Strategies for subtypes--dealing with the diversity of breast cancer: highlights of the St. Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2011

HER2 and ESR1 mRNA expression levels and response to neoadjuvant trastuzumab plus chemotherapy in patients with primary breast cancer

INTRODUCTION

Recent data suggest that benefit from trastuzumab and chemotherapy might be related to expression of HER2 and estrogen receptor (ESR1). Therefore, we investigated HER2 and ESR1 mRNA levels in core biopsies of HER2-positive breast carcinomas from patients treated within the neoadjuvant GeparQuattro trial.

METHODS

HER2 levels were centrally analyzed by immunohistochemistry (IHC), silver in situ hybridization (SISH) and qRT-PCR in 217 pretherapeutic formalin-fixed, paraffin-embedded (FFPE) core biopsies. All tumors had been HER2-positive by local pathology and had been treated with neoadjuvant trastuzumab/ chemotherapy in GeparQuattro.

RESULTS

Only 73% of the tumors (158 of 217) were centrally HER2-positive (cHER2-positive) by IHC/SISH, with cHER2-positive tumors showing a significantly higher pCR rate (46.8% vs. 20.3%, P <0.0005). HER2 status by qRT-PCR showed a concordance of 88.5% with the central IHC/SISH status, with a low pCR rate in those tumors that were HER2-negative by mRNA analysis (21.1% vs. 49.6%, P <0.0005). The level of HER2 mRNA expression was linked to response rate in ESR1-positive tumors, but not in ESR1-negative tumors. HER2 mRNA expression was significantly associated with pCR in the HER2-positive/ESR1-positive tumors (P = 0.004), but not in HER2-positive/ESR1-negative tumors.

CONCLUSIONS

Only patients with cHER2-positive tumors - irrespective of the method used - have an increased pCR rate with trastuzumab plus chemotherapy. In patients with cHER2-negative tumors the pCR rate is comparable to the pCR rate in the non-trastuzumab treated HER-negative population. Response to trastuzumab is correlated to HER2 mRNA levels only in ESR1-positive tumors. This study adds further evidence to the different biology of both subsets within the HER2-positive group.

Omission of axillary dissection according to ACOSOG Z0011: impact on adjuvant treatment recommendations

OBJECTIVE

A recent, randomized trial (ACOSOG Z0011) has demonstrated that omission of completion axillary lymph node dissection (ALND) in patients with one or two sentinel lymph node (SLN) metastases treated with breast conserving therapy (BCT) does not have a negative impact on survival. This study evaluates the impact of omitting ALND on adjuvant treatment recommendations.

METHODS

Performing a search of our clinical database, we identified patients meeting the main inclusion and exclusion criteria of ACOSOG Z0011 treated at the University of Heidelberg Breast Center. We performed blinded mock interdisciplinary tumor boards based on patient and tumor characteristics as well as (1) SLN information or (2) final nodal status after ALND. Differences between treatment recommendations were noted and analyzed.

RESULTS

A total of 132 patients were included; 80.3 % of these had one and 19.7 % had two metastatic sentinel nodes with a rate of micrometastases only of 19.7 %, and 39.7 % of patients had additional nonsentinel node metastases upon ALND. Overall, there was a change in adjuvant chemotherapy in 18.2 % of cases. Treatment recommendations based on ALND lead to a more aggressive therapy in 16.6 % of cases, all of them with additional metastatic nonsentinel nodes. Chemotherapy was not recommended in only two cases (1.5 %) based on ALND. Based on ALND, irradiation of the supraclavicular and infraclavicular nodes was added in 5.3 % of patients.

CONCLUSIONS

Completion ALND for patients with one or two metastatic sentinel nodes in pT1-2 cN0 PBC treated with BCT does have a relevant impact on adjuvant treatment. This should be considered in shared decision making.

Human epidermal growth factor receptor-2-positive breast cancer: does estrogen receptor status define two distinct subtypes?

BACKGROUND

Human epidermal growth factor receptor-2 (HER2) overexpression occurs in ∼20% of breast cancers and has historically been associated with decreased survival. Despite substantial improvements in clinical outcomes, particularly with the emergence of HER2-targeted therapy, a substantial minority of patients still relapses, and progression is inevitable in metastatic disease. Accumulating data indicate that HER2-positive disease is itself a heterogeneous entity.

METHODS AND RESULTS

In this article, we qualitatively review the data supporting the classification of HER2-positive disease as at least two separate entities, distinguished by estrogen receptor (ER) status. We summarize differences in clinical outcomes, including response to neoadjuvant therapy, timing and patterns of dissemination, efficacy of therapy in the metastatic setting and survival outcomes.

CONCLUSIONS

The collective data are sufficiently strong at this point to propose that ER status defines two distinct subtypes within HER2-positive breast cancer, and we highlight the implications of this knowledge in future research, including understanding of the basic biology of HER2-positive breast cancer and the design of future clinical trials.

miR-1290 and its potential targets are associated with characteristics of estrogen receptor α-positive breast cancer

Recent analyses have identified heterogeneity in estrogen receptor α (ERα)-positive breast cancer. Subtypes called luminal A and luminal B have been identified, and the tumor characteristics, such as response to endocrine therapy and prognosis, are different in these subtypes. However, little is known about how the biological characteristics of ER-positive breast cancer are determined. In this study, expression profiles of microRNAs (miRNAs) and mRNAs in ER-positive breast cancer tissue were compared between ER(high) Ki67(low) tumors and ER(low) Ki67(high) tumors by miRNA and mRNA microarrays. Unsupervised hierarchical clustering analyses revealed distinct expression patterns of miRNAs and mRNAs in these groups. We identified a downregulation of miR-1290 in ER(high) Ki67(low) tumors. Among 11 miRNAs that were upregulated in ER(high) Ki67(low) tumors, quantitative RT-PCR detection analysis using 64 samples of frozen breast cancer tissue identified six miRNAs (let-7a, miR-15a, miR-26a, miR-34a, miR-193b, and miR-342-3p). We picked up 11 genes that were potential target genes of the selected miRNAs and that were differentially expressed in ER(high) Ki67(low) tumors and ER(low) Ki67(high) tumors. Protein expression patterns of the selected target genes were analyzed in 256 ER-positive breast cancer samples by immunohistochemistry: miR-1290 and its putative targets, BCL2, FOXA1, MAPT, and NAT1, were identified. Transfection experiments revealed that introduction of miR-1290 into ER-positive breast cancer cells decreased expression of NAT1 and FOXA1. Our results suggest that miR-1290 and its potential targets might be associated with characteristics of ER-positive breast cancer.

Genomic grade adds prognostic value in invasive lobular carcinoma

BACKGROUND

The prognostic value of histologic grade (HG) in invasive lobular carcinoma (ILC) remains uncertain, and most ILC tumors are graded as HG2. Genomic grade (GG) is a 97-gene signature that improves the prognostic value of HG. This study evaluates whether GG may overcome the limitations of HG in ILC.

METHODS

Gene expression data were generated from frozen tumor samples, and GG calculated according to the expression of 97 genes. The prognostic value of GG was assessed in a stratified Cox regression model for invasive disease-free survival (IDFS) and overall survival (OS).

