BC patients have been analyzed based on the type of BC, age, grade, stage, hormonal status, and risk factors. Blood samples from 50 healthy donors were used as a control. Furthermore, CDH1 gene molecular analysis, along with in silico analysis, was provided to assess the invasiveness and progression of BC caused by the E-cadherin protein.

RESULTS

Four variants were identified by genetic screening within the CDH1 gene that included variations in exons 7, 8, 10, 11, and 13. Exon 10 had splice site mutation at position c.1337C>A, affecting the protein structure. In exon 11, there was an insertion of T base at position 1669, resulting in truncated protein compared to a normal one that can lead to the disease-causing non- sense-mediated decay and exon 13 variant c.2076T>C has already known polymorphism. In silico analysis of CDH1 showed the presence of the different variants that indicated the overall disruption of protein structure and function.

CONCLUSIONS

The further functional analysis of these variants and their association with BC can be ensured by increasing the sample size and in vivo studies using mouse models.

Deep-learning and transfer learning identify new breast cancer survival subtypes from single-cell imaging data

Quantitative models that explicitly capture single-cell resolution cell-cell interaction features to predict patient survival at population scale are currently missing. Here, we computationally extracted hundreds of features describing single-cell based cell-cell interactions and cellular phenotypes from a large, published cohort of cyto-images of breast cancer patients. We applied these features to a neural-network based Cox-nnet survival model and obtained high accuracy in predicting patient survival in test data (Concordance Index > 0.8). We identified seven survival subtypes using the top survival features, which present distinct profiles of epithelial, immune, fibroblast cells, and their interactions. We identified atypical subpopulations of TNBC patients with moderate prognosis (marked by GATA3 over-expression) and Luminal A patients with poor prognosis (marked by KRT6 and ACTA2 over-expression and CDH1 under-expression). These atypical subpopulations are validated in TCGA-BRCA and METABRIC datasets. This work provides important guidelines on bridging single-cell level information towards population-level survival prediction.

STATEMENT OF TRANSLATIONAL RELEVANCE

Our findings from a breast cancer population cohort demonstrate the clinical utility of using the single-cell level imaging mass cytometry (IMC) data as a new type of patient prognosis prediction marker. Not only did the prognosis prediction achieve high accuracy with a Concordance index score greater than 0.8, it also enabled the discovery of seven survival subtypes that are more distinguishable than the molecular subtypes. These new subtypes present distinct profiles of epithelial, immune, fibroblast cells, and their interactions. Most importantly, this study identified and validated atypical subpopulations of TNBC patients with moderate prognosis (GATA3 over-expression) and Luminal A patients with poor prognosis (KRT6 and ACTA2 over-expression and CDH1 under-expression), using multiple large breast cancer cohorts.

The impact of histologic subtype on primary site surgery in the management of metastatic lobular versus ductal breast cancer: a population based study from the National Cancer Database

Purpose

Primary site surgery for metastatic breast cancer improves local control but does not impact overall survival. Whether histologic subtype influences patient selection for surgery is unknown. Given differences in surgical management between early-stage lobular versus ductal disease, we evaluated the impact of histology on primary site surgery in patients with metastatic breast cancer.

Methods

The National Cancer Database (NCDB, 2010-2016) was queried for patients with stage IV HR-positive, HER2-negative invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC). We compared clinicopathologic features, primary site surgery rates, and outcomes by histologic subtype. Multivariable Cox proportional hazard models with and without propensity score matching were used for overall survival (OS) analyses.

Results

In 25,294 patients, primary site surgery was slightly but significantly less common in the 6,123 patients with ILC compared to the 19,171 patients with IDC (26.9% versus 28.8%, p = 0.004). Those with ILC were less likely to receive chemotherapy (41.3% versus 47.4%, p < 0.0001) or radiotherapy (29.1% versus 37.9%, p < 0.0001), and had shorter OS. While mastectomy rates were similar, those with ILC had more positive margins (10.6% versus 8.3%, p = 0.005). In both groups, the odds of undergoing surgery decreased over time, and were higher in younger patients with T2/T3 tumors and higher nodal burden.

Conclusion

Lobular histology is associated with less primary site surgery, higher positive margin rates, less radiotherapy and chemotherapy, and shorter OS compared to those with HR-positive HER2-negative IDC. These findings support the need for ILC-specific data and treatment approaches in the setting of metastatic disease.

Breast-Conserving Surgery Margin Guidance Using Micro-Computed Tomography: Challenges When Imaging Radiodense Resection Specimens

BACKGROUND

Breast-conserving surgery (BCS) is an integral component of early-stage breast cancer treatment, but costly reexcision procedures are common due to the high prevalence of cancer-positive margins on primary resections. A need exists to develop and evaluate improved methods of margin assessment to detect positive margins intraoperatively.

METHODS

A prospective trial was conducted through which micro-computed tomography (micro-CT) with radiological interpretation by three independent readers was evaluated for BCS margin assessment. Results were compared to standard-of-care intraoperative margin assessment (i.e., specimen palpation and radiography [abbreviated SIA]) for detecting cancer-positive margins.

RESULTS

Six hundred margins from 100 patients were analyzed. Twenty-one margins in 14 patients were pathologically positive. On analysis at the specimen-level, SIA yielded a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 42.9%, 76.7%, 23.1%, and 89.2%, respectively. SIA correctly identified six of 14 margin-positive cases with a 23.5% false positive rate (FPR). Micro-CT readers achieved sensitivity, specificity, PPV, and NPV ranges of 35.7-50.0%, 55.8-68.6%, 15.6-15.8%, and 86.8-87.3%, respectively. Micro-CT readers correctly identified five to seven of 14 margin-positive cases with an FPR range of 31.4-44.2%. If micro-CT scanning had been combined with SIA, up to three additional margin-positive specimens would have been identified.

DISCUSSION

Micro-CT identified a similar proportion of margin-positive cases as standard specimen palpation and radiography, but due to difficulty distinguishing between radiodense fibroglandular tissue and cancer, resulted in a higher proportion of false positive margin assessments.

Treatment and outcome in metastatic lobular breast cancer in the prospective German research platform OPAL

PURPOSE

Evidence about routine treatment and outcome of patients with invasive lobular cancer (ILC) is limited, especially regarding metastatic disease. Here we present prospective real-world data of patients with metastatic ILC (mILC) as compared to patients with metastatic invasive ductal cancer (mIDC) receiving systemic therapy in routine care in Germany.

METHODS

Prospective data on patient and tumor characteristics, treatments, and outcomes of patients with mILC (n = 466) and mIDC (n = 2100), recruited between 2007 and 2021 into the Tumor Registry Breast Cancer/OPAL were analyzed.

RESULTS

Compared to mIDCs, patients with mILC were older at start of first-line treatment (median 69 vs. 63 years) and had more often lower grade (G1/G2: 72.8% vs. 51.2%), hormone receptor (HR)-positive (83.7% vs. 73.2%) and less often HER2-positive (14.2% vs. 28.6%) tumors, which metastasized more frequently to the bone (19.7% vs. 14.5%) or peritoneum (9.9% vs. 2.0%), and less frequently to the lungs (0.9% vs. 4.0%). Median OS of patients with mILC (n = 209) and mIDC (n = 1158) was 30.2 months [95% confidence interval (CI) 25.3, 36.0] and 33.7 months [95% CI 30.3, 37.9], respectively. Multivariate survival analysis did not show a significant prognostic impact of the histological subtype [HR mILC vs. mIDC 1.18 (95% CI 0.97-1.42)].

