Management Of Invasive Lobular Carcinoma Research Articles

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

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

Abstract P3-01-25: Assessing the impact of preoperative breast MRI on time to treatment for invasive lobular carcinoma

Abstract Background: Invasive lobular carcinoma (ILC) has increased rates of multifocal, multicentric, and bilateral disease. Despite high sensitivity in detection of ILC, preoperative breast MRI is not routinely done. Additional findings requiring biopsy may be necessary, which would possibly delay time to treatment (TTT). Increased TTT is associated with increased risk of mortality in early stage breast cancer. This study investigates the effect of preoperative MRI on TTT in ILC. Methods: A retrospective study utilizing an institutional database identified patients with ILC treated from 2004-2017. Patient and disease characteristics were recorded, including preoperative breast imaging modalities, new findings on preoperative breast MRI, and dates of treatment. Patients who had surgery were studied and separated into four groups: no MRI (No-MRI), MRI without new lesion (MRI-NNL), MRI with new lesion not biopsied (MRI-NL-NB), and MRI with new lesion that was biopsied (MRI-NL-B). TTT was defined as days from diagnosis to surgical management. Results: Of the total 691 patients, 452 (65.4%) received a preoperative MRI. Preoperative MRI was more likely among younger patients (mean age 58.5 vs. 67.4 years old, p<0.001), those with a lower BMI (mean 27.8 vs. 30.1 kg/m2, p<0.001), more advanced clinical tumor stage (II-IV: 55.1% vs. 24.4%, p<0.001), and less clinical node involvement (83.1% vs. 89.9%, p=0.016). Among the 452 patients who had an MRI, 39.4% had an additional lesion identified (MRI-NL-NB 14.4%, MRI-NL-B 25.0%). Bilateral mastectomy occurred more frequently among those in MRI-NL-NB and MRI-NL-B (p<0.001). Overall median (IQR) TTT was 40 (26, 64) days, with median TTT 34 (20, 57) days for patients without MRI and 41 (28, 65) days for patients who received MRI (p=0.0001). Among those who received MRI, the median TTT was 42 days for MRI-NNL, 36 days for MRI-NL-NB, and 42 days for MRI-NL-B (p=0.0005). Median follow up was 6 years. Recurrence free survival (RFS) was similar between patients with and without preoperative MRI. RFS was also similar among No-MRI, MRI-NNL, MRI-NL-NB, and MRI-NL-B (5-year RFS: 91.1%, 89.0%, 93.6%, 90.1%, respectively, p=0.41). Conclusions: This analysis demonstrates an increase in median TTT by up to 8 days for patients receiving preoperative MRI compared to those who did not have a preoperative MRI. Interestingly, patients with new findings on MRI which were not biopsied had TTT more similar to those who did not have a preoperative MRI. Although TTT was different between these four groups, RFS was not decreased in the MRI group despite a delay in TTT, suggesting that the delay does not meaningfully impact clinical outcomes. Optimal management of ILC requires a balance between expedited TTT and a thorough investigation to determine the scope of disease. Citation Format: Matthew D. Wright, Marcus S. Dempster, Ayat ElSherif, Daniela Cocco, Stephanie A. Valente, Hong Li, Megan L. Kruse. Assessing the impact of preoperative breast MRI on time to treatment for invasive lobular carcinoma [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-01-25.

Breast conservation therapy versus mastectomy in the surgical management of invasive lobular carcinoma measuring 4 cm or greater

BackgroundThe safety of breast conservation therapy (BCT) has not been demonstrated in large ILC tumors, potentially contributing to the higher mastectomy rates seen in ILC. MethodsWe queried a prospectively maintained database to identify patients with ILC measuring ≥4 cm and evaluated difference in recurrence free survival (RFS) between those treated with BCT versus mastectomy using a multivariate model. ResultsOf 180 patients, 30 (16.7%) underwent BCT and 150 (83.3%) underwent mastectomy. Patients undergoing mastectomy were younger (56.6 vs. 64.3 years, p = 0.003) and had larger tumors (7.2 vs. 5.4 cm, p < 0.001). While tumor size, nodal stage, receptor subtype, and margin status were significantly associated with RFS, there was no difference in RFS at 5 (p = 0.88) or 10 (p = 0.65) years for individuals undergoing BCT versus mastectomy. ConclusionsFor patients with ILC ≥4 cm, BCT provides similar tumor control as mastectomy, provided that negative margins are achieved.

