Improving attribution of adverse events in oncology clinical trials.

Attribution of adverse events (AEs) is critical to oncology drug development and the regulatory process. However, processes for determining the causality of AEs are often sub-optimal, unreliable, and inefficient. Thus, we conducted a toxicity-attribution workshop in Silver Springs MD to develop guidance for improving attribution of AEs in oncology clinical trials. Attribution stakeholder experts from regulatory agencies, sponsors and contract research organizations, clinical trial principal investigators, pre-clinical translational scientists, and research staff involved in capturing attribution information participated. We also included patients treated in oncology clinical trials and academic researchers with expertise in attribution. We identified numerous challenges with AE attribution, including the non-informative nature of and burdens associated with the 5-tier system of attribution, increased complexity of trial logistics, costs and time associated with AE attribution data collection, lack of training in attribution for early-career investigators, insufficient baseline assessments, and lack of consistency in the reporting of treatment-related and treatment-emergent AEs in publications and clinical scientific reports. We developed recommendations to improve attribution: we propose transitioning from the present 5-tier system to a 2-3 tier system for attribution, more complete baseline information on patients' clinical status at trial entry, and mechanisms for more rapid sharing of AE information during trials. Oncology societies should develop recommendations and training in attribution of toxicities. We call for further harmonization and synchronization of recommendations regarding causality safety reporting between FDA, EMA and other regulatory agencies. Finally, we suggest that journals maintain or develop standardized requirements for reporting attribution in oncology clinical trials.

The European medicines agency review of eribulin for the treatment of patients with locally advanced or metastatic breast cancer: summary of the scientific assessment of the committee for medicinal products for human use.

The European Commission issued on March 17, 2011, a marketing authorization valid throughout the European Union (EU) for eribulin (Halaven; Eisai Limited). The decision was based on the favorable opinion of the Committee for Medicinal Products for Human Use recommending a marketing authorization for the treatment of patients with locally advanced or metastatic breast cancer who have progressed after at least 2 chemotherapeutic regimens for advanced disease. Eribulin mesylate is a structurally simplified synthetic analogue of halichondrin B, which is a natural product isolated from the marine sponge Halichondria okadai (ATC code L01XX41). Eribulin is a nontaxane, microtubule dynamics inhibitor belonging to the halichondrin class of antineoplastic agents. Eribulin inhibits the growth phase of microtubules without affecting the shortening phase and sequesters tubulin into nonproductive aggregates leading to G(2)-M cell-cycle block, disruption of mitotic spindles, and, ultimately, apoptotic cell death after prolonged mitotic blockage. The recommended dose of eribulin is 1.23 mg/m(2) (equivalent to 1.4 mg/m(2) eribulin mesylate) to be administered intravenously over 2 to 5 min on days 1 and 8 of a 3-week cycle. In the pivotal trial, eribulin was associated with increased overall survival in patients with locally advanced or metastatic breast cancer who received at least 2 prior chemotherapy lines for advanced disease (median overall survival was 13.2 months in the eribulin arm vs. 10.6 months in the control arm; HR = 0.805; 95% confidence interval, 0.677-0.958; P = 0.014). The most common side effects are asthenia or fatigue and neutropenia. The objective of this article is to summarize the scientific review of the application leading to approval in the EU. The detailed scientific assessment report and product information, including the summary report and product information, including product characteristics, are available on the European Medicines Agency website.

Gene expression in 16q is associated with survival and differs between Sørlie breast cancer subtypes.