CONCLUSION

Overall, our real-world data confirm clinicopathological differences between mILC and mIDC breast cancer patients. Despite patients with mILC presenting with some favorable prognostic factors, ILC histopathology was not associated with a better clinical outcome in multivariate analysis, suggesting the need for more tailored treatment strategies for patients with the lobular subtype.

Non-enhancing malignant lesions of the breast: A case report and review of literature

Due to the elusive nature of invasive lobular carcinoma, mammography, ultrasound, and magnetic resonance imaging have their limitations in early detection. A 67-year-old woman presented for mammography and found retraction of breast parenchyma of the right breast. Magnetic resonance imaging and contrast mammography showed no contrast uptake in the region in question. Magnetic resonance imaging and ultrasound were found to be superior for the detection of invasive lobular carcinoma, with a sensitivity of more than 90%. On ultrasound examination, invasive lobular carcinoma may occur only with posterior acoustic shadowing. On breast magnetic resonance imaging, it is commonly described as an irregular mass and less commonly as non-mass enhancement. An additional advantage of magnetic resonance imaging is the higher detection rate of multifocal, multicentric, and contralateral breast lesions. The reason for no contrast enhancement in this particular tumor before neoadjuvant chemotherapy followed by enhancement after neoadjuvant chemotherapy is most likely at the molecular and histologic level and requires further investigation in similar cases.

Case Report: Small intestinal metastatic breast cancer: A case report and literature review

Breast cancer is considered a malignant tumor with the highest incidence among women and is prone to develop distant metastasis. Small intestinal metastasis of breast cancer, however, is relatively rare. This case report describes a 49-year-old Chinese female patient who presented with small intestinal obstruction and was diagnosed with lobular breast cancer with small intestinal and contralateral breast metastasis. Clinical manifestations, clinicopathological features and potential mechanisms of metastasis, along with diagnosis and treatment, are discussed with a review of the relevant literature. Although small intestinal metastasis is rare in breast cancer, we should keep high alert on the possibility of gastrointestinal metastasis when treating lobular breast cancer patients.

Circulating tumour DNA characterisation of invasive lobular carcinoma in patients with metastatic breast cancer

BACKGROUND

Limited data exist to characterise molecular differences in circulating tumour DNA (ctDNA) for patients with invasive lobular carcinoma (ILC). We analysed metastatic breast cancer patients with ctDNA testing to assess genomic differences among patients with ILC, invasive ductal carcinoma (IDC), and mixed histology.

METHODS

We retrospectively analysed 980 clinically annotated patients (121 ILC, 792 IDC, and 67 mixed histology) from three academic centers with ctDNA evaluation by Guardant360™. Single nucleotide variations (SNVs), copy number variations (CNVs), and oncogenic pathways were compared across histologies.

FINDINGS

ILC was significantly associated with HR+ HER2 negative and HER2 low. SNVs were higher in patients with ILC compared to IDC or mixed histology (Mann Whitney U test, P < 0.05). In multivariable analysis, HR+ HER2 negative ILC was significantly associated with mutations in CDH1 (odds ratio (OR) 9.4, [95% CI 3.3-27.2]), ERBB2 (OR 3.6, [95% confidence interval (CI) 1.6-8.2]), and PTEN (OR 2.5, [95% CI 1.05-5.8]) genes. CDH1 mutations were not present in the mixed histology cohort. Mutations in the PI3K pathway genes (OR 1.76 95% CI [1.18-2.64]) were more common in patients with ILC. In an independent cohort of nearly 7000 metastatic breast cancer patients, CDH1 was significantly co-mutated with targetable alterations (PIK3CA, ERBB2) and mutations associated with endocrine resistance (ARID1A, NF1, RB1, ESR1, FGFR2) (Benjamini-Hochberg Procedure, all q < 0.05).

INTERPRETATION

Evaluation of ctDNA revealed differences in pathogenic alterations and oncogenic pathways across breast cancer histologies with implications for histologic classification and precision medicine treatment.

FUNDING

Lynn Sage Cancer Research Foundation, OncoSET Precision Medicine Program, and UL1TR001422.

Association of Body Mass Index With 21-Gene Recurrence Score Among Women With Estrogen Receptor-Positive, ERBB2-Negative Breast Cancer

IMPORTANCE

Body mass index (BMI) may affect the 21-gene recurrence score (RS) in patients with ER-positive, ERBB2-negative breast cancer. If high BMI increases genomic risk in ER-positive, ERBB2-negative breast cancer, weight control will become more important.

OBJECTIVE

To assess the association between RS and BMI according to age groups and address BMI as a factor associated with high RS.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 2295 patients with ER-positive, ERBB2-negative breast cancer who had undergone a multigene assay between March 29, 2010, and December 31, 2020, in 2 hospitals. All of the study patients were Korean women, and the median follow-up period was 45 months (range, 1-40 months). The correlations between continuous RS and BMI were investigated. A high BMI was defined as a body mass index greater than or equal to 25. In the younger age group (age ≤45 years), a high RS was defined as an RS of greater than 20.

EXPOSURES

Body mass index.

MAIN OUTCOMES AND MEASURES

The Pearson correlation coefficient was used to estimate the association between RS and BMI. A multivariable binary logistic model was used to identify high RS.

RESULTS

Among the 2295 women included (mean [SD] age, 49.8 [4.00] years; range, 22-81 years), 776 were aged 45 years or younger; RS and BMI were weakly correlated (correlation coefficient, 0.119; P < .001) in this younger group. Among them, the proportion of patients with an RS greater than 20 was significantly higher in the high BMI group than in the normal BMI group (45.5% [46 of 101] vs 27.3% [184 of 675]; P < .001). In the multivariable analysis, high BMI was an associated factor for high RS (odds ratio, 2.06; 95% CI, 1.28-3.32; P = .003). The 21-gene multigene assay-guided chemotherapy rate was significantly higher in patients with high BMI (30.7% [31 of 101] vs 20.2% [136 of 674]; P = .02).

CONCLUSIONS AND RELEVANCE

In this cohort study of women aged 45 years or younger, high BMI was associated with higher RS in those with ER-positive, ERBB2-negative breast cancer; further studies are necessary to examine the underlying mechanisms.

Surgical Management of the Axilla in Invasive Lobular Carcinoma in the Z1071 Era: A Propensity-Score Matched Analysis of the National Cancer Database

In patients with invasive lobular carcinoma (ILC) and clinically positive nodes (cN1) who demonstrate an axillary clinical response to neoadjuvant-chemotherapy (NAC), the outcomes of sentinel lymph node biopsy (SLNB) compared to axillary lymph node dissection (ALND) are not well studied. We sought to evaluate axillary surgery practice patterns and the resultant impact on overall survival (OS) in cN1 ILC. The National Cancer Database (NCDB) was queried (2012-2017) for women with cN1 ILC who were treated with NAC followed by surgery. Propensity-score matching was performed between SLNB and ALND cohorts. Kaplan-Meier and Cox regression analyses were performed to identify predictors of OS. Of 1390 patients, 1192 were luminal A ILCs (85.8%). 143 patients (10.3%) had a complete axillary clinical response, while 1247 (89.7%) had a partial clinical response in the axilla. Definitive axillary surgery was SLNB in 211 patients (15.2%). Utilization of SLNB for definitive axillary management increased from 8% to 16% during the study period. Among 201 propensity-score matched patients stratified by SLNB vs. ALND, mean OS did not significantly differ (81.6 ± 1.8 vs. 81.4 ± 2.0 months; p = 0.56). Cox regression analysis of the entire cohort demonstrated that increasing age, grade, HER2+ and triple-negative tumors, and partial clinical response were unfavorable OS predictors (p < 0.02 each). The definitive axillary operation and administration of adjuvant axillary radiation did not influence OS. In cN1 ILC patients with a clinical response to NAC in the axilla, SLNB vs. ALND did not affect OS. Further axillary therapy may be warranted with ypN+ disease.

