Lobular neoplasia

Lobular Neoplasia Diagnosed by MRI-Guided Breast Biopsy: Identifying Upgrade Rate to Malignancy and Outcomes of Clinical and Surgical Management

OBJECTIVE

The aim of this study was to determine surgical and clinical outcomes of lobular neoplasia (LN) diagnosed by magnetic resonance imaging (MRI) biopsy, including upgrade to malignancy, and to assess for characteristics associated with upgrade.

METHOD

A single-institution retrospective study, between 2013 and 2022, of patients with histopathological findings of LN via MRI-guided biopsy was performed using an institutional database and review of the electronic medical records. Decision for excision or surveillance was made by a multidisciplinary team per institutional practice. Patient demographics and imaging characteristics were summarized using descriptive analyses. Upgrade was defined as upgrade to cancer on surgical pathology for patients treated with excision or the development of cancer at the biopsy site during surveillance. The Wilcoxon rank-sum test and Fisher's exact test were used to compare features of the upgraded cohort with the remainder of the group.

RESULTS

Ninety-four MRI biopsies diagnosing LN were included. Median age was 57 years (range 37-78 years). Forty-six lesions underwent excision while 48 lesions were surveilled. The upgrade rate was 7.4% (7/94). Upgrades in the excised cohort consisted of pleomorphic lobular carcinoma in situ (LCIS; n = 1), ductal carcinoma in situ (DCIS; n = 3) and invasive lobular carcinoma (ILC; n = 2), while one interval development of DCIS was observed at the site of biopsy in the surveillance cohort. No MRI or patient variables were associated with upgrade.

CONCLUSIONS

In this contemporary cohort of MRI-detected LNs, the upgrade rate was low. Omission of surgery for MRI-detected LNs in carefully selected patients may be considered in a shared decision-making capacity between the patient and the treatment team. Larger cohorts are needed to determine factors predictive of upgrade risk.

Updates in the Surgical Management of Benign and High-Risk Breast Lesions

Benign breast disease (BBD) is a heterogenous group of lesions often classified as nonproliferative or proliferative, with the latter group further categorized based on the presence of atypia. Although nonproliferative lesions are more common, the risk of breast cancer is elevated in women with proliferative lesions. Historically, the majority of proliferative lesions were excised due to concern for future and/or concomitant breast cancer at the site of the index lesion. However, contemporary data suggest that the risk of cancer associated with various proliferative lesions may be lower than previously thought, and management of BBD has become more nuanced. In this review, we will focus on recent updates in the management of a select group of benign and high-risk lesions.

WCRC-25: A novel luminal Invasive Lobular Carcinoma cell line model

Breast cancer is categorized by the molecular and histologic presentation of the tumor, with the major histologic subtypes being No Special Type (NST) and Invasive Lobular Carcinoma (ILC). ILC are characterized by growth in a single file discohesive manner with stromal infiltration attributed to their hallmark pathognomonic loss of E-cadherin ( CDH1 ). Few ILC cell line models are available to researchers. Here we report the successful establishment and characterization of a novel ILC cell line, WCRC-25, from a metastatic pleural effusion from a postmenopausal Caucasian woman with metastatic ILC. WCRC-25 is an ER-negative luminal epithelial ILC cell line with both luminal and Her2-like features. It exhibits anchorage independent growth and haptotactic migration towards Collagen I. Sequencing revealed a CDH1 Q706* truncating mutation, together with mutations in FOXA1, CTCF, BRCA2 and TP53 , which were also seen in a series of metastatic lesions from the patient. Copy number analyses revealed amplification and deletion of genes frequently altered in ILC while optical genome mapping revealed novel structural rearrangements. RNA-seq analysis comparing the primary tumor, metastases and the cell line revealed signatures for cell cycle progression and receptor tyrosine kinase signaling. To assess targetability, we treated WCRC-25 with AZD5363 and Alpelisib confirming WCRC-25 as susceptible to PI3K/AKT signaling inhibition as predicted by our RNA sequencing analysis. In conclusion, we report WCRC-25 as a novel ILC cell line with promise as a valuable research tool to advance our understanding of ILC and its therapeutic vulnerabilities.

