Predicting degree of benefit from adjuvant trastuzumab in NSABP trial B-31.

BACKGROUND: National Surgical Adjuvant Breast and Bowel Project (NSABP) trial B-31 suggested the efficacy of adjuvant trastuzumab, even in HER2-negative breast cancer. This finding prompted us to develop a predictive model for degree of benefit from trastuzumab using archived tumor blocks from B-31. METHODS: Case subjects with tumor blocks were randomly divided into discovery (n = 588) and confirmation cohorts (n = 991). A predictive model was built from the discovery cohort through gene expression profiling of 462 genes with nCounter assay. A predefined cut point for the predictive model was tested in the confirmation cohort. Gene-by-treatment interaction was tested with Cox models, and correlations between variables were assessed with Spearman correlation. Principal component analysis was performed on the final set of selected genes. All statistical tests were two-sided. RESULTS: Eight predictive genes associated with HER2 (ERBB2, c17orf37, GRB7) or ER (ESR1, NAT1, GATA3, CA12, IGF1R) were selected for model building. Three-dimensional subset treatment effect pattern plot using two principal components of these genes was used to identify a subset with no benefit from trastuzumab, characterized by intermediate-level ERBB2 and high-level ESR1 mRNA expression. In the confirmation set, the predefined cut points for this model classified patients into three subsets with differential benefit from trastuzumab with hazard ratios of 1.58 (95% confidence interval [CI] = 0.67 to 3.69; P = .29; n = 100), 0.60 (95% CI = 0.41 to 0.89; P = .01; n = 449), and 0.28 (95% CI = 0.20 to 0.41; P < .001; n = 442; P(interaction) between the model and trastuzumab < .001). CONCLUSIONS: We developed a gene expression-based predictive model for degree of benefit from trastuzumab and demonstrated that HER2-negative tumors belong to the moderate benefit group, thus providing justification for testing trastuzumab in HER2-negative patients (NSABP B-47).

One year of sitagliptin treatment protects against islet amyloid-associated ß-cell loss and does not induce pancreatitis or pancreatic neoplasia in mice.

The dipeptidyl peptidase-4 (DPP-4) inhibitor sitagliptin is an attractive therapy for diabetes, as it increases insulin release and may preserve ß-cell mass. However, sitagliptin also increases ß-cell release of human islet amyloid polypeptide (hIAPP), the peptide component of islet amyloid, which is cosecreted with insulin. Thus, sitagliptin treatment may promote islet amyloid formation and its associated ß-cell toxicity. Conversely, metformin treatment decreases islet amyloid formation by decreasing ß-cell secretory demand and could therefore offset sitagliptin's potential proamyloidogenic effects. Sitagliptin treatment has also been reported to be detrimental to the exocrine pancreas. We investigated whether long-term sitagliptin treatment, alone or with metformin, increased islet amyloid deposition and ß-cell toxicity and induced pancreatic ductal proliferation, pancreatitis, and/or pancreatic metaplasia/neoplasia. hIAPP transgenic and nontransgenic littermates were followed for 1 yr on no treatment, sitagliptin, metformin, or the combination. Islet amyloid deposition, ß-cell mass, insulin release, and measures of exocrine pancreas pathology were determined. Relative to untreated mice, sitagliptin treatment did not increase amyloid deposition, despite increasing hIAPP release, and prevented amyloid-induced ß-cell loss. Metformin treatment alone or with sitagliptin decreased islet amyloid deposition to a similar extent vs untreated mice. Ductal proliferation was not altered among treatment groups, and no evidence of pancreatitis, ductal metaplasia, or neoplasia were observed. Therefore, long-term sitagliptin treatment stimulates ß-cell secretion without increasing amyloid formation and protects against amyloid-induced ß-cell loss. This suggests a novel effect of sitagliptin to protect the ß-cell in type 2 diabetes that appears to occur without adverse effects on the exocrine pancreas.

Increased lymphocyte infiltration in patients with head and neck cancer treated with the IRX-2 immunotherapy regimen.

