A multigene expression assay to predict local recurrence risk for ductal carcinoma in situ of the breast

A review of clinical aspects of breast cancer

Breast cancer is the most frequently diagnosed cancer in women and ranks second among causes for cancer related death in women. The ability to identify and diagnose breast cancer has improved markedly. Treatment decisions which were based in the past predominantly on the anatomic extent of the disease are shifting to the underlying biological mechanisms. Gene array technology has led to the recognition that breast cancer is a heterogeneous disease composed of different biological subtypes, and genetic profiling enables response to chemotherapy to be predicted. Breast conservation became an established standard of care and the oncoplastic approach enables wide excisions without compromising the natural shape of the breast. Sentinel lymph node biopsy has replaced axillary dissection as the standard procedure to stage the axilla and spared many patients the excess morbidity of axillary dissection. Targeted therapy to the oestrogen receptor plays a major role in systemic therapy; pathways responsible for endocrine resistance have been targeted as well. Biological therapy has been developed to target HER2 receptor and combination of antibody drug conjugates linked cytotoxic therapy to HER2 antibodies. Meaningful improvements in survival resulted from the new effective systemic agents and patients with metastasis are likely to have a longer survival.

A Comparison of Tumor Biology in Primary Ductal Carcinoma In Situ Recurring as Invasive Carcinoma versus a New In Situ

Introduction. About half of all new ipsilateral events after a primary ductal carcinoma in situ (DCIS) are invasive carcinoma. We studied tumor markers in the primary DCIS in relation to type of event (invasive versus in situ). Methods. Two hundred and sixty-six women with a primary DCIS from two source populations, all with a known ipsilateral event, were included. All new events were regarded as recurrences. Patient and primary tumor characteristics (estrogen receptor (ER), progesterone receptor (PR), HER2, EGFR, and Ki67) were evaluated. Logistic regression was used to calculate odd ratios and 95% confidence intervals in univariate and multivariate analyses. Results. One hundred and thirty-six of the recurrences were invasive carcinoma and 130 were in situ. The recurrence was more often invasive if the primary DCIS was ER+ (OR 2.5, 95% CI 1.2–5.1). Primary DCIS being HER2+ (OR 0.5, 95% CI 0.3–0.9), EGFR+ (OR 0.4, 95% CI 0.2–0.9), and ER95−/HER2+ (OR 0.2, 95% CI 0.1–0.6) had a lower risk of a recurrence being invasive. Conclusions. In this study, comparing type of recurrence after a DCIS showed that the ER−/HER2+ tumors were related to a recurrence being a new DCIS. And surprisingly, tumors being ER+, HER2−, and EGFR− were related to a recurrence being invasive cancer.

Molecular subtypes in ductal carcinoma in situ of the breast and their relation to prognosis: a population-based cohort study

Background

Different molecular subtypes of breast cancer have been identified based on gene expression profiling. Treatment suggestions based on an approximation of these subtypes by immunohistochemical criteria have been published by the St Gallen international expert consensus panel. Ductal carcinoma in situ (DCIS) can be classified into the same molecular subtypes. Our aim was to study the relation between these newly defined subtypes and prognosis in DCIS.

Methods

TMA including 458 women from a population-based cohort with DCIS diagnosed 1986–2004 was used. Stainings for ER, PR, HER2 and Ki67 were used to classify the surrogate molecular subtypes according to the St Gallen criteria from 2011. The associations with prognosis were examined using Kaplan-Meier analyses and Cox proportional hazards regression models.

Results

Surrogate molecular subtyping could be done in 381 cases. Mean follow up was 164 months. Of the classified DCIS 186 were Luminal A (48.8%), 33 Luminal B/HER2- (8.7%), 74 Luminal B/HER2+ (17.4%), 61 HER2+/ER- (16.0%) and 27 Triple Negative (7.1%). One hundred and two women had a local recurrence of which 58 were invasive. Twenty-two women had generalised disease, 8 without a prior local recurrence. We could not find a prognostic significance of the molecular subtypes other than a higher risk of developing breast cancer after more than 10 years of follow-up among women with a Triple Negative DCIS (OR 3.2; 95% CI 1.1-9.8).

Conclusions

The results from this large population-based cohort, with long-term follow up failed to demonstrate a prognostic value for the surrogate molecular subtyping of DCIS using the St Gallen criteria up to ten years after diagnosis. More than ten years after diagnosis Triple Negative DCIS had an elevated risk of recurrence.

Validation of a real-time quantitative polymerase chain reaction method for the quantification of 3 survivin transcripts and evaluation in breast cancer tissues

BACKGROUND

Survivin is a novel antiapoptotic gene, which is a member of the inhibitor of apoptosis protein (IAP) family. Recently, 3 splice variants of this gene were cloned and characterized. This study aimed to validate a sensitive and specific method for the detection of survivin variants in breast cancer.

METHODS

Real-time quantitative polymerase chain reaction (qPCR) was performed on the cDNA with a reverse primer specific for each splice variant and a pair of common hybridization probes.

RESULTS

The expression of wild-type survivin was significantly correlated with survivin-2b, survivin-ΔEx3, and the ratio of survivin-ΔEx3 to wild-type survivin (P < .001). The ratio of survivin-2b to wild-type survivin was strongly associated with the ratio of survivin-ΔEx3 to wild-type survivin (P < .001). There was a strong positive association between the grade of the tumor and survivin-2b mRNA, survivin-ΔEx3 mRNA, and the ratio of survivin-ΔEx3 to wild-type survivin mRNA (P < .05). The ratio of survivin-2b to wild-type survivin was significantly associated with the presence of estrogen receptors (P = .05).

