Genomic characterisation of hormone receptor-positive breast cancer arising in very young women

BACKGROUND

Very young premenopausal women diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+HER2-) early breast cancer (EBC) have higher rates of recurrence and death for reasons that remain largely unexplained.

PATIENTS AND METHODS

Genomic sequencing was applied to HR+HER2- tumours from patients enrolled in the Suppression of Ovarian Function Trial (SOFT) to determine genomic drivers that are enriched in young premenopausal women. Genomic alterations were characterised using next-generation sequencing from a subset of 1276 patients (deep targeted sequencing, n = 1258; whole-exome sequencing in a young-age, case-control subsample, n = 82). We defined copy number (CN) subgroups and assessed for features suggestive of homologous recombination deficiency (HRD). Genomic alteration frequencies were compared between young premenopausal women (<40 years) and older premenopausal women (≥40 years), and assessed for associations with distant recurrence-free interval (DRFI) and overall survival (OS).

RESULTS

Younger women (<40 years, n = 359) compared with older women (≥40 years, n = 917) had significantly higher frequencies of mutations in GATA3 (19% versus 16%) and CN amplifications (CNAs) (47% versus 26%), but significantly lower frequencies of mutations in PIK3CA (32% versus 47%), CDH1 (3% versus 9%), and MAP3K1 (7% versus 12%). Additionally, they had significantly higher frequencies of features suggestive of HRD (27% versus 21%) and a higher proportion of PIK3CA mutations with concurrent CNAs (23% versus 11%). Genomic features suggestive of HRD, PIK3CA mutations with CNAs, and CNAs were associated with significantly worse DRFI and OS compared with those without these features. These poor prognostic features were enriched in younger patients: present in 72% of patients aged <35 years, 54% aged 35-39 years, and 40% aged ≥40 years. Poor prognostic features [n = 584 (46%)] versus none [n = 692 (54%)] had an 8-year DRFI of 84% versus 94% and OS of 88% versus 96%. Younger women (<40 years) had the poorest outcomes: 8-year DRFI 74% versus 85% and OS 80% versus 93%, respectively.

CONCLUSION

These results provide insights into genomic alterations that are enriched in young women with HR+HER2- EBC, provide rationale for genomic subgrouping, and highlight priority molecular targets for future clinical trials.

Impact of HER2 Heterogeneity on Treatment Response of Early-Stage HER2-Positive Breast Cancer: Phase II Neoadjuvant Clinical Trial of T-DM1 Combined with Pertuzumab

Intratumor heterogeneity is postulated to cause therapeutic resistance. To prospectively assess the impact of HER2 (ERBB2) heterogeneity on response to HER2-targeted therapy, we treated 164 patients with centrally confirmed HER2-positive early-stage breast cancer with neoadjuvant trastuzumab emtansine plus pertuzumab. HER2 heterogeneity was assessed on pretreatment biopsies from two locations of each tumor. HER2 heterogeneity, defined as an area with ERBB2 amplification in >5% but <50% of tumor cells, or a HER2-negative area by FISH, was detected in 10% (16/157) of evaluable cases. The pathologic complete response rate was 55% in the nonheterogeneous subgroup and 0% in the heterogeneous group (P < 0.0001, adjusted for hormone receptor status). Single-cell ERBB2 FISH analysis of cellular heterogeneity identified the fraction of ERBB2 nonamplified cells as a driver of therapeutic resistance. These data suggest HER2 heterogeneity is associated with resistance to HER2-targeted therapy and should be considered in efforts to optimize treatment strategies. SIGNIFICANCE: HER2-targeted therapies improve cure rates in HER2-positive breast cancer, suggesting chemotherapy can be avoided in a subset of patients. We show that HER2 heterogeneity, particularly the fraction of ERBB2 nonamplified cancer cells, is a strong predictor of resistance to HER2 therapies and could potentially be used to optimize treatment selection.See related commentary by Okines and Turner, p. 2369.This article is highlighted in the In This Issue feature, p. 2355.

Identifying oncogenic drivers associated with increased risk of late distant recurrence in postmenopausal, estrogen receptor-positive, HER2-negative early breast cancer: results from the BIG 1-98 study

BACKGROUND

In postmenopausal, estrogen receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer, the risk for distant recurrence can extend beyond 5 years of adjuvant endocrine therapy. This study aims to identify genomic driver alterations associated with late distant recurrence.

PATIENTS AND METHODS

Next generation sequencing was used to characterize driver alterations in primary tumors from a subset of 764 postmenopausal estrogen receptor-positive/HER2-negative patients from the BIG 1-98 randomized trial. Late distant recurrence events were defined as ≥5 years from time of randomization). The association of driver alterations with distant recurrence-free interval in early and late time periods was assessed using Cox regression models. Multivariable analyses were carried out to adjust for clinicopathological factors. Weighted analysis methods were used in order to correct for over-sampling of distant recurrences.

RESULTS

A total of 538 of 764 (70%) samples were successfully sequenced including 88 (63%) early and 52 (37%) late distant recurrence events after a median follow up of 8.1 years. In univariable analysis for late distant recurrence, PIK3CA mutations (58.8%) were significantly associated with reduced risk [hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.20-0.82, P = 0.012], whereas amplifications on chromosome 8p11 (10.9%) (HR 4.79, 95% CI 2.30-9.97, P < 0.001) and BRCA2 mutations (2.3%) (HR 5.39, 95% CI 1.51-19.29, P = 0.010) were significantly associated with an increased risk. In multivariable analysis, only amplifications on 8p11 (P = 0.002) and BRCA2 mutations (P = 0.013) remained significant predictors.

CONCLUSIONS

In estrogen receptor-positive/HER2-negative postmenopausal early breast cancer, PIK3CA mutations were associated with reduced risk of late distant recurrence, whereas amplifications on 8p11 and BRCA2 mutations were associated with increased risk of late distant recurrence. The characterization of oncogenic driver alterations may aid in refining treatment choices in the late disease setting, and help identify potential drug targets for testing in future trials.

Association of Somatic Driver Alterations With Prognosis in Postmenopausal, Hormone Receptor-Positive, HER2-Negative Early Breast Cancer: A Secondary Analysis of the BIG 1-98 Randomized Clinical Trial

Importance

A range of somatic driver alterations has been described in estrogen receptor-positive, HER2-negative (ER+/HER2-) early breast cancer (BC); however, the clinical relevance is unknown.

Objective

To investigate associations of driver alterations with prognosis and the role of PIK3CA mutations in prediction of benefit associated with endocrine therapy in postmenopausal patients with ER+/HER2- early BC treated with tamoxifen or letrozole.

Design, Setting, and Participants

The Breast International Group (BIG) 1-98 trial randomized 8010 postmenopausal patients with hormone receptor-positive, operable, invasive BC to monotherapy with letrozole, tamoxifen, or a sequential strategy for 5 years. Driver alterations were characterized using next-generation sequencing in primary tumors from a subset of 764 patients from 7329 eligible patients with ER+/HER2- BC, with 841 distant recurrences after a median of 8.1 years of follow-up. To correct for the oversampling of distant recurrences, weighted analysis methods were used. This analysis was conducted from April 4, 2016, to November 30, 2016.

Main Outcomes and Measures

The prevalence of driver alterations, associations with clinicopathologic factors, distant recurrence-free interval, and treatment interactions were analyzed. Multivariable analyses were performed to adjust for clinicopathologic factors.

Results

Of 764 samples, 538 (70.4%), including 140 distant recurrence events, were successfully sequenced. Nineteen driver alterations were observed with 5% or greater frequency, with a mean of 4 alterations (range, 0-15) per tumor. PIK3CA mutations were the most common (49%) and were significantly associated with reduction in the risk for distant recurrence (hazard ratio [HR], 0.57; 95% CI, 0.38-0.85; P = .006). TP53 mutations (HR, 1.92; 95% CI, 1.21-3.04; P = .006), amplifications on 11q13 (HR, 2.14; 95% CI, 1.36-3.37; P = .001) and 8p11 (HR, 3.02; 95% CI, 1.88-4.84; P < .001), and increasing number of driver alterations (HR per additional alteration, 1.18; 95% CI, 1.11-1.25; P < .001) were associated with significantly greater risk. Amplifications on 11q13 and 8p11 remained significant predictors in multivariable analysis, but not PIK3CA and TP53 mutations. Patients with tumors harboring kinase or helical domain PIK3CA mutations derived significantly greater benefit from letrozole over tamoxifen than patients whose tumors did not (P interaction = .002).

Conclusions and Relevance

In ER+/HER2- postmenopausal, early-stage BC, amplifications on 11q13 and 8p11 were significantly associated with increased risk for distant recurrence and PIK3CA mutations were predictive of greater magnitude of benefit from letrozole. With these findings, DNA-based classification may aid adjuvant treatment decision making in this setting.

Trial Registration

ClinicalTrials.gov Identifier: NCT00004205.

Ki-67 (30-9) scoring and differentiation of Luminal A- and Luminal B-like breast cancer subtypes

INTRODUCTION

Ki-67 labeling index assessed by immunohistochemical assays has been shown useful in assessing the risk of recurrence for estrogen receptor (ER)-positive HER2-negative breast cancers (BC) and distinguishing Luminal A-like from Luminal B-like tumors. We aimed to assess the performance of the Ventana CONFIRM anti-Ki-67 (30-9) Rabbit Monoclonal Primary Antibody.

METHODS

We constructed a case-cohort design based on a random sample (n = 679) of all patients operated on for a first primary, non-metastatic, ER-positive, HER2-negative BC at the European Institute of Oncology (IEO) Milan, Italy during 1998-2002 and all additional patients (n = 303) operated during the same period, who developed an event (metastasis in distant organs or death due to BC as primary event) and were not included in the previous subset. Multivariable Cox proportional hazards regression with inverse subcohort sampling probability weighting was used to evaluate the risk of event according to Ki-67 (30-9) and derived intrinsic molecular subtype, using previously defined cutoff values, i.e., respectively 14% and 20%.

RESULTS

Ki-67 was < 14% in 318 patients (32.4%), comprised between 14 and 19% in 245 patients (24.9%) and ≥ 20 in 419 patients (42.7%). At multivariable analysis, the risk of developing distant disease was 1.88 (95% CI 1.20-2.93; P = 0.006) for those with Ki-67 comprised between 14 and 19%, and 3.06 (95% CI 1.93-4.84; P < 0.0001) for those with Ki-67 ≥ 20% compared to those with Ki-67 < 14%. Patients with Luminal B-like BC had an approximate twofold risk of developing distant disease (HR = 1.91; 95% CI 1.35-2.71; P = 0.0003) than patients with Luminal A-like BC defined using Ki-67 (30-9).

CONCLUSIONS

Ki-67 evaluation using the 30-9 rabbit monoclonal primary antibody was able to stratify patients with ER-positive HER2-negative BC into prognostically distinct groups. Ki-67 assessment, with strict adherence to the international recommendations, should be included among the clinically useful biological parameters for the best treatment of patients with BC.

Abstract PD2-11: Ki-67 (30-9) scoring and differentiation in Luminal A and Luminal B breast cancer subtypes

Introduction

Ki-67 labeling index is a powerful prognostic marker in breast cancer (BC). It is especially useful in assessing the risk of recurrence for estrogen receptor-positive (ER+) BC, where it may be considered a surrogate of the molecular assays for distinguishing Luminal A-like from Luminal B-like BCs. We evaluated the performance of the VENTANA anti Ki-67 (30-9) rabbit monoclonal antibody in assessing the risk of distant relapses for a large series of patients with ER+ BC treated and followed up in a single Institution.