RESULTS

A total of 166 patients were classified by GG. HG classified 33 (20%) tumors as HG1, 120 (73%) as HG2 and 12 (7%) as HG3. GG classified 106 (64%) tumors as GG low (GG1), 29 (17%) as GG high (GG3) and 31 (19%) as equivocal (cases not classified as GG1 or GG3). The median follow-up time was 6.5 years. In multivariate analyses, GG was associated with IDFS [HR(GG3 vs GG1) 5.6 (2.1-15.3); P < 0.001] and OS [HR(GG3 vs GG1) 7.2, 95% CI (1.6-32.2); P = 0.01].

CONCLUSIONS

GG outperformed HG in ILC and added prognostic value to classic clinicopathologic variables, including nodal status.

High expression of LC3B is associated with progression and poor outcome in triple-negative breast cancer

Microtubule-associated protein 1 light chain 3B (LC3B) was involved in autophagosome formation and had been as a marker of autophagy which played an important role in the development of breast cancer. The purpose of this study was to explore the level of LC3B expression in four stages of triple-negative breast cancer (TNBC) and to evaluate the prognostic significance of LC3B expression in TNBC. The ultimate aim was to identify the new factor that could be useful in predicting clinical behavior of TNBC. We evaluated the expression level of LC3B protein in four kinds of TNBC tissue samples, including intraductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC) without metastases, IDC with lymph node metastases (LNM), and IDC with distant metastases (DM). Hundred and four primary TNBC patients were involved in present study, and the expression level of LC3B protein was assessed by immunohistochemistry. Medical records of these patients were reviewed, and the clinicopathological analysis was performed. High expression of LC3B was observed in 7.7 % of DCIS (1 of 13 cases), 16.2 % of IDC (6 of 37 cases), 35.7 % of LNM (15 of 42 cases), and 58.3 % of DM (7 of 12 cases). LC3B high expression was significantly associated with tumor size (P = 0.028), lymph node metastasis (P = 0.002), and Ki-67 expression (P = 0.047). LC3B high expression patients showed poorer DFS and OS rates compared with LC3B low expression patients (P = 0.024, and P = 0.047, respectively). Multivariate analyses confirmed that high LC3B expression was an independent and significant factor for predicting the poor outcome of TNBC patients. These preliminary results demonstrated that high LC3B expression was associated with lymph node and distant metastasis. Furthermore, high LC3B protein expression was correlated with shorter survival in patients with triple-negative breast carcinoma. These findings provided preliminary evidence for the function of LC3B on the progression of TNBC and suggested LC3B was a useful marker in prognostic evaluation for patients with TNBC.

Tumor grade and matrix metalloproteinase 2 expression in stromal fibroblasts help to stratify the high-risk group of patients with early breast cancer identified on the basis of st Gallen recommendations

BACKGROUND

It is still being discussed if the assessment of basal markers or if adhesion molecules expression contributes additional prognostic information to the classic prognostic factors and hence should be included into standard morphologic reports.

PATIENTS AND METHODS

The aim of the study was to assess the prognostic significance of: (i) classification recommended by St Gallen experts (ii) tumor grade, expression of (iii) basal markers, (iv) adhesion molecules, and (v) matrix metalloproteinase 2 (MMP-2) in patients with T1-T2 N0M0 chemotherapy-naive ductal breast cancer.

RESULTS

In 79 patients with tumors characterized by estrogen receptor (ER) and progesterone receptor (PgR) positive, human epidermal growth factor receptor 2 negative (HER2) phenotype and MIB-1 labeling index (MIB-l) LI ≤ 15% (low-risk group) cumulative 17-year breast cancer-specific survival probability was 100% and was significantly higher than in 95 patients from the high-risk group (ER(-)/PgR(-)/HER2(-) or HER2(+) or MIB-1 LI > 15%) (72.5%). We found that MMP-2 fibroblast expression indicated 2 subgroups with significantly different survival rates in women with grade 3 tumor (88.9% for MMP-2 positivity and 56.0% for negativity). Cox multivariate analysis revealed that both grade 3 combined with stromal fibroblast MMP-2(-) and a high-risk group according to St Gallen recommendations are independent negative prognostic factors that influence survival of patients with breast cancer.

CONCLUSION

To the best of our knowledge, we have shown for the first time that MMP-2(-) in stromal fibroblasts might indicate poor survivors in the group of patients with grade 3 tumors and that the cumulative effect of both above-mentioned parameters might be helpful in selecting the high-risk individuals from the group of patients with luminal B subtype/HER2(+)/triple negative phenotype identified according to St Gallen recommendations.

Exemestane versus anastrozole in postmenopausal women with early breast cancer: NCIC CTG MA.27--a randomized controlled phase III trial

PURPOSE

In patients with hormone-dependent postmenopausal breast cancer, standard adjuvant therapy involves 5 years of the nonsteroidal aromatase inhibitors anastrozole and letrozole. The steroidal inhibitor exemestane is partially non-cross-resistant with nonsteroidal aromatase inhibitors and is a mild androgen and could prove superior to anastrozole regarding efficacy and toxicity, specifically with less bone loss.

PATIENTS AND METHODS

We designed an open-label, randomized, phase III trial of 5 years of exemestane versus anastrozole with a two-sided test of superiority to detect a 2.4% improvement with exemestane in 5-year event-free survival (EFS). Secondary objectives included assessment of overall survival, distant disease-free survival, incidence of contralateral new primary breast cancer, and safety.

RESULTS

In the study, 7,576 women (median age, 64.1 years) were enrolled. At median follow-up of 4.1 years, 4-year EFS was 91% for exemestane and 91.2% for anastrozole (stratified hazard ratio, 1.02; 95% CI, 0.87 to 1.18; P = .85). Overall, distant disease-free survival and disease-specific survival were also similar. In all, 31.6% of patients discontinued treatment as a result of adverse effects, concomitant disease, or study refusal. Osteoporosis/osteopenia, hypertriglyceridemia, vaginal bleeding, and hypercholesterolemia were less frequent on exemestane, whereas mild liver function abnormalities and rare episodes of atrial fibrillation were less frequent on anastrozole. Vasomotor and musculoskeletal symptoms were similar between arms.

CONCLUSION

This first comparison of steroidal and nonsteroidal classes of aromatase inhibitors showed neither to be superior in terms of breast cancer outcomes as 5-year initial adjuvant therapy for postmenopausal breast cancer by two-way test. Less toxicity on bone is compatible with one hypothesis behind MA.27 but requires confirmation. Exemestane should be considered another option as up-front adjuvant therapy for postmenopausal hormone receptor-positive breast cancer.

Correlation between Ki67 and breast cancer prognosis

BACKGROUND

Ki67 is an immunohistochemical proliferation marker in many types of cancer and has been widely studied among breast cancer patients mostly through retrospective studies.

METHODS

The MEDLINE/PubMed database was searched for publications with the medical subject heading 'Ki 67' and the key words 'breast', 'cancer', and 'prognosis'. We restricted our search to articles published until 2012.

RESULTS

In this review, we included 78 articles and abstracts that were accessible and available in English. An effort to further explain the role of Ki67 in the prognosis of breast cancer has been made.

CONCLUSIONS

The debate on the prognostic role of Ki67 in breast cancer is still open, although most of the studies have established a relation between Ki67 and overall and disease-free survival. Further research should be made in order to establish Ki67 as a standard prognostic marker in breast cancer.