CONCLUSION

Our validated data suggest that survivin isoforms may be related to clinicopathological features and could be used as molecular prognostic tools or as new therapy targets.

Analytical validation of the Oncotype DX prostate cancer assay - a clinical RT-PCR assay optimized for prostate needle biopsies

Background

The Oncotype DX® Prostate Cancer Assay is a multi-gene RT-PCR expression assay that was developed for use with fixed paraffin-embedded (FPE) diagnostic prostate needle biopsies containing as little as 1 mm of prostate tumor in the greatest dimension. The assay measures expression of 12 cancer-related genes representing four biological pathways and 5 reference genes which are algorithmically combined to calculate the Genomic Prostate Score (GPS). This biopsy-based assay has been analytically and subsequently clinically validated as a predictor of aggressive prostate cancer. The aim of this study was to validate the analytical performance of the Oncotype DX Prostate Cancer Assay using predefined acceptance criteria.

Results

The lowest quartile of RNA yields from prostate needle biopsies (six 5 μm sections) was between 19 and 34 ng. Analytical validation of the process requiring as little as 5 ng of RNA met all pre-defined acceptance criteria. Amplification efficiencies, analytical sensitivity, and accuracy of gene assays were measured by serially diluting an RNA sample and analyzing features of the linear regression between RNA expression measured by the crossing point (Cp) versus the log₂ of the RNA input per PCR assay well. Gene assays were shown to accurately measure expression over a wide range of inputs (from as low as 0.005 ng to 320 ng). Analytical accuracy was excellent with average biases at qPCR inputs representative of patient samples <9.7% across all assays while amplification efficiencies were within ±6% of the median. Assessments of reproducibility and precision were performed by testing 10 prostate cancer RNA samples over multiple instruments, reagent lots, operators, days (precision), and RNA input levels (reproducibility) using appropriately parameterized linear mixed models. The standard deviations for analytical precision and reproducibility were 1.86 and 2.11 GPS units (100-unit scale) respectively.

Conclusions

The Oncotype DX Prostate Cancer Assay, a clinical RT-PCR assay specifically designed for use with prostate needle biopsies, has been analytically validated using very limited RNA inputs. The assay requirements and analytical performance will provide physicians with test results from a robust and reliable assay which will enable improved treatment decisions for men diagnosed with early-stage prostate cancer.

Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer

INTRODUCTION

Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice.

METHODS

More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer 'stem' cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account.

RESULTS

The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working.

CONCLUSIONS

With resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years.

Antibody-mediated rejection, T cell-mediated rejection, and the injury-repair response: new insights from the Genome Canada studies of kidney transplant biopsies

Prospective studies of unselected indication biopsies from kidney transplants, combining conventional assessment with molecular analysis, have created a new understanding of transplant disease states and their outcomes. A large-scale Genome Canada grant permitted us to use conventional and molecular phenotypes to create a new disease classification. T cell-mediated rejection (TCMR), characterized histologically or molecularly, has little effect on outcomes. Antibody-mediated rejection (ABMR) manifests as microcirculation lesions and transcript changes reflecting endothelial injury, interferon-γ effects, and natural killer cells. ABMR is frequently C4d negative and has been greatly underestimated by conventional criteria. Indeed, ABMR, triggered in some cases by non-adherence, is the major disease causing failure. Progressive dysfunction is usually attributable to specific diseases, and pure calcineurin inhibitor toxicity rarely explains failure. The importance of ABMR argues against immunosuppressive drug minimization and stands as a barrier to tolerance induction. Microarrays also defined the transcripts induced by acute kidney injury (AKI), which correlate with reduced function, whereas histologic changes of acute tubular injury do not. AKI transcripts are induced in kidneys with late dysfunction, and are better predictors of failure than fibrosis and inflammation. Thus progression reflects ongoing parenchymal injury, usually from identifiable diseases such as ABMR, not destructive fibrosis.

Progression from ductal carcinoma in situ to invasive breast cancer: revisited

Ductal carcinoma in situ (DCIS) is an intraductal neoplastic proliferation of epithelial cells that is separated from the breast stroma by an intact layer of basement membrane and myoepithelial cells. DCIS is a non-obligate precursor of invasive breast cancer, and up to 40% of these lesions progress to invasive disease if untreated. Currently, it is not possible to predict accurately which DCIS would be more likely to progress to invasive breast cancer as neither the significant drivers of the invasive transition have been identified, nor has the clinical utility of tests predicting the likelihood of progression been demonstrated. Although molecular studies have shown that qualitatively, synchronous DCIS and invasive breast cancers are remarkably similar, there is burgeoning evidence to demonstrate that intra-tumor genetic heterogeneity is observed in a subset of DCIS, and that the process of progression to invasive disease may constitute an 'evolutionary bottleneck', resulting in the selection of subsets of tumor cells with specific genetic and/or epigenetic aberrations. Here we review the clinical challenge posed by DCIS, the contribution of the microenvironment and genetic aberrations to the progression from in situ to invasive breast cancer, the emerging evidence of the impact of intra-tumor genetic heterogeneity on this process, and strategies to combat this heterogeneity.