Mammographic and ultrasound features of invasive lobular carcinoma of the breast

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.

Breast Radiologists' Perceptions on the Detection and Management of Invasive Lobular Carcinoma: Most Agree Imaging Beyond Mammography Is Warranted

OBJECTIVE

To determine breast radiologists' confidence in detecting invasive lobular carcinoma (ILC) on mammography and the perceived need for additional imaging in screening and preoperative settings.

METHODS

A 16-item anonymized survey was developed, and IRB exemption obtained, by the Society of Breast Imaging (SBI) Patient Care and Delivery Committee and the Lobular Breast Cancer Alliance. The survey was emailed to 2946 radiologist SBI members on February 15, 2023. The survey recorded demographics, perceived modality-specific sensitivity for ILC to the nearest decile, and opinions on diagnosing ILC in screening and staging imaging. Five-point Likert scales were used (1 = strongly disagree, 2 = disagree, 3 = neutral, 4 = agree, 5 = strongly agree).

RESULTS

Response rate was 12.4% (366/2946). Perceived median (interquartile range) modality-specific sensitivities for ILC were MRI 90% (80-90), contrast-enhanced mammography 80% (70-90), molecular breast imaging 80% (60-90), digital breast tomosynthesis 70% (60-80), US 60% (50-80), and 2D mammography 50% (30-60). Only 25% (85/340) respondents were confident in detecting ILC on screening mammography in dense breasts, while 67% (229/343) were confident if breasts were nondense. Most agreed that supplemental screening is needed to detect ILC in women with dense breasts (272/344, 79%) or a personal history of ILC (248/341, 73%), with 34% (118/334) indicating that supplemental screening would also benefit women with nondense breasts. Most agreed that additional imaging is needed to evaluate extent of disease in women with newly diagnosed ILC, regardless of breast density (dense 320/329, 97%; nondense 263/329, 80%).

CONCLUSION

Most breast radiologists felt that additional imaging beyond mammography is needed to more confidently screen for and stage ILC.

The Current and Future Roles of Precision Oncology in Advanced Breast Cancer

Breast cancer is a common but heterogeneous disease characterized by several biologic features, including tumor grade, hormone receptor status, human epidermal growth factor receptor 2 status, and gene expression assays. These biologic and genomic features drive treatment decisions. In the advanced disease setting, inter- and intrapatient tumor heterogeneity is increasingly recognized as a challenge for optimizing treatment. Recent evidence and the recent approval of novel radiopharmaceuticals have increased recognition and acceptance of the potential of molecular imaging as a biomarker to impact and guide management decisions for advanced breast cancer.

Contrast-Enhanced Mammography (CEM) compared to Breast Magnetic Resonance (MRI) in the evaluation of breast lobular neoplasia

PURPOSE

To compare the diagnostic performance (detection, assessment of correct disease extent and multifocality/centricity) of Contrast-Enhanced Mammography (CEM) Versus Breast Magnetic Resonance (MRI) in the study of lobular neoplasms.

METHODS

We retrospectively selected all the patients who underwent surgery for a lobular breast neoplasm, either an in situ or an invasive tumor, and had undergone both breast CEM and MRI examinations during the pre-surgical planning. Wilcoxon Signed Rank test was performed to assess the differences between size measurements using the different methods and the post-surgical pathological measurements, considered the gold standard. The agreement in identifying multifocality/multicentricity among the different methods and the pathology was assessed using the Kappa statistics.

RESULTS

We selected 19 patients, of which one presented a bilateral neoplasm. Then, the images of these 19 patients were analyzed, for a total of 52 malignant breast lesions. We found no significant differences between the post-surgical pathological size of the lesions and the calculated size with CEM and MRI (p-value of the difference respectively 0.71 and 0.47). In all 20 cases, neoplasm detection was possible both with CEM and MRI. CEM and MRI showed an excellent ability to identify multifocal and multicentric cases (K statistic equal to 0.93 for both the procedures), while K statistic was 0.11 and 0.59 for FFDM and US, respectively.

CONCLUSION

The findings of this study suggest that CEM is a reliable imaging technique in the preoperative setting of patients with lobular neoplasm, with comparable results to breast MRI.

Defining features of hereditary lobular breast cancer due to CDH1 with magnetic resonance imaging and tumor characteristics

Women with germline pathogenic variants in CDH1, which encodes E-cadherin protein, are at increased lifetime risk of invasive lobular carcinoma (ILC). The associated tumor characteristics of hereditary lobular breast carcinoma (HLBC) in this high-risk population are not well-known. A single-center prospective cohort study was conducted to determine the imaging and pathologic features of HLBC compared to population-based ILC using Surveillance, Epidemiology, and End Results (SEER) data. One hundred fifty-eight women with CDH1 variants were evaluated, of whom 48 (30%) also had an ILC diagnosis. The median age at CDH1 diagnosis was 45 years [interquartile range, IQR 34-57 years] whereas the median age at diagnosis of CDH1 with concomitant ILC (HLBC) was 53 [IQR 45-62] years. Among women with HLBC, 83% (40/48) were identified with CDH1 mutation after diagnosis of ILC. Among 76 women (48%, 76/158) undergoing surveillance for ILC with breast magnetic resonance imaging (MRI), 29% (22/76) had an abnormal MRI result with available biopsy data for comparison. MRI detected ILC in 7 out of 8 biopsy-confirmed cases, corresponding with high sensitivity (88%), specificity (75%), and negative predictive value (98%); however, false-positive and false-discovery rates were elevated also (25% and 68%, respectively). HLBC was most frequently diagnosed at age 40-49 years (44%, 21/48), significantly younger than the common age of diagnosis of ILC in SEER general population data (most frequent age range 60-69 years, 28%; p < 0.001). HLBC tumors were smaller than SEER-documented ILC tumors (median 1.40 vs. 2.00 cm; p = 0.002) and had a higher incidence of background lobular carcinoma in situ (88% vs. 1%; p < 0.001) as well as progesterone receptor positivity (95% vs. 81%, p = 0.032). These findings suggest that HLBC is often detected via conventional screening methods as an early-stage hormone receptor-positive tumor, thus the clinical benefit of intensive screening with MRI may be limited to a subset of women with germline CDH1 variants.

The Japan Society of Ultrasonics in Medicine guidelines on non-mass abnormalities of the breast

It is possible to appropriately diagnose non-mass abnormalities by elucidating ultrasound non-mass abnormality findings and sharing the concept. If non-mass abnormalities can be diagnosed early, the number of curable cases could increase, leading to fewer breast cancer deaths. The Japan Society of Ultrasonics in Medicine (JSUM) Terminology/Diagnostic Criteria Committee has classified non-mass abnormalities into five subtypes: hypoechoic area in the mammary gland, abnormalities of the ducts, architectural distortion, multiple small cysts, and echogenic foci without a hypoechoic area. We herein define the findings for each of these subtypes and present a summary of the JSUM guidelines on non-mass abnormalities of the breast generated based on those findings.