Patients and Methods

The initial cohort (9415 patients) comprised all women operated on for early ER+, HER2-negative (HER2-) BC at the European Institute of Oncology (IEO), who did not receive neo-adjuvant treatment1. We subsequently restricted the cohort to 3986 patients operated on between 1998-2002 and for whom long-term follow-up data was available. A case-cohort was built by randomly selecting 17% of the above cohort (679 patients, including 84 with events). Additional 303 patients who developed an event (metastasis in distant organs or death due to BC as primary events) were added to this cohort.

Ki-67 was evaluated using the anti-Ki-67 (30-9) antibody (Ventana Medical Systems, Inc., Tucson, AZ) using OptiView IHC DAB detection on the BenchMark ULTRA advanced staining platform. The stained slides were evaluated using the scoring method described by the International Ki-67 in BC Working Group.

We considered “Luminal A-like” tumors that were ER+, HER2-, with Ki-67 &lt;14% or with Ki-67 14-19% and PgR ≥20%, and “Luminal B-like” ER+, HER2- tumors with Ki-67 14-19% and PgR &lt;20% or with Ki-67 ≥20%1.

The main outcome was distant disease-free survival (DDFS) and was calculated from the date of surgery to the date of any first event or last contact with the patient.

Cumulative incidence curves were drawn for patients in the sub-cohort and differences between BC subtypes were assessed using the log-rank test. Multivariable Cox regression with inverse sub-cohort sampling probability weighting was used to evaluate the risk of metastasis or death from BC across groups.

Results

In the sub-cohort, 400 (58.9%) patients had “luminal A-like” and 279 (41.1%) “luminal B-like” BC. The 10-year cumulative incidence of distant metastasis (or BC related death as first event) in the two groups were respectively 8.2% and 24.5% (log rank P&lt;0.0001)

In the whole case-cohort, multivariable analysis confirmed statistically significant increased risk of events for women with “Luminal B-Like” BC compared to women with “Luminal A-Like “BC (HR=1.97; 95% CI 1.38-2.79), after adjustment for pT, pN, PVI and menopausal status.

Conclusion

Ki-67 evaluated using the VENTANA anti-Ki67 (30-9) antibody, was able to stratify patients with endocrine responsive BC, maximizing the number of those classified as having 'Luminal A-like' intrinsic subtype for whom the use of cytotoxic drugs could be at large avoided.

Funding source: Ventana Medical Systems, Inc.

References

Maisonneuve P, Disalvatore D, Rotmensz N, et al. (2014) Proposed new clinicopathological surrogate definitions of luminal A and luminal B (HER2-negative) intrinsic breast cancer subtypes. Breast Cancer Res 16:R65

Citation Format: Viale G, Hanlon Newell AE, Walker E, Bai I, Russo L, Dell'Orto P, Maisonneuve P. Ki-67 (30-9) scoring and differentiation in Luminal A and Luminal B breast cancer subtypes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD2-11.

Plasma Cell Granuloma of the Lung (Inflammatory Pseudotumor)

A case of plasma cell granuloma (PCG) of the lung in a 54-year old man is reported. PCG is a rare benign lesion that usually presents as a solitary nodule in the lung (coin lesion) at routine X-ray examination. Microscopically it consists of a granulomatous tissue where the major components are mature plasma cells. The immunohistochemical demonstration of poly-clonality of plasma cells, excluding the diagnosis of plasmacytoma, confirms the inflammatory pseudotumoral nature of this lesion, although the etiology remains obscure. The presence of lymphocytes, histiocytes, macrophages, blood vessels with prominent endothelial cells and peripheral sclero-hyalinized connective tissue may pose problems in the differential diagnosis, with sclerosing hemangioma, pseudolymphoma, nodular amyloidosis, pulmonary hyalinizing granuloma, chronic abscess and neoplasms of true histiocytic origin. The term inflammatory pseudotumor is preferable in describing this type of lesion.

Sensitive and affordable diagnostic assay for the quantitative detection of anaplastic lymphoma kinase (ALK) alterations in patients with non-small cell lung cancer

Accurate detection of altered anaplastic lymphoma kinase (ALK) expression is critical for the selection of lung cancer patients eligible for ALK-targeted therapies. To overcome intrinsic limitations and discrepancies of currently available companion diagnostics for ALK, we developed a simple, affordable and objective PCR-based predictive model for the quantitative measurement of any ALK fusion as well as wild-type ALK upregulation. This method, optimized for low-quantity/-quality RNA from FFPE samples, combines cDNA pre-amplification with ad hoc generated calibration curves. All the models we derived yielded concordant predictions when applied to a cohort of 51 lung tumors, and correctly identified all 17 ALK FISH-positive and 33 of the 34 ALK FISH-negative samples. The one discrepant case was confirmed as positive by IHC, thus raising the accuracy of our test to 100%. Importantly, our method was accurate when using low amounts of input RNA (10 ng), also in FFPE samples with limited tumor cellularity (5-10%) and in FFPE cytology specimens. Thus, our test is an easily implementable diagnostic tool for the rapid, efficacious and cost-effective screening of ALK status in patients with lung cancer.

Abstract PD7-01: Can surrogate pathological subtyping replace molecular subtyping? Outcome results from the MINDACT trial

Background

Molecular subgroups within early breast cancer (EBC), such as Luminal A, Luminal B, HER-2+, Basal-like may help to best to identify patients for specific treatment regimens. Controversy exists as to which methodology is best at identifying these molecular subgroups. Immunohistochemistry (IHC) may be used as a surrogate method to stratify patients. Molecular subtyping gene expression based tests, such as BluePrint, measure a greater number of genes than pathological criteria. ER, PgR, HER-2 and Ki67 are measured individually at the protein level, while BluePrint is designed to capture the functional underlying biologic pathway regulated by these receptors.

Methods

The MINDACT trial is an international, prospective, randomized, phase III trial which has proventhe clinical utility of MammaPrint in selecting EBC patients who can safely avoid chemotherapy. Here we present the results of a preplanned MINDACT sub-study to compare outcome based on molecular subtyping (MS) to surrogate pathological subtyping (PS) as endorsed by 2013 St. Gallen Consensus. MS data were obtained by MammaPrint (MP) and BluePrint classifying patients in the following subtypes: Luminal A (MP Low Risk); Luminal B (MP High Risk); HER2-type; and Basal-type. ER, PgR, HER2 and Ki67 protein status were centrally assessed by IHC/FISH. The primary hypothesis was that among PS Luminal patients, patients with HER-2+ or Basal-type tumors by MS would have a decreased DMFS compared to MS Luminal patients. At α=5% with 220 events, the study has 80% power to demonstrate this for HR=2.44.

Results

The table depicts classification of tumors according to PS versus MS for all patients (n=5,806).

PS versus MSMSPSLum ALum BHER-2+BasalTotalLum A24562708132747Lum B106979422861971HER-2 enriched1189531826557TN14107500531Total365711693556255806

Most pronounced differences: MS classified 54% as Luminal A among the Luminal B by PS. MS classified 38% as Luminal (A and B) and 5% as Basal-type among the HER-2+ by PS. MS classified 5% as Luminal (A and B) among the TN cases by PS.

MS identifies 63% of patients as Luminal A, while PS identifies 47%; 5yr DMFS for both methods was ≥ 96.0%.

PS Luminal cancers that were classified as HER-2+ or Basal-type by MS had a lower 5yr DMFS (88.0% for HER-2+ and 90.2% for Basal), albeit non-significant, than those who were also Luminal by MS (95.9%): HR= 1.40, 95% CI = 0.75-2.60.

In PS TN cancers, MS identified 24 out of 500 patients (5%) as Luminal-type with excellent prognosis (5yr DMFS of 100% versus 71.4% for MS HER-2+ or 90.1% for MS Basal-type).

Among the PS Luminal patients, Ki67 cut at 20% identified patients with ki67 low (69%), with 5yr DMFS ≥ 96.0% (better compared to the 14% cut-off).

Conclusions

1) MS was able to re-stratify 16% of patients to a low risk Luminal A-type group with an excellent outcome. 2) Among TN EBC, 5% were classified as Luminal by MS and had an excellent outcome. 3) Albeit limited by low numbers of patients in each subgroup, this study suggest that MS is better correlated with outcome. 4) The observed subtype discrepancies may have an impact on treatment decision making. 5) Centrally assessed Ki67 labeling index of 20% may be the best cut-off for surrogate differentiation between Luminal A and B.

Citation Format: Cardoso F, Slaets L, de Snoo F, Bogaerts J, van 't Veer LJ, Rutgers EJ, Piccart-Gebhart MJ, Stork-Sloots L, Russo L, Dell'Orto P, Viale G. Can surrogate pathological subtyping replace molecular subtyping? Outcome results from the MINDACT trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD7-01.

The Genomic Grade Assay Compared With Ki67 to Determine Risk of Distant Breast Cancer Recurrence

IMPORTANCE

The Genomic Grade Index (GGI) was previously developed, evaluated on frozen tissue, and shown to be prognostic in early breast cancer. To test the GGI in formalin-fixed, paraffin-embedded breast cancer tumors, a quantitative reverse transcriptase polymerase chain reaction assay was developed and named the Genomic Grade (GG). The GG assay has the potential to increase the clinical application of the GGI, but robust demonstration of the clinical validity of the GG assay is required.

OBJECTIVE

To evaluate the prognostic ability of the GG assay to detect breast cancer recurrence compared with centrally reviewed immunohistochemical testing of Ki67 antigen proliferation.

DESIGN, SETTING, AND PARTICIPANTS

This is an internationally collaborative substudy of a large phase 3 4-arm adjuvant trial. Patients had endocrine receptor-positive, node-positive, or node-negative nonmetastatic primary breast cancer. Patients included in this study had available formalin-fixed, paraffin-embedded samples of their primary tumors and were randomized to either a 5-year tamoxifen monotherapy arm or a 5-year letrozole monotherapy arm. Associations between either GG assay results or log2-transformed Ki67 data and survival end points were evaluated using Cox regression models stratified for chemotherapy use; the 2 vs 4 arm randomization option; and endocrine therapy assignment with and without adjustment for clinicopathological parameters, including centrally reviewed histological grade, hormone receptors, and ERBB2 (formerly HER2 or HER2/neu). The likelihood ratio statistic was used to assess the added prognostic value.

INTERVENTIONS

Central evaluation and comparison, blinded for clinical information, of the GG assay, breast cancer histological grade, and Ki67.

MAIN OUTCOMES AND MEASURES

Distant recurrence-free interval (DRFI).

RESULTS

Genomic Grade assay data were obtained in 883 breast cancer samples (62%). At a median follow-up of 8.1 years, 84 (10%) had distant recurrences. Increasing GG or Ki67 were both significantly associated with lower DRFI and added independent prognostic information to the clinicopathological prognostic factors. In patients with early node-negative breast cancer who were endocrine-only treated, 38% were GG1 with a 10-year DRFI of 99% (95% CI, 97%-100%), and 18% were histological grade 1 with a 10-year DRFI of 100% (95% CI, 100%-100%). For GG equivocal patients, the 10-year DRFI was 94% (95% CI, 90%-98%), and for GG3 patients, the 10-year DRFI was 87% (95% CI, 80%-94%).