We have investigated the relationship between gene expression and chromosomal positions in 402 breast cancer patients. Using an overrepresentation approach based on Fisher's exact test, we identified disproportionate contributions of specific chromosomal positions to genes associated with survival. Our major finding is that the gene expression in the long arm of chromosome 16 stands out in its relationship to survival. This arm contributes 36 (18%) and 55 (11%) genes to lists negatively associated with recurrence-free survival (set to sizes 200 and 500). This is a highly disproportionate contribution from the 313 (2%) genes in this arm represented on the used Affymetrix U133A and B microarray platforms (Bonferroni corrected Fisher test: P < 2.2 x 10(-16)). We also demonstrate differential expression in 16q across tumor subtypes, which suggests that the ERBB2, basal, and luminal B tumors progress along a high grade-poor prognosis path, while luminal A and normal-like tumors progress along a low grade-good prognosis path, in accordance with a previously proposed model of tumor progression. We conclude that important biological information can be extracted from gene expression data in breast cancer by studying non-random connections between chromosomal positions and gene expression. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.

Intrinsic molecular signature of breast cancer in a population-based cohort of 412 patients.

BACKGROUND: Molecular markers and the rich biological information they contain have great potential for cancer diagnosis, prognostication and therapy prediction. So far, however, they have not superseded routine histopathology and staging criteria, partly because the few studies performed on molecular subtyping have had little validation and limited clinical characterization. METHODS: We obtained gene expression and clinical data for 412 breast cancers obtained from population-based cohorts of patients from Stockholm and Uppsala, Sweden. Using the intrinsic set of approximately 500 genes derived in the Norway/Stanford breast cancer data, we validated the existence of five molecular subtypes--basal-like, ERBB2, luminal A/B and normal-like--and characterized these subtypes extensively with the use of conventional clinical variables. RESULTS: We found an overall 77.5% concordance between the centroid prediction of the Swedish cohort by using the Norway/Stanford signature and the k-means clustering performed internally within the Swedish cohort. The highest rate of discordant assignments occurred between the luminal A and luminal B subtypes and between the luminal B and ERBB2 subtypes. The subtypes varied significantly in terms of grade (p < 0.001), p53 mutation (p < 0.001) and genomic instability (p = 0.01), but surprisingly there was little difference in lymph-node metastasis (p = 0.31). Furthermore, current users of hormone-replacement therapy were strikingly over-represented in the normal-like subgroup (p < 0.001). Separate analyses of the patients who received endocrine therapy and those who did not receive any adjuvant therapy supported the previous hypothesis that the basal-like subtype responded to adjuvant treatment, whereas the ERBB2 and luminal B subtypes were poor responders. CONCLUSION: We found that the intrinsic molecular subtypes of breast cancer are broadly present in a diverse collection of patients from a population-based cohort in Sweden. The intrinsic gene set, originally selected to reveal stable tumor characteristics, was shown to have a strong correlation with progression-related properties such as grade, p53 mutation and genomic instability.

The clinical value of somatic TP53 gene mutations in 1,794 patients with breast cancer.

To investigate the clinical value of somatic TP53 mutations in breast cancer, we assembled clinical and molecular data on 1,794 women with primary breast cancer with long-term follow-up and whose tumor has been screened for mutation in exons 5 to 8 of TP53 by gene sequencing. TP53 mutations were more frequent in tumors of ductal and medullar types, aggressive phenotype (high grade, large size, node positive cases, and low hormone receptor content) and in women <60 years old. TP53 mutations within exons 5 to 8 conferred an elevated risk of breast cancer-specific death of 2.27 (relative risk >10 years; P < 0.0001) compared with patients with no such mutation. The prognostic value of TP53 mutation was independent of tumor size, node status, and hormone receptor content, confirming and reconciling previous findings in smaller series. Moreover, an interaction between TP53 mutation and progesterone receptor (PR) status was revealed, TP53 mutation combined with the absence of progesterone receptor being associated with the worst prognosis. Whereas previous studies have emphasized the fact that missense mutations in the DNA-binding motifs have a worse prognosis than missense mutations outside these motifs, we show that non-missense mutations have prognostic value similar to missense mutations in DNA-binding motifs. Nonetheless, specific missense mutants (codon 179 and R248W) seem to be associated with an even worse prognosis. These results, obtained on the largest series analyzed thus far, show that TP53 mutations identified by gene sequencing have an independent prognostic value in breast cancer and could have potential uses in clinical practice.