Challenges and Considerations in Identifying the Origin of Peritoneal Carcinomatosis: A Case Report

Invasive lobular cancer (ILC) of the breast is the second most common type of invasive breast cancer. Clinical determination of the growth pattern of ILC of the breast is difficult. Furthermore, the ILC of the breast has a unique metastatic pattern that involves gastrointestinal and peritoneal sites. Our patient was initially misdiagnosed with left ovarian cancer based on the findings of positron emission tomography and computed tomography. Herein, we report a case of ILC of the breast presenting as peritoneal carcinomatosis. The ESMO Clinical Practice Guidelines for cancers of unknown primary sites were used in the diagnosis of the carcinoma of unknown primary origin. Image-guided biopsy and immunohistochemical staining are also useful in the diagnosis of these cancer types.

Evolution of biological features of invasive lobular breast cancer: comparison between primary tumor and metastases

BACKGROUND

Invasive lobular carcinoma (ILC) has unique clinical-biological features. Phenotypical differences between primary tumours (PTs) and metastases (M) have been described for invasive ductal carcinoma, but data on ILC are limited.

METHODS

We retrospectively analysed patients with recurrent ILC from our institution from 2013 to 2020. We evaluated the discordance of the oestrogen receptor (ER), progesterone receptor (PgR) and HER2 between PT and M, to understand prognostic and therapeutic implications.

RESULTS

Thirteen percent (n = 91) of all patients had ILC. We observed 15%, 44% and 5% of ER, PgR and HER2 status discordance between PT and M. ER/PgR discordance was related to receptor loss and HER2 mainly due to gain. PT presented a luminal-like phenotype (93%); 6% and 1% were triple-negative (TNBC) and HER2-positive. In M, there was an increase in TNBC (16%) and HER2-positive (5%). Metastasis-free survival and overall survival (OS) were different according to clinical phenotype, with poorer prognosis for HER2+ and TNBC (p < 0.001); OS after metastatic progression did not differ across phenotypes (p = 0.079). In luminal-like ILC (n = 85) at diagnosis, we found that OS after relapse was poorer in patients experiencing a phenotype switch to TNBC but improved in patients with HER2 gain (p = 0.0028). Poorer survival was reported in patients with a PgR and/or ER expression loss of ≥25%. There was HER2-low enrichment in M1 (from 37% to 58%): this change was not associated with OS (p > 0.05).

CONCLUSION

Our results suggest that phenotype switch after metastatic progression may be associated with patients' outcomes. Tumour biopsy in recurrent ILC could drive treatment decision-making, with prognostic implications.

Transversal Perspectives of Integrative Oncology Care in Gastric and Lobular Breast Cancer

The occurrence of gastric cancer has been associated with an increased risk of lobular breast tumors in a subset of patients harboring selected germline mutations. Among all, the germline alteration of the gene coding for E-Cadherin (CDH1) was associated with an increased risk of gastric cancer diffuse-histotype and lobular breast cancer. However, the risk assessment of breast neoplasms and the role of multiple prophylactic procedures in these patients has never been systematically addressed. In addition, the performance of the common screening procedures for lobular breast cancer like mammography is suboptimal. Therefore, recalling the need for a better articulation of the patient-centered strategies of surveillance for individuals with germline CDH1 and other similar alterations, to offer comprehensive approaches for prevention, early diagnosis, and treatment. Accordingly, this chapter aims to discuss the value and the role of integrated oncological care in the era of oncology sub-specializations. Additionally, it sheds light on how the harmonization across the health providers can enhance patient care in this setting.

Multimodality imaging in lobular breast cancer: Differences in mammography, ultrasound, and MRI in the assessment of local tumor extent and correlation with molecular characteristics

Introduction

Invasive lobular breast cancer (ILC) is a diagnostic challenge due to the diversity of morphological features. The objective of the study was to investigate the presentation and local extent of ILC using various imaging techniques and to assess the correlation between imaging and molecular profile.

Materials and methods

We reviewed 162 consecutive patients with ILC found on vacuum-assisted biopsy, who underwent evaluation of the lesion morphology and extent using ultrasound (US), mammography (MMG), and magnetic resonance imaging (MRI). Radiographic features were compared with ILC intrinsic subtype based on the expression of Ki-67 and estrogen, progesterone, and HER2 receptors.

Results

A total of 113 mass lesions and 49 non-mass enhancements (NMEs) were found in MRI. Masses were typically irregular and spiculated, showing heterogeneous contrast enhancement, diffusion restriction, and type III enhancement curve. NMEs presented mainly as the area of focal or multiregional distribution with heterogeneous or clumped contrast enhancement, diffusion restriction, and type III enhancement curve. Lesion extent significantly varied between MRI and MMG/ultrasonography (USG) (P < 0.001) but did not differ between MGF and ultrasonography (USG). The larger the ILC, the higher the disproportion when lesion extent in MRI was compared with MMG (P < 0.001) and ultrasonography (USG) (P < 0.001). In the study group, there were 97 cases of luminal A subtype (59.9%), 54 cases of luminal B HER2− (33.3%), nine cases of luminal B HER2+ (5.5%), and two cases of triple negative (1.2%). The HER2 type was not found in the study group. We did not observe any significant correlation between molecular profile and imaging.

Conclusion

MRI is the most effective technique for the assessment of ILC local extent, which is important for optimal treatment planning. Further studies are needed to investigate if the intrinsic subtype of ILC can be predicted by imaging features on MRI.

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.

Diagnostic performance of elastography for breast non-mass lesions: A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the diagnostic performance of ultrasound elastography in the differentiation of benign and malignant breast non-mass lesions (NMLs).

METHODS

PubMed, Cochrane Library, and Embase databases were searched for eligible studies up to end of June 2021. The diagnostic performance of elastography for NMLs was investigated using pooled sensitivity and specificity, likelihood ratio, diagnostic odds ratio (DOR), post-test probability, and the area under hierarchical summary receiver operating characteristic curve (HSROC).

RESULTS

Eleven studies involving 812 NMLs (malignant 414) were included. The pooled sensitivity, specificity, DOR, positive likelihood ratio, and negative likelihood of elastography for the differentiation of benign and malignant breast NMLs were 79% (95 %CI: 71-85), 86% (95 %CI: 79-91), 23.32 (95 %CI: 13.38-40.66), 5.67 (95 %CI: 3.79-8.47), and 0.24 (95 %CI: 0.17-0.34), respectively. No significant publication bias existed. The area under the HSROC curve was 90% (95 %CI: 87-92). Fagan plots demonstrated good clinical utility. However, substantial heterogeneity existed. Country, measurement index, and number of lesions served as potential sources of heterogeneity.

CONCLUSIONS

The results of this study suggest that elastography has high diagnostic accuracy in differentiating between malignant and benign NMLs. Elastography can be a feasible and non-invasive tool for breast NMLs.

Radiomic differentiation of breast cancer molecular subtypes using pre-operative breast imaging - A systematic review and meta-analysis

INTRODUCTION

Breast cancer has four distinct molecular subtypes which are discriminated using gene expression profiling following biopsy. Radiogenomics is an emerging field which utilises diagnostic imaging to reveal genomic properties of disease. We aimed to perform a systematic review of the current literature to evaluate the value radiomics in differentiating breast cancers into their molecular subtypes using diagnostic imaging.

METHODS

A systematic review was performed as per PRISMA guidelines. Studies assessing radiomictumour analysis in differentiatingbreast cancer molecular subtypeswere included. Quality was assessed using the radiomics quality score (RQS). Diagnostic sensitivity and specificity of radiomic analyses were included for meta-analysis; Study specific sensitivity and specificity were retrieved and summary ROC analysis were performed to compile pooled sensitivities and specificities.