CONCLUSIONS AND RELEVANCE

Either the GG assay or centrally reviewed Ki67 significantly improves clinicopathological models to determine distant recurrence of breast cancer. Compared with the histological grade, the GG assay can identify a higher proportion of endocrine-only treated patients with very low risk of distant recurrence at 10 years.

TRIAL REGISTRATION

clinicaltrials.gov Identifiers: NCT00004205 and NCT00004205.

Assessment of HER2 amplification status in breast cancer using a new automated HER2 IQFISH pharmDx™ (Dako Omnis) assay

In breast cancer the human epidermal growth factor receptor 2 (HER2) is an important target for a number of different HER2 inhibitors. Different slide-based assays are available for assessment of treatment eligibility, which include fluorescence in situ hybridization (FISH) or other in situ hybridization (ISH) methods for assessment of the HER2 gene status. Here we report a summary of the validation data on HER2 IQFISH pharmDx™ (Dako Omnis), a newly developed assay for the automated staining platform Dako Omnis. The assay uses a non-toxic buffer that significantly reduces the hybridization time, which results in a total turnaround time of 3½ to 4h from deparaffinization to counting of the gene and centromere signals. The data reported in the current summary covers method comparison, assessment of staining quality, observer-to-observer reproducibility as well as reproducibility within and between laboratories. Based on data from the different studies it was concluded that HER2 IQFISH pharmDx (Dako Omnis) is a reliable and robust assay with a high precision that is at least comparable to the manual HER2 IQFISH pharmDx™ assay and the PathVysion(®)HER-2 DNA Probe Kit.

Analysis of HER2 status in gastroesophageal tumor specimens using a new automated HER2 IQFISH pharmDx™ (Dako Omnis) assay

The human epidermal growth factor receptor 2 (HER2) is an important target for treatment of gastroesophageal cancer. Different slide-based assays are available for assessment of HER2 status. Overexpression of the HER2 protein is assessed by immunohistochemistry (IHC) whereas amplification of the HER2 gene is assessed by fluorescence in situ hybridization (FISH) or other in situ hybridization (ISH) methods. Here we report a summary of the validation data on HER2 IQFISH pharmDx™ (Dako Omnis), a newly developed assay for the automated staining platform Dako Omnis. This assay uses a non-toxic buffer that significantly reduces the hybridization time, which results in a total turnaround time of less than 4 hours from deparaffinization to counting of the gene and centromere signals. The data reported in the current summary cover method comparison, assessment of staining quality, observer-to-observer reproducibility as well as reproducibility within and between laboratories. Based on data from the different studies it was concluded that HER2 IQFISH pharmDx (Dako Omnis) is a reliable and robust assay, with high precision and at least comparable to the manual HER2 IQFISH pharmDx™ assay. The HER2 IQFISH pharmDx (Dako Omnis) assay is currently not commercially available outside the Europe Union.

Abstract P5-07-02: Systematic analysis and modulation of Ki67 interobserver variance in 9069 patients from three clinical trials – How much pathologist concordance is needed for meaningful biomarker results?

Background: Ki67 has been suggested as a marker for diagnosis of luminal A and B breast carcinomas. Interestingly, on one hand a multitude of studies have described significant results for Ki67 as a prognostic marker, while on the other hand the analytical validation and standardization of this marker has been a challenge. The best parameter for Ki67 interobserver performance is the interclass correlation coefficient (ICC). ICC values between 0.59 and 0.92 have been reported. Recently a minimum ICC of 0.8 has been suggested as a goal for the international ring trial and as a prerequisite for introduction of Ki67 into clinical practice. However, this suggested ICC is not derived from analysis of data, and the amount of pathologist variance that is allowed for meaningful biomarker results is still not defined.

Methods: This study is based on a total of 9069 tumor samples from three large clinical cohorts (IBCSG VIII+IX, BIG1-98, and GeparTrio). In a systematic modeling approach, we introduced different amounts of variance to previously generated central pathology Ki67 datasets by simulation of a total of 1800 different pathologist evaluations for each study cohort. These evaluations were grouped into groups with defined ICCs, ranging from very good concordance (ICC=0.9) to extremely poor concordance (ICC=0.1). For each of the simulated pathologist evaluations, all possible Ki67 cutoffs were systematically evaluated using the web-based software Cutoff Finder (http://molpath.charite.de/cutoff/). As endpoints, we used DFS for all three study cohorts as well as pCR for the neoadjuvant cohort.

Results: For the neoadjuvant GeparTrio study, the different groups with ICCs of 0.8, 0.6 and 0.4 showed a very similar performance resulting in significant analyses for prediction of pCR across a wide range of cutoffs. The odd ratios for pCR were slightly lower with lower ICC. Even with an extremely low ICC of 0.2, 99% of the analyses had one or more significant cutpoints.

The survival endpoint DFS was shown to be very stable despite increased interpathologist variance in all three clinical cohorts. Even with a poor ICC of 0.4, the majority of cutpoints were significant for DFS. For IBCSG VIII+IX 85% of the analyses with an ICC of 0.4 had one or more significant cutpoints for Ki67. In the large BIG 1-98 dataset (n=6090) even an ICC of 0.2 resulted in one or more significant DFS cutpoints in 100% of the analyses. Comparable results were obtained if the analysis was restricted to luminal tumors.

Conclusion: Our results suggest that Ki67 is extremely robust to pathologist variation. Even if less than 40% of the variance is attributable to true Ki67-based proliferation (ICC&lt;0.4), this percentage of information is sufficient to obtain statistically significant differences. This stable performance of Ki67 might provide an explanation for the observation that many Ki67 studies achieve significant results despite the interobserver variance and heterogeneity issues. It might also suggest a relevant clinical utility for Ki67 despite considerable variation introduced in the evaluation. Ongoing efforts to further reduce interobserver variability, however, should be continued.

Citation Format: Denkert C, Budczies J, Regan M, Loibl S, Dell'Orto P, von Minckwitz G, Mastropasqua M, Mehta K, Müller V, Kammler R, Pfitzner BM, Fasching PA, Viale G. Systematic analysis and modulation of Ki67 interobserver variance in 9069 patients from three clinical trials – How much pathologist concordance is needed for meaningful biomarker results?. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-07-02.

Abstract P1-01-16: Performance evaluation of two ready-to-use antibodies under development for the Dako Omnis automated staining platform on breast carcinoma specimens: Anti-estrogen receptor α clone EP1 and anti-progesterone receptor clone PgR 1294

Background: The expression of estrogen receptor alpha (ERα) and progesterone receptor (PR) in breast carcinomas is a strong predictor of the efficacy of hormonal therapy for breast cancer patients as well as providing a degree of prognostic information. Anti-ERα (clone EP1) and anti-PR (clone PgR 1294) configured as FLEX ready-to-use antibodies have been tested on the Dako Omnis automated staining platform. These products are in performance evaluation and are not commercially available. A series of concordance studies were performed to evaluate the performance characteristics of these monoclonal antibodies on breast cancer tissue specimens: anti-ERα clone EP1/Dako Omnis was compared to (a) anti-ERα clone EP1/Autostainer Link 48 (238 specimens) and to (b) anti-ERα clone SP1/Autostainer (116 specimens), and anti-PR clone PgR 1294/Dako Omnis was compared to (a) anti-PR clone PgR 636/Autostainer Link 48 (289 specimens) and to (b) anti-PR clone 16 (Leica Biosystems, Newcastle, UK) (144 specimens). In addition, the specificity of the ER and PR antibodies for Dako Omnis was evaluated on a set of normal tissue specimens.

Methods: Formalin-fixed, paraffin-embedded (FFPE) human breast carcinoma specimens and normal tissues were obtained from commercial providers or local hospitals. The specimens had no associated personal information and were not traceable back to the tissue donors. Tissue pretreatment and immunohistochemical staining were performed using the recommended protocol for each antibody and staining platform. The stained slides were evaluated for nuclear ER or PR expression according to ASCO/CAP guidelines (≥1% cut-off for positive) by pathologists who were blinded from the staining method and specimen ID. The concordance studies included breast cancer specimens covering the clinical range of ER or PR expression with approximately half the specimens in the negative (&lt;1%) category, and at least 10% of the specimens in the weakly positive (≥1 ≤10%) category in each study. Two-sided Wilson Score 95% Confidence Intervals were calculated using JMP software (SAS Institute, USA). For the analytical specificity studies the presence or absence of specific staining in the various normal tissue types was recorded.

Results: High concordance rates were observed with both anti-ERα clone EP1/Dako Omnis and anti-PR clone PgR 1294/Dako Omnis compared to the other ER/PR antibodies, with overall agreement rates exceeding 95% in all of the comparative studies. On a set of normal tissues, specific positive nuclear staining was observed only in tissue types known to express ERα or PR.

Conclusions: Monoclonal antibodies anti-ERα clone EP1 and anti-PR clone PgR 1294 configured as FLEX ready-to-use on Dako Omnis are sensitive and specific assays for detecting estrogen receptor and progesterone receptor in FFPE tissues. In comparison testing for assessment of hormonal receptor status on breast carcinoma specimens, anti-ERα clone EP1/Dako Omnis and anti-PR clone PgR 1294/Dako Omnis were highly concordant with commercially-available ER or PR antibodies.

Citation Format: Viale G, Dell'Orto P, Falzon M, Fält A, Hicks D, Hoff K, Jakobsen K, Jensen LB, Levy YY, McMahon L, Miller K, Russo L. Performance evaluation of two ready-to-use antibodies under development for the Dako Omnis automated staining platform on breast carcinoma specimens: Anti-estrogen receptor α clone EP1 and anti-progesterone receptor clone PgR 1294. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-01-16.

Abstract S4-06: HER2 status as predictive marker for AI vs Tam benefit: A TRANS-AIOG meta-analysis of 12129 patients from ATAC, BIG 1-98 and TEAM with centrally determined HER2

There is now significant evidence emerging from the pivotal trials of AIs versus Tamoxifen (AIOG) demonstrating the value of meta-analysis of key clinical questions. The "Trans-AIOG" group has been tasked with the exploration of key molecular/biomarker questions that are pertinent to meta-analyses of biomarkers (past/present/future) in AIOG trials. HER2 has been long proposed as a marker of endocrine "resistance". Data from three trials, before the era of HER-directed therapy, suggest a potential role for HER2 to select patients for treatment with upfront AIs. However the individual trials lack power to test treatment-by-HER2 interaction due to sample size and low HER2+ve rates. A meta-analysis of the predictive value of HER2 status, specifically within the first 3 years of endocrine therapy, has the potential to inform patient selection for upfront or sequential strategies with AIs. The pre-existing standardization of methodology for HER2 (IHC/FISH) facilitates analysis of existing data from BIG-1-98, TEAM and ATAC for this key marker.

Analysis plan: Following a prospectively-designed analysis plan, patient-level data from 3 randomized phase III trials (ATAC, BIG 1-98, TEAM) comparing AIs to tamoxifen during the first 2-3 years of adjuvant treatment were collected at the CRCTU (Birmingham UK), accounting for both the established time-dependency of relapse in HER2+ve, anti-endocrine treated patients and to address the clinical question of "upfront" vs "sequential" strategies for AIs. For each trial, covariate-adjusted Cox models estimated HER2-by-treatment (AI vs Tam) interaction on distant recurrence-free interval-censored at 2-2.75 years follow-up. A meta-analysis of the HER2-by-treatment interaction terms and of treatment effects according to HER2 status was performed.