Overcoming therapeutic resistance to platinum-based drugs by targeting Epithelial–Mesenchymal transition

Platinum-based drugs (PBDs), including cisplatin, carboplatin, and oxaliplatin, have been widely used in clinical practice as mainstay treatments for various types of cancer. Although there is firm evidence of notable achievements with PBDs in the management of cancers, the acquisition of resistance to these agents is still a major challenge to efforts at cure. The introduction of the epithelial-mesenchymal transition (EMT) concept, a critical process during embryonic morphogenesis and carcinoma progression, has offered a mechanistic explanation for the phenotypic switch of cancer cells upon PBD exposure. Accumulating evidence has suggested that carcinoma cells can enter a resistant state via induction of the EMT. In this review, we discussed the underlying mechanism of PBD-induced EMT and the current understanding of its role in cancer drug resistance, with emphasis on how this novel knowledge can be exploited to overcome PBD resistance via EMT-targeted compounds, especially those under clinical trials.

Risk of metachronous contralateral breast cancer in patients with primary invasive lobular breast cancer: Results from a nationwide cohort

Lobular primary breast cancer (PBC) histology has been proposed as a risk factor for contralateral breast cancer (CBC), but results have been inconsistent. We investigated CBC risk and the impact of systemic therapy in lobular versus ductal PBC. Further, CBC characteristics following these histologic subtypes were explored. We selected 74,373 women diagnosed between 2003 and 2010 with stage I-III invasive PBC from the nationwide Netherlands Cancer Registry. We assessed absolute risk of CBC taking into account competing risks among those with lobular (n = 8903), lobular mixed with other types (n = 3512), versus ductal (n = 62,230) histology. Hazard ratios (HR) for CBC were estimated in a cause-specific Cox model, adjusting for age at PBC diagnosis, radiotherapy, chemotherapy and/or endocrine therapy. Multivariable HRs for CBC were 1.18 (95% CI: 1.04-1.33) for lobular and 1.37 (95% CI: 1.16-1.63) for lobular mixed versus ductal PBC. Ten-year cumulative CBC incidences in patients with lobular, lobular mixed versus ductal PBC were 3.2%, 3.6% versus 2.8% when treated with systemic therapy and 6.6%, 7.7% versus 5.6% in patients without systemic therapy, respectively. Metachronous CBCs were diagnosed in a less favourable stage in 19%, 26% and 23% and less favourable differentiation grade in 22%, 33% and 27% than the PBCs of patients with lobular, lobular mixed and ductal PBC, respectively. In conclusion, lobular and lobular mixed PBC histology are associated with modestly increased CBC risk. Personalised CBC risk assessment needs to consider PBC histology, including systemic treatment administration. The impact on prognosis of CBCs with unfavourable characteristics warrants further evaluation.

A Scoping Review on the Status of Female Breast Cancer in Asia with a Special Focus on Nepal

This study aimed to provide updated evidence on the status of female breast cancer and cancer treatment facilities in Asia, with a special focus on Nepal. This review used search phrases that included, breast neoplasm or cancer, health status, epidemiology, breast cancer survivors, cancer care facilities, Asia, Nepal. Researchers examined databases from January 2011 to December 2020 (PubMed, PMC, Google Scholar, and the reference lists of included papers). Studies of any design and reviews, were included in the study, except for qualitative studies. The study findings are presented in a narrative synthesis format using Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews. An initial search resulted in 974 papers, and 896 were reviewed after being checked for duplication using the Zotero software. Accordingly, utilizing the inclusion and exclusion criteria, 188 publications were selected, and after review of titles and abstracts, an additional 98 papers were removed for different reasons. Finally, the study looked at 90 female breast cancer papers. Results showed that the number of cases of breast cancer is growing all around the world, including in Asia and Nepal. Age, early menarche, late menopause, nulliparity, positive family history, excessive fat consumption, alcohol, and smoking are all frequent risk factors for breast cancer found in Asian women. Breast self-examination, clinical breast examination, and mammography screening are common methods for detecting breast carcinoma. Chemotherapy, radiation, and modified mastectomy are commonly used options for treatment. The number of breast cancer survivors is growing throughout the world, indicating better clinical care. There is a paucity of survival data in many Asian countries, including Nepal. There is also a scarcity of health workforce specialized in cancer care and treatment, as well as a few health facilities that are available to treat cancer cases in many Asian countries, including Nepal.

ROSALINE: a phase II, neoadjuvant study targeting ROS1 in combination with endocrine therapy in invasive lobular carcinoma of the breast

Invasive lobular carcinoma (ILC) is the most common histologic subtype of breast cancer after invasive ductal carcinoma (i.e., no special type [NST]). ILC differs from NST in clinical presentation, site-specific metastases and response to conventional therapies. Loss of E-cadherin protein expression, due to alterations in its encoding gene CDH1, is the most frequent oncogenic event in ILC. Synthetic lethality approaches have shown promising antitumor effects of ROS1 inhibitors in models of E-cadherin-defective breast cancer in in vivo studies and provide the rationale for testing their clinical activity in patients with ILC. Entrectinib is a tyrosine kinase inhibitor targeting TRK, ROS1 and ALK tyrosine kinases. Here, the authors present ROSALINE (NCT04551495), a phase II study testing neoadjuvant entrectinib and endocrine therapy in women with estrogen receptor-positive, HER2-negative early ILC.

Generalisation effects of predictive uncertainty estimation in deep learning for digital pathology

Deep learning (DL) has shown great potential in digital pathology applications. The robustness of a diagnostic DL-based solution is essential for safe clinical deployment. In this work we evaluate if adding uncertainty estimates for DL predictions in digital pathology could result in increased value for the clinical applications, by boosting the general predictive performance or by detecting mispredictions. We compare the effectiveness of model-integrated methods (MC dropout and Deep ensembles) with a model-agnostic approach (Test time augmentation, TTA). Moreover, four uncertainty metrics are compared. Our experiments focus on two domain shift scenarios: a shift to a different medical center and to an underrepresented subtype of cancer. Our results show that uncertainty estimates increase reliability by reducing a model’s sensitivity to classification threshold selection as well as by detecting between 70 and 90% of the mispredictions done by the model. Overall, the deep ensembles method achieved the best performance closely followed by TTA.

Invasive Lobular Carcinoma of the Breast With Rectal Metastasis: A Rare Case Report

The rectum is a relatively unusual site for metastasis from invasive lobular carcinoma (ILC) of the breast, and it carries dangers such as perforation and blockage. We reported a case of a 47-year-old female patient complaining of breast ILC for one year. Recently, the patient complained of abdominal distention, mild generalized abdominal pain, and weight loss. The abdominal ultrasound (US) showed moderate ascites without hepatomegaly, and ascitic tapping was positive for malignant cells. Lower colonoscopy showed a congested mass of 8 cm, and anal verge biopsy showed colonic mucosa laminal propria infiltrated with atypical cells and adenocarcinoma metastatic from the breast. In a patient with breast cancer, particularly ILC, who has developed new gastrointestinal tract (GIT) symptoms, there is significantly a high chance of rectal metastatic illness. Early detection is critical for successful treatment.