Prognostic and predictive value of tumor-infiltrating lymphocytes in a phase III randomized adjuvant breast cancer trial in node-positive breast cancer comparing the addition of docetaxel to doxorubicin with doxorubicin-based chemotherapy: BIG 02-98

PURPOSE

Previous preclinical and clinical data suggest that the immune system influences prognosis and response to chemotherapy (CT); however, clinical relevance has yet to be established in breast cancer (BC). We hypothesized that increased lymphocytic infiltration would be associated with good prognosis and benefit from immunogenic CT-in this case, anthracycline-only CT-in selected BC subtypes.

PATIENTS AND METHODS

We investigated the relationship between quantity and location of lymphocytic infiltrate at diagnosis with clinical outcome in 2009 node-positive BC samples from the BIG 02-98 adjuvant phase III trial comparing anthracycline-only CT (doxorubicin followed by cyclophosphamide, methotrexate, and fluorouracil [CMF] or doxorubicin plus cyclophosphamide followed by CMF) versus CT combining doxorubicin and docetaxel (doxorubicin plus docetaxel followed by CMF or doxorubicin followed by docetaxel followed by CMF). Readings were independently performed by two pathologists. Disease-free survival (DFS), overall survival (OS), and interaction with type of CT associations were studied. Median follow-up was 8 years.

RESULTS

There was no significant prognostic association in the global nor estrogen receptor (ER) -positive/human epidermal growth factor receptor 2 (HER2) -negative population. However, each 10% increase in intratumoral and stromal lymphocytic infiltrations was associated with 17% and 15% reduced risk of relapse (adjusted P = .1 and P = .025), respectively, and 27% and 17% reduced risk of death in ER-negative/HER2-negative BC regardless of CT type (adjusted P = .035 and P = .023), respectively. In HER2-positive BC, there was a significant interaction between increasing stromal lymphocytic infiltration (10% increments) and benefit with anthracycline-only CT (DFS, interaction P = .042; OS, P = .018).

CONCLUSION

In node-positive, ER-negative/HER2-negative BC, increasing lymphocytic infiltration was associated with excellent prognosis. Further validation of the clinical utility of tumor-infiltrating lymphocytes in this context is warranted. Our data also support the evaluation of immunotherapeutic approaches in selected BC subtypes.

Utility of prognostic genomic tests in breast cancer practice: The IMPAKT 2012 Working Group Consensus Statement

BACKGROUND

We critically evaluated the available evidence on genomic tests in breast cancer to define their prognostic ability and likelihood to determine treatment benefit.

DESIGN

Independent evaluation of six genomic tests [Oncotype Dx™, MammaPrint(®), Genomic Grade Index, PAM50 (ROR-S), Breast Cancer Index, and EndoPredict] was carried out by a panel of experts in three parameters: analytical validity, clinical validity, and clinical utility based on the principles of the EGAPP criteria. PANEL STATEMENTS: The majority of the working group members found the available evidence on the analytical and clinical validity of Oncotype Dx™ and MammaPrint(®) to be convincing. None of the genomic tests demonstrated robust evidence of clinical utility: it was not clear from the current evidence that modifying treatment decisions based on the results of a given genomic test could result in improving clinical outcome.

CONCLUSIONS

The IMPAKT 2012 Working Group proposed the following recommendations: (i) a need to develop models that integrate clinicopathologic factors along with genomic tests; (ii) demonstration of clinical utility should be made in the context of a prospective randomized trial; and (iii) the creation of registries for patients who are subjected to genomic testing in the daily practice.

Expression of mammaglobin and gross cystic disease fluid protein-15 in breast carcinomas

Immunohistochemical analysis of gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin (MGB) is frequently used in routine practice for assessment of metastases or regional recurrences of breast origin. Breast cancer is highly heterogeneous. Expression of these 2 markers in various breast cancer subtypes has not been well studied. In addition, the usefulness of these two markers in combination in detecting breast origin has not been explored. In this study, a large cohort of breast cancers was evaluated for GCDFP-15 and MGB expression, both individually and combined. Their expression was correlated with cancer subtypes, other biomarkers and clinicopathologic parameters. A higher sensitivity for MGB (42.3%) than GCDFP-15 (31.6%) in detecting cancers of breast origin was observed. Combining both increased the sensitivity further, both for primary tumor (53.0%) and for nodal metastases (69.0%). GCDFP-15 was associated significantly with a breast cancer profile of good prognosis tumors, including lower grade (P < .001), pN (P = .029) and Ki-67 (P < .001) as well as negative basal markers expression (P = .043, .009, and .049 for c-Kit, CK5/6 and epidermal growth factor receptor, respectively) and, thus, may not be sensitive for detection of poor prognosis tumors. MGB has the highest expression in HER2-overexpressing cancers (56.6%), and may be a potentially useful marker for this subtype. Nonetheless, both markers showed low expression in the basal like (BLBC) subtype (11.9% and 21.4% for GCDFP-15 and MGB respectively), therefore, the detection of BLBC remains problematic. Negative results need to be interpreted with caution, and correlation with other clinical findings may be required to exclude the possibility of metastatic BLBC.

GeneSearch™ BLN Assay could replace frozen section and touch imprint cytology for intra-operative assessment of breast sentinel lymph nodes

BACKGROUND

Breast cancer sentinel lymph node (SLN) biopsy has become a common procedure. The GeneSearch™ Breast Lymph Node Assay is a real-time reverse-transcriptase polymerase chain reaction assay for detecting nodal metastases larger than 0.2 mm. The trial is a prospective multi-center clinical trial conducted to validate the assay in China.

METHODS

Four hundred and seventy-nine consecutive prospective patients were enrolled from six centers. SLNs were sectioned along the short axis into multiple blocks. Odd blocks were tested by the assay intra-operatively, and even blocks were assessed by post-operative histology. Six 4- to 6-μm-thick sections were taken every 150 μm per block. In addition, intra-operative histological assessments were performed on the even blocks of 214 patients by frozen section (FS) and all blocks of 156 patients by touch imprint cytology (TIC).

RESULTS

A total of 1046 SLNs were excised. Overall performance of the assay compared to post-operative histology was accuracy of 91.4 %, sensitivity of 87.5 %, and specificity of 92.9 %. There were no significant differences in assay performance of each center. After a learning curve of about 10 cases, the assay could be performed in a median time of about 35 min. The sensitivity of the assay was similar to the FS (84.9 %, P = 0.885) and was significantly higher than the TIC (70.0 %, P = 0.007) while the specificity of all were comparable.

CONCLUSION

The GeneSearch™ Breast Lymph Node Assay is an accurate and rapid intra-operative assay for breast SLNs and it can replace FS and TIC for application.

Immunohistochemical profile and clinical-pathological variables in breast cancer

OBJECTIVE

To describe the main characteristics of women with breast cancer, according to the immunohistochemical profile.

METHODS

The population comprised a hospital cohort, consisting of women diagnosed with breast cancer between 2003 and 2005 (n = 601) and treated at a referral center for cancer care in Juiz de Fora, MG, Brazil. Only 397 women who had complete immunohistochemistry analysis were selected. To define the groups according to the immunohistochemical profile, the assessment of estrogen and progesterone receptors, Ki-67 cell proliferation index, and overexpression of human epidermal growth factor receptor 2 (HER2) was chosen. According to the different phenotypes, five subtypes were defined: luminal A, luminal B HER2 negative, luminal B HER2 positive, triple negative, and HER2 overexpression.