Results: 12129 patients with centrally-confirmed ER and HER2 status, 1092 (9%) HER2+ve, with 473 (4%; 111 among HER2+ve) distant recurrences were analyzed. The meta-analysis estimated a pooled HER2-by-treatment interaction of 1.61 (95% CI 1.01,2.57), reflecting treatment effect hazard ratio(AI/Tam) of HR=1.13 (0.75,1.71) among HER2+ve and HR=0.70 (0.56,0.87) among HER2-ve. There was heterogeneity among interaction terms (I-squared=59%, p=.09) that resulted from treatment effect heterogeneity among HER2+ve subgroup (I2=71%, p=.03), not the HER2-ve subgroup (I2=0%). The results for disease-free survival were similar.

Conclusion: An individual patient data meta-analysis across 3 trials (ATAC, BIG 1-98, TEAM) conducted prior to standard use of HER2-directed adjuvant therapy demonstrated a marginally-significant interaction between HER2 status and treatment with AIs vs Tamoxifen in the 2-2.75 years prior to potential "switching" between Tamoxifen and AIs. Patients with HER2-ve cancers experienced improved outcomes when treated with AIs vs Tamoxifen whilst patients with HER+ve cancers fared no better, or slightly worse, during AI treatment. However, the small number of HER2+ve cancers and events even in this meta-analysis may explain a large degree of heterogeneity in the treatment effects within the HER2+ve subgroups across the 3 trials. Other causes, perhaps related to subtle differences between AIs, cannot be excluded.

Citation Format: Bartlett JMS, Ahmed I, Regan MM, Sestak I, Mallon EA, Dell'Orto P, Thürlimann BJK, Seynaeve C, Putter H, Brookes CL, Forbes JF, Colleoni MA, Bayani J, van de Velde CJH, Viale G, Cuzick J, Dowsett M, Rea DW, On Behalf of the Translational Aromatase Inhibitor Overview Group (Trans-AIOG). HER2 status as predictive marker for AI vs Tam benefit: A TRANS-AIOG meta-analysis of 12129 patients from ATAC, BIG 1-98 and TEAM with centrally determined HER2. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S4-06.

Predictive value and clinical utility of centrally assessed ER, PgR, and Ki-67 to select adjuvant endocrine therapy for premenopausal women with hormone receptor-positive, HER2-negative early breast cancer: TEXT and SOFT trials

The SOFT and TEXT randomized phase III trials investigated adjuvant endocrine therapies for premenopausal women with hormone receptor-positive (HR+) early breast cancer. We investigated the prognostic and predictive value of centrally assessed levels of estrogen receptor (ER), progesterone receptor (PgR), and Ki-67 expression in women with HER2-negative disease. Of 5707 women enrolled, 4115 with HER2-negative (HR+/HER2-) disease had ER, PgR, and Ki-67 centrally assessed by immunohistochemistry. Breast cancer-free interval (BCFI) was defined from randomization to first invasive local, regional, or distant recurrence or contralateral breast cancer. The prognostic and predictive values of ER, PgR and Ki-67 expression levels were assessed using Cox modeling and STEPP methodology. In this HR+/HER2- population, the median ER, PgR, and Ki-67 expressions were 95, 90, and 18 % immunostained cells. As most patients had strongly ER-positive tumors, the predictive value of ER levels could not be investigated. Lower PgR and higher Ki-67 expression were associated with reduced BCFI. There was no consistent evidence of heterogeneity of the relative treatment effects according to PgR or Ki-67 expression levels, though there was a greater 5-year absolute benefit of exemestane + ovarian function suppression (OFS) versus tamoxifen with or without OFS at lower levels of PgR and higher levels of Ki-67. Women with poor prognostic features of low PgR and/or high Ki-67 have greater absolute benefit from exemestane + OFS versus tamoxifen + OFS or tamoxifen alone, but individually PgR and Ki-67 are of limited predictive value for selecting adjuvant endocrine therapy for premenopausal women with HR+/HER2- early breast cancer.

CYP19A1 polymorphisms and clinical outcomes in postmenopausal women with hormone receptor-positive breast cancer in the BIG 1-98 trial

To determine whether CYP19A1 polymorphisms are associated with abnormal activity of aromatase and with musculoskeletal and bone side effects of aromatase inhibitors. DNA was isolated from tumor specimens of 4861 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Tumors were genotyped for six CYP19A1 polymorphisms using PCR-based methods. Associations with breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI), musculoskeletal and bone adverse events (AEs) were assessed using Cox proportional hazards models. All statistical tests were two-sided. No association between the CYP19A1 genotypes and BCFI or DRFI was observed overall. A reduced risk of a breast cancer event for tamoxifen-treated patients with rs700518 variants was observed (BCFI CC/TC vs. TT: HR 0.53, 95 % CI 0.34-0.82, interaction P = 0.08), but not observed for letrozole-treated patients. There was an increased risk of musculoskeletal AEs for patients with rs700518 variants CC/TC versus TT (HR 1.22, 95 % CI 1.03-1.45, P = 0.02), regardless of treatment. Tamoxifen-treated patients with rs4646 variants had a reduced risk of bone AEs (AA/CA vs. CC: HR 0.76, 95 % CI 0.59-0.98), whereas an increase of minor allele (C) of rs10046 was associated with an increased risk of bone AEs (HR 1.28, 95 % CI 1.07-1.52). rs936308 variants were associated with a reduced risk of bone AEs in letrozole-treated patients (GG/GC vs. CC: HR 0.73, 95 % CI 0.54-0.99), different from in tamoxifen-treated patients (GG/GC vs. CC: HR 1.32, 95 % CI 0.92-1.90, interaction P = 0.01). CYP19A1 rs700518 variants showed associations with BCFI, DRFI, in tamoxifen treated patients and musculoskeletal AEs regardless of treatment. SNPs rs4646, rs10046, and rs936308 were associated with bone AEs.

Biology of breast cancer during pregnancy using genomic profiling

Breast cancer during pregnancy is rare and is associated with relatively poor prognosis. No information is available on its biological features at the genomic level. Using a dataset of 54 pregnant and 113 non-pregnant breast cancer patients, we evaluated the pattern of hot spot somatic mutations and did transcriptomic profiling using Sequenom and Affymetrix respectively. We performed gene set enrichment analysis to evaluate the pathways associated with diagnosis during pregnancy. We also evaluated the expression of selected cancer-related genes in pregnant and non-pregnant patients and correlated the results with changes occurring in the normal breast using a pregnant murine model. We finally investigated aberrations associated with disease-free survival (DFS). No significant differences in mutations were observed. Of the total number of patients, 18.6% of pregnant and 23% of non-pregnant patients had a PIK3CA mutation. Around 30% of tumors were basal, with no differences in the distribution of breast cancer molecular subtypes between pregnant and non-pregnant patients. Two pathways were enriched in tumors diagnosed during pregnancy: the G protein-coupled receptor pathway and the serotonin receptor pathway (FDR <0.0001). Tumors diagnosed during pregnancy had higher expression of PD1 (PDCD1; P=0.015), PDL1 (CD274; P=0.014), and gene sets related to SRC (P=0.004), IGF1 (P=0.032), and β-catenin (P=0.019). Their expression increased almost linearly throughout gestation when evaluated on the normal breast using a pregnant mouse model underscoring the potential effect of the breast microenvironment on tumor phenotype. No genes were associated with DFS in a multivariate model, which could be due to low statistical power. Diagnosis during pregnancy impacts the breast cancer transcriptome including potential cancer targets.

High concordance of protein (by IHC), gene (by FISH; HER2 only), and microarray readout (by TargetPrint) of ER, PgR, and HER2: results from the EORTC 10041/BIG 03-04 MINDACT trial

BACKGROUND

To investigate the correlation of TargetPrint with local and central immunohistochemistry/fluorescence in situ hybridization assessment of estrogen (ER), progesterone (PgR), and human epidermal growth factor receptor 2 (HER2) in the first 800 patients enrolled in the MINDACT trial.

PATIENTS AND METHODS

Data from local (N = 800) and central (N = 626) assessments of receptor status were collected and compared with TargetPrint results.

RESULTS

For ER, the positive agreement (the percentage of central pathology positive assessments that were also TargetPrint/local laboratory positive) for TargetPrint in comparison to centralized assessment was 98% with a negative agreement (the percentage of central pathology negative assessments that were also TargetPrint/local laboratory negative) of 96%. For PgR, the positive agreement was 83% with a negative agreement of 92%. For HER2, the positive agreement was 75% with a negative agreement of 99%. Even though the local assessment showed higher positive agreement for PgR (89%) and higher positive agreement for HER2 (85%), the range of discordant local versus central assessments were as high as 6.7% for ER, 12.9% for PgR, and 4.3% for HER2.

CONCLUSION

TargetPrint and local assessment of ER, PgR, and HER2 show high concordance with central assessment in the first 800 MINDACT patients. However, there are concerns about the higher discordance rates for some local sites. TargetPrint can improve the reliability of hormone receptor and HER2 testing for those centers with a lower rate of concordance with the reference laboratory, with the limitation of a positive agreement of 75% for HER2. TargetPrint consequently has important implications for treatment decisions in clinical practice and is a reliable alternative to local assessment for ER.

CLINICAL TRIALS NUMBER

NCT00433589.

Abstract P3-05-02: Pathological assessment of discordant cases for molecular (BluePrint and MammaPrint) versus clinical subtypes for breast cancer among 621 patients from the EORTC 10041/BIG 3–04 (MINDACT) trial

Background: Biology has become the main driver of breast cancer therapy. Intrinsic biological subtypes by gene expression profiling have been identified. Pathology can be used to define surrogates of these subtypes but these are not always concordant, which may lead to different treatment plans. We investigated the concordance between BluePrint and MammaPrint (microarray-based) breast cancer subtypes and pathological surrogates (based on ER, PR, HER2 & Ki67).

Methods: Using available data (centrally assessed pathology and genomics) from the MINDACT pilot phase [Rutgers et al. EJC 2011] 621 tumors were analyzed. Patients were classified according to 4-category based pathology (ER, PR, HER2 and Ki67); additionally, classification was performed adhering to the recent St. Gallen recommendations [Goldhirsch et al. 2011], which recognizes an additional category (Luminal B HER2+). Based on BluePrint and MammaPrint 4 subtypes are formed: Luminal A (Luminal-type/MammaPrint Low Risk); Luminal B (Luminal-type/MammaPrint High Risk); HER2-type; and Basal-type. This study is an analysis of discordant patient groups (i.e. clinical HER2+/BluePrint Luminal-type; clinical Hormone Receptor (HR)-positive/BluePrint Basal-type) providing comparison of centrally assessed tumor heterogeneity as well as comparison of quantified ER, PR and HER2 results.