RESULTS

Forty-one studies were included. Overall, there were 10,090 female patients (mean age of 47.6 ± 11.7 years, range: 21-93) and molecular subtypewas reported in 7,693 of cases, with Luminal A (LABC), Luminal B (LBBC), Human Epidermal Growth Factor Receptor-2 overexpressing (HER2+), and Triple Negative (TNBC) breast cancers representing 51.3%, 19.9%, 12.3% and 16.3% of tumour respectively. Seven studies provided radiomic analysis to determine molecular subtypes using mammography to differentiateTNBCvs.others (sensitivity: 0.82,specificity:0.79). Thirty-five studies reported on radiomic analysis of magnetic resonance imaging (MRI); LABC versus others(sensitivity:0.78,specificity:0.83),HER2+versusothers(sensitivity:0.87,specificity:0.88), andLBBCversusTNBC (sensitivity: 0.79,specificity:0.88) respectively.

CONCLUSION

Radiomic tumour assessment of contemporary breast imaging provide a novel option in determining breast cancer molecular subtypes. However, amelioration of such techniques are required and genetic expression assessment will remain the gold standard.

Survival patterns of invasive lobular and invasive ductal breast cancer in a large population-based cohort with two decades of follow up

BACKGROUND

Invasive lobular carcinoma (ILC) comprises 8-15 % of all invasive breast cancers and large population-based studies with >10 years of follow-up are rare. Whether ILC has a long-time prognosis different from that of invasive ductal carcinoma, (IDC) remains controversial.

PURPOSE

To investigate the excess mortality rate ratio (EMRR) of patients with ILC and IDC and to correlate survival with clinical parameters in a large population-based cohort.

MATERIAL AND METHODS

From 1989 through 2006, we identified 17,481 patients diagnosed with IDC (n = 14,583) or ILC (n = 2898), younger than 76 years from two Swedish Regional Cancer Registries. Relative survival (RS) during 20 years of follow up was analysed.

RESULTS

ILC was significantly associated with older age, larger tumours, ER positivity and well differentiated tumours. We noticed an improved survival for patients with ILC during the first five years, excess mortality rate ratio (EMRR) 0.64 (CI 95 % 0.53-0.77). This was shifted to a significant decreased survival 10-15 years after diagnosis (EMRR 1.49, CI 95 % 1.16-1.93). After 20 years the relative survival rates were similar, 0.72 for ILC and 0.73 for IDC.

CONCLUSIONS

During the first five years after surgery, the EMRR was lower for patients with ILC as compared to patients with IDC, but during the years 10-15 after surgery, we observed an increased EMRR for patients with ILC as compared to IDC. These EMRR between ILC and IDC were statistically significant but the absolute difference in excess mortality between the two groups was small.

Effectiveness of a Short Duration of Neoadjuvant Endocrine Therapy in Patients with HR+ Breast Cancer-An NCDB Analysis (2004-2016)

Background

National medical/surgical organizations have recommended the use of neoadjuvant endocrine therapy (NET) to bridge surgery delay of weeks to months for patients with hormone receptor positive (HR+) breast cancer during the ongoing coronavirus disease 2019 (COVID-19) pandemic. The effects of NET of varying durations on pathologic response are unclear. Using the National Cancer Database (NCDB), we evaluated objective response to short (< 9 weeks), moderate (9–27 weeks), and long (> 27 weeks) duration of NET.

Patients and Methods

The study cohort included female patients diagnosed with nonmetastatic invasive HR+ breast cancer, stratifying by those who received NET versus no NET between 2004 and 2016. Pathologic response was grouped into four categories (complete, downstaged, stable, upstaged) by comparing clinical and pathologic staging data. Objective response to NET included complete, downstaged, and stable pathologic response. Clinical characteristics were compared using χ² and analysis of variance (ANOVA) tests. Multivariable logistic regression was used to determine factors associated with NET use and objective response according to NET duration.

Results

A minority (1.2%) received NET in our cohort. Factors associated with NET use included older age, non-Black patients, more advanced clinical stage, higher comorbidity score, government insurance, and lobular histology. Objective response rate (ORR) was 56.7%, 52.1%, and 49.0% after short, moderate, and long NET duration, respectively.

Conclusion

Short NET duration did not result in an inferior ORR. Future study to evaluate the interaction between surgery delay and NET use on clinical outcome will provide insights into the safety of NET to bridge potential surgery delay in patients with HR+ breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10287-5.

Nonmass Findings at Breast US: Definition, Classifications, and Differential Diagnosis

A nonmass finding at US has been described as a discrete identifiable area of altered echotexture compared with that of the surrounding breast tissue that does not conform to a mass shape. Recognizing nonmass findings is important because breast cancer can manifest as such lesions, and US correlate findings for mammographic and breast MRI abnormalities may manifest as nonmass findings. The term nonmass finding is not part of the current Breast Imaging Reporting and Data System US terminology, and no standardized approach to classify and evaluate nonmass findings at US currently exists, despite the various classification systems proposed in the literature. There is also considerable overlap between the sonographic features of benign and malignant causes of nonmass findings. These limitations cause diagnostic difficulty in evaluating clinical significance and recommending appropriate management. The authors review the definitions and classification systems of US nonmass findings proposed in the literature and illustrate the sonographic features of nonmass findings to help radiologists identify them at US. A range of benign and malignant causes of nonmass findings are reviewed, and sonographic-histopathologic correlations of nonmass findings are discussed. Cases of breast MRI and mammographic findings that may manifest as US nonmass findings are presented. Radiologists can improve detection and interpretative accuracy, as well as correlation of mammographic and MRI breast lesions, by increasing their recognition and understanding of nonmass findings at US.^©RSNA, 2020.

Epidemiology of De Novo Metastatic Breast Cancer

Most cases of metastatic breast cancer (MBC) arise as a recurrence of a previously treated early breast cancer. Distinct from recurrent MBC is de novo MBC (dnMBC), which describes patients who present with distant sites of disease at initial diagnosis and is reviewed here. dnMBC represents approximately 3% to 6% of new breast cancer diagnoses in high-income countries. This incidence has not declined despite decades of widespread use of population-based mammography screening. Overrepresentation of both biologically aggressive tumors and patients negatively impacted by social determinants of health are characteristics of dnMBC. Survival has generally been superior for patients with dnMBC compared with those with recurrent MBC, although it is similar to that for patients with recurrent MBC with long disease-free intervals. Subgroups of patients with dnMBC who experience prolonged survival include those with human epidermal growth factor receptor-2-positive disease or hormone receptor-positive bone-only disease. Opportunities to decrease dnMBC presentation may include novel screening modalities suited for biologically aggressive breast tumors and improved access to health care. Recognizing that there will remain some women diagnosed with dnMBC, refining our ability to identify those likely to be long-term survivors could allow for appropriate escalation or de-escalation of care. Finally, evaluation of tumor genomics in robust sample sizes has the potential to advance our knowledge of the biology of dnMBC as an entity distinct from recurrent MBC.