RESULTS

Most patients were white (80.7%) and post-menopausal (64.9%), with a mean age of 57.4 years (± 13.5). At diagnosis, 57.5% had tumor size > 2.0 cm, and 41.7% had lymph node involvement. The most common subtypes were luminal B - HER2 negative (41.8%) and triple negative (24.2%). In the luminal A subtype, 72.1% of patients were post-menopausal, while the highest percentage of premenopausal women were observed in the luminal B - HER2 positive and triple negative subtypes (45.2% and 44.2%, respectively). A higher frequency of tumors > 2.0 cm and lymph node involvement was observed in triple negative and HER2 positive subtypes.

CONCLUSION

This study allowed the distribution assessment of the main clinical and pathological characteristics and those related to health services in a cohort of Brazilian women with breast cancer, according to the immunohistochemical tumor subtypes.

Breast cancer subtype approximations and loco-regional recurrence after immediate breast reconstruction

BACKGROUND

A small but significant proportion of patients with breast cancer (BC) will develop loco-regional recurrence (LRR) after immediate breast reconstruction (IBR). The LRR also varies according to breast cancer subtypes and clinicopathological features.

METHODS

We studied 1742 consecutive BC patients with IBR between 1997 and 2006. According to St Gallen conference consensus 2011, its BC approximations were applied to classify BC into five subtypes: estrogen receptor (ER) and/or progesterone receptor (PgR) positive, HER2 negative, and low Ki67 (<14%) [luminal A]; ER and/or PgR positive, HER2 negative and high Ki67(≥ 14%) [luminal B/HER2 negative]; ER and/or PgR positive, any Ki67 and HER2 positive [luminal B/HER2 positive]; ER negative, PgR negative and HER2 positive [HER2 positive/nonluminal]; and ER negative, PgR negative and HER2 negative [triple negative]. Cumulative incidences of LRR were compared across different subgroups by means of the Gray test. Multivariable Cox regression models were applied.

RESULTS

Median follow up time was 74 months (range 3-165). The cumulative incidence of LRR was 5.5% (121 events). The 5-year cumulative incidence of LRR was 2.5% for luminal A; 5.0% for luminal B/HER2 negative; 9.8% for luminal B/HER2 positive; 3.8% for HER2 non luminal; and 10.9% for triple negative. On multivariable analysis, tumor size (pT) >2 cm, body mass index (BMI) ≥ 25, triple negative and luminal B/HER2 positive subtypes were associated with increased risk of LRR.

CONCLUSION

Luminal B/HER2 positive, triple negative subtypes and BMI ≥ 25 are independent prognostic factors for risk of LRR after IBR.

Breast cancer subtype and distant recurrence after ipsilateral breast tumor recurrence

BACKGROUND

There is little information about the impact of breast cancer subtype on prognosis after ipsilateral breast tumor recurrence (IBTR).

METHODS

One hundred eighty-five patients were classified according to breast cancer subtype, as approximated by estrogen receptor, human epidermal growth factor receptor 2 (HER2), and Ki-67, of IBTR, and we evaluated whether breast cancer subtype was associated with distant recurrence after IBTR.

RESULTS

There was a significant difference in distant disease-free survival (DDFS) after IBTR according to breast cancer subtype defined by a cutoff of the Ki-67 index of 20 % (p = 0.0074, log-rank test). The 5-year DDFS rates for patients with luminal A, luminal B, triple-negative, and HER2 types were 86.3, 57.1, 56.6, and 65.9 %, respectively. In addition, breast cancer subtype was significantly associated with distant recurrence after IBTR on adjustment for various clinicopathologic factors (p = 0.0027, Cox proportional hazards model).

CONCLUSIONS

Our study suggests that breast cancer subtype based on immunohistochemical staining predicts the outcomes of patients with IBTR. Further analyses are needed (UMIN-CTR number UMIN000008136).

Analysis of pattern, time and risk factors influencing recurrence in triple-negative breast cancer patients

The aim of the study was to assess the rate, pattern, and time of recurrence in patients with triple-negative breast cancer (TNBC) and to evaluate factors influencing recurrence and overall survival in this group of patients. Out of 2,534 consecutive breast cancer patients diagnosed between January 2005 and December 2006, 228 (9 %) were TNBC (ER/PR/HER2-negative). The clinicopathological characteristics were determined using descriptive statistics. The overall survival (OS) and disease-free survival (DFS) were calculated using the Kaplan-Meier method. The univariate and multivariate analyses were developed to identify factors influencing recurrence and survival in TNBC patients. After 6 years of observation, metastatic disease occurred in 35 % of all TNBC patients: 15 % in the brain, 14 % in the lungs, 11 % in the bones, 8 % in the liver, and 14 % had locoregional relapse. The highest risk of recurrence was during the first 3 years after primary treatment, and then, during the next 2 years of observation, it did not change. 6-year DFS and OS were 68 and 62 %, respectively. Factors influencing recurrence were tumor size and systemic adjuvant chemotherapy, while factors influencing overall survival were tumor size, nodal status, adjuvant/neoadjuvant treatment, and metastases in the brain, liver, and bones. Characteristic pattern of recurrence in time was revealed. The tumor size was responsible for recurrence despite lack of involvement of lymph nodes. Aggressive adjuvant/neoadjuvant treatment ordered in all clinical stages of TNBC (including N0) was factor responsible for avoiding local and distant relapse and prolonging overall survival.

High expression of ATP-binding cassette transporter ABCC11 in breast tumors is associated with aggressive subtypes and low disease-free survival

ATP-binding cassette (ABC) transporters are membrane proteins that efflux various compounds from cells, including chemotherapeutic agents, and are known to affect multidrug resistance. Recent reports disagree on whether ABCC11 is a risk factor for breast tumorigenesis, but its expression in breast cancer is poorly investigated. We hypothesized that both frequency and expression levels of ABC transporters in breast tumors would vary by cancer subtype, and be associated with prognosis. Here, we constructed a tissue microarray breast tumor samples from 281 patients, and analyzed expressions of ABCB1, ABCC1, ABCC11, and ABCG2 immunohistochemically. Breast cancer subtypes were determined by immunohistochemistry of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2). Protein expression was correlated to clinicopathological characteristics, clinical follow-up, and pathological complete response to neoadjuvant chemotherapy. The tissue microarray comprised 191 luminal A (68.0 %), 17 luminal B (6.0 %), 27 HER2 (9.6 %), and 46 triple-negative (16.4 %) samples. ABCC1 and ABCC11 expressions were associated with significantly shorter disease-free survival (P = 0.027 and P = 0.003, respectively). ABCC1, ABCC11, and ABCG2, but not ABCB1, were expressed significantly more, and more frequently, in aggressive subtypes. Patients with HER2+ and triple-negative tumor subtypes that expressed high levels of ABCC11 had significantly worse disease-free survival (P = 0.017 and P < 0.001, respectively). We have shown, for the first time, that ABCC1, ABCC11, and ABCG2 are highly expressed in aggressive breast cancer subtypes, and that tumor ABCC11 expression is associated with poor prognosis.