Financial support

The work was in part supported by a Susan G Komen Leadership Grant to SO (SAC160073) and NCI R01 CA252378 (SO/AVL). AVL and SO are Komen Scholars, Hillman Foundation Fellows and supported by BCRF. This project used the UPMC Hillman Cancer Center and Tissue and Research Pathology/Pitt Biospecimen Core shared resource which is supported in part by award P30CA047904. This research was also supported in part by the University of Pittsburgh Center for Research Computing, RRID:SCR_022735, through the resources provided. Specifically, this work used the HTC cluster, which is supported by NIH award number S10OD028483. Finally, partial support was provided by the Magee-Womens Research Institute and Foundation, The Shear Family Foundation, and The Metastatic Breast Cancer Network.

Screening MRI Does Not Increase Cancer Detection or Result in an Earlier Stage at Diagnosis for Patients with High-Risk Breast Lesions: A Propensity Score Analysis

BACKGROUND

Guidelines recommend consideration of screening MRI for patients with high-risk breast lesions (HRLs), acknowledging limited data for this moderate-risk population.

METHODS

This study identified patients with atypical ductal/lobular hyperplasia (ADH/ALH), lobular carcinoma in situ, (LCIS) or both evaluated at our high-risk clinic. Patients were categorized as having received screening mammography (MMG) alone vs. MMG and breast MRI (MMG+MRI). Inverse probability weighting based on propensity scores (PS) representing likelihood of MRI use was applied to Kaplan-Meier and Cox regression analyses to determine cancer detection and biopsy rates by screening group.

RESULTS

Among 908 eligible patients, 699 (77%) patients with available follow-up data were analyzed (542 with ADH/ALH and 157 with LCIS). Of the 699 patients, 540 (77%) received MMG alone, and 159 (23%) received MMG + MRI. The median follow-up period was 25 months, during which a median of two MRIs were performed. After PS-weighting, the characteristics of each screening group were well-balanced with respect to age, race, body mass index (BMI), menopausal status, breast density, family history, HRL type, and chemoprevention use. The 4 year breast cancer detection rate was 3.6% with both MMG alone and MMG+MRI (p = 0.89). The breast biopsy rates were significantly higher with MMG+MRI (30.5% vs12.6%; hazard ratio [HR], 2.67; p < 0.001). All breast cancers were clinically node-negative and pathologic stage 0 or 1. Among five cancers in the MMG+MRI group, two were MRI-detected, two were MMG-detected, and one was detected on clinical exam.

CONCLUSIONS

Screening MRI did not improve cancer detection, and cancer characteristics were favorable whether screened with MMG alone or MMG + MRI. These findings question the benefit of MRI for patients with HRL, although longer-term follow-up study is needed.

Presence of Non-classic LCIS Is Not a Contraindication to Breast Conservation in Patients with Concomitant Invasive Breast Cancer or DCIS

BACKGROUND

Non-classic lobular carcinoma in situ (NC-LCIS) represents a spectrum of lesions, histologically distinct from classic LCIS (C-LCIS) and ductal carcinoma in situ (DCIS). Several studies have reported on the safety of breast conservation (BCS) in patients with DCIS or invasive breast cancer and concomitant C-LCIS, yet there are no data addressing this question for patients with concomitant NC-LCIS. We evaluated local recurrence (LR) after BCS in patients with DCIS or invasive cancer and concomitant NC-LCIS.

PATIENTS AND METHODS

We searched institutional databases using natural language processing to identify patients with DCIS or invasive breast cancer and concomitant NC-LCIS treated with BCS between 2000 and 2015. Charts were reviewed to collect demographics, disease and treatment details, and recurrence events. All results represent descriptive analyses.

