Timothy M. D'Alfonso

Accurately Assessing HER-2/neu Status in Needle Core Biopsies of Breast Cancer Patients in the Era of Neoadjuvant Therapy: Emerging Questions and Considerations Addressed

BackgroundEmerging data show that patients with operable, HER-2/neu overexpressed/amplified breast carcinomas have significantly better responses (more frequently obtaining pathologic complete response and greater percent disease-free survival) when treated with trastuzumab (Herceptin) simultaneously with neoadjuvant chemotherapy than with chemotherapy alone. With the increasing use of neoadjuvant therapies, clinicians require information on biomarkers including HER-2/neu status at the time of needle core biopsy. Concordance rates between fluorescence in situ hybridization (FISH)-determined HER-2/neu status on needle core biopsies and on subsequent excisional biopsies of the same tumor have not been well studied. Moreover, the practice of automatically performing (“reflexing”) 2+ immunohistochemical (IHC) staining needle core biopsies for FISH analysis on the same sample needs to be validated. In this study, we set out to (1) determine the accuracy of HER-2/neu status as determined by FISH on needle core biopsy material compared with FISH on the subsequent excisional biopsy of the same tumor with special consideration of IHC 2+staining cases and (2) determine the constancy of HER-2/neu status in pre-neoadjuvant and post-neoadjuvant chemotherapy-treated tumor in the form of needle core biopsy and excisional biopsy samples, respectively. Design100 patients whose needle core biopsies and subsequent excisional biopsy samples were pathologically evaluated at our institution were studied. For each patient, unstained sections from both specimens were prepared and used for IHC or FISH. IHC was carried out using the HercepTest kit (DAKO, Carpinteria, CA). Parallel unstained slides were used to carry out FISH (dual probe, Vysis). Statistical analyses were carried out on the resulting data generated after interpretation. ResultsThe concordance rate between FISH results determined on the needle core biopsy and subsequent excisional biopsy of the same tumor was 86% (κ=0.56, P=2×10−8). If equivocal FISH cases (≥1.8 to ≤2.2 amplification ratio) in a needle core biopsy or excisional biopsy specimen or both, were excluded, the concordance rate increased to 95% (κ coefficient=0.86, P=2×10−15). Fourteen of 100 (14%) cases showed 2+ IHC staining in the needle core biopsy specimen with good concordance of FISH-determined HER-2/neu status between the needle core biopsy and excisional biopsy specimens (79% agreement and κ=0.512, P=0.05). Nine, 3, and 2 cases of the 14 cases were amplified, equivocal, and negative on the excisional biopsy specimens, respectively. Of the 15 patients who received neoadjuvant chemotherapy, 93% and 87% had no change in HER-2/neu status as determined by IHC or FISH, respectively, in the excisional biopsy specimen when compared with that determined on the prior core biopsy sample. ConclusionsExcellent overall concordance was achieved between FISH-determined HER-2/neu status on the needle core biopsy and that determined on the subsequent excisional biopsy of the same tumor. These results suggest that intratumoral heterogeneity of HER-2/neu assessed by FISH is not a significant confounding factor when analyzing smaller sized samples. Furthermore, 79% of 2+IHC staining needle core biopsy cases showed concordant FISH results in the needle core biopsy and subsequent excisional biopsy specimens. Our results show good concordance, however, larger cohorts need to be studied to verify this finding. HER-2/neu status remains unchanged in the majority of cases when comparing pre-neoadjuvant and post-neoadjuvant chemotherapy-treated specimens.

Diagnostic utility of MYC amplification and anti-MYC immunohistochemistry in atypical vascular lesions, primary or radiation-induced mammary angiosarcomas, and primary angiosarcomas of other sites

Breast cancer patients who receive radiation therapy or develop chronic lymphedema following axillary dissection can develop secondary mammary angiosarcomas (ASs) and, additionally, atypical vascular lesions (AVLs) in the former group. Recently, MYC amplification by fluorescence in situ hybridization (FISH) has been identified in secondary mammary AS but not in AVL and most primary mammary AS as well as AS of other sites. We studied MYC amplification and MYC protein expression in 7 radiation-induced AVLs, 9 secondary mammary ASs, 17 primary mammary ASs, and 20 primary ASs of other sites by FISH analysis and immunohistochemistry. All 9 secondary mammary ASs showed gene amplification and protein expression, whereas neither was found in any of 7 AVLs. No MYC amplification or protein expression was identified in any of the 17 primary mammary ASs. Among primary ASs of other sites, 1 cardiac AS and 1 skin AS showed gene amplification and protein expression. The remaining 18 did not show amplification (90%), but some demonstrated protein expression (39%). We conclude that MYC amplification by FISH is present in secondary mammary AS but not in AVL. We also found MYC amplification in 1 primary skin AS and 1 primary cardiac AS. There was 100% concordance between MYC amplification and protein expression in all AVL, primary mammary AS, and secondary mammary AS, whereas only 65% concordance was found in AS of other sites. MYC protein expression in AS can be helpful in certain diagnostic scenarios in the breast but not in other sites.