Twenty-seven subjects with squamous cell cancer of the head and neck received the neoadjuvant IRX-2 immunotherapy regimen prior to surgery in a Phase 2 trial. Pretreatment tumor biopsies were compared with the primary tumor surgical specimens for lymphocyte infiltration, necrosis and fibrosis, using hematoxylin and eosin stain and immunohistochemistry in 25 subjects. Sections were examined by three pathologists. Relative to pretreatment biopsies, increases in lymphocyte infiltration (LI) were seen using H and E or immunohistochemistry. CD3+ CD4+ T cells and CD20+ B cells were primarily found in the peritumoral stroma and CD3+ CD8+ T cells and CD68+ macrophages were mainly intratumoral. LI in the surgical specimens were associated with reductions in the primary tumor size. Improved survival at 5 years was correlated with high overall LI in the tumor specimens. Neoadjuvant IRX-2 immunotherapy regimen may restore immune responsiveness presumably by mobilizing tumor infiltrating effector lymphocytes and macrophages into the tumor.

Determining true HER2 gene status in breast cancers with polysomy by using alternative chromosome 17 reference genes: implications for anti-HER2 targeted therapy.

PURPOSE: The ratio of human epidermal growth factor receptor 2 (HER2) to CEP17 by fluorescent in situ hybridization (FISH) with the centromeric probe CEP17 is used to determine HER2 gene status in breast cancer. Increases in CEP17 copy number have been interpreted as representing polysomy 17. However, pangenomic studies have demonstrated that polysomy 17 is rare. This study tests the hypothesis that the use of alternative chromosome 17 reference genes might more accurately assess true HER2 gene status. PATIENTS AND METHODS: In all, 171 patients with breast cancer who had HER2 FISH that had increased mean CEP17 copy numbers (> 2.6) were selected for additional chromosome 17 studies that used probes for Smith-Magenis syndrome (SMS), retinoic acid receptor alpha (RARA), and tumor protein p53 (TP53) genes. A eusomic copy number exhibited in one or more of these loci was used to calculate a revised HER2-to-chromosome-17 ratio by using the eusomic gene locus as the reference. RESULTS: Of 132 cases classified as nonamplified on the basis of their HER2:CEP17 ratios, 58 (43.9%) were scored as amplified by using alternative chromosome 17 reference gene probes, and 13 (92.9%) of 14 cases scored as equivocal were reclassified as amplified. Among the cases with mean HER2 copy number of 4 to 6, 41 (47.7%) of 86 had their HER2 gene status upgraded from nonamplified to amplified, and four (4.7%) of 86 were upgraded from equivocal to amplified. CONCLUSION: Our results support the findings of recent pangenomic studies that true polysomy 17 is uncommon. Additional FISH studies that use probes to the SMS, RARA, and TP53 genes are an effective way to determine the true HER2 amplification status in patients with polysomy 17 and they have important potential implications for guiding HER2-targeted therapy in breast cancer.

Positive response to neoadjuvant cyclophosphamide and doxorubicin in topoisomerase II nonamplified/HER2/neu negative/polysomy 17 absent breast cancer patients.

PURPOSE: Human epidermal growth factor receptor 2 (HER2)/neu, topoisomerase II alpha (TOP2A), and polysomy 17 may predict tumor responsiveness to doxorubicin (DOX) therapy. METHODS: We identified neoadjuvant DOX/cyclophosphamide treated breast cancer patients in our registry from 1997 to 2008 with sufficient tissue for testing (n = 34). Fluorescence in situ hybridization (FISH) testing was done on deparaffinized tissue sections pretreated using vendor's standard protocol modification, and incubated with US Food and Drug Administration approved Abbott Diagnostics Vysis PathVysion™ probe set, including Spectrum-Green-conjugated probe to α-satellite DNA located at the centromere of chromosome 17 (17p11.1-q11.1) and a Spectrum-Orange-conjugated probe to the TOP2A gene. Morphometric analysis was performed using a MetaSystems image analysis system. Manual counting was performed on all samples in which autofluorescence and/or artifact prevented the counting of sufficient numbers of cells. A ratio >2.0 was considered positive for TOP2A amplification. Polysomy 17 (PS17) presence was defined as signals of ≥2.5. Outcomes were pathological complete response (pCR), partial response (PR), and nonresponse (NR). RESULTS: Of 34 patients tested, one was TOP2A amplified (hormone receptor negative/HER2 negative, partial responder). The subset of TOP2A nonamplified, HER2 negative, and PS17 absent (n = 23) patients had treatment response: pCR = 2 (9%), PR = 14 (61%), and NR = 7 (30%). Including the two PS17 present and HER2-positive patients (n = 33), 76% of TOP2A nonamplified patients had pCR or PR. CONCLUSIONS: We observed substantial treatment response in patients lacking three postulated predictors that would be difficult to attribute to cyclophosphamide alone. Patients who are HER2 negative and lack TOP2A amplification and PS17 should not be excluded from receiving DOX-containing regimens.