Cancer Predisposition Genes in Adolescents and Young Adults (AYAs): a Review Paper from the Italian AYA Working Group

PURPOSE OF REVIEW

The present narrative systematic review summarizes current knowledge on germline gene mutations predisposing to solid tumors in adolescents and young adults (AYAs).

RECENT FINDINGS

AYAs with cancer represent a particular group of patients with specific challenging characteristics and yet unmet needs. A significant percentage of AYA patients carry pathogenic or likely pathogenic variants (PV/LPVs) in cancer predisposition genes. Nevertheless, knowledge on spectrum, frequency, and clinical implications of germline variants in AYAs with solid tumors is limited. The identification of PV/LPV in AYA is especially critical given the need for appropriate communicative strategies, risk of second primary cancers, need for personalized long-term surveillance, potential reproductive implications, and cascade testing of at-risk family members. Moreover, these gene alterations may potentially provide novel biomarkers and therapeutic targets that are lacking in AYA patients. Among young adults with early-onset phenotypes of malignancies typically presenting at later ages, the increased prevalence of germline PV/LPVs supports a role for genetic counseling and testing irrespective of tumor type.

Vitamin D and Histological Features of Breast Cancer: Preliminary Data from an Observational Retrospective Italian Study

Background: Vitamin D (vitD) may be involved in different extraskeletal conditions as well as skeletal muscle diseases. It has been hypothesized that, at least in part, a low level of vitD could contribute to facilitating cancer development. Breast cancer (BC) seems to be associated with low levels of vitD. Materials and methods: This was an observational retrospective evaluation of 87 women (mean age: 54 ± 12 years old) who underwent surgery for the treatment of BC. Our main purpose was to correlate the types of BC and the levels of vitD. Results: A positive significant correlation (R > 0.7) was found between non-invasive carcinoma in situ and 25(OH)D levels and age (R = 0.82, p < 0.05). A positive, but nonsignificant, correlation was reported between invasive ductal carcinoma and 25(OH)D and age (R = 0.45, p > 0.05). A negative but nonsignificant correlation was found between invasive lobular carcinoma and 25(OH)D and age (R = 0.24, p > 0.05). Discussion and Conclusions: We did not find a significant relationship between vitD and BC subtypes. Considering the positive significant correlation between vitD levels and age for in situ BC, although preliminary, our results seem to suggest a possible role of vitD in in situ BC. However, these findings need to be confirmed in larger studies.

De novo metastatic lobular breast carcinoma: A population-based study from SEER database

PURPOSE

Patients with metastatic lobular breast carcinoma constitute a heterogeneous group with distinguishing features. Our aim was to describe the features and survival of them, and further subdivide them into subcategories for prognostic stratification and treatment planning.

PATIENTS AND METHODS

Patients with de novo metastatic breast cancer from 2010 to 2018 were identified using the SEER database. Multivariate logistic regression analysis was conducted to calculate odds ratios. The within-pair difference was minimized by propensity score matching. Multiple comparisons based on Cox proportional hazards model were performed to investigate the interactions of M1 subcategory and treatment modality on survival.

RESULTS

A total of 1,675 patients with de novo metastatic lobular breast carcinoma were identified, they were more likely to have HR+/HER2- subtype, low histologic grade, low T/N stage, fewer metastatic sites, but worse prognosis compared with patients with metastatic ductular breast carcinoma. The M1 stage was subdivided into 3 subcategories with significantly different prognoses. The benefits of primary tumor surgery were more pronounced in M1a/b disease, whereas the benefits of chemotherapy increased with the progression of metastatic disease.

CONCLUSION

Patients with metastatic lobular breast carcinoma have unique clinicopathological characteristics and metastatic patterns. M1 subcategory assists prognosis stratification and treatment planning for such patients.

Occupational exposure to organic solvents and breast cancer risk: a systematic review and meta-analysis

Breast cancer is the most common cancer worldwide. Recent studies suggest that organic solvent exposure could be closely related to breast cancer, although the evidence remains controversial. Thus, we evaluated existing epidemiological evidence for the association between occupational solvent exposure and breast cancer. PubMed, Embase, and Cochrane Library were searched to identify published case-control and cohort studies that addressed occupational exposure to organic solvents and breast cancer, up to April, 2021. Meta-analyses using random-effects models were conducted to obtain the pooled odds ratios (OR) and 95% confidence intervals (CI) on the incidence of breast cancer in relation to occupational exposure. The pooled OR of breast cancer among workers exposed to organic solvents overall was 1.18 (95%CI, 1.11 ~ 1.25; I² = 76.3%; 24 studies), compared to those with no exposure. After stratification by menopause and study location, it was revealed that the association between occupational exposure to organic solvents and the risk of breast cancer in postmenopausal women (OR, 1.35; 95% CI, 1.09 ~ 1.67; I² = 73.4%; 7 studies) was significant, and there was also a clear association in workers in Europe (OR, 1.21; 95% CI, 1.12 ~ 1.32; I² = 82.9%; 13 studies). We observed a significant association between occupational exposure to organic solvents and breast cancer in both cohort and case-control studies.

Bioactive cationic peptides as potential agents for breast cancer treatment

Breast cancer continues to affect millions of women worldwide, and the number of new cases dramatically increases every year. The physiological causes behind the disease are still not fully understood. One in every 100 cases can occur in men, and although the frequency is lower than among women, men tend to have a worse prognosis of the disease. Various therapeutic alternatives to combat the disease are available. These depend on the type and progress of the disease, and include chemotherapy, radiotherapy, surgery, and cancer immunotherapy. However, there are several well-reported side effects of these treatments that have a significant impact on life quality, and patients either relapse or are refractory to treatment. This makes it necessary to develop new therapeutic strategies. One promising initiative are bioactive peptides, which have emerged in recent years as a family of compounds with an enormous number of clinical applications due to their broad spectrum of activity. They are widely distributed in several organisms as part of their immune system. The antitumoral activity of these peptides lies in a nonspecific mechanism of action associated with their interaction with cancer cell membranes, inducing, through several routes, bilayer destabilization and cell death. This review provides an overview of the literature on the evaluation of cationic peptides as potential agents against breast cancer under different study phases. First, physicochemical characteristics such as the primary structure and charge are presented. Secondly, information about dosage, the experimental model used, and the mechanism of action proposed for the peptides are discussed.

Germline Pathogenic Variants in Cancer Predisposition Genes Among Women With Invasive Lobular Carcinoma of the Breast

PURPOSE

To determine the contribution of germline pathogenic variants (PVs) in hereditary cancer testing panel genes to invasive lobular carcinoma (ILC) of the breast.

MATERIALS AND METHODS

The study included 2,999 women with ILC from a population-based cohort and 3,796 women with ILC undergoing clinical multigene panel testing (clinical cohort). Frequencies of germline PVs in breast cancer predisposition genes (ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, PALB2, PTEN, RAD51C, RAD51D, and TP53) were compared between women with ILC and unaffected female controls and between women with ILC and infiltrating ductal carcinoma (IDC).

