Recommendations for human epidermal growth factor receptor 2 testing in breast cancer: American Society of Clinical Oncology/College of American Pathologists clinical practice guideline update

Pleomorphic lobular carcinoma in situ of the breast: clinicopathological review of 47 cases

AIMS

Pleomorphic lobular carcinoma in situ (PLCIS) of the breast is a distinctive entity, but its behaviour and management are unclear. The purpose of this study was to review a relatively large number of cases and to evaluate the risk of recurrence.

METHODS AND RESULTS

Cases of PLCIS (n = 47) from a 12-year period were reviewed. The clinical, radiological and pathological findings were recorded. Immunohistochemistry for oestrogen receptor (ER), progesterone receptor (PR) and HER2 was performed. Thirty-one patients had no concurrent breast cancer or past history of breast cancer, and six (19.4%) of these had local recurrence; all tumours (four invasive carcinoma and two PLCIS) were ipsilateral. Younger age at presentation was a risk factor for local recurrence: patients with recurrence had a mean age (range) of 52.5 years (44-59 years), versus 60.6 years (40-81 years) for those without (P = 0.03). Three of 31 patients were treated with radiation therapy (RT), and none of these developed local recurrence. PLCIS had an adverse ER/PR/HER2 molecular profile, with at least 41.2% of the cases overexpressing HER2. Moreover, at least 11.7% of the cases were triple-negative.

CONCLUSIONS

This study included the largest number of patients who had no concurrent breast cancer or past history of breast cancer with the longest clinical follow-up, providing insights into management practices for PLCIS and the risk of recurrence.

Tools to assess tissue quality

Biospecimen science has recognized the importance of tissue quality for accurate molecular and biomarker analysis and efforts are made to standardize tissue procurement, processing and storage conditions of tissue samples. At the same time the field has emphasized the lack of standardization of processes between different laboratories, the variability inherent in the analytical phase and the lack of control over the pre-analytical phase of tissue processing. The problem extends back into tissue samples in biorepositories, which are often decades old and where documentation about tissue processing might not be available. This review highlights pre-analytical variations in tissue handling, processing, fixation and storage and emphasizes the effects of these variables on nucleic acids and proteins in harvested tissue. Finally current tools for quality control regarding molecular or biomarker analysis are summarized and discussed.

Androgen receptor status is a prognostic marker in non-basal triple negative breast cancers and determines novel therapeutic options

Triple negative breast cancers are a heterogeneous group of tumors characterized by poor patient survival and lack of targeted therapeutics. Androgen receptor has been associated with triple negative breast cancer pathogenesis, but its role in the different subtypes has not been clearly defined. We examined androgen receptor protein expression by immunohistochemical analysis in 678 breast cancers, including 396 triple negative cancers. Fifty matched lymph node metastases were also examined. Association of expression status with clinical (race, survival) and pathological (basal, non-basal subtype, stage, grade) features was also evaluated. In 160 triple negative breast cancers, mRNA microarray expression profiling was performed, and differences according to androgen receptor status were analyzed. In triple negative cancers the percentage of androgen receptor positive cases was lower (24.8% vs 81.6% of non-triple negative cases), especially in African American women (16.7% vs 25.5% of cancers of white women). No significant difference in androgen receptor expression was observed in primary tumors vs matched metastatic lesions. Positive androgen receptor immunoreactivity was inversely correlated with tumor grade (p<0.01) and associated with better overall patient survival (p = 0.032) in the non-basal triple negative cancer group. In the microarray study, expression of three genes (HER4, TNFSF10, CDK6) showed significant deregulation in association with androgen receptor status; eg CDK6, a novel therapeutic target in triple negative cancers, showed significantly higher expression level in androgen receptor negative cases (p<0.01). These findings confirm the prognostic impact of androgen receptor expression in non-basal triple negative breast cancers, and suggest targeting of new androgen receptor-related molecular pathways in patients with these cancers.