Gene expression profiling spares early breast cancer patients from adjuvant therapy: derived and validated in two population-based cohorts.

INTRODUCTION: Adjuvant breast cancer therapy significantly improves survival, but overtreatment and undertreatment are major problems. Breast cancer expression profiling has so far mainly been used to identify women with a poor prognosis as candidates for adjuvant therapy but without demonstrated value for therapy prediction. METHODS: We obtained the gene expression profiles of 159 population-derived breast cancer patients, and used hierarchical clustering to identify the signature associated with prognosis and impact of adjuvant therapies, defined as distant metastasis or death within 5 years. Independent datasets of 76 treated population-derived Swedish patients, 135 untreated population-derived Swedish patients and 78 Dutch patients were used for validation. The inclusion and exclusion criteria for the studies of population-derived Swedish patients were defined. RESULTS: Among the 159 patients, a subset of 64 genes was found to give an optimal separation of patients with good and poor outcomes. Hierarchical clustering revealed three subgroups: patients who did well with therapy, patients who did well without therapy, and patients that failed to benefit from given therapy. The expression profile gave significantly better prognostication (odds ratio, 4.19; P = 0.007) (breast cancer end-points odds ratio, 10.64) compared with the Elston-Ellis histological grading (odds ratio of grade 2 vs 1 and grade 3 vs 1, 2.81 and 3.32 respectively; P = 0.24 and 0.16), tumor stage (odds ratio of stage 2 vs 1 and stage 3 vs 1, 1.11 and 1.28; P = 0.83 and 0.68) and age (odds ratio, 0.11; P = 0.55). The risk groups were consistent and validated in the independent Swedish and Dutch data sets used with 211 and 78 patients, respectively. CONCLUSION: We have identified discriminatory gene expression signatures working both on untreated and systematically treated primary breast cancer patients with the potential to spare them from adjuvant therapy.

An expression signature for p53 status in human breast cancer predicts mutation status, transcriptional effects, and patient survival.

Perturbations of the p53 pathway are associated with more aggressive and therapeutically refractory tumors. However, molecular assessment of p53 status, by using sequence analysis and immunohistochemistry, are incomplete assessors of p53 functional effects. We posited that the transcriptional fingerprint is a more definitive downstream indicator of p53 function. Herein, we analyzed transcript profiles of 251 p53-sequenced primary breast tumors and identified a clinically embedded 32-gene expression signature that distinguishes p53-mutant and wild-type tumors of different histologies and outperforms sequence-based assessments of p53 in predicting prognosis and therapeutic response. Moreover, the p53 signature identified a subset of aggressive tumors absent of sequence mutations in p53 yet exhibiting expression characteristics consistent with p53 deficiency because of attenuated p53 transcript levels. Our results show the primary importance of p53 functional status in predicting clinical breast cancer behavior.

Thrombospondin-1 expression in relation to p53 status and VEGF expression in human breast cancers.

The aim of the present study was to study the expression and relationship of potential angiogenic factors. Paraffin-embedded tumour sections from 261 breast cancer patients were stained immunohistochemically for thrombospondin (TSP-1) expression. p53 status was previously determined by cDNA-based sequencing, and vascular endothelial growth factor (VEGF) protein expression had been previously analysed using an immunoassay. 241 cancers (92%) had detectable levels of TSP-1. No associations between TSP-1 and p53 status or VEGF were found. No correlations between TSP-1 and relapse-free (P=0.3), breast cancer-corrected (P=0.2) or overall survival (P=0.5) were found. A correlation was found for patients with p53 mutations, but negative p53 expression, with higher VEGF levels (P=0.009), but there was no correlation between this p53 group and those with low TSP-1 levels (P=0.2). In conclusion, TSP-1 expression was not prognostic and was not associated with neither p53-status or VEGF expression.