RESULTS

The frequency of PVs in breast cancer predisposition genes among women with ILC was 6.5% in the clinical cohort and 5.2% in the population-based cohort. In case-control analysis, CDH1 and BRCA2 PVs were associated with high risks of ILC (odds ratio [OR] > 4) and CHEK2, ATM, and PALB2 PVs were associated with moderate (OR = 2-4) risks. BRCA1 PVs and CHEK2 p.Ile157Thr were not associated with clinically relevant risks (OR < 2) of ILC. Compared with IDC, CDH1 PVs were > 10-fold enriched, whereas PVs in BRCA1 were substantially reduced in ILC.

CONCLUSION

The study establishes that PVs in ATM, BRCA2, CDH1, CHEK2, and PALB2 are associated with an increased risk of ILC, whereas BRCA1 PVs are not. The similar overall PV frequencies for ILC and IDC suggest that cancer histology should not influence the decision to proceed with genetic testing. Similar to IDC, multigene panel testing may be appropriate for women with ILC, but CDH1 should be specifically discussed because of low prevalence and gastric cancer risk.

Palpable multifocal and multicentric invasive lobular breast carcinoma in a young female

Breast cancer is the most common carcinoma plaguing women in the United States. Invasive lobular carcinoma is the second most prevalent type of breast carcinoma with an incidence rate of 5% and 15% with high propensity for multifocal manifestation of disease. Multifocal disease is defined by two or more malignant foci within a single quadrant. Invasive lobular carcinoma is strongly associated with early menarche, late menopause, late age at first birth, and is typically seen in women ages 50 and older. Invasive lobular carcinoma can be difficult to detect clinically because lesions typically fail to form palpable masses, and it can be challenging to diagnose mammographically due to subtle imaging features of the lesions. Here we present a rare case of a palpable, unilateral, multifocal and multicentric lobular breast carcinoma in a young, previously healthy 41-year-old woman with no family history of breast cancer.

A Rare Metastatic Site of Invasive Lobular Breast Carcinoma: A Case Report

Here, we report a case of a 42-year-old female patient with left lobular breast cancer-gastric metastasis (initially misdiagnosed five years ago as an invasive ductal carcinoma) presenting with dyspepsia, weight loss, and persistent vomiting lasting for four weeks. Upper GI endoscopy revealed evidence of linitis plastica, and histological and immunocytochemical analyses of the biopsy confirmed gastric metastasis secondary to invasive lobular breast carcinoma.

Differences in sensitivity to neoadjuvant chemotherapy among invasive lobular and ductal carcinoma of the breast and implications on surgery-A systematic review and meta-analysis

Meta-analysis of >87,000 patients demonstrates that patients with invasive lobular carcinoma of the breast are far less likely to achieve pCR of the breast or axilla compared to their ductal counterparts, receive less BCS and more frequently return positive margins.

BACKGROUND

Neoadjuvant chemotherapy (NACT) facilitates tumour downstaging, increases breast conserving surgery (BCS) and assesses tumour chemosensitivity. Despite clinicopathological differences in Invasive Ductal Carcinoma (IDC) and Invasive Lobular Carcinoma (ILC), decision making surrounding the use NACT does not take account of histological differences.

AIM

To determine the impact NACT on pathological complete response (pCR), breast conserving surgery (BCS), margin status and axillary pCR in ILC and IDC.

METHODS

A systematic review was performed in accordance with the PRISMA guidelines. Studies reporting outcomes among ILC and IDCs following NACT were identified. Dichotomous variables were pooled as odds ratios (ORs) with 95% confidence intervals_(CI) using the Mantel-Haenszel method. P-values <0.05 were statistically significant.

RESULTS

40 studies including 87,303 (7596 ILC [8.7%]and 79,708 IDC [91.3%]) patients were available for analysis. Mean age at diagnosis was 54.9 vs. 50.9 years for ILC and IDC, respectively. IDCs were significantly more likely to achieve pCR (22.1% v 7.4%, OR: 3.03 [95% CI 2.5-3.68] p < 0.00001), axillary pCR (23.6% vs. 13.4%, OR: 2.01 [95% CI 1.77-2.28] p < 0.00001) and receive BCS (45.7% vs. 33.3%, OR 2.14 [95% CI 1.87-2.45] p < 0.00001) versus ILCs. ILCs were significantly more likely to have positive margins at the time of surgery (36% vs 13.5%, OR 4.84 [95% CI 2.88-8.15] p < 0.00001).

CONCLUSION

This is the largest study comparing the impact of NACT among ILC and IDC with respect to pCR and BCS. ILC has different outcomes to IDC following NACT and incorporate it into treatment decisions and future clinical guidelines.

Obesity and menopausal status impact the features and molecular phenotype of invasive lobular breast cancer

Purpose

We investigated the relationship between obesity, menopausal status, and invasive lobular carcinoma (ILC), the second most common histological subtype of breast cancer. Specifically, we evaluated the association between body mass index (BMI), metabolic syndrome, the 21-gene Oncotype Recurrence Score (Oncotype RS), and pathological features in patients with hormone receptor (HR)-positive, human epidermal growth factor receptor-2-negative ILC.

Methods

The study cohort included 491 patients from a prospectively maintained institutional database consisting of patients with stage I-III, HR-positive ILC who underwent surgical treatment between 1996 and 2019.

Results

Contrary to our expectations, we found that lower BMI was significantly associated with having higher Oncotype RS (18.9% versus 4.8%, p = 0.028) in post-menopausal patients, but was not related to tumor characteristics in pre-menopausal patients. Multivariate network analyses suggested a strong relationship between post-menopausal status itself and tumor characteristics, with lesser influence of BMI.

Conclusion

These findings provide further insight into the recently appreciated heterogeneity within ILC and support the need for further investigation into the drivers of this disease and tailored treatment strategies.

Mediator of DNA Damage Checkpoint 1 (MDC1) Is a Novel Estrogen Receptor Coregulator in Invasive Lobular Carcinoma of the Breast

Invasive lobular carcinoma (ILC) is the most common special histologic subtype of breast cancer, and nearly all ILC tumors express estrogen receptor alpha (ER). However, clinical and laboratory data suggest ILC are strongly estrogen-driven but not equally antiestrogen-sensitive. We hypothesized ILC-specific ER coregulators mediate ER functions and antiestrogen resistance in ILC, and profiled ER-associated proteins by mass spectrometry. Three ER+ ILC cell lines (MDA MB 134VI, SUM44PE, and BCK4) were compared with ER+ invasive ductal carcinoma (IDC) line data, and we examined whether siRNA of identified proteins suppressed ER-driven proliferation in ILC cells. This identified mediator of DNA damage checkpoint 1 (MDC1), a tumor suppressor in DNA damage response (DDR), as a novel ER coregulator in ILC. We confirmed ER:MDC1 interaction was specific to ILC versus IDC cells, and found MDC1 knockdown suppressed ILC cell proliferation and tamoxifen resistance. Using RNA-sequencing, we found in ILC cells MDC1 knockdown broadly dysregulates the ER transcriptome, with ER:MDC1 target genes enriched for promoter hormone response elements. Importantly, our data are inconsistent with MDC1 tumor suppressor functions in DDR, but suggest a novel oncogenic role for MDC1 as an ER coregulator. Supporting this, in breast tumor tissue microarrays, MDC1 protein was frequently low or absent in IDC, but MDC1 loss was rare in ER+ ILC. ER:MDC1 interaction and MDC1 coregulator functions may underlie ER function in ILC and serve as targets to overcome antiestrogen resistance in ILC. IMPLICATIONS: MDC1 has novel ER coregulator activity in ILC, which may underlie ILC-specific ER functions, estrogen response, and antiestrogen resistance.