Abstract P4-13-01: Trends in primary management of invasive lobular carcinoma: An analysis of the National Cancer Database (NCDB)

Abstract Background: Invasive lobular carcinoma (ILC) is typically strongly hormone receptor (HR) positive, with unique characteristics. It has been shown to have poor response to neoadjuvant chemotherapy (NAC) and recent studies describe the benefits of neoadjuvant endocrine therapy (NET). We sought to determine how the primary management strategy in ILC has changed over time, and the impact of ILC tumor biology on its management. Specifically, we hypothesized that use of NAC has decreased, while NET use increased. Additionally, we investigated whether NET is associated with higher rates of breast conservation surgery (BCS) than other primary management strategies. Methods: We queried the NCDB from 2010-2016 and identified all women with ILC who underwent surgical therapy. Patients with stage IV disease were excluded. First course of treatment was classified as: NAC (chemotherapy starting 31-365 days before surgery), NET (short course defined as 7-30 days before surgery; long course defined as 31-365 days before surgery), and primary surgery. Tumors were considered HR+ if they were estrogen receptor and/or progesterone receptor positive. Trends over time in first treatment strategy were compared using Cochrane-Armitage tests. The association between first treatment strategy and use of BCS was assessed using multivariable logistic regression. Results: Among 79,709 women with ILC, 94.0% were HR+/HER2-, 4.7% were HER2+, and 1.3% were triple negative. The most common primary treatment strategy was surgery (92.3%), but the percent undergoing systemic treatment before surgery increased from 7.1% in 2010 to 8.8% in 2016 (p&amp;lt;0.001). The use of NAC increased significantly over the study period in patients with triple negative (12.1% in 2010 to 23.7% in 2016, p=0.007) and HER2+ (12.2% in 2010 to 29.1% in 2016, p&amp;lt;0.001) ILC tumors. Among patients with HR+/HER2- tumors, however, the use of NAC decreased from 4.7% in 2010 to 4.2% in 2016, p=0.007, and the use of long course NET increased significantly, from 1.6% in 2010 to 2.7% in 2016, p&amp;lt;0.001. The use of short course NET in HR+/HER2- patients remained very low over the study period (0.4% in 2010 to 0.5% in 2016, p=0.14). Analyzing the HR+/HER2- subset, 48.4% (295/609) of patients undergoing long course NET with a cT2 tumor underwent BCS compared to 35.3% for primary surgery, 27.3% for NAC, and 24.8% for short course NET (p&amp;lt;0.001). Long course NET was also associated with a higher BCS rate in cT3/cT4 tumors: 22.6% BCS for long course NET, 8.3% BCS for primary surgery, 9.6% BCS for NAC, 7.8% BCS for short course NET (p&amp;lt;0.001). In multivariable analysis including a clinical T category by treatment interaction, long course NET was the only treatment that was associated with higher rates of BCS compared to primary surgery in cT2 (OR 1.51, 95% CI: 1.27-1.79) tumors, while both long course NET (OR 2.52, 95% CI: 1.97-3.22) and NAC (OR 1.54, 95% CI: 1.27-1.88) were associated with increased use of BCS in cT3/cT4 tumors, see Table. Conclusions: The primary management of ILC is slowly evolving over time with a decrease in primary surgery. NAC use has increased appropriately in tumor subtypes with greatest potential benefit (i.e., triple negative or HER2 positive). In HR+/HER2- disease, NAC use has decreased, however NET use has increased and in cT2+ tumors NET was associated with higher rates of BCS. Variable1Odds ratio for BCS (95% CI)p-valueAge, per 1 year increase1.04 (1.03-1.04)&amp;lt;0.001Charlson-Deyo comorbidity score&amp;lt;0.0011 vs 00.86 (0.82-0.90)2+ vs 00.72 (0.66-0.79)Grade2&amp;lt;0.001Moderately/Poorly vsWell Differentiated0.91 (0.88-0.95)Clinical N category2&amp;lt;0.001cN1 vs cN00.49 (0.46-0.52)cN2/cN3 vs cN00.41 (0.35-0.47)Multicentric&amp;lt;0.001Yes vs No0.36 (0.34-0.38)Primary treatment by clinical T category2&amp;lt;0.001For cT1 tumorsLong course NET vs primary surgery0.65 (0.51-0.83)NAC vs Primary surgery0.31 (0.24-0.41)Short course NET vs primary surgery0.85 (0.58-1.24)For cT2 tumorsLong course NET vs primary surgery1.51 (1.27-1.79)NAC vs primary surgery1.04 (0.90-1.20)Short course NET vs primary surgery0.53 (0.33-0.85)For cT3/cT4 tumorsLong course NET vs primary surgery2.52 (1.97-3.22)NAC vs primary surgery1.54 (1.27-1.88)Short course NET vs primary surgery0.79 (0.31-2.02)1Model additionally adjusted for year of diagnosis, race, ethnicity, and insurance status.2Unknown level included in the model but not reported Citation Format: Rita A Mukhtar, Tanya L. Hoskin, Elizabeth B. Habermann, Judy C. Boughey. Trends in primary management of invasive lobular carcinoma: An analysis of the National Cancer Database (NCDB) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-13-01.