RESULTS

We identified 71 patients with DCIS (n = 13) or invasive cancer (n = 58) and concomitant NC-LCIS treated with BCS. Median patient age was 59 years (33-77 years), and median invasive tumor size was 1.2 cm (0.1-6.9 cm); 62% of DCIS and 79% of invasive cancer patients had hormone receptor (HR)-positive disease. Among DCIS patients, seven (54%) received radiation and none hormonal therapy. Among those with invasive cancer, 52 (90%) received radiation, 17 (29%) received chemotherapy and 44 of 55 with HR-positive disease (78%) received hormonal therapy. At median follow-up of 79 months (1-265 months), the LR rate was 8% and 2% among patients with DCIS and invasive cancer, respectively.

CONCLUSION

NC-LCIS is rarely present in association with DCIS or invasive cancer, and it does not appear to impact LR outcomes following BCS.

Factors Indicating Surgical Excision in Classical Type of Lobular Neoplasia of the Breast

PURPOSE

Classical type of lobular neoplasia (LN) encompassing both atypical lobular hyperplasia and classical lobular carcinoma in situ of the breast is a lesion with uncertain malignant potential and has been the topic of several studies with conflicting outcome results. The aim of our study was to clarify outcome-relevant factors and treatment options of classical LN.

METHODS

We performed a pathological re-evaluation of the preoperative biopsy specimens and a retrospective clinical and radiological data analysis of 160 patients with LN from the Breast Center Zurich. Open surgery was performed in 65 patients, vacuum-assisted biopsy (VAB) in 79 patients, and surveillance after breast core needle biopsy (CNB) in 16 patients.

RESULTS

The upgrade rate into ductal carcinoma in situ/invasive cancer was the highest in case of imaging/histology discordance (40%). If the number of foci in the biopsy specimen was ≥3, the upgrade rate in the consecutive surgical specimens was increased (p = 0.01). The association of classical LN with histological microcalcification correlated with shortened disease-free survival (p < 0.01), whereas other factors showed no impact on follow-up.

CONCLUSIONS

Surveillance or subsequent VAB after CNB of LN is sufficient in most cases. Careful consideration of individual radiological and histological factors is required to identify patients with a high risk of upgrade into malignancy. In those cases, surgical excision is indicated.

Atypical Lobular Hyperplasia and Classic Lobular Carcinoma In Situ Can Be Safely Managed Without Surgical Excision

BACKGROUND

Based on modern series demonstrating low upgrade rates for pure lobular neoplasia (LN) diagnosed on core needle biopsy (CNB), our institution no longer recommends routine excision, provided imaging is concordant. This study describes outcomes in patients managed without surgical excision.

METHODS

From an institutional database, we identified all patients with a diagnosis of pure atypical lobular hyperplasia and/or classic lobular carcinoma in situ on CNB managed without surgical excision (i.e., conservative management) from 2015 to 2019. The primary outcome of interest was failure of conservative management, defined as development of ipsilateral same-quadrant ductal carcinoma in situ or invasive breast cancer within 2 years of CNB, or need for ipsilateral same-quadrant excisional biopsy. We also evaluated rates of ipsilateral same-quadrant CNB during follow-up.

RESULTS

Among 96 pure LN lesions on CNB since 2015, 80 (83%) were managed without surgical excision. Median follow-up was 27 months (IQR: 16-28), with only 2 (2%) patients lost to follow-up. No patients developed an ipsilateral, same-quadrant breast cancer. The 3-year risk of conservative management failure was 6.2% (95% CI 2.3-15.7%). All failures were a result of need for excisional biopsy due to progressive imaging abnormalities at the initial CNB site, with benign final pathology. The 3-year risk of ipsilateral same-quadrant CNB was 9.2% (95% CI 3.8-21.5%).

CONCLUSION

Non-surgical management of pure LN is safe, and the likelihood of requiring subsequent surgical excision or repeat CNB during follow-up is low. These data provide reassurance that routine excision of pure LN in the setting of radiologic-pathologic concordance is not required.