Magnetic resonance imaging in breast cancer treated with neoadjuvant chemotherapy: radiologic-pathologic correlation of the response and disease-free survival depending on molecular subtype

OBJECTIVES

To evaluate the radiologic and pathologic responses to neoadjuvant chemotherapy and their correlation in the molecular subtypes of breast cancer and to analyze their impact in disease-free survival.

MATERIAL AND METHODS

We included 205 patients with breast cancer treated with neoadjuvant chemotherapy. We evaluated the radiologic response by comparing MRI images acquired before and after chemotherapy. The pathologic response was classified on the Miller and Payne scale. For each subtype (HER2+, TN, luminal A, luminal B HER2-, and luminal B HER2+), we used the χ(2) test, Student's t-test, ANOVA, and Kendall's Tau-b to evaluate the radiologic response and the pathologic response, the radiologic-pathologic correlation, and the disease-free survival.

RESULTS

The subtypes HER2+ (62.1%) and TN (45.2%) had higher rates of complete radiologic response. The pathologic response was 65.5% in the HER2+ subtype, 38.1% in the TN subtype, 2.6% in the luminal A subtype, 8.2% in the luminal B HER2- subtype, and 31% in the luminal B HER2+ subtype. The rate of radiologic-pathologic correlation was significant in all subtypes, higher in TN and HER2 (Tau-b coefficients 0.805 and 0.717, respectively). Disease-free survival was higher in HER2+ (91.9±3.3 months) and lower in TN (69.5±6.3 months), with significant differences between the cases with poor and good radiologic responses (P=.040). Survival was greater in cases with good radiologic response, except in cases with luminal A subtype.

CONCLUSION

MRI can be a useful tool that provides information about the evolution of breast cancer treated with neoadjuvant chemotherapy, which varies with the immunohistochemical subtype.

Clinical significance following breast conservation therapy with or without irradiation in breast cancer patients

BACKGROUND

We retrospectively examined the clinical outcome of irradiated versus non-irradiated groups of Japanese breast cancer patients according to their clinical and histopathological characteristics following breast-conserving therapy.

METHODS

We retrospectively evaluated a total of 1197 Japanese female breast cancer patients (598 irradiated and 599 non-irradiated) who received breast-conserving therapy. The median age of the patients was 54 years (range: 24-99 years). We retrospectively examined the local recurrence-free survival rates in those with or without post-operative irradiation according to age, surgical margin status and histopathological characteristics including histological grade, estrogen receptor expression and HER2 status.

RESULTS

Local recurrence-free survival rates in the irradiated group were significantly higher than those in the non-irradiated group, especially in surgical margin-positive [hazard ratio (HR): 0.334, 95% confidence interval: 0.14-0.79, P = 0.001], estrogen receptor-positive (HR: 0.249, 95% confidence interval: 0.11-0.54, P < 0.001), HER2-negative (HR: 0.382, 95% confidence interval: 0.21-0.69, P = 0.001) and non-triple-negative (HR: 0.382, 95% confidence interval: 0.21-0.69, P = 0.001) breast cancer patients.

CONCLUSION

The results indicated that irradiation after breast-conserving therapy is strongly recommended in Japanese breast cancer patients, especially those with surgically positive margins, estrogen receptor-positive tumors and HER2-negative invasive breast cancers.

Molecular subtyping of male breast cancer using alternative definitions and its prognostic impact

BACKGROUND

Male breast cancer (MBC) is an uncommon disease and there is limited information on the prognostic impact of routinely used clinicopathological parameters.

MATERIAL AND METHODS

In a retrospective setting, we reviewed 197 MBC patients with accessible paraffin-embedded tumor tissue and clinicopathological data. Immunohistochemical (IHC) stainings were performed on tissue microarrays and histological grading on conventional slides. Cox proportional regression models were applied for uni- and multivariate analyses using breast cancer death as the event.

RESULTS

Estrogen receptor (ER) and progesterone receptor positivity were demonstrated in 93% and 77% of patients, respectively. Nottingham histologic grade (NHG) III was seen in 41% and HER2 positivity in 11%. Classification into molecular subtypes using IHC markers according to three alternative definitions revealed luminal A and luminal B in 81% vs. 11%; 48% vs. 44% and 41% vs. 42% of cases. Two cases of basal-like were identified, but no cases of HER2-like. Factors associated with an increased risk of breast cancer death were node positivity (HR 4.5; 95% CI 1.8-11.1), tumor size > 20 mm (HR 3.3; 95% CI 1.4-7.9) and ER negativity (HR 10.9; 95% CI 3.2-37.9). No difference in breast cancer death between the luminal subgroups was demonstrated, regardless of definition.

CONCLUSION

MBC tumors were more often of high grade, whereas HER2 overexpression was as frequent as in FBC. Lymph nodes, tumor size and ER status were independent predictors of breast cancer death. The prognostic impact of molecular subtyping in MBC seems to differ from that previously established in FBC.

Competing risks in low-risk breast cancer

In recent years a growing amount of data on prognostic features of breast cancer has allowed for identification of tumors with a very low risk of recurrence. Markers used to predict the risk of distant spread include classic clinicopathologic features as well as newer tumor gene signatures, which have been validated and are being used in cohorts of patients with breast cancer patients who have low-risk disease. However, the definition of "low-risk" breast cancer requires consideration of patient-related factors such as comorbidities and age in addition to tumor characteristics, as high competing risks for mortality might be more important than cancer recurrence from a patient's point of view. In addition, identification of low-risk breast cancer cohorts is only valuable if treatment decisions are based on this information. Therefore, the magnitude of any treatment benefit in low-risk disease needs to be quantified in a comprehensible way. However, treatment benefit in low-risk situations is hard to quantify, may vary over time, and needs to be compared to individual risks for side effects. Decision models considering tumor and patient characteristics as well as predictive markers for treatment efficacy and toxicity will be needed. Tools such as Adjuvant! Online ultimately need to include information from gene signatures in order to reliably recommend specific treatment options for patients with breast cancer patients who have low-risk disease.

Association of tissue inhibitor of metalloproteinases-1 and Ki67 in estrogen receptor positive breast cancer

BACKGROUND

The role of tissue inhibitor of metalloproteinases-1 (TIMP-1) in estrogen receptor (ER) positive breast cancer remains to be fully elucidated. We evaluated TIMP-1 as a prognostic marker in patients treated with adjuvant tamoxifen and investigated TIMP-1s association with Ki67 and ER/progesterone receptor (PR)/human epidermal growth factor receptor 2 (HER2) profiles.

MATERIAL AND METHODS

TIMP-1 expression was evaluated by immunohistochemistry (IHC) on formalin fixed paraffin embedded primary tumor tissue in two independent cohorts comprised of 236 and 192 patients, respectively.

RESULTS

No differences in disease free survival (HR 0.98; 95% CI 0.63-1.53; p = 0.92) and overall survival (HR 0.94; 95% CI 0.63-1.43; p = 0.79) were observed according to TIMP-1 status. A significant negative association between TIMP-1 and Ki67 was identified (p = 0.015). TIMP-1 expression did not differ significantly according to ER/PR/HER2 profiles. When analyzed as separate variables PR and HER2 status tended to have a positive but non-significant association with TIMP-1 (PR: p = 0.08; OR 2.54; 95% CI 0.91-7.10, HER2: p = 0.08; OR 0.48; 95% CI 0.21-1.08) whereas ER status was not associated with TIMP-1 expression (p = 0.48; OR 0.68; 95% CI 0.23-1.99).