Survival Outcomes in Invasive Lobular Carcinoma Compared to Oestrogen Receptor-Positive Invasive Ductal Carcinoma

Invasive lobular breast cancer (ILC) accounts for 10-15% of breast cancers and has distinct characteristics compared with the more common invasive ductal carcinoma (IDC). Studies have shown that ILC may be less sensitive to chemotherapy than IDC, with lower rates of complete pathological response after neo-adjuvant chemotherapy, but it is not clear how this affects long-term survival. Patients at Guy's and St Thomas' NHS Foundation Trust between 1975 and 2016 diagnosed with ER+ IDC or ER+ ILC were eligible for inclusion. Kaplan-Meier plots and Cox proportional-hazards regression models were used for analysis. There was no difference in overall survival comparing ER+ ILC to ER+ IDC (OR: 0.94, 95% CI: 0.83, 1.04) with a median follow-up time of 8.3 years compared to 8.4 years in IDC. However, ER+HER2- ILC had worse survival compared to ER+HER2- IDC in those that received chemotherapy (OR: 1.46, 95% CI: 1.06, 2.01). Here, median follow-up time was 7.0 years in ILC compared to 8.1 years in IDC. These results indicate worse overall survival after chemotherapy (neo-adjuvant and adjuvant) in ILC compared to ER+HER2- IDC even when correcting for tumour grade, age, size, and nodal involvement, but validation is needed in a larger study population.

Investigation of monogenic causes of familial breast cancer: data from the BEACCON case-control study

Breast cancer (BC) has a significant heritable component but the genetic contribution remains unresolved in the majority of high-risk BC families. This study aims to investigate the monogenic causes underlying the familial aggregation of BC beyond BRCA1 and BRCA2, including the identification of new predisposing genes. A total of 11,511 non-BRCA familial BC cases and population-matched cancer-free female controls in the BEACCON study were investigated in two sequencing phases: 1303 candidate genes in up to 3892 cases and controls, followed by validation of 145 shortlisted genes in an additional 7619 subjects. The coding regions and exon–intron boundaries of all candidate genes and 14 previously proposed BC genes were sequenced using custom designed sequencing panels. Pedigree and pathology data were analysed to identify genotype-specific associations. The contribution of ATM, PALB2 and CHEK2 to BC predisposition was confirmed, but not RAD50 and NBN. An overall excess of loss-of-function (LoF) (OR 1.27, p = 9.05 × 10⁻⁹) and missense (OR 1.27, p = 3.96 × 10⁻⁷³) variants was observed in the cases for the 145 candidate genes. Leading candidates harbored LoF variants with observed ORs of 2–4 and individually accounted for no more than 0.79% of the cases. New genes proposed by this study include NTHL1, WRN, PARP2, CTH and CDK9. The new candidate BC predisposition genes identified in BEACCON indicate that much of the remaining genetic causes of high-risk BC families are due to genes in which pathogenic variants are both very rare and convey only low to moderate risk.

Integrated Analyses Reveal the Multi-Omics and Prognostic Characteristics of ATP5B in Breast Cancer

The beta subunit of F1Fo-ATP synthase (ATP5B) has been demonstrated to play an essential role in tumor progression and metastasis. However, there has been no comprehensive pan-cancer multi-omics analysis of ATP5B, while the clinical relevance of ATP5B and its potential mechanism in regulating breast cancer are still poorly understood. In this study, we demonstrated that ATP5B has a higher frequency of amplification than deletion in most cancer types, and the copy number variation (CNV) of ATP5B was significantly positively correlated with its mRNA expression level. DNA methylation analysis across pan-cancer also revealed a strong correlation between ATP5B expression and epigenetic changes. We identified 6 significant methylation sites involved in the regulation of ATP5B expression. Tissue microarrays (TMA) from 129 breast cancer samples, integrated with multiple additional breast cancer dataset, were used to evaluate the ATP5B expression and its correlation with prognosis. Higher levels of ATP5B expression were consistently associated with a worse OS in all datasets, and Cox regression analysis suggested that ATP5B expression was an independent prognostic factor. Gene enrichment analysis indicated that the gene signatures of DNA damage recognition, the E-cadherin nascent pathway and the PLK1 pathway were enriched in ATP5B-high patients. Moreover, somatic mutation analysis showed that a significant different mutation frequency of CDH1 and ADAMTSL3 could be observed between the ATP5B-high and ATP5B-low groups. In conclusion, this study reveals novel significance regarding the genetic characteristics and clinical value of ATP5B highlighted in predicting the outcome of breast cancer patients.

CDH1 Gene Mutation Hereditary Diffuse Gastric Cancer Outcomes: Analysis of a Large Cohort, Systematic Review of Endoscopic Surveillance, and Secondary Cancer Risk Postulation

Simple Summary

Some patients carry a mutated copy of the CDH1 gene that can lead to a very rare form of hereditary gastric cancer called signet-ring cell adenocarcinoma (SRCC). SRCCs rarely form visible tumors prior to spreading. Hence, patients are recommended to have prophylactic gastrectomies at a young age. Many patients wish to avoid surgery and thus have regular checks with upper endoscopy with biopsies to rule out cancer. Further, these patients may also be at risk of other cancers beyond the already known breast cancer risks, but this is not known. In this study, we show that despite systematic biopsy protocols, many early cancers might be missed on endoscopy. Therefore, patients should not rely on endoscopy to delay surgery. These patients may also be at increased risk of colorectal SRCC, which has very poor survival outcomes. To confirm this, we need a central database that captures outcomes for this patient population.

Abstract

Hereditary diffuse gastric cancer (HDGC) is a rare signet-ring cell adenocarcinoma (SRCC) linked to CDH1 (E-cadherin) inactivating germline mutations, and increasingly other gene mutations. Female CDH1 mutation carriers have additional risk of lobular breast cancer. Risk management includes prophylactic total gastrectomy (PTG). The utility of endoscopic surveillance is unclear, as early disease lacks macroscopic lesions. The current systematic biopsy protocols have unknown efficacy, and other secondary cancer risks are postulated. We conducted a retrospective study of consecutive asymptomatic HDGC patients undergoing PTG, detailing endoscopic, pathologic, and outcome results. A systematic review compared endoscopic biopsy foci detection via random sampling versus Cambridge Protocol against PTG findings. A population-level secondary-cancer-risk postulation among sporadic gastric SRCC patients was completed using the Surveillance, Epidemiology, and End Results database. Of 97 patients, 67 underwent PTG, with 25% having foci detection on random endoscopic biopsy despite 75% having foci on final pathology. There was no improvement in the endoscopic detection rate by Cambridge Protocol. The postulated hazard ratio among sporadic gastric SRCC patients for a secondary colorectal SRCC was three-fold higher, relative to conventional adenocarcinoma patients. Overall, HDGC patients should not rely on endoscopic surveillance to delay PTG, and may have secondary SRCC risks. A definitive determination of actual risk requires collaborative patient outcome data banking.