Management of High-Risk Breast Lesions

High-risk breast lesions (HRLs) are a group of heterogeneous lesions that can be associated with a synchronous or adjacent breast cancer and that confer an elevated lifetime risk of breast cancer. Management of HRLs after core needle biopsy may include close imaging and clinical follow-up or excisional biopsy to evaluate for cancer. This article reviews histologic features and clinical presentation of each of the HRLs, current evidence with regard to management, and guidelines from the American Society of Breast Surgeons and National Comprehensive Cancer Network. In addition, imaging surveillance and risk-reduction strategies for women with HRLs are discussed.

Risk for Upgrade to Malignancy After Breast Core Needle Biopsy Diagnosis of Lobular Neoplasia: A Systematic Review and Meta-Analysis

PURPOSE

Lobular neoplasia (LN) detected on breast core needle biopsy is frequently managed with surgical excision because of concern for undersampled malignancy. The authors performed a systematic review and meta-analysis to estimate the risk for upgrade to malignancy in the setting of imaging-concordant classic LN diagnosed on core biopsy.

METHODS

PubMed and Embase were searched for original articles published from 1998 to 2020 that reported rates of upgrade to malignancy for classic LN, including atypical lobular hyperplasia (ALH) and classic lobular carcinoma in situ (LCIS). Two reviewers extracted study data and assessed the following quality criteria: exclusion of variant LCIS, exclusion of imaging-discordant lesions, and outcome reporting for ≥70% of lesions. For studies meeting all criteria, pooled risks for upgrade to any malignancy (invasive carcinoma or ductal carcinoma in situ) and invasive malignancy for all LN, ALH, and LCIS were estimated using random-effects models.

RESULTS

For 65 full-text articles included in the review, the risk for upgrade to any malignancy ranged from 0% to 45%. Among the 16 studies that met all quality criteria for the meta-analysis, pooled risks for upgrade to any malignancy were 3.1% (95% confidence interval [CI], 1.8%-5.2%) for all LN, 2.5% (95% CI, 1.6%-3.9%) for ALH, and 5.8% (95% CI, 2.9%-11.3%) for LCIS. Risks for upgrade to invasive malignancy were 1.3% (95% CI, 0.7%-2.4%) for all LN, 0.4% (95% CI, 0.0%-4.2%) for ALH, and 3.5% (95% CI, 2.0%-5.9%) for LCIS.

CONCLUSIONS

The risk for upgrade to malignancy for LN found on breast biopsy is low. Imaging surveillance can likely be offered as an alternative to surgical management for LN, particularly for ALH.

Inter-observer reproducibility of classical lobular neoplasia (B3 lesions) in preoperative breast biopsies: a study of the Swiss Working Group of breast and gynecopathologists

PURPOSE

Classical type of lobular neoplasia (LN) spans a spectrum of disease, including atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), classical lobular neoplasia (LN), and the three-tiered classification of lobular intraepithelial neoplasia (LIN-1, -2, -3). This study addressed inter-observer variability of classical lobular neoplasias (LN) (B3 lesions) in preoperative breast biopsies among breast and gynecopathologists METHODS: A retrospective, observational, cross-sectional study was conducted. 40 preoperative digital images of breast core/vacuum biopsies were analyzed by eight experienced breast- and gynecopathologists. Evaluation criteria were ALH, LCIS, LN classic, LIN-1, LIN-2, LIN-3, focal B3 (one focus), extensive B3 (> one focus). Kappa-index and Chi-square tests were used for statistics. Digital scanned slides were provided to each participant. Agreement between the categories was defined as at least six of eight (cut-off 75%) concordant diagnoses.

RESULTS

The highest agreement between eight pathologists was reached using the category lobular neoplasia (LN, classical), 26/40 (65%) cases were diagnosed as such. Agreements in other categories was low or poor: 12/40 (30%) (ALH), 9/40 (22%) (LCIS), 8/40 (20%) (LIN-1), 8/40 (20%) (focal B3), 3/40 (7.5%) (LIN-2), and 2/40 (5%) (extensive B3). Chi-square-test (classical LN versus the other nomenclatures) was significant (p = 0.001137).