Comprehensive Review of Molecular Mechanisms and Clinical Features of Invasive Lobular Cancer

Invasive lobular carcinoma (ILC) accounts for 10% to 15% of breast cancers in the United States, 80% of which are estrogen receptor (ER)-positive, with an unusual metastatic pattern of spread to sites such as the serosa, meninges, and ovaries, among others. Lobular cancer presents significant challenges in detection and clinical management given its multifocality and multicentricity at presentation. Despite the unique features of ILC, it is often lumped with hormone receptor-positive invasive ductal cancers (IDC); consequently, ILC screening, treatment, and follow-up strategies are largely based on data from IDC. Despite both being treated as ER-positive breast cancer, querying the Cancer Genome Atlas database shows distinctive molecular aberrations in ILC compared with IDC, such as E-cadherin loss (66% vs. 3%), FOXA1 mutations (7% vs. 2%), and GATA3 mutations (5% vs. 20%). Moreover, compared with patients with IDC, patients with ILC are less likely to undergo breast-conserving surgery, with lower rates of complete response following therapy as these tumors are less chemosensitive. Taken together, this suggests that ILC is biologically distinct, which may influence tumorigenesis and therapeutic strategies. Long-term survival and clinical outcomes in patients with ILC are worse than in stage- and grade-matched patients with IDC; therefore, nuanced criteria are needed to better define treatment goals and protocols tailored to ILC's unique biology. This comprehensive review highlights the histologic and clinicopathologic features that distinguish ILC from IDC, with an in-depth discussion of ILC's molecular alterations and biomarkers, clinical trials and treatment strategies, and future targets for therapy. IMPLICATIONS FOR PRACTICE: The majority of invasive lobular breast cancers (ILCs) are hormone receptor (HR)-positive and low grade. Clinically, ILC is treated similar to HR-positive invasive ductal cancer (IDC). However, ILC differs distinctly from IDC in its clinicopathologic characteristics and molecular alterations. ILC also differs in response to systemic therapy, with studies showing ILC as less sensitive to chemotherapy. Patients with ILC have worse clinical outcomes with late recurrences. Despite these differences, clinical trials treat HR-positive breast cancers as a single disease, and there is an unmet need for studies addressing the unique challenges faced by patients diagnosed with ILC.

Lobular Breast Cancer: A Review

Invasive lobular carcinoma accounts for 5%–15% of all invasive breast cancers, with a marked increase in incidence rates over the past two decades. Distinctive biological hallmarks of invasive lobular carcinoma include the loss of cell adhesion molecule E-cadherin leading to cells with a discohesive morphology, proliferating into single-file strands and estrogen receptor positivity. These key molecular features can make diagnosis difficult, as invasive lobular carcinoma is challenging to detect both physically and with current standard imaging. Treatment of invasive lobular carcinoma strongly favors endocrine therapy due to low chemosensitivity and lower rates of pathological response as a result. This review will summarize the distinct biological and molecular features of invasive lobular carcinoma, focusing on the diagnostic challenges faced and the subsequent surgical and medical management strategies. Prospective therapeutic options will also be explored, highlighting how furthering our understanding of the unique biology of lobular breast carcinoma is essential in guiding and informing the treatment of patients in the future.

Pleomorphic Invasive Lobular Carcinoma of the Breast With Extracellular Mucin and HER2 Amplification

Invasive lobular carcinoma with extracellular mucin is an uncommon pattern of invasive breast carcinoma. The 5th Edition of the World Health Organization Classification of Breast Tumors states that it is unknown whether these tumors are a subtype of mucinous carcinoma or invasive lobular carcinoma. Invasive lobular carcinoma with extracellular mucin frequently presents as a palpable mass and may be more likely to be grade 2 to 3 and HER2-positive than classic invasive lobular carcinoma. This case of pleomorphic invasive lobular carcinoma with extracellular mucin was detected by imaging only and was HER2-amplified, suggesting that a subset of these tumors may be clinically occult with an aggressive phenotype. Invasive lobular carcinoma with extracellular mucin is infrequently encountered and awareness of this entity is helpful in avoiding misdiagnosis.

Imaging of Breast Cancers With Predilection for Nonmass Pattern of Growth: Invasive Lobular Carcinoma and DCIS-Does Imaging Capture It All?

OBJECTIVE. Invasive lobular carcinoma (ILC) and ductal carcinoma in situ (DCIS) are distinct histopathologic entities with several commonalities: both have subtle clinical and imaging presentation, have been linked with controversy regarding optimal imaging techniques and management, and exemplify the codependence of adequate imaging evaluation and optimal treatment strategies in breast care. CONCLUSION. We review molecular mechanisms and histopathologic patterns that define the biologic behavior of both ILC and DCIS and discuss how these mechanisms translate into distinct clinical and imaging presentations that affect the staging workup and patient management algorithm.

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.

Intraoperative ultrasonography-guided surgery: An effective modality for breast conservation after neo-adjuvant chemotherapy

Margin status is one of the significant prognostic factors for recurrence in breast-conserving surgery (BCS). The issue that merits consideration for oncologic safety and cost-effectiveness about the modalities to assure clear margins at initial surgical intervention remains controversial after neo-adjuvant chemotherapy (NAC). The presented study aimed to assess the impact of intraoperative ultrasound (IOUS)-guided surgery on accurate localization of tumor site, adequacy of excision with clear margins, and healthy tissue sacrifice in BCS after NAC. Patients who had IOUS-guided BCS ater NAC were reviewed. No patient had preoperative localization with wire or radiotracer. Intraoperative real-time sonographic localization, sonographic margin assessment during resection, macroscopic and sonographic examination of specimen, and cavity shavings (CS) were done as the standard procedure. No frozen assessment was performed. One hundred ninety-four patients were included, in which 42.5% had pCR. IOUS-guided surgery accomplished successful localization of the targeted lesions in all patients. Per protocol, all inked margins on CS specimens were reported to be tumor-free in permanent histopathology. No re-excision or mastectomy was required. For a setting without CS, the negative predictive value (NPV) of IOUS rate was 96%. IOUS was found to over and underestimate tumor response to NAC both in 2% of patients. IOUS-guided surgery seems to be an efficient modality to perform adequate BCS after NAC with no additional localization method. Especially, when CS is integrated as a standard to BCS, IOUS seems to provide safe surgery for patients with no false negativity and a high rate of NPV.

Surgeon Bias in the Management of Positive Sentinel Lymph Nodes

BACKGROUND

The standard of care for clinically node-negative (cN0) patients following positive sentinel lymph node biopsy (SLNB) was completion axillary lymph node dissection (CALND). Publication of ACOSOG Z0011 in 2010 changed this standard for patients undergoing lumpectomy. Clinicians have since expanded this practice to mastectomy patients, and ongoing prospective studies are seeking to validate this practice. Here, we evaluate patient and tumor characteristics that led surgeons to forego a second surgery for CALND in cN0 mastectomy patients with positive SLNB.

PATIENTS AND METHODS

A single institution, retrospective review of cN0 patients with invasive primary breast cancer and positive SLNB from 2010 to 2016 was performed. Patients with T4 disease, positive preoperative axillary biopsy, prior neoadjuvant therapy or axillary surgery were excluded. Patients with positive SLNB undergoing CALND were compared with patients for whom CALND was omitted. Statistical analysis was performed using Kruskal-Wallis tests for continuous variables and χ² tests or Fischer exact tests for categorical variables.

RESULTS

Of 259 patients with positive SLNB, 180 (69.4%) patients underwent mastectomy. CALND was performed at the time of mastectomy in 54 (30%) patients, at time of second operation in 22 (12.2%) patients, and not performed in 104 (57%) patients. Delayed CALND was significantly associated with younger age, larger tumors, increased number of positive sentinel nodes, invasive lobular carcinoma, extranodal extension, and lymphovascular invasion.