Breast Cancer Predisposition Genes and Synthetic Lethality

BRCA1 and BRCA2 are tumor suppressor genes with pivotal roles in the development of breast and ovarian cancers. These genes are essential for DNA double-strand break repair via homologous recombination (HR), which is a virtually error-free DNA repair mechanism. Following BRCA1 or BRCA2 mutations, HR is compromised, forcing cells to adopt alternative error-prone repair pathways that often result in tumorigenesis. Synthetic lethality refers to cell death caused by simultaneous perturbations of two genes while change of any one of them alone is nonlethal. Therefore, synthetic lethality can be instrumental in identifying new therapeutic targets for BRCA1/2 mutations. PARP is an established synthetic lethal partner of the BRCA genes. Its role is imperative in the single-strand break DNA repair system. Recently, Olaparib (a PARP inhibitor) was approved for treatment of BRCA1/2 breast and ovarian cancer as the first successful synthetic lethality-based therapy, showing considerable success in the development of effective targeted cancer therapeutics. Nevertheless, the possibility of drug resistance to targeted cancer therapy based on synthetic lethality necessitates the development of additional therapeutic options. This literature review addresses cancer predisposition genes, including BRCA1, BRCA2, and PALB2, synthetic lethality in the context of DNA repair machinery, as well as available treatment options.

Extended gene panel testing in lobular breast cancer

Purpose: Lobular breast cancer (LBC) accounts for ~ 15% of breast cancer. Here, we studied the frequency of pathogenic germline variants (PGVs) in an extended panel of genes in women affected with LBC. Methods: 302 women with LBC and 1567 without breast cancer were tested for BRCA1/2 PGVs. A subset of 134 LBC affected women who tested negative for BRCA1/2 PGVs underwent extended screening, including: ATM, CDH1, CHEK2, NBN, PALB2, PTEN, RAD50, RAD51D, and TP53.Results: 35 PGVs were identified in the group with LBC, of which 22 were in BRCA1/2. Ten actionable PGVs were identified in additional genes (ATM(4), CDH1(1), CHEK2(1), PALB2(2) and TP53(2)). Overall, PGVs in three genes conferred a significant increased risk for LBC. Odds ratios (ORs) were: BRCA1: OR = 13.17 (95%CI 2.83–66.38; P = 0.0017), BRCA2: OR = 10.33 (95%CI 4.58–23.95; P < 0.0001); and ATM: OR = 8.01 (95%CI 2.52–29.92; P = 0.0053). We did not detect an increased risk of LBC for PALB2, CDH1 or CHEK2. Conclusion: The overall PGV detection rate was 11.59%, with similar rates of BRCA1/2 (7.28%) PGVs as for other actionable PGVs (7.46%), indicating a benefit for extended panel genetic testing in LBC. We also report a previously unrecognised association of pathogenic variants in ATM with LBC.

Single-Cell Transcriptomic Heterogeneity in Invasive Ductal and Lobular Breast Cancer Cells

Invasive lobular breast carcinoma (ILC), one of the major breast cancer histologic subtypes, exhibits unique features compared with the well-studied ductal cancer subtype (IDC). The pathognomonic feature of ILC is loss of E-cadherin, mainly caused by inactivating mutations, but the contribution of this genetic alteration to ILC-specific molecular characteristics remains largely understudied. To profile these features transcriptionally, we conducted single-cell RNA sequencing on a panel of IDC and ILC cell lines, and an IDC cell line (T47D) with CRISPR-Cas9-mediated E-cadherin knockout (KO). Inspection of intracell line heterogeneity illustrated genetically and transcriptionally distinct subpopulations in multiple cell lines and highlighted rare populations of MCF7 cells highly expressing an apoptosis-related signature, positively correlated with a preadaptation signature to estrogen deprivation. Investigation of E-cadherin KO-induced alterations showed transcriptomic membranous systems remodeling, elevated resemblance to ILCs in regulon activation, and increased sensitivity to IFNγ-mediated growth inhibition via activation of IRF1. This study reveals single-cell transcriptional heterogeneity in breast cancer cell lines and provides a resource to identify drivers of cancer progression and drug resistance. SIGNIFICANCE: This study represents a key step towards understanding heterogeneity in cancer cell lines and the role of E-cadherin depletion in contributing to the molecular features of invasive lobular breast carcinoma.

Risk factors of breast cancer among patients in a tertiary care hospitals in Afghanistan: a case control study

Background

Breast cancer is the second most common causes of women’s death, worldwide. Data on risk factors associated with female breast cancer in the Afghan population is very limited. The aim of our study was to identifying risk factor associated with female breast cancer in Afghanistan.

Methods

A retrospective case-control study was conducted with inclusion of 201 cases and 201 controls. Patient information was collected by interviewing the patient through a structured questionnaire. Histopathological information was collected from the hospital integrated laboratory management system. The data was analyzed by using logistic regression with univariate and multivariable analyses to determine the association between breast cancer and predictors.

Results

The results of the current study showed that factors such as: age (OR = 1.02; 95%CI: 0.99–1.04; p-0.148); age at menarche (OR = 0.83; 95%CI: 0.72–0.92; p-0.008); age at first baby (OR = 1.14; 95%CI: 1.07–1.20; p- < 0.001); illiteracy (OR = 1.93; 95%CI: 1.16–3.22; p-0.011); smoking (OR = 2.01; 95%CI: 1.01–3.99; p-0.04) and family history of cancer (OR = 1.98; 95%CI: 1.18–3.32; p-0.009) were significantly associated with breast cancer. However, our study did not demonstrate any statistically significant correlation between breast cancer and some of the predictors that were previously highlighted in literature, such as: marital status, Body Mass Index (BMI), use of hormonal contraceptive, breastfeeding and exercise.

Conclusion

Our study demonstrated that age at menarche, and age at first baby birth, illiteracy, smoking and family history of cancer were significant risk factors associated with development of breast cancer among women in Afghanistan. Health education of women regarding aforementioned predisposing factors are therefore, expected to be valuable in decreasing the burden of breast cancer with reduction of its burden on the healthcare system in Afghanistan.

Human papillomavirus, gene mutation and estrogen and progesterone receptors in breast cancer: a cross-sectional study

Introduction

recent studies show a good relationship between breast cancer (BC) and human papillomaviruses (HPV) wich is responsible for about 18% of BC cases. This study aimed to assess the relationship between different genotypes of HPV and the expression of P53 and retinoblastoma (RB) genes and estrogen and progesterone receptors in BC among Sudanese women.

Methods

one hundred and fifty tissue blocks were obtained from females diagnosed with BC. Positive samples were used to determine genotypes with an applied biosystem (ABI 3730XL) genetic analyzer for sequencing and immunohistochemistry.

Results

13/150 samples showed HPV DNA. High-risk HPV-16 was detected in 5 cases, high-risk-HPV-58 was found in four cases, and HPV-18 was detected in three cases. Low-risk-HPV-11 was detected in a single invasive lobular carcinoma (ILC) case. P53 and RB gene mutations were detected in 35 and 30 BC cases, respectively. P53 gene mutation was frequently identified in grade (III) BC while RB gene mutation was positive in grade (II). Grade (II) BC had a higher incidence of HPV-16 and 58. On the other hand, HPV-18 had a higher incidence in grade (III). Estrogen and progesterone receptors were expressed in 94 and 79 HPV cases among the study group, respectively.

Conclusion

this study elucidates the associations between HPV genotypes and BC. A statistically significant association was observed among p53 and RB gene mutations and different BC histological types. On the other hand, there was a statistically insignificant association between HPV genotyping and different BC gradings, BC histological types, P53 and RB genes mutations, and estrogen and progesterone receptor expression. Also, there was a statistically insignificant association among estrogen and progesterone receptors expression and BC grading. RB gene mutation was significantly associated with different BC grades. On the other hand, there was a statistically insignificant association between progesterone receptor expression and BC.