CONCLUSION

TIMP-1 does not appear to be prognostic in breast cancer patients receiving adjuvant tamoxifen. We identified a negative association between TIMP-1 and Ki67. We did not confirm our previous in vitro findings of a negative association between TIMP-1 and PR.

Comparison of prognostic values between combined immunohistochemical score of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki-67 and the corresponding gene expression score in breast cancer

In the clinical diagnosis of breast cancer, immunohistochemistry panels with estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2) and Ki-67 are routinely used, and they have been proposed for the classification of breast tumors into distinct subtypes. Gene expression analysis with formalin-fixed paraffin-embedded material have also become widely available recently, but the prognostic values of corresponding gene panels compared with these four immunohistochemical panels had never tested. We independently evaluated the 5-year relapse risk-estimation scores using semiquantitative data of four immunohistochemical panels (Ku-IHC4 score) and compared these with the results of four-gene expression profiling of formalin-fixed paraffin-embedded specimens (Ku-FFPE4 score) in a consecutive series of 235 primary invasive breast cancer patients. Ku-IHC4 score was revealed to be an independent predictor of recurrence other than Ku-FFPE4 score in a multivariate model analyzed by classical clinical parameters (Ku-IHC4 score vs Ku-FFPE4 score; χ(2): 14.2 vs 2.5, P: 0.0002 vs 0.11). When patients were trichotomized into high-, intermediate- and low-risk groups using the thresholds determined from the approximately calculated 5-year relapse rate, Kaplan-Meier analyses showed a significant difference among the three groups in Ku-IHC4 score (log-rank, P<0.0001), but not in Ku-FFPE4 score. The high-risk group according to Ku-FFPE4 score showed contradictory low recurrence rates (Ku-IHC4 score vs Ku-FFPE4 score, 53.1 vs 24.8%), which might be caused by risk-dependently extended error ranges. We show that the Ku-IHC4 score, consisted with semiquantitative measures of immunohistochemistry, provides better prognostic information than the corresponding quantitative RNA measurements. Prognostication tools such as the Ku-IHC4 score may be potentially useful in screening which patients had better be assessed by further testing using other genes rather than ER, PgR, HER2 and Ki-67 to determine critical aspects of therapeutic decision making.

Combined analysis of vascular invasion, grade, HER2 and Ki67 expression identifies early breast cancer patients with questionable benefit of systemic adjuvant therapy

INTRODUCTION

Over-treatment of low-risk early breast cancer patients with adjuvant systemic therapies is an important clinical challenge. Better techniques are required which can be used to distinguish between the large group of patients with no residual disease after surgery and consequently no benefit of adjuvant treatment, from the smaller group with high relapse risk. A better integration of available prognostic factors might contribute to improved prediction of clinical outcome.

MATERIAL AND METHODS

The current study included 346 unselected pT1pN0 patients who did not receive adjuvant systemic treatment. In Norway, no patients with this stage were recommended systemic treatment at the time of the study (1995-1998). Histological type, tumour size, grade, vascular invasion (VI), hormone receptor (HR) status, HER2 and Ki67 (cut-off 10%) were analysed. Median follow-up was 86 months for relapse and 101 months for death.

RESULTS

Thirty-eight patients experienced relapse, 31 with distant metastasis. Twenty-one patients died of breast cancer. In univariate analysis grade, HER2, HR, VI and Ki67 had impact on clinical outcome (p < 0.005, log rank). In multivariate analysis, only grade 1-2 vs. grade 3, HER2, VI, and Ki67 status were significant for disease free survival, distant disease free survival, and/or breast cancer specific survival. These factors were used in combination, to separate patients into groups based on the number of unfavourable factors present [combined prognostic score (CPS) 0-4]. Close to 2/3 of the patients (61.4%) had no unfavourable factor (CPS0), whilst 18.4% had CPS ≥ 2. Only 3.6% of those with CPS0 developed metastasis (p < 0.001). The outcome was clearly worse for patients with CPS ≥ 2 (p < 0.001), systemic relapse was detected in approximately 40%.

CONCLUSIONS

This study indicates that the combined use of grade, VI, HER2 and Ki67 identifies a subgroup of breast cancer patients with a relapse risk that may question the benefit of adjuvant systemic therapy.

Uncommon Breast Malignancies: Presentation Pattern, Prognostic Issue and Treatment Outcome in an Italian Single Institution Experience

Aims and background

Often neglected by large clinical trials, patients with uncommon breast malignancies have been rarely analyzed in large series.

Patients and methods

Of 2,052 patients diagnosed with breast cancer and followed in our Institution from January 1985 to December 2009, we retrospectively collected data on those with uncommon histotypes, with the aim of investigating their presentation characteristics and treatment outcome.

Results

Rare histotypes were identified in 146 patients (7.1% of our total breast cancer population), being classified as follows: tubular carcinoma in 75 (51.4%), mucinous carcinoma in 36 (24.7%), medullary carcinoma in 25 (17.1%) and papillary carcinoma in 10 patients (6.8%). Whereas age at diagnosis was not significantly different among the diverse diagnostic groups, patients with medullary and papillary subtypes had a higher rate of lymph node involvement, similar to that of invasive ductal carcinoma. Early stage diagnosis was frequent, except for medullary carcinoma. Overall, in comparison with our invasive ductal carcinoma patients, those with rare histotypes showed a significantly lower risk of recurrence, with a hazard ratio of 0.28 (95% CI, 0.12–0.62; P = 0.002).

Conclusions

According to our analysis, patients with uncommon breast malignancies are often diagnosed at an early stage, resulting in a good prognosis with standard treatment.

Multifocal breast cancer documented in large-format histology sections: long-term follow-up results by molecular phenotypes

BACKGROUND

The prognostic significance of molecular phenotype in breast cancer is well established in the literature. Recent studies have demonstrated that subgross lesion distribution (unifocal, multifocal, and diffuse) and disease extent also carry prognostic significance in this disease. However, the correlation of molecular phenotypes with subgross parameters has not yet been investigated in detail.

METHODS

In total, 444 consecutive invasive breast cancers that were documented in large-format histology slides and worked up with detailed radiologic-pathologic correlation were sampled into tissue microarray blocks and stained immunohistochemically to delineate the molecular subtypes.

RESULTS

Diffuse or multifocal distribution of the invasive component of breast carcinomas in this series was associated with a 4.14-fold respectively 2.75-fold risk of cancer-related death compared with unifocal tumors irrespective of molecular phenotype. Patients who had human epidermal growth factor receptor 2 (HER2)-positive cancers; estrogen receptor-negative, progesterone receptor-negative, and HER2-negative (triple-negative) cancers; or basal-like cancers had a 2.18-fold, 2.33-fold, and 4.07-fold risk of dying of disease, respectively, compared with patients who had luminal A carcinomas. Unifocal luminal A, HER2-positive, and basal-like cancers were associated with significantly better long-term survival outcomes than their multifocal or diffuse counterparts; luminal B and triple-negative tumors also had the same tendency. In multivariate analysis, patient age, tumor size category, lymph node status, lesion distribution, and molecular phenotypes remained significant.