CONCLUSIONS

The management of cN0 patients with positive SLNB that do not meet ACOSOG Z0011 criteria is evolving and is influenced by tumor and patient characteristics in an attempt to balance the morbidity of CALND with the low rate of local regional recurrence.

Case report: acute abdominal pain in a 37-year-old patient and the consequences for his family

Background

Hereditary diffuse gastric cancer is a rare condition that accounts for approximately 1–3% of all gastric cancer cases. Due to its rapid and invasive growth pattern, it is associated with a very poor prognosis. As a result, comprehensive genetic testing is imperative in patients who meet the current testing criteria in order to identify relatives at risk. This case report illustrates the substantial benefit of genetic testing in the family of a patient diagnosed with hereditary diffuse gastric cancer.

Case presentation

A 37-year-old patient was admitted to the emergency department with acute abdominal pain. Following explorative laparoscopy, locally advanced diffuse gastric cancer was diagnosed. The indication for genetic testing of CDH1 was given due to the patient’s young age. A germline mutation in CDH1 was identified in the index patient. As a result, several family members underwent genetic testing. The patient’s father, brother and one aunt were identified as carriers of the familial CDH1 mutation and subsequently received gastrectomy. In both the father and the aunt, histology of the surgical specimen revealed a diffuse growing adenocarcinoma after an unremarkable preoperative gastroscopy.

Conclusion

Awareness and recognition of a potential hereditary diffuse gastric cancer can provide a substantial health benefit not only for the patient but especially for affected family members.

Defining clinicopathological and radiological features of breast cancer in women under the age of 35: an epidemiological study

INTRODUCTION

Breast cancer is the most commonly diagnosed female cancer. Diagnosis in younger women (under 35 years) is different to their older counterparts, and mammography is not considered as sensitive in this cohort. Consequentially, younger patients may present later with more advanced disease.

METHODS

This is a retrospective analysis of a prospectively updated database containing consecutive patients who presented to the symptomatic breast unit of Galway University Hospital between 2009 and 2015. Patient clinicopathologic factors, clinical examination features, diagnostic radiological modalities and Bi-RADS score were all assessed. Data was analysed using Statistical Package for the Social Sciences version 25.

RESULTS

One thousand eight hundred thirty-six patients were diagnosed with breast cancer, and of these, 51 (2.8%) patients were < 35 years. Invasive ductal carcinoma made up 90% of diagnosis, and 42% had an associated ductal carcinoma in situ. Fifty-four percent were high-grade tumours and 52% presented with stage III disease or greater. The main radiological tool used was ultrasound, which had a sensitivity of 87.50% (95% confidence interval [CI] 74.75 to 95.27%). Mammogram sensitivity was 86.84% (95% CI 71.91 to 95.59%). Magnetic resonance imaging was used in 29% of cases, with a sensitivity of 100.00% (95% CI 78.20 to 100.00%).

CONCLUSION

Females under 35 tend to be diagnosed with aggressive, advanced stage tumours. Ultrasound remains the radiological test of choice, although diagnosis using mammography demonstrated a relatively high sensitivity compared with previous reports. This study emphasises the varying epidemiology of breast cancer in younger patients and the potential role of mammography in making radiological diagnosis in those who are symptomatic.

Breast Cancer Screening: a Paradigm Change Is Needed-the PB Desai Oration

This editorial summarizes the key points of the PB Desai Oration, delivered by the author at the National Conference of the Indian Association of Surgical Oncology in Kolkata, India, on September 21, 2019.

Truncated ASPP2 Drives Initiation and Progression of Invasive Lobular Carcinoma via Distinct Mechanisms

Invasive lobular carcinoma (ILC) accounts for 8%-14% of all breast cancer cases. The main hallmark of ILCs is the functional loss of the cell-cell adhesion protein E-cadherin. Nonetheless, loss of E-cadherin alone does not predispose mice to mammary tumor development, indicating that additional perturbations are required for ILC formation. Previously, we identified an N-terminal truncation variant of ASPP2 (t-ASPP2) as a driver of ILC in mice with mammary-specific loss of E-cadherin. Here we showed that expression of t-ASPP2 induced actomyosin relaxation, enabling adhesion and survival of E-cadherin-deficient murine mammary epithelial cells on stiff matrices like fibrillar collagen. The induction of actomyosin relaxation by t-ASPP2 was dependent on its interaction with protein phosphatase 1, but not on t-ASPP2-induced YAP activation. Truncated ASPP2 collaborated with both E-cadherin loss and PI3K pathway activation via PTEN loss in ILC development. t-ASPP2-induced actomyosin relaxation was required for ILC initiation, but not progression. Conversely, YAP activation induced by t-ASPP2 contributed to tumor growth and progression while being dispensable for tumor initiation. Together, these findings highlight two distinct mechanisms through which t-ASPP2 promotes ILC initiation and progression. SIGNIFICANCE: Truncated ASPP2 cooperates with E-cadherin and PTEN loss to drive breast cancer initiation and progression via two distinct mechanisms. ASPP2-induced actomyosin relaxation drives tumor initiation, while ASPP2-mediated YAP activation enhances tumor progression.

Response of metastatic mouse invasive lobular carcinoma to mTOR inhibition is partly mediated by the adaptive immune system

Effective treatment of invasive lobular carcinoma (ILC) of the breast is hampered by late detection, invasive growth, distant metastasis, and poor response to chemotherapy. Phosphoinositide 3-kinase (PI3K) signaling, one of the major druggable oncogenic signaling networks, is frequently activated in ILC. We investigated treatment response and resistance to AZD8055, an inhibitor of mammalian target of rapamycin (mTOR), in the K14-cre;Cdh1^Flox/Flox;Trp53^Flox/Flox (KEP) mouse model of metastatic ILC. Inhibition of mTOR signaling blocked the growth of primary KEP tumors as well as the progression of metastatic disease. However, primary tumors and distant metastases eventually acquired resistance after long-term AZD8055 treatment, despite continued effective suppression of mTOR signaling in cancer cells. Interestingly, therapeutic responses were associated with increased expression of genes related to antigen presentation. Consistent with this observation, increased numbers of tumor-infiltrating major histocompatibility complex class II-positive (MHCII+) immune cells were observed in treatment-responsive KEP tumors. Acquisition of treatment resistance was associated with loss of MHCII+ cells and reduced expression of genes related to the adaptive immune system. The therapeutic efficacy of mTOR inhibition was reduced in Rag1^−/- mice lacking mature T and B lymphocytes, compared to immunocompetent mice. Furthermore, therapy responsiveness could be partially rescued by transplanting AZD8055-resistant KEP tumors into treatment-naïve immunocompetent hosts. Collectively, these data indicate that the PI3K signaling pathway is an attractive therapeutic target in invasive lobular carcinoma, and that part of the therapeutic effect of mTOR inhibition is mediated by the adaptive immune system.