Differences in breast carcinoma immunohistochemical subtypes between immigrant Arab and European women

Background

There is a dearth of information on the clinicopathological differences, including the molecular subtypes, of breast carcinomas from immigrant Arab women in Europe. Therefore, the aim of our study was to examine and compare these features in immigrant Arab/Moroccan patients with those of European women.

Methods

Included in this study were 441 cases of breast cancer: 91 Arab/Moroccan women and 350 European women. Age, size, grade, node involvement, and immunohistochemical profile (classification into the following subtypes: luminal A, luminal B, HER2 +/ER -, and triple negative) were analyzed.

Results

The average age of breast cancer presentation in Arab women is almost a decade earlier than in European women (49 versus 60 years old; p = 0.00001). Arab patients also had a higher average tumor size (25 mm versus 19 mm; p =0,008) and more grade 3 and less grade 1 tumors (p = 0.02). It should be noted, however, that this variability in the size and grade do not appear statistically significant when compared in Arab and European patients under 50 years old. In contrast, independent of age, the immunohistochemical subtypes were different between the two populations, with a greater number of luminal B subtype and fewer luminal A subtype (p <0.02) in Arab patients.

Conclusions

Arab patients with breast carcinoma have different clinicopathological features from European patients, mainly the age of cancer presentation. Their immunohistochemical profile is also different, with more luminal B and less luminal A subtypes, suggesting that there are not only clinicopathological differences but also disparities in the expression profiling in these women.

Virtual slide

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2104813621113288.

Molecular tests as prognostic factors in breast cancer

In early breast cancer, prognostic tests are used to guide decisions on adjuvant systemic hormonal therapy, chemotherapy and targeted therapy treatment. This has led to large research efforts to identify novel prognostic markers in breast cancer. At present, the tissue factors used to guide treatment of breast cancer patients are tumor size, lymph node status, histologic grade, ER status, PR status, and HER2 status; in addition, multigene-expression-based prognostic tests are rapidly emerging. While identification of prognostic gene expression profiles has been successful, it has not been possible yet to identify robust clinically useful predictors of response to systemic treatment. As a result of rapid advances in technology and bioinformatics, it has become possible to analyze large series of breast carcinomas using high-throughput genetic techniques, including whole genome sequence analysis and gene expression profiling. These genomic studies will lead to the development of additional prognostic and predictive tissue-based tests. The most important aspects of the currently used tissue-based prognostic and predictive tests and the research in this area are reviewed.

Ductal carcinoma in situ of the breast: morphological and molecular features implicated in progression

The spread of mammographic screening programmes around the world, including in developing countries, has substantially contributed to the diagnosis of small non-palpable lesions, which has increased the detection rate of DCIS (ductal carcinoma in situ). DCIS is heterogeneous in several ways, such as its clinical presentation, morphology and genomic profile. Excellent outcomes have been reported; however, many questions remain unanswered. For example, which patients groups are overtreated and could instead benefit from minimal intervention and which patient groups require a more traditional multidisciplinary approach. The development of a comprehensive integrated analysis that includes the radiological, morphological and genetic aspects of DCIS is necessary to answer these questions. This review focuses on discussing the significant findings about the morphological and molecular features of DCIS and its progression that have helped to uncover the biological and genetic heterogeneity of this disease. The knowledge gained in recent years might allow the development of tailored clinical management for women with DCIS in the future.