CONCLUSIONS

Multifocality and diffuse distribution of the invasive component were associated with significantly poorer survival in women with breast carcinomas compared with unifocal disease in patients with luminal A, HER2 type, and basal-like cancers. Molecular classification of breast cancer is a powerful tool but gains in power when combined with conventional and subgross morphologic parameters.

Invasive breast cancer: a significant correlation between histological types and molecular subgroups

INTRODUCTION

The special types of breast cancer seem to have not only distinct morphological features but also distinct biological features.

MATERIALS AND METHODS

Women diagnosed with a first primary invasive breast cancer in the 2004-2005 period were identified through Tuscan Cancer Registry. Information on age, tumor size, lymph node status, histological type and grade, hormonal receptors, HER2 immunohistochemical expression were collected. Five subtypes were defined: luminal A, luminal B HER2+, luminal B HER2-, triple negative, and HER2 positive. The association between the histological type and molecular subgroups was assessed by a Fisher's exact test, and a multinomial logistic regression model was used.

RESULTS

Out of 1,487 patients, 34 % were luminal A subtype, 25 % luminal B HER2-, 11 % luminal B HER2+, 19 % triple negative, and 10.2 % HER2+; 58.5 % of cancers were ductal NOS types. With luminal A as reference, histological types distribution was significantly different between the subgroups. Mucinous, tubular, and cribriform histotypes were found among luminal A cancers more than in other subgroups; all medullary carcinomas were triple negative cancers. Pathological stage at diagnosis was more advanced, and histological grade was lower among subgroups other than luminal A.

CONCLUSIONS

Significant association between breast cancer histotypes and molecular subgroups was found.

Clinical Significance of CK19 Negative Breast Cancer

Analysis of sentinel lymph nodes (SLNs) by means of One-Step Nucleic Acid Amplification (OSNA) is gaining widespread use as a quick and accurate method. This assay detects the expression level of cytokeratin 19 (CK19) which is present in some but not all breast tumors. In this study, the clinical significance of negative CK19 was investigated in 219 cases of primary breast cancer. In 179 patients with clinically negative nodes, OSNA and imprint smear cytology of SLN were performed simultaneously. The OSNA revealed a node-positive rate of 24.6%. Negative CK19 correlated significantly with negative ER/PgR and higher Ki-67 values, and marginally with higher nuclear grade and p53 overexpression. The triple negative subtype showed lower CK19 expression. OSNA revealed that one of the negative CK19 cases was actually a false negative but this was corrected with the use of the imprint smear cytology. In conclusion, CK19 negativity reflected the aggressiveness of primary breast cancer. OSNA assay used to analyze SLN was useful, but there is a possibility that it will mistakenly detect false negatives in CK19 negative tumors. Therefore, in tumors with negative CK19, the imprint smear cytology may be more useful in cases with macrometastasis.

PTP1B expression is an independent positive prognostic factor in human breast cancer

Protein tyrosine phosphatase 1B (PTP1B) is a non-transmembrane protein tyrosine phosphatase that has come into focus as a critical regulator of multiple signaling pathways. The role of PTP1B in breast cancer remains unclear with evidence suggesting that PTP1B can exert both tumor-suppressing and tumor-promoting effects. To better define the role of PTP1B in human breast cancer, and its relationship with HER2, we performed immunohistochemical studies on a large cohort of functionally annotated primary breast cancer specimens. 683 of 1,402 (49 %) evaluable primary breast cancers are positive for PTP1B. There is no statistically significant association between PTP1B expression and age, tumor size, T stage, histologic grade, lymph node status, or histological subtype. Of note, there is no significant association between PTP1B expression and HER2 expression (PTP1B expression 53.1 % in HER2(+) cancers vs. 47.5 % in HER2(-) cancers, p = 0.0985). However, PTP1B expression is significantly associated with estrogen receptor expression (PTP1B expression 50.7 % in ER(+) cancers vs. 43.1 % in ER(-) cancers, p = 0.0137) and intrinsic molecular subtype (PTP1B expression 53.9 % in the luminal B HER2(+) subtype and 37.9 % in the basal-like subtype). Of note, multivariate analyses demonstrate that PTP1B is an independent predictor of improved survival in breast cancer (HR 0.779, p = 0.006). Taken together, we demonstrate in the largest study to date that (1) PTP1B is commonly expressed in breast cancer, (2) there is no association or functional impact of PTP1B expression in HER2(+) breast cancer, and (3) PTP1B expression in breast cancer is associated with significantly improved clinical outcome. Until additional studies are performed, caution should be exercised in using PTP1B inhibitors in human breast cancer.

Prognostic value of breast cancer subtypes, Ki-67 proliferation index, age, and pathologic tumor characteristics on breast cancer survival in Caucasian women

Estrogen receptor (ER), progesterone receptor (PR), and epidermal growth factor receptor 2 (HER2) status are well-established prognostic markers in breast cancer management. The triple negative breast carcinoma subtype (ER-/PR-/HER2-) has been associated with worse overall prognosis in comparison with other subtypes in study populations consisting of ethnic minorities and young women. We evaluated the prognostic value of breast cancer subtypes, Ki-67 proliferation index (Ki-67PI), and pathologic tumor characteristics on breast cancer survival in Caucasian women in our institution, where greater than 90% of the total patient population is white. From 628 new invasive breast cancer cases in our data base (2000-late 2004), 593 (94%) were identified in Caucasian women. ER/PR/HER2 breast cancer subtypes were classified based on St. Gallen International Expert Consensus recommendations from 2011. ER/PR/HER2 status and its effect on survival were analyzed using a Kaplan-Meier curve. ER/PR/HER2 status, grade, tumor-node-metastasis status (TNM)/anatomic stage, and age were analyzed in terms of survival in a multivariate fashion using a Cox regression. Ki-67PI was analyzed between ER/PR/HER2 groups using the Kruskal-Wallis, Mann-Whitney U-tests, and 2 × 5 ANOVA. Our results showed that patients with stage IIB through stage IV breast carcinomas were 2.1-16 times more likely to die than patients with stages IA-B and IIA disease, respectively (95% CI 1.17-3.81 through 9.68-28.03, respectively), irrespective of ER/PR/HER2 subtype. Similar effect was seen with T2, N2/N3, or M1 tumors in comparison with T1, N0/N1, and M0 tumors. Chances of dying increase approximately 5% for every year increase in age. There was a significant main effect of Ki-67PI between ER/PR/HER2 subtypes, p < .001, but Ki-67PI could not predict survival. In summary, TNM status/anatomic stage of breast carcinomas and age are predictive of survival in our patient population of Caucasian women, but breast carcinoma subtypes and Ki-67 proliferation index are not.

High-risk estrogen-receptor-positive breast cancer: identification and implications for therapy

The estrogen receptor (ER) has long been recognized as a key discriminative feature of breast cancer, which carries profound implications for management. However, recent advances in the understanding of breast cancer heterogeneity have demonstrated the importance of biologic context to the interpretation of ER as a prognostic and predictive factor. The use of tumor subtyping methods and prognostic indicators based on molecular profiling of tumor tissue is now helping to delineate high-risk ER-positive cancer types that have distinct risk and treatment response profiles. These new approaches to breast cancer classification will have a major impact on the conduct of clinical trials and individual patient assessment in the future.