CONCLUSION

Our data suggest that among Swiss breast pathologists, the most reproducible diagnosis for B3 lobular lesions is the category of classical LN. These data further support lack of consistent data in retrospective studies using different terminologies. Validation of reproducible nomenclature is warranted in further studies. This information is useful especially in view of retro- and prospective data analysis with different diagnostic categories.

Lobular Carcinomas In Situ Display Intralesion Genetic Heterogeneity and Clonal Evolution in the Progression to Invasive Lobular Carcinoma

PURPOSE

Lobular carcinoma in situ (LCIS) is a preinvasive lesion of the breast. We sought to define its genomic landscape, whether intralesion genetic heterogeneity is present in LCIS, and the clonal relatedness between LCIS and invasive breast cancers.Experimental Design: We reanalyzed whole-exome sequencing (WES) data and performed a targeted amplicon sequencing validation of mutations identified in 43 LCIS and 27 synchronous more clinically advanced lesions from 24 patients [9 ductal carcinomas in situ (DCIS), 13 invasive lobular carcinomas (ILC), and 5 invasive ductal carcinomas (IDC)]. Somatic genetic alterations, mutational signatures, clonal composition, and phylogenetic trees were defined using validated computational methods.

RESULTS

WES of 43 LCIS lesions revealed a genomic profile similar to that previously reported for ILCs, with CDH1 mutations present in 81% of the lesions. Forty-two percent (18/43) of LCIS were found to be clonally related to synchronous DCIS and/or ILCs, with clonal evolutionary patterns indicative of clonal selection and/or parallel/branched progression. Intralesion genetic heterogeneity was higher among LCIS clonally related to DCIS/ILC than in those nonclonally related to DCIS/ILC. A shift from aging to APOBEC-related mutational processes was observed in the progression from LCIS to DCIS and/or ILC in a subset of cases.

CONCLUSIONS

Our findings support the contention that LCIS has a repertoire of somatic genetic alterations similar to that of ILCs, and likely constitutes a nonobligate precursor of breast cancer. Intralesion genetic heterogeneity is observed in LCIS and should be considered in studies aiming to develop biomarkers of progression from LCIS to more advanced lesions.

Lobular Breast Cancer: Different Disease, Different Algorithms?

Invasive lobular carcinoma (ILC) is the second most common type of breast cancer, with a unique pathogenesis and distinct clinical biology. ILCs display a characteristic loss of E-cadherin, are largely estrogen receptor positive, HER2 negative, and low to intermediate grade. These features portend a favorable prognosis, but there is a tendency for late recurrences and atypical metastases. ILCs tend to be insidious and infiltrative, which can pose a challenge for diagnosis, and emerging data suggest they may have a propensity for a differing response to standard therapies.

The Pathologic Finding of Combined Lobular Carcinoma in Situ and Invasive Lobular Cancer May Indicate more than Just a High-Risk Marker Role of Lobular Carcinoma in Situ

For years, lobular carcinoma in situ (LCIS) has been considered a high-risk marker for developing breast cancer. It is well known that ductal carcinoma in situ is a precursor for the development of invasive ductal carcinoma, and ductal carcinoma in situ is reported to be present in invasive ductal carcinoma in at least 40 per cent of cases. A similar relationship between LCIS and invasive lobular carcinoma (ILC) remains in question. This study evaluates the incidence of synchronous LCIS and ILC at our institution. This is a retrospective review of our tumor registry database of women diagnosed with LCIS or ILC from 2000 to 2014. Pathology reports were evaluated to determine the incidence of pure ILC and mixed ILC/LCIS. Those with both LCIS/ILC (mixed group) and those with pure ILC (pure group) were compared for age, surgical intervention, lymph node involvement, tumor size, nuclear grade, and margins between these two groups. A total of 182 women were identified with LCIS, ILC, or mixed LCIS and ILC. There were76 subjects with pure ILC and 90 with mixed LCIS and ILC. The median and age range for each group were 63.6 (range: 40–97) for the mixed and 64.1 (range: 40–86) for pure groups. Tumor size was evaluated for each group and the median tumor size was 2.5 cm (range: 0.1–7.0cm) for the mixed group and 3.0 cm (range: 0.5–12.5 cm) for the pure group. Nodal involvement was present in 35.23 per cent of the mixed group and 46.3 per cent in the pure group. Surgical treatment for each group was similar, with mastectomy being the preferred surgical option over breast conservation therapy in the mixed and pure groups, 67.07 and 64.71 per cent, respectively. Presently, LCIS is considered a marker, or risk factor, for development of future breast cancer. This retrospective study does identify a strong relationship, 54 per cent, between LCIS and ILC at diagnosis. This high percentage of concurrent LCIS and ILC in surgical/ pathological specimens supports the notion that LCIS may in fact have a precursory role in development of invasive lobular carcinoma of the breast. Additional studies to further investigate this relationship between LCIS and ILC, including genomic analysis, are presently underway.