Reproductive risk factors and breast cancer subtypes: a review of the literature

Aside from age, sex, and family history, risk of developing breast cancer is largely linked to reproductive factors, which characterize exposure to sex hormones. Given that, molecular testing at the tumor level is currently possible, clinical characterization of tumor subtypes is routinely conducted to guide treatment decisions. However, despite the vast amount of published data from observational studies on reproductive factor associations and breast cancer risk, relatively fewer reports have been published on associations specific to breast tumor subtypes. We conducted a review of the literature and summarized the results of associations between reproductive factors and risk or odds of three distinct tumor subtypes: estrogen receptor/progesterone receptor positive (hormone receptor positive, HR+ tumors), tumors overexpressing the human epidermal receptor 2 protein (HER2+), and triple negative breast cancer (TNBC), which lacks the three markers. Results show that the most consistent evidence for associations with reproductive risk factors exists for HR+ breast cancers, with nulliparity, current use of menopausal hormone therapy, and prolonged interval between menarche and age at first birth being the strongest risk factors; increased age at first birth and decreased age at menarche were fairly consistently associated with HR+ cancers; and though less consistent, older age at menopause was also positively associated, while lactation was inversely associated with HR+ tumors. Fewer consistent associations have been reported for TNBC. The single protective factor most consistently associated with TNBC was longer duration of breastfeeding. Increased parity, younger age at first birth, older age at menarche, and oral contraceptive use were less consistently shown to be associated with TNBC. No remarkable associations for HER2+ breast cancers were evident, although this was based on relatively scarce data. Findings suggest heterogeneity in reproductive risk factors for the distinct subtypes of breast tumors, which may have implications for recommended prevention strategies.

Central pathology laboratory review of HER2 and ER in early breast cancer: an ALTTO trial [BIG 2-06/NCCTG N063D (Alliance)] ring study

Choice of therapy for breast cancer relies on human epidermal growth factor receptor-2 (HER2) and estrogen receptor α (ER) status. Before randomization in the phase III Adjuvant Lapatinib and/or Trastuzumab Treatment Optimisation (ALTTO) trial for HER2-positive disease, HER2 and ER were centrally reviewed by Mayo Clinic (Rochester, MN, and Scottsdale, AZ) for North America and by the European Institute of Oncology (IEO; Milan, Italy) for the rest of world (except China). Discordance rates (local vs. central review) differed between Mayo and IEO. Among locally HER2-positive cases, 5.8 % (Mayo) and 14.5 % (IEO) were centrally HER2 negative. Among locally ER-positive cases, 16.2 % (Mayo) and 4.2 % (IEO) were centrally ER-negative. Among locally ER-negative cases, 3.4 % (Mayo) and 21.4 % (IEO) were centrally ER-positive. We, therefore, performed a ring study to identify features contributing to these differing discordance rates. Mayo and IEO exchanged slides for 25 HER2 and 35 ER locally/centrally discordant cases. Both laboratories performed IHC and FISH for HER2 using the HercepTest(®) and PathVysion HER2 DNA probe kit/HER2/centromere 17 probe mixture. IHC for ER was tested centrally using the monoclonal ER 1D5 antibody (Mayo) or the DAKO cocktail of ER 1D5 and 2.123 antibodies (IEO). Mayo and IEO confirmed the central HER2-negative result in 100 % of 25 cases. Mayo and IEO confirmed the central ER result in 29 (85 %) of 34 evaluable cases. The five Mayo-negative/IEO-positive cases were ER-positive when retested at Mayo using the DAKO ER cocktail. In this ring study, ALTTO ineligibility did not change when HER2 testing was performed by either IEO or Mayo central laboratories. However, a dual antibody ER assay had fewer false-negative test results than an assay with a single antibody, and there was more discordance between the two ER reagents than has been previously reported. Using even slightly different assay methods yielded different results, even between experienced central laboratories.

For or against adjuvant trastuzumab for pT1a-bN0M0 breast cancer patients with HER2-positive tumors: a meta-analysis of published literatures

BACKGROUND

Although the prognosis of patients with small (≤1cm) tumors is generally favorable, emerging data suggests that biological behavior varies between intrinsic subtypes in such patients. Furthermore, it still remains unclear whether HER2-positive pT1a-bN0M0 patients could benefit from adjuvant trastuzumab. For further evaluation, we sought to conduct a meta-analysis so as to get a better understanding of the prognosis for HER2-positive pT1a-bN0M0 patients and their survival benefit from adjuvant trastuzumab, accordingly, offering the implications for current practice.