Results: Ki67 is often used as biomarker to distinguish Luminal A from Luminal B subgroups. The concordance between MammaPrint and centrally assessed Ki67 in Luminal-type patients is 71%, with a κ score of 0.35 (95% CI 0.26–0.45) indicating that Ki67 and MammaPrint cannot reliably substitute for each other. There is a relatively large group of clinical HER2+ cases that are BluePrint Luminal-type (29 out of 76; 38%) indicating that tumor expression of the Luminal profile is dominant compared with expression of the HER2 profile. These patients have high IHC ER results and fall into the group that St Gallen separately defines as Luminal B HER2-type. These patients may have lower response to trastuzumab [von Minckwitz et al. JCO 2012]. 12 out of 76 BluePrint Basal-type patients are clinical HR+. These patients have low centrally assessed IHC ER and PR expression (≥1% and &lt;10%).

Conclusions: Marked differences are observed between BluePrint and MammaPrint (microarray based) breast cancer subtypes and centrally re-assessed pathological surrogates (based on ER, PR, HER2 & Ki67). The greatest discordance is seen in the sub-stratification of Luminal patients, and in the HR+/HER2+ patients. The observed subtype discrepancies may have an important impact on treatment decision making.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-05-02.

Abstract P6-07-14: Mutational and transcriptomic characterization of breast cancer (BC) arising in young patients (pts) and during pregnancy and their associations with long-term outcome

Background: BC arising in young age is biologically distinct. Whether diagnosis during pregnancy has an impact on prognosis and tumor biology remains to be elucidated. We report for the first time mutational and transcriptomic profiling of BC arising in young pts and the impact of diagnosis during pregnancy. We also correlate these findings with clinical outcome.

Methods: 65 pts with BC during pregnancy diagnosed at the European Institute of Oncology in the period 1999–2009 were matched to 130 BC pts who were diagnosed and treated at the same period/institute. We screened for 84 somatic hotspot mutations on 17 cancer-related genes using mass spectroscopy-based sequencing (Sequenom). We evaluated the pattern of mutations in the two cohorts and according to BC subtype defined using central immunohistochemistry as follows: Luminal A (ER+, HER2−, Ki67 &lt;14%), Luminal-B (ER+, HER2−, Ki67 &gt;14%), HER2+ (HER2+ irrespective of ER), and triple negative (ER−, PgR−, HER2−). Survival endpoints included distant relapse free survival (DRFS) and overall survival (OS).

Results: Median age at diagnosis was 36 years (range: 28–47). At a median follow-up of 74 months (IQR: 42–96), 44 (23%) and 29 (15%) pts developed a DRFS and OS event respectively. Pts diagnosed during pregnancy had inferior DRFS (HR: 3.2 [1.5–6.7]) and OS (HR: 2.9 [1.1–7.9]) after adjusting for pT, pN, grade, BC subtype, and therapy. Mutational profiling was successful in 97% of pts. A total of 57 hotspot mutations (30%) were detected in 51 pts (15 [23%] pregnant and 36 [28%] controls). The differences in mutations between the two groups are summarized in the table.

Abstract PD03-01: EFFECT OF METFORMIN ON APOPTOSIS IN A PRESURGICAL TRIAL IN NON-DIABETIC PATIENTS WITH BREAST CANCER

BACKGROUND: metformin has been associated with antitumor activity in epidemiological and clinical studies. This effect has been related to different mechanisms of actions, including a reduction of the proliferative activity and an increase of apoptosis. We have recently shown that a 4 week pre-surgical treatment with metformin did not affect Ki-67 LI overall but reduced tumor proliferation Ki67 LI in breast cancer (BC) patients with insulin resistance (IR) (HOMA, fasting blood glucose (mmol/L)*insulin (mU/L)/22.5&gt;2.8) or BMI&gt;27 (Bonanni et al. JCO epub May 7, 2012). The objective of the current analysis was to determine whether metformin induced a modulation of apoptosis (TUNEL) overall and by HOMA index.

TRIAL DESIGN: After tumor biopsy we randomly allocated 200 non-diabetic women with operable breast cancer to either metformin (850 mg/bid) or placebo for 4 weeks prior to surgery. The primary outcome measure was the difference between arms in Ki-67 after 4 weeks of treatment. Here we analyzed the apoptotic cell nuclei in 88 consecutive core biopsies and their paired surgical samples from the initial 100 randomized subjects.

RESULTS: Median TUNEL levels at surgery (Metformin = 10%, IQR, 4–20, Placebo = 8%, IQR, 3–15) were significantly higher as compared with baseline (Metformin = 4%, IQR, 2–7, Placebo = 3%, IQR, 2–6, p &lt; 0.0001), but no difference between arms was noted (p = 0.2, adjusted for age, BMI, TUNEL and Ki67 at baseline). Interestingly, Ki67 and TUNEL levels were highly and positively correlated both at baseline and at surgery (Spearman r=0.51, p &lt; 0.0001). Furthermore, we found a trend to a different metformin effect by the HOMA index (p = 0.1). In the 59 women with HOMA &lt;2.8 there was a higher level of TUNEL at surgery on metformin versus placebo (p = 0.05), while an opposite trend was found in the 28 women with HOMA&gt;2.8 (p = 0.6).

CONCLUSIONS: The levels of TUNEL are significantly higher in the surgical specimens compared with baseline biopsy and are directly correlated with those of Ki-67 (TUNEL is high when Ki-67 is high). We found no significant modulation of TUNEL by metformin but a trend to a different effect according to the IR state, with a similar pattern to Ki-67: decrease by metformin in IR women and increase in non-IR women. Our findings confirm the notion that metformin has dual effects on breast cancer according to IR state. As expected, cancer apoptosis and proliferation are directly related. Our results strengthen the importance of placebo control arms in biomarker trials.

ACKNOWLEDGEMENTS: 2 Grants by AIRC and Italian Ministry of Health.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD03-01.

Comparison of molecular (BluePrint and MammaPrint) and pathological subtypes for breast cancer among the first 800 patients from the EORTC 10041/BIG 3-04 (MINDACT) trial

32

Background: Biology has become the main driver of breast cancer therapy. Intrinsic biological subtypes by gene expression profiling have been identified. Pathology can be used to define surrogates of these subtypes but these are not always concordant, which may lead to different treatment plans. We investigated the concordance between BluePrint (BP) + MammaPrint (MP) (micro array based) breast cancer subtypes and pathological surrogates (based on ER, PR, HER2 and Ki67). Contrary to the Perou gene set (evolved into PAM50), BluePrint was trained using pathological data. Methods: Using available data (centrally assessed pathology and genomic) from the MINDACT pilot phase (Rutgers et al 2011) 621 tumors were analyzed. Two pathology classifications were used: one with 4 categories and one with 5 categories (Goldhirsch et al 2011). Based on BP 3 subtypes are formed: Luminal, HER2 and Basal. The Luminal subtype is further split into Luminal A (MP low risk) and Luminal B (MP high risk). Results: See table. Conclusions: All pathological Basal cases are BP Basal, apart from 1 BP HER2 case. Of the BP Basal cases, 15 are not pathological Basal: 1 is Luminal A, 11 are Luminal B (of which 8 are IHC ER/PR borderline (≥1% and < 10%)) and 3 are HER2. All pathological Luminal (A & B) that are BP HER2 are HER2- by TargetPrint. 25 of the 26 pathological HER2+ that are BP Luminal A are ER+. Most discordant cases are seen within the Luminal subtype, indicating that Ki67 discriminates Luminal A vs. B differently than MammaPrint does. The observed subtype discrepancies reveal potential important impact for treatment-decision making. MINDACT will provide important information. [Table: see text]

Comparison of molecular (BluePrint+MammaPrint) and pathological subtypes for breast cancer among the first 800 patients from the EORTC 10041/BIG 3-04 (MINDACT) trial

1022

Background: Biology has become the main driver of breast cancer therapy. Intrinsic biological subtypes by gene expression profiling have been identified. Pathology can be used to define surrogates of these subtypes but these are not always concordant, which may lead to different treatment plans. We investigated the concordance between BluePrint (BP) + MammaPrint (MP) (micro array based) breast cancer subtypes and pathological surrogates (based on ER, PR, HER2, and Ki67). Contrary to the Perou gene set (evolved into PAM50), BluePrint was trained using pathological data. Methods: Using available data (centrally assessed pathology and genomic) from the MINDACT pilot phase (Rutgers et al 2011) 621 tumors were analyzed. Two pathology classifications were used: one with 4 categories and one with 5 categories (Goldhirsch et al 2011). Based on BP 3 subtypes are formed: Luminal, HER2 and Basal. The Luminal subtype is further split into Luminal A (MP low risk) and Luminal B (MP high risk). Results: See table. Conclusions: All pathological Basal cases are BP Basal, apart from 1 BP HER2 case. Of the BP Basal cases, 15 are not pathological Basal: 1 is Luminal A, 11 are Luminal B (of which 8 are IHC ER/PR borderline (≥1% and < 10%)) and 3 are HER2. All pathological Luminal (A & B) that are BP HER2 are HER2- by TargetPrint. 25 of the 26 pathological HER2+ that are BP Luminal A are ER+. Most discordant cases are seen within the Luminal subtype, indicating that Ki67 discriminates Luminal A vs. B differently than MammaPrint does. The observed subtype discrepancies reveal potential important impact for treatment-decision making. MINDACT will provide important information. [Table: see text]

Prognostic and predictive value of TP53 mutations in node-positive breast cancer patients treated with anthracycline- or anthracycline/taxane-based adjuvant therapy: results from the BIG 02-98 phase III trial

INTRODUCTION

Pre-clinical data suggest p53-dependent anthracycline-induced apoptosis and p53-independent taxane activity. However, dedicated clinical research has not defined a predictive role for TP53 gene mutations. The aim of the current study was to retrospectively explore the prognosis and predictive values of TP53 somatic mutations in the BIG 02-98 randomized phase III trial in which women with node-positive breast cancer were treated with adjuvant doxorubicin-based chemotherapy with or without docetaxel.

METHODS

The prognostic and predictive values of TP53 were analyzed in tumor samples by gene sequencing within exons 5 to 8. Patients were classified according to p53 protein status predicted from TP53 gene sequence, as wild-type (no TP53 variation or TP53 variations which are predicted not to modify p53 protein sequence) or mutant (p53 nonsynonymous mutations). Mutations were subcategorized according to missense or truncating mutations. Survival analyses were performed using the Kaplan-Meier method and log-rank test. Cox-regression analysis was used to identify independent predictors of outcome.

RESULTS

TP53 gene status was determined for 18% (520 of 2887) of the women enrolled in BIG 02-98. TP53 gene variations were found in 17% (90 of 520). Nonsynonymous p53 mutations, found in 16.3% (85 of 520), were associated with older age, ductal morphology, higher grade and hormone-receptor negativity. Of the nonsynonymous mutations, 12.3% (64 of 520) were missense and 3.6% were truncating (19 of 520). Only truncating mutations showed significant independent prognostic value, with an increased recurrence risk compared to patients with non-modified p53 protein (hazard ratio = 3.21, 95% confidence interval = 1.740 to 5.935, P = 0.0002). p53 status had no significant predictive value for response to docetaxel.

CONCLUSIONS

p53 truncating mutations were uncommon but associated with poor prognosis. No significant predictive role for p53 status was detected.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00174655.

P1-07-06: High Concordance of Protein (by IHC), Gene (by FISH; HER-2 Only) and Microarray Readout (by TargetPrint) of ER/PR/HER2: Results from the MINDACT Trial

Background

Previously, the micro-array readout of ER, PR and HER2 by TargetPrint was shown to be strongly correlated with high quality immunohistochemistry (IHC)/FISH assessment, especially for ER and HER2. Concordance rates were 93% (k=0.79) for ER; 83% (k=0.65) for PR and 96% for HER2 (k=0.88) in 636 patients (Roepman et al., Clin Cancer Res, 2009).