Human epidermal growth factor receptor 2 assessment in a case-control study: comparison of fluorescence in situ hybridization and quantitative reverse transcription polymerase chain reaction performed by central laboratories.

PURPOSE: The optimal method to assess human epidermal growth factor receptor 2 (HER2) status remains highly controversial. Before reporting patient HER2 results, American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines mandate that laboratories demonstrate ≥ 95% concordance to another approved laboratory or methodology. Here, we compare central laboratory HER2 assessed by fluorescence in situ hybridization (FISH) and quantitative reverse transcriptase polymerase chain reaction (RT-PCR) using Oncotype DX in lymph node-negative, chemotherapy-untreated patients from a large Kaiser Permanente case-control study. PATIENTS AND METHODS: Breast cancer specimens from the Kaiser-Genomic Health study were examined. Central FISH assessment of HER2 amplification and polysomy 17 was conducted by PhenoPath Laboratories (ratios > 2.2, 1.8 to 2.2, and < 1.8 define HER2 positive, HER2 equivocal, and HER2 negative, respectively). HER2 expression by RT-PCR was conducted using Oncotype DX by Genomic Health (normalized expression units ≥ 11.5, 10.7 to < 11.5, and < 10.7 define HER2 positive, HER2 equivocal, and HER2 negative, respectively). Concordance analyses followed ASCO/CAP guidelines. RESULTS: HER2 concordance by central FISH and central RT-PCR was 97% (95% CI, 96% to 99%). Twelve percent (67 of 568 patients) and 11% (60 of 568 patients) of patients were HER2 positive by RT-PCR and FISH, respectively. HER2-positive patients had increased odds of dying from breast cancer compared with HER2-negative patients. Polysomy 17 was demonstrated in 12.5% of all patients and 33% of FISH-positive patients. Nineteen of 20 FISH-positive patients with polysomy 17 were also RT-PCR HER2 positive. Although not statistically significantly different, HER2-positive/polysomy 17 patients tended to have the worst prognosis, followed by HER2-positive/eusomic, HER2-negative/polysomy 17, and HER2-negative/eusomic patients. CONCLUSION: There is a high degree of concordance between central FISH and quantitative RT-PCR using Oncotype DX for HER2 status, and the assay warrants additional study in a trastuzumab-treated population.

Relationship between clinical and pathologic features of ductal carcinoma in situ and patient age: an analysis of 657 patients.

Prior studies have shown that young patient age at diagnosis is associated with an increased risk of local recurrence among women with ductal carcinoma in situ (DCIS) treated with breast-conserving therapy. Whether this can be explained by differences in clinical or pathologic features of DCIS according to age is an unresolved issue. We compared clinical and pathologic features of DCIS among 657 women in 4 age groups: <45 years (n=111), 45 to 54 years (n=191), 55 to 64 years (n=160), and 65+ years (n=195). DCIS presented as a mammographic abnormality less often in younger than in older women (68%, 82%, 81%, and 86% for women <45, 45 to 54, 55 to 64, and 65+ y, respectively; P=0.003). Among the pathologic features analyzed, DCIS extent as determined by the number of low power fields was greater in younger than in older women (mean number of low power fields were 18.6, 14.2, 10.8, and 11.3 in women <45, 45 to 54, 55 to 64 and 65+ y; P<0.001). In addition, cancerization of lobules was present more often in younger than in older women (77%, 73%, 66%, and 50% for women <45, 45 to 54, 55 to 64 and 65+ y, respectively; P<0.0001). Of note, we found no statistically significant relationship between age and DCIS architectural pattern, nuclear grade, comedo necrosis or expression of estrogen receptor, progesterone receptor or human epidermal growth factor receptor 2. We conclude that DCIS in younger women is more often symptomatic, is more extensive, and more often shows cancerization of lobules than DCIS in older women. Whether these features contribute to the higher local recurrence risk in young women with DCIS treated with the breast-conserving therapy requires further study.

High concordance between immunohistochemistry and fluorescence in situ hybridization testing for HER2 status in breast cancer requires a normalized IHC scoring system.