[Diagnostic and therapeutic features of invasive lobular carcinoma of the breast: a study of 30 cases]

Le cancer lobulaire infiltrant (CLI) du sein représente 5 à 15% des cancers du sein, il est classé le deuxième type histologique le plus fréquent, après le cancer infiltrant de type non spécifique (CINS) et son incidence est en nette augmentation. Son diagnostic clinique et radiologique est difficile. Il est plus fréquemment bilatéral. C'est un cancer d'évolution plus lente que le CINS avec de meilleurs facteurs pronostiques notre étude vise à détailler les caractéristiques cliniques, radiologiques, thérapeutiques et pronostiques du CLI. Il s'agit d'une étude rétrospective descriptive de 30 cas de CLI du sein colligé au Centre de Maternité et Néonatologie Monastir sur une période de 10 ans. L'incidence du CLI était de 5,2%. L'âge moyen est de 53,43 ans. Dix pourcent avaient des antécédents personnels de mastopathies bénignes, 6,66% avaient des antécédents personnels du cancer du sein et 3,33% avaient des antécédents familiaux du cancer du sein. Le CLI était diagnostiqué à un stade tardif chez 18 cas. La masse était bifocale chez 5 patientes, multifocale chez 4 patientes et bilatérale chez 3 patientes. Une seule patiente avait présenté une métastase hépatique lors du diagnostic. La chirurgie radicale type Patey était réalisée d'emblée chez 63,33% des patientes. Des lésions multifocales étaient détectées dans 44,80% des cas lors de l'examen anatomopathologique. Le curage ganglionnaire était positif chez 21 patientes. Vingt-huit patientes soit 93,33% avaient bénéficié d'une radiothérapie et d'hormonothérapie adjuvante. La survie globale à 5 ans était estimée à 77,3%.

Pre-operative management of Pleomorphic and florid lobular carcinoma in situ of the breast: Report of a large multi-institutional series and review of the literature

BACKGROUND

Pleomorphic and Florid Lobular carcinoma in situ (P/F LCIS) are rare variants of LCIS, the exact nature of which is still debated.

AIM

To collect a large series of P/F LCIS diagnosed on preoperative biopsies and evaluate their association with invasive carcinoma and high grade duct carcinoma in situ (DCIS). Data obtained were compared with those reported in the literature.

METHODS

A multi-institutional series of P/F LCIS was retrieved. All cases were diagnosed on pre-operative biopsies, which was followed by an open surgical excision. Data on post-operative histopathology were available. A literature review was performed.

RESULTS

A total of 117 cases were collected; invasive carcinoma and/or DCIS was present in 78/117 cases (66.7%). Seventy cases of P/F LCIS were pure on biopsy and 31 of these showed pathological upgrade in post-surgical specimens. Pre-operative biopsy accuracy was 47/78 (60.3%); pre-operative biopsy underestimation of cancer was 31/78 (39,7.%). In the literature review papers, invasive carcinoma or DCIS was associated with 274 of 418 (65.5%) cases of P/F LCIS. Pre-operative biopsy accuracy was 66% (181/274) whereas pre-operative biopsy underestimation of cancer was 33.9% (93/274).

CONCLUSIONS

The data presented here indicate that P/F LCIS is frequently associated with invasive carcinoma or high grade DCIS and that pre-operative biopsy is associated with an underestimation of malignancy. Open surgery is indicated when P/F LCIS is diagnosed pre-operatively.

LobSig is a multigene predictor of outcome in invasive lobular carcinoma

Invasive lobular carcinoma (ILC) is the most common special type of breast cancer, and is characterized by functional loss of E-cadherin, resulting in cellular adhesion defects. ILC typically present as estrogen receptor positive, grade 2 breast cancers, with a good short-term prognosis. Several large-scale molecular profiling studies have now dissected the unique genomics of ILC. We have undertaken an integrative analysis of gene expression and DNA copy number to identify novel drivers and prognostic biomarkers, using in-house (n = 25), METABRIC (n = 125) and TCGA (n = 146) samples. Using in silico integrative analyses, a 194-gene set was derived that is highly prognostic in ILC (P = 1.20 × 10-5)-we named this metagene 'LobSig'. Assessing a 10-year follow-up period, LobSig outperformed the Nottingham Prognostic Index, PAM50 risk-of-recurrence (Prosigna), OncotypeDx, and Genomic Grade Index (MapQuantDx) in a stepwise, multivariate Cox proportional hazards model, particularly in grade 2 ILC cases (χ 2, P = 9.0 × 10-6), which are difficult to prognosticate clinically. Importantly, LobSig status predicted outcome with 94.6% accuracy amongst cases classified as 'moderate-risk' according to Nottingham Prognostic Index in the METABRIC cohort. Network analysis identified few candidate pathways, though genesets related to proliferation were identified, and a LobSig-high phenotype was associated with the TCGA proliferative subtype (χ 2, P < 8.86 × 10-4). ILC with a poor outcome as predicted by LobSig were enriched with mutations in ERBB2, ERBB3, TP53, AKT1 and ROS1. LobSig has the potential to be a clinically relevant prognostic signature and warrants further development.

Invasive lobular breast cancer: A review of pathogenesis, diagnosis, management, and future directions of early stage disease

Invasive lobular carcinoma (ILC) is the second most common type of invasive breast cancer after invasive ductal carcinoma (IDC). Invasive lobular carcinoma has unique clinical, pathologic, and radiographic features which suggest that it is a distinct clinical entity; however, it is treated with the same treatment paradigms as IDC. Information regarding the specific treatment of ILC, including response to standard therapy, is sparse. Neoadjuvant treatment considerations are of great importance in this space as ILC is often found at a locally advanced stage. In this review, we summarize the classic features of ILC and the available data regarding efficacy of both endocrine therapy and chemotherapy in curative treatment of breast cancer.

Value of Ultrasonic Elastography and Conventional Ultrasonography in the Differential Diagnosis of Non-Mass-like Breast Lesions

The purpose of this study was to evaluate the diagnostic value of ultrasonic elastography (UE) and conventional ultrasonography (CUS) in the differential diagnosis of non-mass-like (NML) breast lesions. Static sonograms of 39 pathologically diagnosed NML breast lesions were reviewed. Lesions were evaluated by CUS and UE using CUS subjective ratings (benign, malignant or indeterminate), a 5-point subjective elasticity scoring system and the quantitative strain ratio (SR). Receiver operating characteristic curves and diagnostic tests were used to assess the diagnostic value of CUS and UE. Areas under the receiver operating characteristic curves (Az) of the CUS, 5-point elasticity and SR methods were 0.848 (p < 0.001), 0.895 (p < 0.001) and 0.943 (p < 0.001), respectively. In diagnosing NML breast lesions, there was no significant difference between the 5-point elasticity and CUS methods. The combination of UE and CUS helps to improve the accuracy of the ultrasonic diagnosis of NML breast lesions.

Breast cancer diagnosis in a specialised breast clinic: Are cancers detected by ultrasound alone less aggressive?

INTRODUCTION

The aim of this study was to determine the relationship between the way breast cancer is diagnosed and its prognostic features.

METHODS

We studied new primary invasive and non-invasive breast cancers (670) diagnosed between 2013 and 2015 where detection included at least clinical examination, mammography and breast ultrasound (BUS). The cancers were classified into six Diagnostic Groups according to the results of each modality.