Surgical Outcomes of Lobular Neoplasia Diagnosed in Core Biopsy: Prospective Study of 316 Cases

BACKGROUND

Management recommendations for lobular neoplasia (LN) including lobular carcinoma-in-situ (LCIS) and atypical lobular hyperplasia (ALH) diagnosed in core biopsies (CB) are controversial. Our aim was to prospectively identify a subset of patients who do not require subsequent surgical excision (SE).

PATIENTS AND METHODS

All patients diagnosed with LN on CB were enrolled and referred for SE. Cases with coexistent ductal carcinoma-in-situ or invasive carcinoma were excluded. Cases with coexistent ductal atypia (LN-DA) and LCIS variants (LN-V) were separated from pure classic LN (LN-C). Dedicated breast pathologists and radiologists reviewed cases with careful imaging/pathology correlation.

RESULTS

Of 13,772 total percutaneous breast CB procedures, 302 of 370 patients diagnosed with LN underwent SE. Upgrade to carcinoma was present in 3.5% (8/228) LN-C, 26.7% LN-V (4/15), and 28.3% LN-DA (15/53). Calcifications were the imaging target for 180 (79%) of 228 LN-C cases; 7 were associated with upgrade (3.9%). Upgrades were rare for mass lesions (1/32) and magnetic resonance imaging-targeted lesions (0/14). Upgrades were similar for ALH and LCIS (3.4% vs. 4.5%). During postsurgical follow-up (mean, 34.5 months), 6.5% LN-C patients developed carcinoma in either breast.

CONCLUSION

Although LN with nonclassic morphology or with associated ductal atypia requires SE, this can be avoided in LN-C diagnosed on CB targeting calcifications when careful imaging/pathology correlation is applied. Until larger numbers are studied, excising LN-C diagnosed as masses or magnetic resonance imaging-detected lesions may be prudent. Regardless of their selection for surgical management, LN patients need close surveillance in view of their long-term risk of breast cancer.

The radiological features, diagnosis and management of screen-detected lobular neoplasia of the breast: Findings from the Sloane Project

OBJECTIVES

To investigate the radiological features, diagnosis and management of screen-detected lobular neoplasia (LN) of the breast.

MATERIALS AND METHODS

392 women with pure LN alone were identified within the prospective UK cohort study of screen-detected non-invasive breast neoplasia (the Sloane Project). Demography, radiological features and diagnostic and therapeutic procedures were analysed.

RESULTS

Non-pleomorphic LN (369/392) was most frequently diagnosed among women aged 50-54 and in 53.5% was at the first screen. It occurred most commonly on the left (58.0%; p = 0.003), in the upper outer quadrant and confined to one site (single quadrant or retroareolar region). No bilateral cases were found. The predominant radiological feature was microcalcification (most commonly granular) which increased in frequency with increasing breast density. Casting microcalcification as a predominant feature had a significantly higher lesion size compared to granular and punctate patterns (p = 0.034). 326/369 (88.3%) women underwent surgery, including 17 who underwent >1 operation, six who had mastectomy and six who had axillary surgery. Two patients had radiotherapy and 15 had endocrine treatment. Pleomorphic lobular carcinoma in situ (23/392) presented as granular microcalcification in 12; four women had mastectomy and six had radiotherapy.