MYB-NFIB gene fusion in adenoid cystic carcinoma of the breast with special focus paid to the solid variant with basaloid features

Adenoid cystic carcinomas (ACCs) from various anatomical sites harbor a translocation t(6;9)(q22-23;p23-24), resulting in MYB-NFIB gene fusion. This gene fusion is not well studied in mammary ACCs, and there are no studies examining this abnormality in solid variant of ACC with basaloid features (SBACC), a high-grade variant thought to behave more aggressively than ACCs with conventional histologic growth. Our aim was to investigate the frequency of MYB-NFIB gene fusion in mammary ACCs with a focus paid to SBACC. MYB rearrangement and MYB-NFIB fusion were assessed by fluorescence in situ hybridization and reverse-transcription polymerase chain reaction, respectively. Histologic features and the presence of MYB rearrangement were correlated with clinical outcome. MYB rearrangement was present in 7 (22.6%) of 31 mammary ACCs (5/15 [33.3%] ACCs with conventional growth; 2/16 [12.5%] SBACCs). One patient with conventional ACC developed distant metastasis, and no patients had axillary lymph node involvement by ACC (mean follow-up, 34 months; range, 12-84 months). Two patients with SBACC had axillary lymph node involvement at initial surgery, and 2 additional patients experienced disease recurrence (1 local, 1 distant; mean follow-up, 50 months; range, 9-192 months). MYB-NFIB fusion status did not correlate with clinical outcome in studied patients. We confirm that MYB-NFIB gene fusion is observed in mammary ACCs and that a subset lacks this abnormality. This study is the first to confirm the presence of MYB rearrangement in SBACC. Additional validation with long-term follow-up is needed to determine the relationship, if any, between MYB-NFIB gene fusion and clinical outcome.

Pathologic Upgrade Rates on Subsequent Excision When Lobular Carcinoma In Situ Is the Primary Diagnosis in the Needle Core Biopsy With Special Attention to the Radiographic Target

CONTEXT Lobular carcinoma in situ (LCIS) as the primary pathologic diagnosis in a needle core biopsy is an infrequent finding, and the management of patients in this setting is controversial. OBJECTIVE To determine the rate of pathologic upgrade (defined as the presence of a clinically more-significant lesion in the subsequent excision) in patients with a primary pathologic diagnosis of LCIS in the needle core biopsy. DESIGN Patients with a primary diagnosis of LCIS in a needle core biopsy who underwent subsequent excision were identified. Core biopsies containing a concurrent high-risk lesion and cases with radiologic-pathologic discordance were excluded. The presence of selected microscopic features in the needle core biopsy was correlated with pathologic upgrade. Microscopic findings were correlated with the radiographic target in the needle core biopsy. RESULTS Sixty-one women with primary LCIS in their needle core biopsy showed a 10% pathologic upgrade rate. The percentage of cores involved by LCIS was significantly associated with pathologic upgrade (P= .04), whereas the remaining measured parameters were not. When LCIS represented the radiographic target, the pathologic upgrade rate was 18%, whereas when it was an incidental finding, the pathologic upgrade rate was 4%. CONCLUSIONS It may be reasonable for patients with primary, yet incidental, LCIS on needle core biopsy to be managed in a nonsurgical fashion. Larger studies are needed to confirm our findings.

Axl receptor tyrosine kinase expression in breast cancer

Aims Triple-negative breast cancer comprises a clinically aggressive group of invasive carcinomas. We examined a published gene expression screen of a panel of breast cancer cell lines to identify a potential triple-negative breast cancer-specific gene signature, and attempted to verify our findings by performing immunohistochemical analysis on tissue microarrays containing a large cohort of invasive breast carcinomas. Methods The microarray dataset for a panel of human breast cancer cell lines was interrogated for triple-negative breast cancer-specific genes. Membranous immunohistochemical expression of the protein product of the AXL gene was assessed semiquantitatively in 569 invasive breast carcinomas grouped according to molecular subgroup by immunohistochemistry. Results AXL was significantly upregulated in triple-negative/basal B cell lines compared with luminal or basal A cell lines. No significant difference was observed in the level of immunohistochemical expression of Axl protein between triple-negative breast cancers and other molecular subgroups (p=0.257). Axl expression was significantly associated with lymphovascular invasion (LVI) in all subgroups combined (p=0.033), and within the luminal A (p=0.002) and triple-negative breast cancer subgroups (p=0.026). Conclusions Despite preferential upregulation of AXL in triple-negative/basal B cell lines, analysis of Axl protein expression in a large series of patients’ breast tumours revealed no association between Axl expression and triple-negative breast cancer or other subtype. The association of Axl expression with LVI supports previous work that implicates Axl as a promoter of invasiveness in breast cancer cell lines. Further studies are necessary to explore whether Axl expression of individual breast cancer tumours can be clinically useful.