Abstract P6-05-03: Exogenous steroid hormone exposure and the biology of lobular breast cancer

Abstract Introduction. Invasive lobular carcinoma (ILC) accounts for 10-15% of breast cancer diagnoses and is characterized by a high rate of estrogen and progesterone receptor (ER and PR) expression, low rate of HER2 amplification, and a defining lack of e-cadherin expression. Multiple population-based, observational studies have shown that the risk of ILC is significantly elevated with the intake of combined estrogen/progestin (E+P) hormone replacement therapy (HRT) but not with estrogen-alone (E alone) HRT. In addition, recent studies have revealed that ILCs might respond differently to hormone therapies than IDCs. We sought to understand the influence of exogenous hormone exposure in the form of HRT on biological pathways in ILCs compared to the more common histologic subtype, ER+ invasive ductal carcinoma (IDC). Specimens and Methods. We assessed 297 ER+/HER2- FFPE breast carcinomas, 165 IDCs and 132 ILCs, previously collected from an epidemiological study of HRT use and breast cancer in post-menopausal women. These tumors were characterized for histopathological features and protein marker expression by immunohistochemistry along with the extensive clinical and demographic data, including HRT use, collected in the parent study. Using the Nanostring nCounter assay, we measured expression of ~1000 genes representing canonical cancer-promoting pathways and steroid hormone-associated pathways to determine the relationship between HRT use and pathway alterations in ER+ breast cancer subtypes. Results. From the histopathological assessment, we observed that ILCs had lower overall lymphocyte response than IDCs (p=0.005), but HRT use shifted the lymphocyte response higher than what was observed in ILCs from never/former HRT users (p=0.002). In the gene expression analysis, we found that IDCs and ILCs have distinct expression profiles after adjusting for HRT use, including genes in cell cycle, steroid hormone-response pathways, and cytokine/cytokine receptor interactions, with increased signaling seen in the IL6/12-like family. When comparing gene expression between the HRT-use groups, adjusting for histology, we observed that E+P and E alone are both associated with down-regulation of cell cycle and DNA repair genes compared to the never/former use group. When we focused on expression patterns specific to progestin exposure, (i.e., E+P versus all others), we found decreased expression of genes related to DNA replication initiation and G1/S transition and WNT4. Unsupervised hierarchical clustering revealed additional subgroups within each histologic subtype including a group of low-grade, low-proliferating IDCs enriched for E+P exposure, which clusters with the majority of the ILCs. While many gene expression changes with HRT use are shared across the tumors, we observed alterations that are specific to either ILCs or IDCs, suggesting different steroid hormone-responsive pathways between the subtypes. Conclusions. Our study demonstrates there are potentially specific pathways differentially activated between ILCs and IDCs dependent on the type of hormone exposure. Further, while our study is focused on tumor molecular pathways modulated in response to HRT use, steroid hormone exposure can come from multiple sources, and we propose that the results from this study can provide insight into hormonally-driven breast cancers that develop with excess estrogen and/or progesterone exposure. This could have implications in clinical management of ILCs and IDCs that arise in HRT users. Citation Format: Jamie Guenthoer, Isaac C Jenkins, Beti Thompson, Mei-Tzu C Tang, Nancy E Davidson, Ryan L Ashley, Christopher I Li, Li Hsu, Peggy L Porter. Exogenous steroid hormone exposure and the biology of lobular breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-05-03.