The American Society of Clinical Oncologists and College of American Pathologists have recently released new guidelines for laboratory testing of HER2 status in breast cancer, which require high levels (95%) of concordance between immunohistochemistry positive (3+) and fluorescence in situ hybridization-amplified cases, and between immunohistochemistry negative (0/1+) and fluorescence in situ hybridization-nonamplified cases; these required levels of concordance are significantly higher than those found in most published studies. We tested the hypothesis that a modification of the HER2 immunohistochemistry scoring system could significantly improve immunohistochemistry and fluorescence in situ hybridization concordance. A total of 6604 breast cancer specimens were evaluated for HER2 status by both immunohistochemistry and fluorescence in situ hybridization using standard methodologies. Results were compared when the standard immunohistochemistry scoring system was replaced by a normalized scoring system in which the HER2 score was derived by subtracting the score on the non-neoplastic breast epithelium from that on the tumor cells. Among the 6604 tumors, using a non-normalized immunohistochemistry scoring system, 267/872 (30.6%) of the immunohistochemistry 3+ cases proved to be fluorescence in situ hybridization nonamplified, whereas using the normalized scoring system only 30/562 (5.3%) of immunohistochemistry 3+ cases proved to be 'false positive'. The concordance rate between immunohistochemistry 3+ and fluorescence in situ hybridization-amplified cases using the normalized scoring method was 94.7%, whereas the concordance using the non-normalized method was only 69.4%. Extremely high concordance between immunohistochemistry and fluorescence in situ hybridization assessment of HER2 status in breast cancer is achievable, but to attain this high level of concordance, modification of the FDA-approved immunohistochemistry scoring system is required.

HER2 in well differentiated breast cancer: is testing necessary?

BACKGROUND: In addition to providing a timely and accurate diagnosis, pathologists routinely provide prognostic and predictive information to assist in the treatment of patients with invasive breast cancer. As our understanding of breast cancer at the molecular and genetic level improves, sophisticated new treatment options have become available to patients. The demonstrated improvements in disease-free and overall survival with the use of trastuzumab (Herceptin) has made HER2 testing a standard of care in the evaluation of patients with breast cancer. Specialized breast centers have accumulated sufficient experience to recognize that HER2 positive tumors tend to be of higher grade and to be estrogen receptor negative, whereas well-differentiated breast cancers rarely are HER2 positive. METHODS: To determine whether HER2 testing is necessary in well-differentiated breast cancer, we analyzed the frequency of HER2 positivity among 1,162 cases from 7 major breast centers or commercial laboratories in the United States and Europe. RESULTS: Well-differentiated breast cancers, defined by either nuclear grading or the Scarff-Bloom-Richardson system, rarely are HER2 positive (mean 1.6%, range 0-2.8%). CONCLUSIONS: Given the low rate of well differentiated HER2 positive tumors, falling within the range reported for false negative IHC tests for HER2, and the absence of published data demonstrating a beneficial effect of trastuzumab therapy in this subset of patients, HER2 testing should not be considered a standard of care for all patients with well-differentiated breast cancer.

Automated quantitative analysis of estrogen receptor expression in breast carcinoma does not differ from expert pathologist scoring: a tissue microarray study of 3,484 cases.

BACKGROUND: Estrogen receptor (ER) expression is routinely assessed by immunohistochemistry (IHC) in breast carcinoma. Our study compares visual scoring of ER in invasive breast cancer by histopathologists to quantitation of staining using a fully automated system. MATERIALS AND METHODS: A tissue microarray was constructed from 4,049 cases (3,484 included in analysis) of invasive breast carcinoma linked to treatment and outcome information. Slides were scored independently by two pathologists and scores were dichotomised, with ER positivity recognized at a cut-off of >1% positive nuclei. The slides were scanned and analyzed with an Ariol automated system. RESULTS: Using data dichotomised as ER positive or negative, both visual and automated scores were highly consistent: there was excellent concordance between two pathologists (kappa = 0.918 (95%CI: 0.903-0.932)) and between two Ariol machines (kappa = 0.913 (95%CI: 0.897-0.928)). The prognostic significance of ER positivity was similar whether determined by pathologist or automated scoring for both the entire patient cohort and subsets of patients treated with tamoxifen alone or receiving no systemic adjuvant therapy. The optimal cut point for the automated scores using breast cancer disease-specific survival as an endpoint was >0.4% positive nuclei. The concordance between dextran-coated charcoal ER biochemical assay data and automated scores (kappa = 0.728 (95%CI: 0.69-0.75); 0.74 (95%CI: 0.71-0.77)) was similar to the concordance between biochemical assay and pathologist scores (kappa = 0.72 (95%CI: 0.70-0.75; 0.70 (95%CI: 0.67-0.72)). CONCLUSION: Fully automated quantitation of ER immunostaining yields results that do not differ from human scoring against both biochemical assay and patient outcome gold standards.