RESULTS

Overall, 79% of cancers were positive on mammography, but another 20% were diagnosed on BUS after a negative mammogram. The largest group (37.6% of cases), had all three modalities positive (Group 1). BUS was the only modality positive in 14.6% (Group 4). Mammography alone was positive in 21.2%, of which 73.9% were ductal carcinoma in situ (DCIS). Invasive lobular carcinoma comprised 9.6% of the groups where mammography was positive, but 16.5% of the groups where mammography was negative and BUS positive. Dense breast tissue was more common in the groups where mammography was negative and BUS positive. Invasive cancers comprised 82.7% of Group 4 and 95.2% of Group 1. For those in Group 4, the average size (10.2 mm) and the percentages with lymphovascular invasion (11.1%), lymph node involvement (17.3%) and poor differentiation (12.3%) were less than half the corresponding figures for Group 1 (27.3 mm, 35%, 44%, 44%).

CONCLUSION

This study illustrates the complementary benefits of mammography and BUS, especially where breast density is high. Tumours diagnosed by BUS alone had better prognostic features in terms of size, lymphovascular invasion, lymph node status, differentiation and hormone receptors, compared with cancers where all three modalities were positive.

Clinical, mammographic, and ultrasonographic characteristics of diabetic mastopathy: A case series

PURPOSE

Diabetic mastopathy (DMP) is a rare benign breast lesion that mimics breast cancer on ultrasound. Our aims were to identify patient characteristics and imaging features of the disease.

METHODS

We conducted retrospective searches of our database for DMP lesions that were pathologically confirmed between January 2004 and November 2015. Mammographic and ultrasound features were reviewed by two experienced radiologists.

RESULTS

Twelve women were identified with 16 lesions. Most patients (83%) had type 2 diabetes mellitus (DM) and over half were insulin-dependent (58.3%), with a mean time of 16.9 years between the diagnosis of DM and that of DMP. There were negative findings on mammography for 46.7% of the lesions, including larger-sized lesions. Ultrasound revealed various features, including irregular shape (81.3%), indistinct margins (100%), parallel orientation to the chest wall (93.8%), marked hypoechogenicity (87.5%), and posterior shadowing (62.5%).

CONCLUSIONS

DMP was more common in patients with longstanding DM; in particular, type 2 DM and insulin-dependent patients. DMP lesions were usually occult on mammography, despite the relatively large size of DMP, which may help distinguish DMP from invasive cancer. Ultrasound detected several features that are also present in invasive cancer, making tissue sampling necessary to distinguish these.

Value Added of Preoperative Contrast-Enhanced Digital Mammography in Patients With Invasive Lobular Carcinoma of the Breast

BACKGROUND

Invasive lobular carcinoma (ILC) is the second most frequently diagnosed breast cancer, accounting for 5% to 15% of all invasive breast cancers, yet it remains radiologically elusive in many cases. The goal of this study was to compare the ability to accurately assess disease extent with contrast-enhanced digital mammography (CEDM) and full-field digital mammography (FFDM) in patients with biopsy-proven ILC.

PATIENTS AND METHODS

A single-institution retrospective review of patients diagnosed with ILC with preoperative CEDM was performed. One of 3 blinded radiologist readers rereviewed cases within 1 month of another. Final size diameter was based on the largest dimension on recombined CEDM or FFDM and compared to the reference standard histopathology. Bland-Altman plots were used to visualize the differences between tumor size on imaging and pathology.

RESULTS

Thirty women were included. Mean tumor diameter was 27.0 mm (range, 7.0-118 mm) on postoperative histology, 26.0 mm on CEDM, and 16.4 mm on standard mammogram. For CEDM versus FFDM, 5 (16.7%) of 30 versus 9 (30.0%) of 30 cases underestimated pathology by > 10 mm and 5 (16.7%) of 30 versus 3 (10.0%) of 30 overestimated histopathology by > 10 mm, respectively. Two (6.7%) of 30 cases required surgical reexcision. Both Lin (0.87 vs. 0.55) and Pearson (0.87 vs. 0.70) correlation coefficient measures were higher for CEDM versus FFDM.

CONCLUSION

CEDM outperforms standard digital mammography in ability to accurately assess disease extent in patients with biopsy-proven ILC, resulting in improved surgical outcomes. Future studies should compare surgical outcomes in patients with preoperative magnetic resonance imaging and CEDM in patients with ILC.

Cumulative Risk Distribution for Interval Invasive Second Breast Cancers After Negative Surveillance Mammography

Purpose The aim of the current study was to characterize the risk of interval invasive second breast cancers within 5 years of primary breast cancer treatment. Methods We examined 65,084 surveillance mammograms from 18,366 women with a primary breast cancer diagnosis of unilateral ductal carcinoma in situ or stage I to III invasive breast carcinoma performed from 1996 to 2012 in the Breast Cancer Surveillance Consortium. Interval invasive breast cancer was defined as ipsilateral or contralateral cancer diagnosed within 1 year after a negative surveillance mammogram. Discrete-time survival models-adjusted for all covariates-were used to estimate the probability of interval invasive cancer, given the risk factors for each surveillance round, and aggregated across rounds to estimate the 5-year cumulative probability of interval invasive cancer. Results We observed 474 surveillance-detected cancers-334 invasive and 140 ductal carcinoma in situ-and 186 interval invasive cancers which yielded a cancer detection rate of 7.3 per 1,000 examinations (95% CI, 6.6 to 8.0) and an interval invasive cancer rate of 2.9 per 1,000 examinations (95% CI, 2.5 to 3.3). Median cumulative 5-year interval cancer risk was 1.4% (interquartile range, 0.8% to 2.3%; 10th to 90th percentile range, 0.5% to 3.7%), and 15% of women had ≥ 3% 5-year interval invasive cancer risk. Cumulative 5-year interval cancer risk was highest for women with estrogen receptor- and progesterone receptor-negative primary breast cancer (2.6%; 95% CI, 1.7% to 3.5%), interval cancer presentation at primary diagnosis (2.2%; 95% CI, 1.5% to 2.9%), and breast conservation without radiation (1.8%; 95% CI, 1.1% to 2.4%). Conclusion Risk of interval invasive second breast cancer varies across women and is influenced by characteristics that can be measured at initial diagnosis, treatment, and imaging. Risk prediction models that evaluate the risk of cancers not detected by surveillance mammography should be developed to inform discussions of tailored surveillance.

Hereditary lobular breast cancer with an emphasis on E-cadherin genetic defect

Recent studies have reported germline CDH1 mutations in cases of lobular breast cancer (LBC) not associated with the classical hereditary diffuse gastric cancer syndrome. A multidisciplinary workgroup discussed genetic susceptibility, pathophysiology and clinical management of hereditary LBC (HLBC). The team has established the clinical criteria for CDH1 screening and results' interpretation, and created consensus guidelines regarding genetic counselling, breast surveillance and imaging techniques, clinicopathological findings, psychological and decisional support, as well as prophylactic surgery and plastic reconstruction. Based on a review of current evidence for the identification of HLBC cases/families, CDH1 genetic testing is recommended in patients fulfilling the following criteria: (A) bilateral LBC with or without family history of LBC, with age at onset <50 years, and (B) unilateral LBC with family history of LBC, with age at onset <45 years. In CDH1 asymptomatic mutant carriers, breast surveillance with clinical examination, yearly mammography, contrast-enhanced breast MRI and breast ultrasonography (US) with 6-month interval between the US and the MRI should be implemented as a first approach. In selected cases with personal history, family history of LBC and CDH1 mutations, prophylactic mastectomy could be discussed with an integrative group of clinical experts. Psychodecisional support also plays a pivotal role in the management of individuals with or without CDH1 germline alterations. Ultimately, the definition of a specific protocol for CDH1 genetic screening and ongoing coordinated management of patients with HLBC is crucial for the effective surveillance and early detection of LBC.