Advocating Nonsurgical Management of Patients With Small, Incidental Radial Scars at the Time of Needle Core Biopsy: A Study of 77 Cases.

CONTEXT Radial scars are benign sclerosing lesions that are routinely excised when diagnosed in a needle core biopsy. Optimal management for patients with incidental and small (≤5 mm) radial scars is uncertain. OBJECTIVE To assess pathologic upgrade of radial scars diagnosed in needle core biopsy samples and identify a subset of patients who could benefit from conservative management. DESIGN Patients with a diagnosis of radial scar in a needle core biopsy who underwent excision of the biopsied area were identified. Radial scars greater than 5 mm in size and those with coexisting atypia, carcinoma, and papillary lesions were excluded. After histologic-radiographic correlation, rates of pathologic upgrade were assessed. RESULTS Seventy-seven radial scars diagnosed in 66 patients were included. Overall, 9 of 77 (12%) showed upgrade to a high-risk lesion (6 lobular carcinoma in situ, 2 atypical ductal hyperplasia, 1 atypical lobular hyperplasia), while none (0%) showed upgrade to invasive carcinoma or ductal carcinoma in situ. One of 22 incidental radial scars (4.5%) showed upgrade on excision versus 6 of 36 (16.7%) for radial scars considered to be the radiographic target (P = .23). Older age was associated with upgrade (P < .001). CONCLUSIONS No incidental or small (≤5 mm) radial scars excised revealed invasive carcinoma or ductal carcinoma in situ on excision. Provided there is good pathologic-radiologic concordance, it appears reasonable for these patients to be managed conservatively.

Cystic Neutrophilic Granulomatous Mastitis: Further Characterization of a Distinctive Histopathologic Entity Not Always Demonstrably Attributable to Corynebacterium Infection.

Granulomatous lobular mastitis (GLM) is an uncommon condition that typically occurs in parous, reproductive-aged women and can simulate malignancy on the basis of clinical and imaging features. A distinctive histologic pattern termed cystic neutrophilic granulomatous mastitis (CNGM) is seen in some cases of GLM and has been associated with Corynebacterium infection. We sought to further characterize the clinical, imaging, and histopathologic features of CNGM by studying 12 cases and attempted to establish the relationship of this disease with Corynebacterium infection. Patients were women ranging in age from 25 to 49 years (median: 34 y), and all presented with a palpable mass that was painful in half of the cases. In 2 of 9 cases, imaging was highly suspicious for malignancy (BI-RADS 5). CNGM was characterized by lobulocentric granulomas with mixed inflammation and clear vacuoles lined by neutrophils within granulomas. Gram-positive bacilli were identified in 5/12 cases. In 4 patients, the disease process worsened after the diagnostic core biopsy, with the development of a draining sinus in 2 cases. No growth of bacteria was seen in any microbial cultures. No bacterial DNA was identified by 16S rDNA polymerase chain reaction for 1 case that showed gram-positive bacilli on histology. Patients were treated with variable combinations of surgery, antibiotics, and steroids. The time to significant resolution of symptoms ranged from 2 weeks to 6 months. Similar to other forms of GLM, CNGM can mimic malignancy clinically and on imaging. When encountered in a needle core biopsy sample, recognition of the characteristic histologic pattern and its possible association with Corynebacterium infection can help guide treatment.

Cystic hypersecretory (in situ) carcinoma of the breast: a clinicopathologic and immunohistochemical characterization of 10 cases with clinical follow-up.