CONCLUSION

Screen-detected LN occurs in relatively young women and is predominantly non-pleomorphic and unilateral. It is typically associated with granular or punctate microcalcification in the left upper outer quadrant. Management, including surgical resection, is highly variable and requires evidence-based guideline development.

Bioanalytical LC-MS Method for the Quantification of Plasma Androgens and Androgen Glucuronides in Breast Cancer

The physiological and pathological development of the breast is strongly affected by the hormonal milieu consisting of steroid hormones. Mass spectrometry (MS) technologies of high sensitivity and specificity enable the quantification of androgens and consequently the characterization of the hormonal status. The aim of this study is the assessment of plasma androgens and androgen glucuronides, in the par excellence hormone-sensitive tissue of the breast, through the application of liquid chromatography-mass spectrometry (LC-MS). A simple and efficient fit-for-purpose method for the simultaneous identification and quantification of dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), androsterone glucuronide (ADTG) and androstane-3α, 17β-diol-17-glucuronide (3α-diol-17G) in human plasma was developed and validated. The presented method permits omission of derivatization, requires a single solid-phase extraction procedure and the chromatographic separation can be achieved on a single C18 analytical column, for all four analytes. The validated method was successfully applied for the analysis of 191 human plasma samples from postmenopausal women with benign breast disease (BBD), lobular neoplasia (LN), ductal carcinoma in situ and invasive ductal carcinoma (IDC). DHEAS plasma levels exhibited significant differences between LN, IDC and BBD patients (P < 0.05). Additionally, ADTG levels were significantly higher in patients with LN compared with those with BBD (P < 0.05).

Molecular drivers of lobular carcinoma in situ

Lobular carcinoma in situ (LCIS) is considered to be a risk factor for the development of invasive breast carcinoma, but it may also be a non-obligate precursor to invasive lobular carcinoma (ILC). Many LCIS lesions do not progress to ILC, and the molecular changes that are necessary for progression from LCIS to ILC are poorly understood. Disruption in the E-cadherin complex is the hallmark of lobular lesions, but other signaling molecules, such as PIK3CA and c-src, are consistently altered in LCIS. This review focuses on the molecular drivers of lobular carcinoma, a more complete understanding of which may give perspective on which LCIS lesions progress, and which will not, thus having immense clinical implications.

Lobular carcinoma in situ (LCIS) of the breast: is long-term outcome similar to ductal carcinoma in situ (DCIS)? Analysis of 200 cases

Background

Lobular carcinomas in situ (LCIS) represent 1-2% of all breast cancers. Both significance and treatment remain widely debated, as well as the possible similarities with DCIS.

Materials and methods

Two hundred patients with pure LCIS were retrospectively analyzed in seven centres from 1990 to 2008. Median age was 52 years; 176 patients underwent breast-conserving surgery (BCS) and 24 mastectomy. Seventeen patients received whole breast irradiation (WBRT) after BCS and 20 hormonal treatment (15 by tamoxifen).

Results

With a 144-month median follow-up (FU), there were no local recurrences (LR) among 24 patients treated by mastectomy. With the same FU, 3 late LR out of 17 (17%) occurred in patients treated by BCS and WBRT (with no LR at 10 years). Among 159 patients treated by BCS alone, 20 developed LR (13%), but with only a 72-month FU (17.5% at 10 years). No specific LR risk factors were identified. Three patients developed metastases, two after invasive LR; 22 patients (11%) developed contralateral BC (59% invasive) and another five had second cancer.

Conclusions

LCIS is not always an indolent disease. The long-term outcome is quite similar to most ductal carcinomas in situ (DCIS). The main problems are the accuracy of pathological definition and a clear identification of more aggressive subtypes, in order to avoid further invasive LR. BCS + WBRT should be discussed in some selected cases, and the long-term results seem comparable to DCIS.