METHODS

The PubMed database, the online proceedings of the American Society of Clinical Oncology (ASCO) Annual Meetings, the online proceedings of the San Antonio Breast Cancer Symposium, and the CD proceedings of the International St. Gallen Breast Cancer Conference were searched for all relevant studies published before September 2012. Relative risks (RRs) were used to compare the prognosis of different intrinsic subtypes for pT1a-bN0M0 breast cancer. Analyses were also performed to estimate the association between adjuvant trastuzumab and various survival outcomes.

RESULTS

With eight eligible studies identified, this meta-analysis demonstrated a deleterious effect of HER2+ phenotype on disease-free survival (DFS; RR = 3.677, 95% CI 2.606-5.189, p <0.001) and distant disease-free survival (DDFS; RR = 3.824, 95% CI 2.249-6.501, p<0.001) as compared to HR+/HER2- subgroup. However, significant difference failed to be achieved in terms of any endpoint between HER2+ and triple negative breast cancer (TNBC). Besides, a marked improvement in DFS was observed with the addition of trastuzumab for HER2-positive pT1a-bN0M0 patients (RR = 0.323, 95% CI 0.191-0.547, p<0.001).

CONCLUSION

This meta-analysis clarifies that intrinsic subtypes might be a reliable marker to predict the prognosis in pT1a-bN0M0 breast cancer. Besides, even for such early stage HER2-positive patients, adjuvant trastuzumab might bring significant survival benefit.

Characterization of HER2 status by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC)

The use of human epidermal growth factor receptor type 2 (HER2) gene amplification and overexpression as a molecular predictive marker has become critically important for proper selection of breast cancer patients for treatment with targeted therapeutic agents such as trastuzumab, lapatinib, pertuzumab, and T-DM1. A high level of sensitivity and specificity of molecular tests for this alteration is desirable. The American Society of Clinical Oncology and College of American Pathology have jointly established consensus guidelines to standardize characterization of this alteration in breast cancers. This chapter provides a brief overview of pre-analytic and analytical processing of breast specimens as well as subsequent molecular evaluation for HER2 status.

"To be or not to be in a good shape": diagnostic and clinical value of nuclear shape irregularities in thyroid and breast cancer

Variation in both nuclear shape and size ("pleomorphism"), coupled with changes in chromatin amount and distribution, remains the basic criteria for microscopy in a cytologic diagnosis of cancer. The biological determinants of nuclear shape irregularities are not clarified, so, rather than on the genesis of nuclear irregularities, we here focus our attention on a descriptive analysis of nuclear pleomorphism. We keep in mind that evaluation of nuclear shape as currently practiced in routine preparations is improper because it is indirectly based on the distribution of DNA as revealed by the affinity for basic dyes. Therefore, over the last years we have been using as criteria morphological features of nuclei of thyroid and breast carcinomas as determined by immunofluorescence, in situ hybridization, and 3D reconstruction. We have translated this approach to routine diagnostic pathology on tissue sections by employing immunoperoxidase staining for emerin. Direct detection of nuclear envelope irregularities by tagging nuclear membrane proteins such as lamin B and emerin has resulted in a more objective definition of the shape of the nucleus. In this review we discuss in detail methodological issues as well as diagnostic and prognostic implications provided by decoration/staining of the nuclear envelope in both thyroid and breast cancer, thus demonstrating how much it matters "to be in the right shape" when dealing with pathological diagnosis of cancer.

Breast cancer: updated guideline recommendations for HER2 testing

The recently updated HER2 testing guidelines by ASCO and the College of American Pathologists (CAP) are a significant step towards personalized medicine. It is excellent news that such great effort has been put into standardizing biomarker assessment. Undoubtedly, these recommendations will improve the analytical validity of HER2 testing, its clinical utility and the communication among health-care providers.