Imaging features of breast cancers on digital breast tomosynthesis according to molecular subtype: association with breast cancer detection

OBJECTIVE

To evaluate imaging features of breast cancers on digital breast tomosynthesis (DBT) according to molecular subtype and to determine whether the molecular subtype affects breast cancer detection on DBT.

METHODS

This was an institutional review board--approved study with a waiver of informed consent. DBT findings of 288 invasive breast cancers were reviewed according to Breast Imaging Reporting and Data System lexicon. Detectability of breast cancer was quantified by the number of readers (0-3) who correctly detected the cancer in an independent blinded review. DBT features and the cancer detectability score according to molecular subtype were compared using Fisher's exact test and analysis of variance.

RESULTS

Of 288 invasive cancers, 194 were hormone receptor (HR)-positive, 48 were human epidermal growth factor receptor 2 (HER2) positive and 46 were triple negative breast cancers. The most common DBT findings were irregular spiculated masses for HR-positive cancer, fine pleomorphic or linear branching calcifications for HER2 positive cancer and irregular masses with circumscribed margins for triple negative breast cancers (p < 0.001). Cancer detectability on DBT was not significantly different according to molecular subtype (p = 0.213) but rather affected by tumour size, breast density and presence of mass or calcifications.

CONCLUSION

Breast cancers showed different imaging features according to molecular subtype; however, it did not affect the cancer detectability on DBT. Advances in knowledge: DBT showed characteristic imaging features of breast cancers according to molecular subtype. However, cancer detectability on DBT was not affected by molecular subtype of breast cancers.

Imaging features and conspicuity of invasive lobular carcinomas on digital breast tomosynthesis

OBJECTIVE

To review the imaging features of invasive lobular carcinoma (ILC) seen on digital breast tomosynthesis (DBT) in comparison with invasive ductal carcinoma (IDC), and to evaluate whether DBT could improve conspicuity and tumour size assessment of ILC in comparison with digital mammography (DM).

METHODS

Institutional review board with waiver of informed consent was obtained for this retrospective study. Patients with ILC or IDC who underwent DBT and DM at the time of diagnosis were included. DM and DBT images were reviewed in consensus by two breast radiologists in order to assess imaging features, conspicuity and maximum tumour diameter of ILC and IDC. Pathology on the surgical specimen was considered the standard of reference for assessment of tumour size.

RESULTS

43 patients (20 patients with ILC and 23 patients with IDC) were included. On DBT, compared with IDC, ILC presented less frequently as masses (40% vs 78%) (p = 0.01) and more frequently as isolated distortion (20% vs 0%) (p = 0.03). ILC presented more often as asymmetries (60%) than masses (20%) on DM (p = 0.02) but not on DBT (35% vs 40%; p = 1.00). Conspicuity of ILC was significantly higher on DBT than on DM (p = 0.002), while the difference between the two techniques was not significant for IDC (p = 0.2). Regarding ILC, concordance in tumour size measurement between DBT and pathology was fair (intraclass correlation coefficient = 0.24).

CONCLUSION

ILC rarely presented as dense masses but frequently demonstrated architectural distortion on DBT. DBT increased lesion conspicuity but failed to accurately assess tumour size of ILC. Advances in knowledge: (1) This study describes specific features of ILC on DBT. (2) It shows that DBT can improve conspicuity of ILC.

Repeated surgeries in invasive lobular breast cancer with preoperative MRI: Role of additional carcinoma in situ and background parenchymal enhancement

OBJECTIVES

Analysing the influence of additional carcinoma in situ (CIS) and background parenchymal enhancement (BPE) in preoperative MRI on repeated surgeries in patients with invasive lobular carcinoma (ILC) of the breast.

METHODS

Retrospective analysis of 106 patients (mean age 58.6±9.9years) with 108 ILC. Preoperative tumour size as assessed by MRI, mammography and sonography was recorded and compared to histopathology. In contrast-enhanced MRI, the degree of BPE was categorised by two readers. The influence of additionally detected CIS and BPE on the rate of repeated surgeries was analysed.

RESULTS

Additional CIS was present in 45.4% of the cases (49/108). The degree of BPE was minimal or mild in 80% of the cases and moderate or marked in 20% of the cases. In 17 cases (15.7%) at least one repeated surgery was performed. In n=15 of these cases, repeated surgery was performed after BCT (n=9 re-excisions, n=6 conversions to mastectomy), in n=2 cases after initial mastectomy. The initial surgical procedure (p=0.008) and additional CIS (p=0.046) significantly influenced the rate of repeated surgeries, while tumour size, patient age and BPE did not (p=ns).

CONCLUSIONS

Additional CIS was associated with a higher rate of repeated surgeries, whereas BPE had no influence.

CDH1 germline mutations and hereditary lobular breast cancer

Hereditary diffuse gastric cancer is an autosomal dominant inherited disease associated of CDH1 germline mutations (that encodes for the E-cadherin protein), and lobular breast cancer is the second most frequent type of neoplasia. Recently, novel E-cadherin constitutional alterations have been identified in pedigree clustering only for lobular breast carcinoma without evidence of diffuse gastric tumors and in absence of BRCA1/2 mutations. This first evidence opens novel questions about the inherited correlation between diffuse gastric and lobular breast cancers. In this brief review we revise the literature data about the CDH1 mutation frequency affecting exclusively lobular breast cancer, providing clinical recommendation for asymptomatic mutation carriers.

Ultrasound-guided breast-conserving surgery for early-stage palpable and nonpalpable invasive breast cancer: decreased excision volume at unchanged tumor-free resection margin

Ultrasound guidance (USG) during breast-conserving surgery improves tumor-free surgical resection margins. The objective of this study was to evaluate whether USG reduces resection volumes without compromising margin status. 134 patients with palpable or nonpalpable T1-2N0-1 invasive breast cancer were treated with USG and compared with a historical reference control group (CON) consisting of palpation-guided (PAG) or wire-guided localization (WIG) breast-conserving surgery. Primary outcomes were excess resection volume and clear margin status, and secondary outcome was re-excision rate. 66 patients underwent USG. In the CON group (n = 68), PAG was performed in 24 (35 %) and WIG in 44 (64 %) patients. Median excision volume [39 (IQR 20-66) vs 56 (38-94) cm(3); p = 0.001] and median calculated resection ratio [1.7 (1.0-2.9) vs 2.8 (1.4-4.6) (p = 0.005)] were significantly smaller in the USG than in the CON group. Median minimal distance to the resection margin [4 mm (IQR 2-5 mm) vs 2 mm (1-4 mm), p = 0.004] was significantly larger. Clear resection margins were achieved in 58 of the USG patients (88 %) and in 58 of the CON patients (86 %) (p = 0.91); this was true in patients with palpable as well as nonpalpable lesions. Reexcision was needed in 6.1 and 7.2 % respectively. Relative risk for re-excision in the USG group was 0.82 (95 % CI 0.23-2.93). In patients with palpable and nonpalpable breast cancers, USG allows for lower excision volume and reduced resection of healthy breast tissue, without increased re-excision rate.