Immunohistochemical detection using the new rabbit monoclonal antibody SP1 of estrogen receptor in breast cancer is superior to mouse monoclonal antibody 1D5 in predicting survival.

PURPOSE: Estrogen receptor (ER) expression predicts improved breast cancer-specific survival and reduced risk of recurrence and is targeted in breast cancer therapy. A high-quality antibody to identify ER-positive patients plays an important role in clinical decision making for women with breast cancer. This study evaluates immunohistochemistry using two anti-ER antibodies, a new rabbit monoclonal antibody (SP1) and the mouse monoclonal antibody (1D5), in relation to biochemical ER assay results and clinical data on survival and adjuvant systemic therapy. PATIENTS AND METHODS: A population-based tissue microarray series of 4,150 invasive breast cancers was constructed. All patients had staging, pathology, treatment, and follow-up information. The median follow-up was 12.4 years and the median age at diagnosis 60 years. Survival analysis and log-rank tests were used to evaluate the prognostic value of ER status and correlations with clinical data. RESULTS: Among the 4,105 samples interpretable for both antibodies, SP1 detected ER positivity in 69.5% and 1D5 in 63.1% of cases. Both monoclonal antibodies are demonstrated to be good prognostic indictors for breast cancer-specific and relapse-free survival. In multivariate analysis, including age, tumor size, grade, and lymphovascular and nodal status, SP1 was a better independent prognostic factor than 1D5. Among patients with discrepant ER results, the 8% of patients who were SP1 positive/1D5 negative showed good outcomes, and the 2% SP1-negative/1D5 positive had poor outcomes. Maintaining the same 92% specificity and 98% positive predictive value, SP1 is 8% more sensitive than 1D5 using biochemical assay as gold standard. CONCLUSION: SP1 represents an improved standard for ER immunohistochemistry assessment in breast cancer.

HER-2 testing in breast cancer using parallel tissue-based methods.

CONTEXT: Testing for HER-2 oncogene in breast cancer has increased because of its role as a prognostic and predictive factor. Some advocate gene testing by fluorescence in situ hybridization (FISH) vs protein testing by immunohistochemistry as the method which most accurately evaluates and predicts response to the anti-HER-2 antibody, trastuzumab. However, critical examination of FISH on a screening basis has yet to be performed. OBJECTIVES: To determine the correlation between FISH and immunohistochemistry results by determining HER-2/neu gene status on tumor sections with indeterminate immunohistochemistry results (2+ score), confirm gene amplification on tumor sections with positive results (3+ score), and verify gene status on tumor sections with negative results (0 or 1+ score). DESIGN, SETTING, AND PATIENTS: A quality control and quality assurance program for HER-2 testing by FISH, which used tumor specimens from 2963 patients (median age, 56 years) with breast cancer received from 135 hospitals and cancer centers in 29 states, was performed at a reference laboratory from January 1, 1999, to May 15, 2003. Every specimen evaluated by FISH was parallel tested with immunohistochemistry tests. MAIN OUTCOME MEASURES: With FISH as the presumed standard testing method, the positive and negative predictive values and sensitivity and specificity of immunohistochemistry were calculated. RESULTS: A total of 3260 clinical HER-2 tests by FISH were performed on 2963 serially referred breast cancer specimens. Of these, 2933 tests were successful and 2913 breast cancer specimens had both FISH and immunohistochemistry results available. With FISH as the standard testing method, the positive predictive value of positive immunohistochemistry score (3+) was 91.6%, and the negative predictive value of negative immunohistochemistry score (0 or 1+) was 97.2%. The sensitivity of immunohistochemistry tests, including tumor sections with scores of 2+ or 3+, was 92.6% and the specificity of immunohistochemistry tests with scores of 3+ was 98.8%. The FISH test had a significantly higher failure rate (5% vs 0.08%) and reagent cost (140 dollars vs 10 dollars), and longer testing (36 hours vs 4 hours) and interpretation times (7 minutes vs 45 seconds) vs immunohistochemistry tests. CONCLUSIONS: A testing algorithm for HER-2 determination is most efficient by using immunohistochemistry as the method of choice, with FISH performed for cancers with indeterminate results (2+ score). Successful quality control and quality assurance programs are a prerequisite for such approaches.