Metastatic Lobular Carcinoma of the Breast Presenting with Small Bowel Metastases: Case Report and Literature Review

Introduction: Invasive lobular carcinoma (ILC) is the second most common histologic type of breast cancer, representing 5% to 15% of invasive tumors. ILC tends to spread to bones, lungs, central nervous system, reproductive organs, and the gastrointestinal tract (GI tract). The most commonly affected organs in the GI tract are the stomach, small intestine, followed by colon and rectum. Case presentation: A 78-year-old woman who was referred to our institution after having a bowel obstruction that required a diagnostic laparoscopy where they identified an obstructing ulcerative lesion in the distal ileum that was managed with a segmental bowel resection. Pathology report showed an invasive lobular breast carcinoma that occluded 90% of the bowel lumen. A PET/CT scan revealed a left breast tumor with increased metabolism. The patient was staged as a clinical cT4b, cN0, cM1 left breast invasive lobular carcinoma (ER/PgR positive, HER-2 negative). She was managed with endocrine therapy with Letrozole (an eight-week course). A follow-up PET/CT showed a peritoneal hypermetabolic nodule adjacent to the previous ileal anastomosis. The lesion decreased in size and metabolic activity. In a multidisciplinary fashion, the endocrine therapy was extended for another three months. Another follow-up PET/CT scan was performed three months after the identification of the peritoneal implant that showed that the nodule increased in size and in metabolism. The lesion continued to decrease significantly in size and became metabolically inactivity. Due to the good breast response and the possibility that the ileal nodule could be a granuloma, she underwent an exploratory laparoscopy with excision of the peritoneal nodule, and a modified left radical mastectomy with immediate breast reconstruction (complex wound closure). The final pathology report of the nodule was negative for malignancy. She continued on endocrine therapy and underwent whole breast irradiation four weeks after the operation. Currently, she is free of disease with no evidence of local, regional, or distant recurrence, and she is still on endocrine therapy. Discussion: The time interval between primary breast cancer and gastrointestinal involvement may range from synchronous presentation to as long as 30 years. The clinical manifestations in GI lobular breast cancer metastasis may range from non-specific complaints to acute GI symptoms, such as a bowel obstruction. There are multiple controversies in the management of ILC. Systemic treatment should be initiated as soon as possible. Indications for postmastectomy radiotherapy are also controversial, given the propensity for multifocal/multicentric tumors and late recurrences, sometimes in atypical locations. Five years of postoperative adjuvant hormonal therapy is an option for women with poor prognosis. Remissions are observed in 32% to 53% of patients. Conclusion: Metastatic lobular carcinoma of the breast has a wide range of clinical presentations. Patients with a history of breast cancer who present with new GI tumors should have these lesions evaluated for evidence of metastasis through histopathologic and immunohistochemical analysis, this will allow for appropriate management. Currently, breast cancer management involves a multidisciplinary approach including surgery, radiotherapy, and systemic medical therapy, and the treatment must be tailored to the patient’s needs.

Success rates of re-excision after positive margins for invasive lobular carcinoma of the breast

Rates of positive margins after surgical resection of invasive lobular carcinoma (ILC) are high (ranging from 18 to 60%), yet the efficacy of re-excision lumpReceptor subtypeectomy for clearing positive margins is unknown. Concerns about the diffuse nature of ILC may drive increased rates of completion mastectomy to treat positive margins, thus lowering breast conservation rates. We therefore determined the success rate of re-excision lumpectomy in women with ILC and positive margins after surgical resection. We identified 314 cases of stage I-III ILC treated with breast conserving surgery (BCS) at the University of California, San Francisco. Surgical procedures, pathology reports, and outcomes were analyzed using univariate and multivariate statistics and Cox-proportional hazards models. We evaluated outcomes before and after the year 2014, when new margin management consensus guidelines were published. Positive initial margins occurred in 118 (37.6%) cases. Of these, 62 (52.5%) underwent re-excision lumpectomy, which cleared the margin in 74.2%. On multivariate analysis, node negativity was significantly associated with successful re-excision (odds ratio [OR] 3.99, 95% CI 1.15–13.81, p = 0.029). After 2014, we saw fewer initial positive margins (42.7% versus 25.5%, p = 0.009), second surgeries (54.6% versus 20.2%, p < 0.001), and completion mastectomies (27.7% versus 4.5%, p < 0.001). In this large cohort of women with ILC, re-excision lumpectomy was highly successful at clearing positive margins. Additionally, positive margins and completion mastectomy rates significantly decreased over time. These findings highlight improvements in management of ILC, and suggest that completion mastectomy may not be required for those with positive margins after initial BCS.