Adjuvant lapatinib for women with early-stage HER2-positive breast cancer: a randomised, controlled, phase 3 trial

BACKGROUND

Worldwide, many patients with HER2-positive early stage breast cancer do not receive trastuzumab-the standard adjuvant treatment. We investigated the efficacy and safety of adjuvant lapatinib for patients with trastuzumab-naive HER2-positive early-stage breast cancer, started at any time after diagnosis.

METHODS

This study was a placebo-controlled, multicentre, randomised phase 3 trial. Women outpatients from 405 [corrected] centres in 33 countries [corrected] with HER2-positive early-breast cancer who had previously received adjuvant chemotherapy but not trastuzumab were randomly assigned (1:1) to receive daily lapatinib (1500 mg) or daily placebo for 12 months. Randomisation was done with a computer-generated sequence, stratified by time since diagnosis, lymph node involvement at diagnosis, and tumour hormone-receptor status. Investigators, site staff, and patients were masked to treatment assignment. The primary endpoint was disease-free survival in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT00374322.

FINDINGS

Between August, 2006, and May, 2008, 3161 women were enrolled and 3147 were assigned to lapatinib (n=1571) or placebo (n=1576). After a median follow-up of 47·4 months (range 0·4-60·0) in the lapatinib group and 48·3 (0·7-61·3) in the placebo group, 210 (13%) disease-free survival events had occurred in the lapatinib group versus 264 (17%) in the placebo group (hazard ratio [HR] 0·83, 95% CI 0·70-1·00; p=0·053). Central review of HER2 status showed that only 2490 (79%) of the randomised women were HER2-positive. 157 (13%) of 1230 confirmed HER2-positive patients in the lapatinib group and in 208 (17%) of 1260 in the placebo group had a disease-free survival event (HR 0·82, 95% 0·67-1·00; p=0·04). Serious adverse events occurred in 99 (6%) of 1573 patients taking lapatinib and 77 (5%) of 1574 patients taking placebo, with higher incidences of grade 3-4 diarrhoea (97 [6%] vs nine [<1%]), rash (72 [5%] vs three [<1%]), and hepatobiliary disorders (36 [2%] vs one [<1%]).

INTERPRETATION

Our data show that there was no significant difference in disease-free survival between groups when analysed in the intention-to-treat population. However, exploratory analyses restricted to patients who had HER2-positive disease confirmed by central fluorescence in-situ hybridisation review suggested marginal benefit with lapatinib in terms of disease-free survival. Thus lapatinib might be an option for women with HER2-positive breast cancer who do not or cannot receive adjuvant trastuzumab.

FUNDING

GlaxoSmithKline.

Prognostic significance of progesterone receptor-positive tumor cells within immunohistochemically defined luminal A breast cancer

PURPOSE

Current immunohistochemical (IHC)-based definitions of luminal A and B breast cancers are imperfect when compared with multigene expression-based assays. In this study, we sought to improve the IHC subtyping by examining the pathologic and gene expression characteristics of genomically defined luminal A and B subtypes.

PATIENTS AND METHODS

Gene expression and pathologic features were collected from primary tumors across five independent cohorts: British Columbia Cancer Agency (BCCA) tamoxifen-treated only, Grupo Español de Investigación en Cáncer de Mama 9906 trial, BCCA no systemic treatment cohort, PAM50 microarray training data set, and a combined publicly available microarray data set. Optimal cutoffs of percentage of progesterone receptor (PR) -positive tumor cells to predict survival were derived and independently tested. Multivariable Cox models were used to test the prognostic significance.

RESULTS

Clinicopathologic comparisons among luminal A and B subtypes consistently identified higher rates of PR positivity, human epidermal growth factor receptor 2 (HER2) negativity, and histologic grade 1 in luminal A tumors. Quantitative PR gene and protein expression were also found to be significantly higher in luminal A tumors. An empiric cutoff of more than 20% of PR-positive tumor cells was statistically chosen and proved significant for predicting survival differences within IHC-defined luminal A tumors independently of endocrine therapy administration. Finally, no additional prognostic value within hormonal receptor (HR) -positive/HER2-negative disease was observed with the use of the IHC4 score when intrinsic IHC-based subtypes were used that included the more than 20% PR-positive tumor cells and vice versa.

CONCLUSION

Semiquantitative IHC expression of PR adds prognostic value within the current IHC-based luminal A definition by improving the identification of good outcome breast cancers. The new proposed IHC-based definition of luminal A tumors is HR positive/HER2 negative/Ki-67 less than 14%, and PR more than 20%.

Safe chemotherapy and hormone therapy for treating early breast cancer in a glucose 6-phosphate dehydrogenase-deficient patient: case report

Breast cancer is the leading cause of neoplasia-related deaths among women, but no data are available in the literature on the safe use of oncological treatments in glucose 6-phosphate dehydrogenase (G6PD)-deficient patients. This case report describes, for the first time, the treatment of a G6PD-deficient woman diagnosed with breast cancer who underwent adjuvant treatment after quadrantectomy and axillary node dissection. After conservative surgery, many patients require adjuvant treatment with hormone therapy (HT) and/or chemotherapy. Anthracyclines are considered a cornerstone in this setting but, because of their oxidative properties, are contraindicated in G6PD-deficient patients. Despite the absence of data in the literature on their use in G6PD-deficient patients, we chose to use docetaxel and cyclophosphamide because these agents were not predicted to elicit oxidative stress. The patient completed six cycles of docetaxel and cyclophosphamide chemotherapy, and no adverse reactions were observed. Tamoxifen was excluded as a HT as a nonoxidative agent was required; therefore, an aromatase inhibitor was used as adjuvant therapy. Considering the high frequency of breast cancer and G6PD deficiency worldwide, there are little data available in the literature on the oxidative properties of oncological drugs. The oncological community must report cases in which patients with hereditary enzymatic deficiencies are treated successfully with anticancer agents. This would enable clinicians to have access to data that would be very useful in the choice of a safe treatment program.

Molecular subclasses of breast cancer: how do we define them? The IMPAKT 2012 Working Group Statement

The 2012 IMPAKT task force investigated the medical usefulness of current methods for the classification of breast cancer into the 'intrinsic' molecular subtypes (luminal A, luminal B, basal-like and HER2). A panel of breast cancer and/or gene expression profiling experts evaluated the analytical validity, clinical validity and clinical utility of two approaches for molecular subtyping of breast cancer: the prediction analysis of microarray (PAM)50 assay and an immuno-histochemical (IHC) surrogate panel including oestrogen receptor (ER), HER2 and Ki67. The panel found the currently available evidence on the analytical validity and clinical utility of Ki67 based on a 14% cut-off and PAM50 to be inadequate. The majority of the working group members found the available evidence on the analytical validity, clinical validity and clinical utility of ER/HER2 to be convincing. The panel concluded that breast cancer classification into molecular subtypes based on the IHC assessment of ER, HER2 and Ki67 with a 14% cut-off and on the PAM50 test does not provide sufficiently robust information to modify systemic treatment decisions, and recommended the use IHC for ER and HER2 for the identification of clinically relevant subtypes of breast cancers. Methods for breast cancer classification into molecular subtypes should, however, be incorporated into clinical trial design.