This study analysis was undertaken to further determine the correlation of microarray readout with IHC/FISH assessment both locally and centrally determined in the 1st 800 pts enrolled in the MINDACT trial. This work is essential to determine the quality of biological data in the two risk assessment methods used in MINDACT based upon which adjuvant chemotherapy decision is made, in order to exclude bias.

Methods: ER/PR/HER2 IHC assessment was performed on the 1st 800 primary breast cancers (BC) of pts enrolled in the MINDACT study. The assessment was performed locally at each center (n=800) and by central review at the laboratory of the European Institute of Oncology (n=626). A tumor was classified positive for ER and PR when 1% of tumor cells showed positive staining. HER2 IHC status was scored as 0, 1+, 2+ or 3+; a score of 3+ was considered positive. In 2+ cases FISH was performed to assess final HER2 status. Gene expression data for ER, PR and HER2 were obtained by TargetPrint stratified as receptor positive or negative using previously determined and validated thresholds for ER, PR and HER2 mRNA levels (n=800).

Results: Comparison of local assessment (IHC & FISH for HER2) with central review indicated highly similar results for receptor readout with a concordance of 98% (k=0.90) for ER; and 96% for HER2 (k=0.80) and slightly lower for PR (90% (k=0.72)).

Comparison of central assessment (IHC & FISH for HER2) with micro array readout by TargetPrint indicated highly similar results for receptor readout with a concordance of 97% (k=0.88) for ER and 95% for HER2 (k=0.76). For PR the concordance was lower but still quite acceptable (85% (k=0.62)).

Conclusion: Local and centrally assessed ER, PR and HER2 status in the first 800 MINDACT patient samples indicate a high level of quality for pathology in the local participating hospitals. These results exclude any bias induced by a lower quality of “traditional” pathology results as compared to the centrally assessed MammaPrint, both used for risk assessment and adjuvant chemotherapy decision in the MINDACT trial. The microarray-based assessment of ER, PR and HER2 gives results comparable to IHC & FISH and provides an objective and quantitative assessment of tumor receptor status. These results indicate that TargetPrint can serve as a second pathology assessment for locally assessed parameters, especially since TargetPrint is part of a multi-profile platform for breast cancer treatment management. This work was funded by the Breast Cancer Research Foundation and the EU Framework Program VI.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-07-06.

Which patients benefit most from adjuvant aromatase inhibitors? Results using a composite measure of prognostic risk in the BIG 1-98 randomized trial

BACKGROUND

On average, aromatase inhibitors are better than tamoxifen when used as initial or sequential therapy for postmenopausal women with endocrine-responsive early breast cancer. Because there may be contraindications to their use based on side-effects or cost, we investigated subgroups in which aromatase inhibitors may be more or less important.

PATIENTS AND METHODS

Breast International Group 1-98 trial randomized 6182 women among four groups comparing letrozole and tamoxifen with sequences of each agent; 5177 (84%) had centrally confirmed estrogen receptor (ER) positivity. We assessed whether centrally determined ER, progesterone receptor (PgR), human epidermal growth factor receptor 2, and Ki-67 labeling index, alone or in combination with other prognostic features, predicted the magnitude of letrozole effectiveness compared with either sequence or tamoxifen monotherapy.

RESULTS

Individually, none of the markers significantly predicted differential treatment effects. Subpopulation treatment effect pattern plot analysis of a composite measure of prognostic risk revealed three patterns. Estimated 5-year disease-free survival for letrozole monotherapy, letrozole→tamoxifen, tamoxifen→letrozole, and tamoxifen monotherapy were 96%, 94%, 93%, and 94%, respectively, for patients at lowest risk; 90%, 91%, 93%, and 86%, respectively, for patients at intermediate risk; and 80%, 76%, 74%, and 69%, respectively, for patients at highest risk.

CONCLUSION

A composite measure of risk informs treatment selection better than individual biomarkers and supports the choice of 5 years of letrozole for patients at highest risk for recurrence.

Abstract P3-02-13: Is HER2 Evaluation with the CellSearch System a Method Reliable for Detecting HER2 Overexpression?

Background. Circulating tumor cells (CTCs) detected in patients with both localized and metastatic breast cancer are significantly associated with a worse outcome. In addition to enumeration, an exciting area of CTC research involves the phenotyping and expression profiling of CTCs. In this regard, in patients with metastatic breast cancer, the evaluation of CTCs could be considered as a “real-time” biopsy allowing the detection of possible changes in tumor phenotype, such as a shift in patients HER2- negative on the primary tumor to HER2-positive CTCs. This could be of relevance as these patients may become suitable to targeted anti-HER2 therapy. Currently, there is no standardized and widely accepted method available for the determination of HER2 status on CTC. Aims. Objectives of this study were: 1. verifying the feasibility and reliability of HER2 determination on cells from scraping of breast cancer tissue by FISH analysis, 2. evaluating the concordance of HER2 status determined on primary breast tumor by immunohistochemistry (IHC) and on scraped cells, obtained from the same breast tumor and spiked in blood from healthy subjects, using the CellSearch System, and finally 3. evaluating the concordance of HER2 expression determinated by FISH analysis and by CellSearch on the same scraped cells. Methods. Cells from scraping of fresh breast cancer tissues with different level of HER2 expression were spiked in 18 healthy subjects blood samples. The determination of the HER2 expression on these cells was performed with the CellSearch System (Veridex, USA) by the addition of a fluorescein conjugated monoclonal antibody to be used in conjunction with the CellSearch™ Epithelial Cell Kit to phenotype CTCs for the presence of HER-2/neu. The HER2 characterisation of the primary breast tumors was performed by IHC by FISH analysis according to standard procedures. FISH was also performed on cells from scraping of fresh breast cancer tissues after CellSearch enumeration and characterization, by removing them from the “MagNest” cartridge. Tumors with a score of 3+ were considered positive.

Results. The results of the FISH analysis performed on the cells aspirated from the cartridge demonstrated a 100% concordance with the FISH performed on fresh tissue (9 not amplified and 9 amplified). The evaluation of HER2 expression on scraped cells by CellSearch System and by IHC on the corresponding tumor showed that the CellSearch method is reliable in identifying HER2 overexpression, as in all the 3+ tumors it was possible to detect variable percentage of scraped cells overexpressing HER2. Finally, different number of HER2+ scraped cells were found in 16 out of the 18 samples: the only 2 negative samples were both IHC negative and FISH not amplified. On the contrary 2 of the 4 remaining negative/1+ IHC samples, showed some scraped cells HER2+ which resulted FISH amplified. Conclusion. This study demonstrates that FISH analysis is feasible and the results are reliable when performed on cells after CellSearch procedure. Moreover HER2 expression may be evaluated with the CellSearch System and it may be used as a preliminary method to indicate possibly HER2 positive samples which may be confirmed by FISH analysis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-02-13.

Prognostic and predictive value of centrally reviewed Ki-67 labeling index in postmenopausal women with endocrine-responsive breast cancer: results from Breast International Group Trial 1-98 comparing adjuvant tamoxifen with letrozole

PURPOSE

To evaluate the prognostic and predictive value of Ki-67 labeling index (LI) in a trial comparing letrozole (Let) with tamoxifen (Tam) as adjuvant therapy in postmenopausal women with early breast cancer.

PATIENTS AND METHODS

Breast International Group (BIG) trial 1-98 randomly assigned 8,010 patients to four treatment arms comparing Let and Tam with sequences of each agent. Of 4,922 patients randomly assigned to receive 5 years of monotherapy with either agent, 2,685 had primary tumor material available for central pathology assessment of Ki-67 LI by immunohistochemistry and had tumors confirmed to express estrogen receptors after central review. The prognostic and predictive value of centrally measured Ki-67 LI on disease-free survival (DFS) were assessed among these patients using proportional hazards modeling, with Ki-67 LI values dichotomized at the median value of 11%.

RESULTS

Higher values of Ki-67 LI were associated with adverse prognostic factors and with worse DFS (hazard ratio [HR; high:low] = 1.8; 95% CI, 1.4 to 2.3). The magnitude of the treatment benefit for Let versus Tam was greater among patients with high tumor Ki-67 LI (HR [Let:Tam] = 0.53; 95% CI, 0.39 to 0.72) than among patients with low tumor Ki-67 LI (HR [Let:Tam] = 0.81; 95% CI, 0.57 to 1.15; interaction P = .09).

CONCLUSION

Ki-67 LI is confirmed as a prognostic factor in this study. High Ki-67 LI levels may identify a patient group that particularly benefits from initial Let adjuvant therapy.

Epidermal growth factor receptor serum (sEGFR) level may predict response in patients with EGFR-positive advanced colorectal cancer treated with gefitinib?

PURPOSE

Epidermal growth factor receptor-overexpression reported in colorectal cancer, justifies therapeutic use of EGFR-inhibitors. We have recently conducted a phase II study in 57 patients with EGFR-positive advanced colorectal cancer (ACC) who received gefitinib-FOLFOX6 followed by gefitinib-single agent as maintenance. Main biological objective was to assess sEGFR as surrogate marker of tyrosine kinase inhibition and as predictor of response.

METHODS

sEGFR, evaluated by quantitative ELISA, was investigated as predictive factor both taking into account the basal value only, and its whole pattern over time. sEGFR was collected at baseline and at every 2-months assessment in 42 cases. Thirty-three patients reported CR/PR as best objective response (BOR), while nine showed SD/PD.

RESULTS

Retrospectively, on average, the sEGFR values reported by both responders (CR/PR) and not responders (SD/PD) were already different at baseline (49.4 +/- 6.2 and 42.4 +/- 8.4 ng/ml respectively). This difference was statistically significant (p = 0.042). Although sEGFR trend over time confirmed the basal difference (p = 0.032), this result should be taken with caution, due to the small number of patients reporting EGFR values besides the basal one.

CONCLUSIONS

Higher sEGFR at baseline was associated to BOR and may be considered a significant predictor of outcome in patients with ACC.

Adjuvant letrozole versus tamoxifen according to centrally-assessed ERBB2 status for postmenopausal women with endocrine-responsive early breast cancer: supplementary results from the BIG 1-98 randomised trial

BACKGROUND

The Breast International Group (BIG) 1-98 trial (a randomised double-blind phase III trial) has shown that letrozole significantly improves disease-free survival (DFS) compared with tamoxifen in postmenopausal women with endocrine-responsive early breast cancer. Our aim was to establish whether the benefit of letrozole versus tamoxifen differs according to the ERBB2 status of tumours.

METHODS

The BIG 1-98 trial consists of four treatment groups that compare 5 years of monotherapy with letrozole or tamoxifen, and sequential administration of one drug for 2 years followed by the other drug for 3 years. Our study includes data from the 4922 patients randomly assigned to the two monotherapy treatment groups (letrozole or tamoxifen for 5 years; 51 months median follow-up [range <1 to 90 months]). A central assessment of oestrogen receptor (ER), progesterone receptor (PgR) and ERBB2 status using paraffin-embedded primary tumour material was possible for 3650 (74%) patients. ER, PgR, and ERBB2 expression were measured by immunohistochemistry (IHC) and ERBB2-positivity was confirmed by fluorescence in-situ hybridisation (FISH). Positive staining in at least 1% of cells was considered to show presence of ER or PgR expression. Tumours were deemed ERBB2-positive if amplified by FISH, or, for the few tumours with unassessable or unavailable FISH results, if they were IHC 3+. Hazard ratios (HR) estimated by Cox modelling were used to compare letrozole with tamoxifen for DFS, which was the primary endpoint, and to assess treatment-by-covariate interactions. The BIG 1-98 trial is registered on the clinical trials site of the US National Cancer Institute website http://www.clinicaltrials.gov/ct/show/NCT00004205.