520 (PB-153) - The role of breast MRI in the surgical planning and management of invasive lobular carcinoma: A four-year retrospective study

520 (PB-153) - The role of breast MRI in the surgical planning and management of invasive lobular carcinoma: A four-year retrospective study

The Importance of Applying ACOSOG Z0011 Criteria in the Axillary Management of Invasive Lobular Carcinoma: A Multi-institutional Cohort Study.

The American College of Surgeons Oncology Group (ACOSOG) Z0011 trial led to a significant change in the management of patients with early stage breast cancer and limited sentinel lymph node (SLN) metastases. However, only 27 patients with invasive lobular carcinoma (ILC) were randomized to the completion axillary lymph node dissection (ALND) arm. To assess the generalizability of the Z0011 trial, the primary aim of this study was to determine the risk of residual nodal burden (RNB) for ILC. A multi-institutional cohort study was completed. RNB was determined for women of any age with an ILC and at least one positive SLN who underwent a primary breast procedure (lumpectomy or mastectomy) and both a SLN biopsy followed by a completion ALND between July 1, 1999, and June 30, 2009, at two large academic centers. A total of 59 patients (60 ILCs) met the inclusion criteria. Although the overall RNB was 40%, it was significantly greater in the T3+ group compared to T1/T2 (87 vs. 24%, respectively, p < 0.0001). When comparing only ILCs that met all of the inclusion criteria for ACOSOG Z0011 (T1 or T2, 1 or 2 SLNs positive, no SLN extranodal extension, and breast conservation) to those ILCs that did not, the RNB was significantly greater in the latter (56 vs. 17 %; p < 0.003). Overall, the clinical practice changes that have occurred after publication of the ACOSOG Z0011 trial appear to be generalizable to ILCs within the inclusion criteria of the study.

Abstract P5-21-09: Oncologist treatment choices in patients with early stage invasive lobular breast carcinoma - a survey

Abstract Introduction: Invasive lobular carcinoma (ILC) is common and accounts for 5-15% of all breast cancers. ILC has distinct clinical and histological features that separate it from invasive ductal carcinoma (IDC) with regards to its breast imaging characteristics, patterns of recurrence and sensitivity to systemic therapy. ILC presents challenges to the physician in many aspects of local-regional and systemic therapy choices. We surveyed breast cancer physicians on their beliefs and practice patterns on issues around the management of ILC. Methods: A questionnaire was developed and circulated electronically using a modified Dillman technique to surgical, radiation, and medical oncologists across Canada and Ireland. Results: The questionnaire was completed by 91 of 429 physicians (21% response rate). Response rate by specialty was 25/69 (36%), 21/54 (41%) and 45/306 (13%) for surgical, radiation and medical oncologists respectively. Most surgeon responders (77%) would feel "uncomfortable making treatment decisions for ILC with a mammogram alone" and 100% would be "more comfortable with an MRI". Although 55% reported treating ILC as they would IDC, 22% of surgeons will purposefully obtain larger gross margins intra-operatively. Some radiation oncologists believe ILC is an independent risk factor for local-regional recurrence after breast conserving surgery (49%), and after mastectomy (29%). 33% of radiation oncologists would offer radiation therapy after mastectomy specifically because of the ILC subtype even in the absence of usual indications for radiotherapy. Most medical oncologists treat ILC comparably to IDC with the factors having the largest influence on systemic treatment decisions being tumour stage, hormone receptor status and HER-2 status. 51% of medical oncologists treat ILC with adjuvant chemotherapy as they do for IDC at least ‘most of the time’, while 40% use neoadjuvant chemotherapy as frequently as they do for IDC at least ‘most of the time’. 75% of medical oncologists manage the hormonal treatment of ILC as they do IDC ‘most of the time’ or ‘always’. Conclusions: There remains significant clinical equipoise in the local-regional and systemic management of ILC. This survey has demonstrated wide variations in both beliefs and practices of management for ILC. Clinical guidance, developed on clinical trials specifically assessing the management of ILC, is required. Citation Format: Carmel Jacobs, Mark Clemons, Mohamed FK Ibrahim, Christina Addison, Jean-Michel Caudrelier, Ian D Graham, Brain Hutton, Angel Arnaout. Oncologist treatment choices in patients with early stage invasive lobular breast carcinoma - a survey [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-21-09.