Characteristics of Breast Cancer Metastasizing to Bone in a Mediterranean Population

Aim: This study examines clinicopathological, molecular, and radiological characteristics of breast cancer metastasizing to the bone in a Mediterranean population.

Methods: Cases of breast cancer with metastasis to bone were retrieved from the pathology department archives. Descriptive statistics and bivariate inferential statistics of retrieved clinical (demographic, focality, laterality, axillary lymph node status, and metastasis-free interval), radiological (skeletal site of bone metastasis, type of bone lesion), and microscopic (grade, subtype of breast cancer, lymphovascular status, perineural status, lymph node involvement, nodal extracapsular extension, molecular subtype) data were conducted.

Results: Out of 123 cases analyzed, 93.5% were ductal, 90% had axillary lymph node metastasis, 60.5% were luminal A, 59.6% were osteolytic, and 54.4% had grade III. Discordance in the status of ER, PR, and HER2 between the primary breast tumor and the corresponding bone metastases was noted, with the highest rate of change reported for PR (35.7%). Significance was detected at the level of difference between the subtype of breast cancer with regards to the radiologic features where the ductal subtype was found to be mostly osteolytic while the lobular subtype was mostly either osteoblastic or mixed (p-value=0.05). The metastasis-free interval was significantly associated with the number of metastatic bone lesions (P=0.001).

Conclusion: The significant association between metastasis-free interval and the number of metastatic bone lesions suggests that a higher interval allows more time for tumors to manifest multiple lesions. The high rate of discordance in the status of PR, ER, and HER2 was congruent with the literature highlighting the need to further investigate underlying mechanisms.

Estrogen Regulation of mTOR Signaling and Mitochondrial Function in Invasive Lobular Carcinoma Cell Lines Requires WNT4

Simple Summary

Invasive lobular carcinoma (ILC) is a common but understudied breast cancer subtype. ILC is presumed to be a low-risk disease in part because nearly all ILCs contain the estrogen receptor (ER). However, we previously showed that ER has unique functions in ILC cells, including driving expression of the Wnt ligand WNT4. WNT4 signaling is required for ILC cell proliferation and survival, but the mechanisms and targets of WNT4 signaling in ILC is unknown. We found that WNT4 regulates mTOR signaling via S6 kinase, and controls levels of MCL-1 protein, ultimately regulating mitochondrial function and cellular metabolism. These findings offer new insight into a novel Wnt signaling pathway and identify new targets to inhibit WNT4 signaling as potential treatments against ILC cells.

Abstract

Invasive lobular carcinoma of the breast (ILC) is strongly estrogen-driven and represents a unique context for estrogen receptor (ER) signaling. In ILC, ER controls the expression of the Wnt ligand WNT4, which is critical for endocrine response and anti-estrogen resistance. However, signaling mediated by WNT4 is cell type- and tissue-specific, and has not been explored in ILC. We utilized reverse phase protein array (RPPA) to characterize ER and WNT4-driven signaling in ILC cells and identified that WNT4 mediates downstream mTOR signaling via phosphorylation of S6 Kinase. Additionally, ER and WNT4 control levels of MCL-1, which is associated with regulation of mitochondrial function. In this context, WNT4 knockdown led to decreased ATP production and increased mitochondrial fragmentation. WNT4 regulation of both mTOR signaling and MCL-1 were also observed in anti-estrogen resistant models of ILC. We identified that high WNT4 expression is associated with similar mTOR pathway activation in ILC and serous ovarian cancer tumors, suggesting that WNT4 signaling is active in multiple tumor types. The identified downstream pathways offer insight into WNT4 signaling and represent potential targets to overcome anti-estrogen resistance for patients with ILC.

Correlation between Lsp1 (Rs3817198) and Casc (Rs4784227) Polymorphisms and the Susceptibility to Breast Cancer

BACKGROUND

Breast cancer is classified as one of the common cancers among women worldwide. Within numerous genetic factors involved in the development of breast cancer, lsp1 and casc genes are both located on breast cancer susceptibility locus. While the SNP rs3817198 in lsp1 gene has a twilight association with breast cancer in different populations, casc rs4784227 polymorphisms have been reported to associate with breast tumor appearance in Asian, European, and African ancestry populations. The present report was designed a case-control group aimed at assessing the association of these two SNPs with breast cancer risk in the Iranian population.

METHODS

In the case-control study of rs3817198 and rs4784227 polymorphisms in 100 women with breast cancer and 100 healthy women were examined by Tetra Arms PCR. Data collected using SPSS software and chi-square test and correlation coefficient were used for statistical analysis.

RESULTS

The results of current study showed that the Chi-square of lsp1 rs3817198 and casc rs4784227 polymorphism genotypes in breast cancer, were reported to be 51.613 and 47.920, respectively. Also there has been a significance level of both polymorphisms resulting in the frequency of genotypes in these two polymorphisms between case and control group.

CONCLUSION

Our finding thus suggested that in both polymorphisms, homozygote genotype showed strong correlation with cancer susceptibility. While, TT genotype in lsp1 rs3817198 showed significant association with pathogenic properties, in the case of casc rs4784227 genotypes CC, and in second place, TT showed similar correlation.

Whole Breast Invasive Lobular Carcinoma Not Detected Radiographically

Breast cancer is the most commonly occurring cancer in women, with invasive lobular carcinoma being the second most common histologic form. A 78-year-old female patient presented complaining of an enlarged palpable lymph node in the left axilla. Breast ultrasound, digital mammography, and contrast-enhanced spectral mammography (CESM) revealed no abnormal findings. Core needle biopsy of the lymph node revealed infiltrative, diffuse neoplastic growth suggestive of adenocarcinoma, indicating that the primary site should be sought in the breast. The patient underwent mastectomy and the histopathology was suggestive of invasive lobular carcinoma throughout the whole extent of the breast parenchyma. Breast cancer should be definitely included in the differential diagnosis of enlarged axillary lymph nodes, even if there is no other clinical or radiographic presentation of breast disease.

Heritable Susceptibility to Breast Cancer among African-American Women in the Detroit Research on Cancer Survivors Study

BACKGROUND

African-American women have high rates of breast cancer associated with hereditary features. However, no studies have reported the prevalence of inherited variation across all genes known to be breast cancer risk factors among African-American patients with breast cancer not selected for high-risk characteristics.

METHODS

We evaluated 182 African-American women diagnosed with invasive breast cancer in metropolitan Detroit via targeted capture and multiplex sequencing of 13 well-established breast cancer risk genes and five suggested breast cancer risk genes.

RESULTS

We identified 24 pathogenic variants in 23 women [12.6%; 95% confidence interval (CI), 8.2%-18.4%] and five genes (BRCA2, BRCA1, ATM, RAD50, CDH1). BRCA1 and BRCA2 accounted for 58.3% of all pathogenic variants. An additional six pathogenic variants were found in suggested breast cancer risk genes (MSH6, MUTYH, NF1, BRIP1).

CONCLUSIONS

The prevalence of germline pathogenic variants is relatively high among African-American patients with breast cancer unselected for high-risk characteristics across a broad spectrum of genes.

IMPACT

This study helps to define the genomic landscape of breast cancer susceptibility in African-American women who could benefit from enhanced surveillance and screening.