FINDINGS

By central assessment 7% (257 of 3650) of tumours were classified as ERBB2-positive. In 3533 patients with tumours confirmed to express ER, DFS was poorer in patients with ERBB2-positive tumours (n=239) than in those with ERBB2-negative tumours (n=3294; HR 2.09 [95% CI 1.59-2.76]; p<0.0001). There was no statistical evidence of heterogeneity in the treatment effect according to ERBB2 status of the tumour (p=0.60 for interaction), thus, letrozole improves DFS compared with tamoxifen regardless of ERBB2 status. The observed HRs were 0.62 (95% CI 0.37-1.03) for ERBB2-positive tumours and 0.72 (0.59-0.87) for ERBB2-negative tumours.

INTERPRETATION

A benefit of letrozole over tamoxifen was noted, irrespective of ERBB2 status of the tumour, and, therefore, ERBB2 status does not seem to be a selection criterion for treatment with letrozole versus tamoxifen in postmenopausal women with endocrine-responsive early breast cancer.

Prognostic and predictive value of centrally reviewed expression of estrogen and progesterone receptors in a randomized trial comparing letrozole and tamoxifen adjuvant therapy for postmenopausal early breast cancer: BIG 1-98

PURPOSE

To evaluate locally versus centrally assessed estrogen (ER) and progesterone (PgR) receptor status and the impact of PgR on letrozole adjuvant therapy compared with tamoxifen in postmenopausal women with early breast cancer.

PATIENTS AND METHODS

Breast International Group (BIG) 1-98 randomly assigned 8,010 patients to four arms comparing letrozole and tamoxifen with sequences of each agent. The Central Pathology Office received material for 6,549 patients (82%), of which 79% were assessable (6,291 patients). Prognostic and predictive value of both local and central hormone receptor expression on disease-free survival (DFS) were evaluated among 3,650 assessable patients assigned to the monotherapy arms. Prognostic value and the treatment effect were estimated for centrally assessed ER and PgR expression levels using the Subpopulation Treatment Effect Pattern Plot.

RESULTS

Central review confirmed 97% of tumors as hormone receptor-positive (ER and/or PgR > or =10%). Of 105 tumors locally ER-negative, 73 were found to have more than 10% positive cells, and eight had 1% to 9%. Of 6,100 tumors locally ER positive, 66 were found to have no staining, and 54 had only 1% to 9%. Discordance was more marked for PgR than ER. Patients with tumors reclassified centrally as ER-negative, or as hormone receptor-negative, had poor DFS. Centrally assessed ER and PgR showed prognostic value. Among patients with centrally assessed ER-expressing tumors, letrozole showed better DFS than tamoxifen, irrespective of PgR expression level.

CONCLUSION

Central review changed the assessment of receptor status in a substantial proportion of patients, and should be performed whenever possible in similar trials. PgR expression did not affect the relative efficacy of letrozole over tamoxifen.

Comparison of the Digene HC2 assay and the Roche AMPLICOR human papillomavirus (HPV) test for detection of high-risk HPV genotypes in cervical samples

Many different methods with different sensitivity and specificity have been proposed to detect the presence of high-risk human papillomavirus (HR HPV) in cervical samples. The HC2 is one of the most widely used. Recently, a new standardized PCR-based method, the AMPLICOR HPV test, has been introduced. Both assays recognize the same 13 HR HPV genotypes. The performances of these two commercially available assays were compared in 167 consecutive women (for a total of 168 samples) who presented at the Colposcopy Clinic either for a follow-up or for a diagnostic visit. Concordant results were found in 140/168 cervical samples (overall agreement, 83%; Cohen's kappa = 0.63). Twenty-eight samples gave discordant results: 20 were positive with the AMPLICOR HPV test and negative with the HC2 assay, and 8 were negative with the AMPLICOR HPV test and positive with the HC2 assay. The genotyping showed that no HR HPV was detected in the 8 HC2 assay-positive AMPLICOR HPV test-negative samples, while in 8/20 AMPLICOR HPV test-positive HC2 assay-negative samples, an HR HPV genotype was found. The AMPLICOR HPV test scored positive in a significantly higher percentage of subjects with normal Pap smears. All 7 cervical intraepithelial neoplasia grade 3 patients scored positive with the AMPLICOR HPV test, while 2 of them scored negative with HC2. Both tests had positive results in the only patient with squamous cell carcinoma. In conclusion, this study shows that the HC2 assay and the AMPLICOR HPV test give comparable results, with both being suitable for routine use. The differences noted in some cases may suggest a different optimal clinical use.

Restoration of Posterior Aspect of Rhabdosphincter Shortens Continence Time After Radical Retropubic Prostatectomy

PURPOSE

Prolonged postoperative incontinence is a major drawback of RRP. Age, scars in the rhabdosphincter, nonnerve sparing surgery and postoperative sphincter insufficiency can cause temporary or definitive urinary incontinence. We believe that sphincter deficiency is the main cause of early incontinence. Urinary leakage results from the shortening of anatomical and functional sphincter length due to caudal retraction of the urethral sphincteric complex and disruption of the median posterior fibrous raphe. We describe a modification of the Walsh RRP that overcomes caudal retraction, reconstructs the posterior fibrous raphe and decreases time to continence. The primary study end point was early continence rate assessment. Long-term continence (1 year) and erectile function assessment were secondary end points.

MATERIALS AND METHODS

To avoid caudal retraction of the urethrosphincteric complex, before completing the vesicourethral anastomosis the posterior semicircumference of the sphincter is joined to the residuum of Denonvilliers' fascia and fixed to the posterior bladder wall 1 to 2 cm cranial and dorsal to the new bladder neck. Vesicourethral anastomosis is subsequently performed with care taken not to involve the neurovascular bundles. A total of 161 patients with clinically confined disease underwent modified RRP (group 1). They were compared with a historical series of 50 patients who underwent standard RRP (group 2). Early continence was defined as no pad use but patients using 1 diaper were also considered continent. Continence, assessed prospectively as the number of pads daily, was evaluated 3, 30 and 90 days, and 1 year after catheter removal. The continence state was assessed by a multivariate logistic model. Erectile function was evaluated using the International Index of Erectile Function questionnaire preoperatively and after 18 months in patients younger than 65 years who underwent nerve sparing surgery.

RESULTS

In group 1, 116 (72%), 127 (78.8%) and 139 patients (86.3%) were continent 3, 30 and 90 days after catheter removal compared with 7 (14%), 15 (30%) and 23 (46%), respectively, in group 2. One-year continence rates were 96% and 90%, respectively. Erectile function was similar in groups 1 and 2 (46% and 42%, respectively). Multivariate analysis showed that continence was significantly influenced by operation type, stage and patient age.

CONCLUSIONS

Careful reconstruction of the posterior aspect of the rhabdosphincter markedly shortens time to continence.

Assessing the status of axillary sentinel lymph nodes of breast carcinoma patients by a real-time quantitative RT-PCR assay for mammaglobin 1 mRNA

The aim of the study was to assess the accuracy of a real-time quantitative RT-PCR (qRT-PCR) assay for mammaglobin 1 mRNA in the detection of metastatic breast cancer in axillary sentinel lymph nodes (SLN), comparing the results with those of qualitative RT-PCR assays and of an extensive histopathological examination. A retrospective series of 81 SLN from 72 patients and a validation series of 61 SLN from 61 patients were evaluated. In the retrospective series, the qRT-PCR assay was positive for 23 (28.4%) of the 81 SLN. The overall concordance with histopathology was 93.8%, with a sensitivity of 90.9%, a specificity of 94.9%, a positive predictive value (PPV) of 87% and a negative predictive value (NPV) of 96.6%. In the same series, qualitative RT-PCR showed an overall concordance with histopathology of 86.4%, a sensitivity of 72.7%, a specificity of 91.5%, a PPV of 76.2% and a NPV of 90%. In the validation series, including 23 patients with pure in situ carcinoma, the real-time qRT-PCR assay showed an overall concordance with the histopathologic findings of 93.4%, with a sensitivity of 75.0%, a specificity of 94.7%, a PPV of 50.0% and a NPV of 98.2%. We conclude that real-time qRT-PCR assays for mammaglobin 1 are more sensitive and specific that qualitative RT-PCR assays for the detection of metastatic breast carcinoma in axillary SLN, but it should not be regarded as a possible substitute for an extensive histopathological scrutiny of the SLN in the clinical practice.

The transactivating isoforms of p63 are overexpressed in high-grade follicular lymphomas independent of the occurrence ofp63 gene amplification

p63 is a p53-related gene mapping to 3q28 that codes for multiple mRNA transcripts with (TA-p63) or without (DeltaN-p63) transactivating effects on genes that promote cell differentiation and apoptosis. We analysed p63 alterations by immunohistochemistry, quantitative real-time RT-PCR and FISH in a series of 45 follicular lymphomas (FL). None of the tumours showed immunoreactivity for the p40 antibody, which recognizes only the truncated isoforms of p63, or DeltaN-p63 mRNA expression. Immunoreactivity for the 4A4 antibody, which recognizes both the transactivating and the truncated p63 isoforms, was found in 5 +/- 5.5%, 6.85 +/- 4.88% and 33.2 +/- 22.31% of grade I, II and III FL cells, respectively (p < 0.0001). Quantitative RT-PCR analysis showed that all cases but one had TA-p63 mRNA levels higher than non-neoplastic lymphocytes, and that TA-p63 mRNA expression correlated significantly (r = 0.9194, p < 0.0001) with the prevalence of p63 immunoreactivity. FISH extra signals for the p63 gene were found in seven (23.3%) of the 30 cases analysed (0/6 grade I, 2/15 grade II and 5/9 grade III; p = 0.01937). Further hybridizations showed a pattern highly suggestive of chromosome 3 polysomy in six cases. One of these cases also bore extra copies of the p63 and bcl-6 genes. Co-localization of p63 and IgH signals was found in one case. No association between the prevalence of p63 immunoreactivity and extra p63 gene signals was detectable when the cases were dichotomized according to a p63 immunoreactivity threshold of 10%. Our data suggest that TA-p63 is overexpressed in high-grade FL, possibly independent of the occurrence of gene abnormalities, and that it may be involved in the highly complex mechanism of regulation of apoptosis of FL cells.