Discordance and clinical significance of ER, PR, and HER2 status between primary breast cancer and synchronous axillary lymph node metastasis

Discordance of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status between primary breast cancer, metastatic lesion and synchronous axillary lymph node metastasis has been reported in the series studies. Systemic treatment of primary invasive breast cancer patients with synchronous axillary metastasis is currently based on the biomarker characteristics of the primary tumor; however, hormone receptors and HER2 status may change throughout tumor progression from the primary tumor to the synchronous axillary metastasis. As local metastasis, the synchronous axillary lymph node metastasis may represent the potentially metastatic breast cancer cells much better than the primary tumor. Hence, the determination of hormone receptors and HER2 status should be routinely performed in synchronous axillary nodal metastasis, together with primary tumor, to guide therapy management and evaluate the recurrent risk of primary invasive breast cancer patients with synchronous axillary nodal metastasis, which may even change the postoperative risk categories (St. Gallen consensus) of breast cancer in these patients. This article will review the studies on the discordance and clinical significance of ER, PR, and HER2 receptor status between primary breast cancer and synchronous axillary lymph node metastasis.

Preliminary results of centralized HER2 testing in ductal carcinoma in situ (DCIS): NSABP B-43

NSABP B-43 is the first prospective, randomized phase III multi-institution clinical trial targeting high-risk, HER2-positive DCIS. It compares whole breast irradiation alone with WBI given concurrently with trastuzumab in women with HER2-positive DCIS treated by lumpectomy. The primary aim is to determine if trastuzumab plus radiation will reduce in-breast tumor recurrence. HER2-positive DCIS was previously estimated at >50 %, occurring primarily in ER-negative, comedo-type DCIS of high nuclear grade. There has been no documented centralized multi-institutional HER2 analysis of DCIS. NSABP B-43 provides a unique opportunity to evaluate this in a large cohort of DCIS patients. Patients undergoing lumpectomy for DCIS without evidence of an invasive component are eligible. A central review of each patient's pure DCIS lesion is carried out by immunohistochemistry analysis. If the lesion is 2+, FISH analysis is performed. Patients whose tumors are HER2 3+ or FISH-positive are randomly assigned to receive two doses of trastuzumab during WBI or WBI alone. NSABP B-43 opened 11/9/08. As of 7/31/2013, 5,861 patients have had specimens received centrally, and 5,645 of those had analyzable blocks; 1,969 (34.9 %) were HER2 positive. A total of 1,428 patients have been accrued, 1,137 (79.6 %) of whom have follow-up information. The average follow-up time for the 1,137 patients is 23.3 months. No grade 4 or 5 toxicity has been observed. In NSABP B-43 the HER2-positive rate for pure DCIS among patients undergoing breast-preserving surgery is 34.9 %, lower than the previously reported rate. No trastuzumab-related safety signals have been observed. Interest in this trial has been robust.

Acute myeloblastic leukemia in patients with multiple myeloma

Background

The continuum of anti-HER2 agents is a standard treatment of HER2 + metastatic breast cancer (MBC). This study evaluated the efficacy of lapatinib plus vinorelbine in patients progressed on both trastuzumab and lapatinib treatments.

Methods

A total of 149 patients were randomly assigned to lapatinib with vinorelbine (LV) (n = 75; lapatinib, 1000 mg daily; vinorelbine 20 mg/m² D1, D8 q3w) or vinorelbine (V) (n = 74; 30 mg/m² D1, D8 q3w). The primary endpoint was progression-free survival (PFS) rate at 18 weeks.

Results

The median number of previous anti-HER2 therapies was 2 (range 2–5). There was no significant difference in PFS rate at 18 weeks between LV and V arms (45.9% vs 38.9%, p = 0.40). ORR was 19.7% in LV arm, and 16.9% in V arm (p = 0.88). PFS and OS did not differ between two arms (LV vs V; median PFS, 16 vs 12 weeks, HR = 0.86, 95% CI 0.61–1.22; median OS, 15.0 vs 18.9 months, HR = 1.07, 95% CI 0.72–1.58). Toxicity profiles were similar in both arms and all were manageable.

Conclusions

Lapatinib plus vinorelbine treatment was tolerable; however, it failed to demonstrate the clinical benefits over vinorelbine alone in patients with HER2 + MBC after progression on both trastuzumab and lapatinib.

Clinical trial registration

ClinicalTrials.gov number NCT01730677.