Skin toxicity as a risk factor for major infections in breast cancer patients treated with docetaxel.

Docetaxel-related skin toxicity, oral and gastrointestinal mucosal toxicity, and changes in blood cell counts were investigated as predictive factors for major infections in 143 women treated with 3-weekly docetaxel (100 mg/m2) as second-line therapy for metastatic breast cancer in a randomized trial. Each patient with a major infection (n = 37) was compared with two controls. Skin toxicity (odds ratio 2.97, 95% CI 1.37-6.47), oral mucositis (1.98, CI 1.30-3.04), and the leukocyte nadir (0.12, CI 0.02-0.51) were significantly associated with a major infection in a univariate logistic regression analysis. In a multivariate analysis, skin toxicity was the only independent factor predictive for grade 3 to 4 infection (2.75, CI 1.00-7.58). A major infection was diagnosed in 62% (8 out of 13) of the docetaxel cycles in severely (grade 4) leukopenic patients who had grade 2 to 4 skin toxicity. Major infections are common in leukopenic patients who develop docetaxel-associated skin toxicity, and leukopenic patients presenting with docetaxel-induced skin toxicity may be candidates for prophylactic anti-infection measures such as prophylactic therapy with hematopoietic growth factors.

Overexpression of cyclin E protein is associated with specific mutation types in the p53 gene and poor survival in human breast cancer.

Cyclin E is one of the key regulators of the G(1)/S transition in the cell cycle. Overexpression of cyclin E has been observed in several malignancies and is associated with high proliferation, aberrant expression of other cell cycle regulators and chromosomal instability in vitro. To explore potential associations between cyclin E deregulation and inactivation of the p53 tumor suppressor gene in human breast cancer, we investigated the immunohistochemical expression of cyclin E in paraffin embedded breast cancers from 270 women with known p53 status by cDNA based sequencing of the p53 gene. The breast cancers were divided into three subgroups according to the percentage of cyclin E-positive cells. One hundred and seventy-one patients (63%) had low cyclin E, 72 (27%) medium and 27 (10%) had high cyclin E content. Fifty-six percent (15/27) of the breast cancers with high cyclin E had p53 gene mutations, compared with 14% (24/171) of those with low cyclin E content (P < 0.0001). In p53 mutated breast cancers high cyclin E content was associated with insertions, deletions and nonsense point mutations in the p53 tumor suppressor gene, whereas low cyclin E was linked to p53 missense point mutations. We also observed statistically significant associations between a high cyclin E content and aneuploidy, high S phase, larger tumor size, estrogen receptor negativity, presence of axillary node metastases and high tumor grade. High cyclin E content was associated with poor overall survival in univariate and multivariate analysis (hazard ratio 2.4, 95% confidence interval 1.3-4.5). In summary, our findings demonstrate that overexpression of cyclin E is associated with an aggressive tumor phenotype and specific types of p53 mutations.

A population-based study on the first forty-eight breast cancer patients receiving trastuzumab (Herceptin) on a named patient basis in Sweden.

Several studies have presented data on the efficacy and tolerability of trastuzumab within clinical trials. As a minority of patients is included in these trials, we undertook this retrospective study to describe trastuzumab therapy in clinical routine and its tolerability. We reviewed the medical records of the first 48 patients in Sweden who received treatment with trastuzumab on a named patient basis with (n = 29) and without (n = 19) chemotherapy. Forty-six patients had metastatic disease and had failed to respond to several prior regimens before starting antibody treatment. Two patients had locally advanced breast cancer failing on given neoadjuvant therapy. Patients with breast cancers with strong (3+) c-erbB-2 overexpression tended to have an improved survival from start of trastuzumab treatment versus those with a moderate (2+) overexpression (p = 0.09). Adverse events were registered in 22 patients (46%). The most common and acute side effects were fever and chills (7 patients, 15%). The toxicity seemed reasonable but two patients (4%) suffered serious cardiac events, both of them having received previous treatment with antracyclines.