Histopathologic examination of axillary sentinel lymph nodes in breast carcinoma patients

The axillary sentinel lymph node biopsy (SLNB) has gained increasing popularity as a novel surgical approach for staging patients with breast carcinoma and for guiding the choice of adjuvant therapy with minimal morbidity. Patients with negative SLNB represent a subset of breast carcinoma patients with definitely better prognosis, because their pN0 status is based on a very thorough examination of the sentinel lymph nodes (SLNs), with a very low risk of missing even small micrometastatic deposits, as compared with routine examination of the 20 or 30 lymph nodes obtained by the traditional axillary clearing. The histopathologic examination of the SLNs may be performed after fixation and embedding in paraffin, or intraoperatively on frozen sections. Whatever is the preferred tracing technique and surgical procedure, the histopathologic examination of each SLN must be particularly accurate, to avoid a false-negative diagnosis. Unfortunately, because of the lack of standardised guidelines or protocols for SLN examination, different institutions still adopt their own working protocols, which differ substantially in the number of sections cut and examined, in the cutting intervals (ranging from 50 to more than 250 microm), and in the more or less extensive use of immunohistochemical assays for the detection of micrometastatic disease. Herein, a very stringent protocol for the examination of the axillary SLN is reported, which is applied either to frozen SLN for the intraoperative diagnosis, and to fixed and embedded SLN as well.

Lack of prognostic implications of HER-2/neu abnormalities in 345 stage I nonsmall cell carcinomas (NSCLC) and 207 stage I-III neuroendocrine tumours (NET) of the lung

HER-2/neu oncogene activation by either gene amplification and/or protein overexpression has been documented in several human malignancies. Irrespective of protein overexpression, HER-2/neu gene amplification is rare in lung cancer and studies on its prevalence and clinicopathological implications in early stage non-small cell lung cancer (NCSLC) and neuroendocrine tumours (NET) of the lung are lacking. We evaluated HER-2/neu abnormalities in 345 Stage I NSCLC and 207 Stage I-III NET of the lung of all the diverse histological types, by using immunohistochemistry and fluorescent in situ hybridization in selected cases. Overall, HER-2/neu immunoreactivity was detected in 23% of 345 NSCLC and in 7% of 207 NET. Gene amplification was seen in only 7 (7.4%) of the immunoreactive tumours, with high-level amplification (HER-2/neu gene to chromosome 17 ratio > 4.0) in 3 adenocarcinomas, 1 squamous-cell carcinoma and 1 large-cell neuroendocrine carcinoma (LCNEC), and low-level amplification (HER-2/neu gene to chromosome 17 ratio from 2.0 to 4.0) in 1 squamous-cell carcinoma and 1 LCNEC. None of tested carcinoids and SCLC showed gene amplification. All but 1 gene amplified case exhibited 2+ or 3+ membrane labeling. No relationship was found between gene amplification or protein overexpression and patients' survival or other clinicopathological variables. HER-2/neu gene amplification and protein overexpression are not closely correlated in lung carcinomas and do not bear any prognostic implication. Among neuroendocrine tumours, LCNEC show a slightly higher prevalence of either HER-2/neu gene amplification or protein overexpression.

Reverse transcription-polymerase chain reaction assay for multiple mRNA markers in the detection of breast cancer metastases in sentinel lymph nodes

The identification of specific tumor mRNA markers by reverse transcription-polymerase chain reaction might be a valuable diagnostic adjunct for the detection of breast cancer metastases in axillary sentinel lymph nodes (SLNs). In this study we have compared the diagnostic accuracy of an extensive histopathologic examination of 146 SLNs from 123 breast carcinoma patients with that of the evaluation of 5 mRNA markers. When analyzed individually, none of the different markers attained a sensitivity higher than 77.8%, and the general concordance with the histopathologic findings ranged from 78.8 to 83.6%. In a multiple-marker assay, taking into account the expression of at least 1 of the 5 tumor markers, the sensitivity of the test rose to 95.6%, with a specificity of 66.3% and a general concordance with the histopathologic status of 75.3%. Finally, when at least 2 of 3 markers (maspin, cytokeratin 19 and mammaglobin 1) were expressed, the concordance with either SLN or axillary lymph node status was highest (88.4% and 84.6%, respectively). The high prevalence of positive reverse transcription-polymerase chain reaction assays in histologically uninvolved SLNs, however, may hamper extensive application of these techniques in the clinical setting.

Reverse transcription-polymerase chain reaction assay for multiple mRNA markers in the detection of breast cancer metastases in sentinel lymph nodes

The identification of specific tumor mRNA markers by reverse transcription-polymerase chain reaction might be a valuable diagnostic adjunct for the detection of breast cancer metastases in axillary sentinel lymph nodes (SLNs). In this study we have compared the diagnostic accuracy of an extensive histopathologic examination of 146 SLNs from 123 breast carcinoma patients with that of the evaluation of 5 mRNA markers. When analyzed individually, none of the different markers attained a sensitivity higher than 77.8%, and the general concordance with the histopathologic findings ranged from 78.8 to 83.6%. In a multiple-marker assay, taking into account the expression of at least 1 of the 5 tumor markers, the sensitivity of the test rose to 95.6%, with a specificity of 66.3% and a general concordance with the histopathologic status of 75.3%. Finally, when at least 2 of 3 markers (maspin, cytokeratin 19 and mammaglobin 1) were expressed, the concordance with either SLN or axillary lymph node status was highest (88.4% and 84.6%, respectively). The high prevalence of positive reverse transcription-polymerase chain reaction assays in histologically uninvolved SLNs, however, may hamper extensive application of these techniques in the clinical setting.

[Physiology of the urethral sphincteric vesico-prostatic complex]

We propose a review of the literature about innervation and physiology of the urethral sphincteric complex. Parasympathetic innervation of the pelvic viscera comes from ventral branches of the sacral nerves (S2-S4). The orthosympathetic component derives from superior hypogastric plexus and runs down the hypogastric nerves to form the right and left pelvic plexus together with the parasympathetic component. The pelvic plexus is situated inferolaterally with respect to the rectum and runs on the surface of the levator ani muscle down to the prostatic apex. The pelvic plexus gives innervation to the rectum, the bladder, the prostate and the urethral sphincteric complex. The pelvic muscular floor is innervated by the somatic component (pudendal nerve) derived from the sacral branches (S2-S4). Bladder neck and smooth muscle urethral sphincter innervation is given mostly by the orthosympathetic component. The rhabdosphincter innervation comes from the pudendal nerve and from the pelvic plexus; its role in the continence mechanism is probably to give steady tonic urethral compression. Levator ani muscle takes part in the sphincteric complex with its anteromedial pubococcygeal portion. It plays its role strengthening the sphincteric tone during increase of the abdominal pressure or during active quick stop cessation of the urinary stream.

[Personal research: reconstruction of the urethral striated sphincter]

OBJECTIVE

Incontinence is one of the drawbacks of radical prostatectomy. The causes of post-operative incontinence are sphincter deficiency (SD) and bladder dysfunction (BD). SD seems to be the main cause of incontinence and long time to continence. We present a surgical modification of the anatomical radical retropubic prostatectomy consisting in the reconstruction of the posterior aspect of the striated urethral sphincter in order to obtain a quick recovery of continence postoperatively.

MATERIALS AND METHODS

Caudal retraction of the urethro-sphincteric complex after apical dissection of the prostate often occurs. Furthermore posterior fibrous raphe interruption can cause shortening of anatomical and functional urethral length and affect continence. In order to avoid caudal retraction of the sphincteric complex, after completing vesico-urethral anastomosis, the posterior emicircumference of the striated sphincter is fixed to the posterior aspect of the bladder one centimeter cranially and posteriorly to the urethro-vesical anastomosis. The rabdosphincter is sutured separately from the urethro-vesical suturing. This technical modification makes it possible to obtain an anatomical length of the urethra of about a centimeter more than with the standard technique, replacing it in a more anatomical position. Furthermore, this technique provides the new posterior platform for the urethro-sphincteric complex. Twenty-four patients with clinical organ confined disease and age range 54-74 years (mean 64 years) underwent Walsh's anatomical radical retropubic prostatectomy with reconstruction of the rabdosphincter (group A). Catheter was removed 7 to 11 days postoperatively. Early continence was assessed objectively with the number of pads per day as follows: 0-1 mini pad = continent; 1-2 pads per day = mild incontinence; 2 or more pads per day = severe incontinence. Continence was evaluated at 3 days and one month after catheter removal. Group A compared to 21 patients (group B) who underwent standard anatomical RPP (historical control group).

RESULTS

In group A 16/24 patients (66.7%) and 19/24 patients (79.2%) were continent respectively at three days after removal of the catheter and after one month; mild incontinence (1-2 pads/day) was present in 6/24 patients (25%) and 3/24 (12.5%) respectively, 2/24 patients (8.3%) suffered from severe incontinence after 3 days and one month. In group B 7/21 patients (33%) were continent at hospital discharge, 11/21 (52%) after one month.

CONCLUSIONS

Careful reconstruction of the posterior aspects of the rabdosphincter shortens time to continence after RRP.

Immunoreactivity for latent membrane protein 1 of Epstein-Barr virus in nevi and melanomas is not related to the viral infection

Epstein-Barr virus (EBV) is a human herpes virus with oncogenic potential, associated with several malignancies. The EBV-encoded latent membrane protein 1 (LMP1) is one of nine proteins regularly expressed in virally infected and immortalised B lymphocytes. We now document the consistent immunoreactivity for LMP1 in 90% of 65 nevi and melanomas, using the monoclonal antibody cocktail CS1-4. The immunocytochemical findings, however, were not confirmed using reverse-transcription polymerase chain reaction (RT-PCR) experiments, which failed to demonstrate any actual expression of LMP1 mRNA. In situ hybridisation for EBV-encoded RNAs (EBERs 1 and 2) and PCR amplification of EBV genomic sequences also failed to document any viral infection. Several normal and neoplastic human tissues have also been immunostained for LMP1, without any positive staining, with the exception of a minor percentage of skin melanocytes and of normal blasts of the myeloid and erythroid lineages. We conclude that the vast majority of nevi and melanomas express a still uncharacterised molecule, cross-reacting with anti-LMP1 (CS1-4) antibodies, which may be considered a consistent marker of melanocytic proliferations. The immunoreactivity of normal and neoplastic human tissues for the anti-LMP1 reagent should not be taken as evidence of EBV infection.

Down-regulation of beta(1C) integrin in breast carcinomas correlates with high proliferative fraction, high histological grade, and larger size

beta(1C) integrin is an unspliced form of the integrin beta(1) subfamily, which has been shown to inhibit cell proliferation in vitro. Using an affinity-purified rabbit antibody, we have investigated 283 previously untreated breast carcinomas, with the aim of ascertaining the actual prevalence of beta(1C) expression in these tumors and of defining its pathological correlates. Immunoblotting and reverse transcriptase-polymerase chain reaction experiments have also been performed in selected cases, to confirm the immunocytochemical findings. Overall, beta(1C) immunoreactivity was down-regulated (ie, expressed in < 50% of the neoplastic cells) in 114 cases (40.3%). Down-regulation of beta(1C) expression in breast carcinomas correlated significantly with the tumor grade, the proliferative fraction (as evaluated by Ki-67 immunostaining with the MIB-1 monoclonal antibody), the estrogen and progesterone receptor status, and the tumor size (pT classification) and marginally with the node status. In a multivariate analysis with all available measures fitted simultaneously, tumor grade (P = 0.004), Ki-67 immunolabeling (P = 0.01), and pT categories (P = 0.04) were significantly associated with beta(1C) immunoreactivity. Although the short follow-up time (2-3 years) of the current series of patients does not allow the performance of survival analyses, the correlation of beta(1C) expression with tumor size, grade, and proliferative fraction and its alleged role as an upstream regulator of p27(kip1) make this integrin variant a likely novel prognostic parameter for invasive carcinomas of the breast.