Cystic hypersecretory carcinoma (CHC) is an uncommon variant of ductal carcinoma in situ characterized by, among other features, the presence of luminal secretion resembling thyroidal colloid. CHC is thought to behave in an indolent manner but has the potential to give rise to invasive carcinoma, which is often poorly differentiated. We studied the immunohistochemical, clinical, and morphologic features of 10 cases of CHC. All patients were women averaging 62.8 years in age (range, 47 to 79 y). The clinical/radiographic presentation was a mass (5/10), calcifications (3/10), bloody nipple discharge (1/10), and unknown (1/10). Microscopic size of CHC ranged from 0.2 to 2.7 cm (mean, 0.9 cm). Micropapillary growth was present in all cases. Nuclear grade was intermediate (5/10) or high (5/10). One case also showed microinvasive carcinoma. All cases arose in a background of cystic hypersecretory hyperplasia (CHH) and/or CHH with atypia. CHC was ER+ in 8/10 cases (ER+/PR+, 4/10; ER+/PR−, 4/10). Two cases were ER−/PR−, including the case with microinvasive carcinoma. All were HER2−. Androgen receptor was expressed in 3/10 (30%) cases. Myoepithelial stains p63, smooth muscle myosin, and CK5 showed circumferential staining in 9/10 (90%) cases, whereas 1 case was negative for p63, smooth muscle myosin, and CK5 in both CHC and adjacent CHH. Basal-like carcinoma markers EGFR, CK14, and CK5 were negative in all cases, with the exception of 1 case that was positive for EGFR. Four patients with follow-up information showed no evidence of disease (mean, 5.5 y). CHC is a distinct variant of ductal carcinoma in situ that arises in a background of CHH and is characterized by micropapillary growth, intermediate-grade to high-grade nuclei, and luminal colloid-like secretion. CHC is usually ER+ and HER2−. Negative or discontinuous reactivity with myoepithelial markers may be seen, despite its in situ nature. CHC usually behaves in a nonaggressive manner as was seen in our patients who were all free from disease at last follow-up.

Expression of p40 and laminin 332 in metaplastic spindle cell carcinoma of the breast compared with other malignant spindle cell tumours

Aims To determine the use of p40 and laminin 332 (LN332) immunostains for diagnosing metaplastic carcinoma by studying the expression of these and other routine markers in spindle cell metaplastic carcinomas and other malignant spindle cell tumours. Methods We identified cases of spindle cell metaplastic carcinoma (n=36) and other atypical/malignant spindle cell tumours, including 20 phyllodes tumours (14 borderline, six malignant) and 23 spindle cell sarcomas (three primary to breast). Immunohistochemical staining was performed for p40 and two LN332 chains, β3 (kalinin B1) and γ2 (lamC2). The expression of these markers was compared with p63 and cytokeratins. Results p40 and p63 expression was seen in 21 of 36 (58.3%) and 33 of 36 (91.7%) metaplastic carcinomas, respectively. No phyllodes tumours showed stromal expression of p40 or p63. One of 23 (4.3%) sarcomas showed focal weak p63 staining. LamC2 and kalinin B1 expression was seen in 28 of 36 (77.8%) and 26 of 36 (72.2%) metaplastic carcinomas, respectively. LamC2 and kalinin B1 each showed positive stromal cell expression in two of 20 (10%) phyllodes tumours. No sarcomas showed staining with lamC2. Kalinin B1 staining was seen in 17 of 23 (73.9%) sarcomas, including two of three primary breast sarcomas. Cytokeratin expression was seen in 32 of 36 (88.9%) metaplastic carcinomas and diffuse staining was most often seen in 34βE12 and CK5. Conclusions The diagnostic value of relatively novel markers p40 and LN332 was found to be less than that of routinely used markers (p63 and cytokeratins). p40 proved to be a specific marker but lacked the sensitivity of p63, while LN332 showed staining in a significant proportion of phyllodes tumours and sarcomas.

Current Concepts in Diagnosis, Molecular Features, and Management of Lobular Carcinoma In Situ of the Breast With a Discussion of Morphologic Variants

CONTEXT - Lobular carcinoma in situ (LCIS) refers to a neoplastic proliferation of cells that characteristically shows loss of E-cadherin expression and has long been regarded as a risk factor for invasive breast cancer. Long-term outcome studies and molecular data have also implicated LCIS as a nonobligate precursor to invasive carcinoma. In the past few decades, pleomorphic and florid LCIS have been recognized as morphologic variants of LCIS with more-aggressive histopathologic features, less-favorable biomarker profiles, and more-complex molecular features compared with classic LCIS. There is still a lack of consensus regarding certain aspects of managing patients with LCIS. OBJECTIVES - To review recently published literature on LCIS and to provide an overview of the current morphologic classification of LCIS, recent molecular advances, and trends in patient management. DATA SOURCES - Sources included peer-reviewed, published journal articles in PubMed (US National Library of Medicine, Bethesda, Maryland) and published guidelines from the National Comprehensive Cancer Network (Fort Washington, Pennsylvania). CONCLUSIONS - Lobular carcinoma in situ represents a marker for increased risk of breast cancer, as well as a nonobligate precursor to invasive carcinoma. Morphologic variants of LCIS-florid and pleomorphic LCIS-are genetically more-complex lesions and are more likely to be associated with invasive carcinoma. Further investigation into which molecular alterations in LCIS are associated with progression to invasive carcinoma is needed to help guide medical and surgical management.