Impact of MRI in Management of Invasive Lobular Carcinoma of Breast

Impact of MRI in Management of Invasive Lobular Carcinoma of Breast

Clinical Presentation and Surgical Management of Invasive Lobular Carcinoma of the Breast

Invasive lobular carcinoma is the second most common histological type of breast cancer and differs from invasive ductal carcinoma also in some clinical features. Multifocal or multicentric as well as contralateral diseases are more frequently found among patients with lobular carcinoma. Tumor size at diagnosis is larger than in patients with ductal carcinoma due to diagnostic challenges associated with lobular histology. For surgical management, breast conserving surgery followed by radiotherapy offers equal local control as mastectomy. Controversy however exists regarding risk for positive margins and subsequent need for second operations. Axillary staging can be safely performed by sentinel node biopsy if lymph nodes are clinically negative, even in multifocal or multicentric disease.

Invasive Lobular Carcinoma of the Breast: Spectrum of Mammographic, US, and MR Imaging Findings

The reported prevalence of invasive lobular carcinoma (ILC) is variable, with more recent studies indicating that ILC accounts for 10%-15% of all invasive breast carcinomas. However, the radiologic diagnosis and management of ILC can be uniquely challenging. Current imaging modalities are not very specific for differentiating ILC from other invasive breast cancers, and ILC has a tendency to have appearances at mammography that are atypical for invasive ductal carcinomas, resulting in higher false-negative rates. The clinical detection of ILC can also be difficult, since ILC frequently fails to form a palpable lesion. This tendency of ILC to have atypical imaging and clinical appearances is related to its histopathologic features and its failure to elicit a desmoplastic response. Despite these diagnostic challenges, however, imaging remains crucial in the detection and management of ILC. Mammography, ultrasonography (US), and magnetic resonance (MR) imaging all play important roles, with each modality having its own advantages and limitations. The use of US and MR imaging as adjuncts to mammography increases sensitivity in the detection of ILC and provides useful information for further management and presurgical planning. Familiarity with the spectrum of imaging appearances of ILC is essential.

MRI compared to conventional diagnostic work-up in the detection and evaluation of invasive lobular carcinoma of the breast: a review of existing literature

PurposeThe clinical diagnosis and management of invasive lobular carcinoma (ILC) of the breast presents difficulties. Magnetic resonance imaging (MRI) has been proposed as the imaging modality of choice for the evaluation of ILC. Small studies addressing different aspects of MRI in ILC have been presented but no large series to date. To address the usefulness of MRI in the work-up of ILC, we performed a review of the currently published literature.Materials and methodsWe performed a literature search using the query “lobular AND (MRI OR MR OR MRT OR magnetic)” in the Cochrane library, PubMed and scholar.google.com, to retrieve all articles that dealt with the use of MRI in patients with ILC. We addressed sensitivity, morphologic appearance, correlation with pathology, detection of additional lesions, and impact of MRI on surgery as different endpoints. Whenever possible we performed meta-analysis of the pooled data.ResultsSensitivity is 93.3% and equal to overall sensitivity of MRI for malignancy in the breast. Morphologic appearance is highly heterogeneous and probably heavily influenced by interreader variability. Correlation with pathology ranges from 0.81 to 0.97; overestimation of lesion size occurs but is rare. In 32% of patients, additional ipsilateral lesions are detected and in 7% contralateral lesions are only detected by MRI. Consequently, MRI induces change in surgical management in 28.3% of cases.ConclusionThis analysis indicates MRI to be valuable in the work-up of ILC. It provides additional knowledge that cannot be obtained by conventional imaging modalities which can be helpful in patient treatment.