Michael Hubalek

Endocrine therapy plus zoledronic acid in premenopausal breast cancer.

BACKGROUND Ovarian suppression plus tamoxifen is a standard adjuvant treatment in premenopausal women with endocrine-responsive breast cancer. Aromatase inhibitors are superior to tamoxifen in postmenopausal patients, and preclinical data suggest that zoledronic acid has antitumor properties. METHODS We examined the effect of adding zoledronic acid to a combination of either goserelin and tamoxifen or goserelin and anastrozole in premenopausal women with endocrine-responsive early breast cancer. We randomly assigned 1803 patients to receive goserelin (3.6 mg given subcutaneously every 28 days) plus tamoxifen (20 mg per day given orally) or anastrozole (1 mg per day given orally) with or without zoledronic acid (4 mg given intravenously every 6 months) for 3 years. The primary end point was disease-free survival; recurrence-free survival and overall survival were secondary end points. RESULTS After a median follow-up of 47.8 months, 137 events had occurred, with disease-free survival rates of 92.8% in the tamoxifen group, 92.0% in the anastrozole group, 90.8% in the group that received endocrine therapy alone, and 94.0% in the group that received endocrine therapy with zoledronic acid. There was no significant difference in disease-free survival between the anastrozole and tamoxifen groups (hazard ratio for disease progression in the anastrozole group, 1.10; 95% confidence interval [CI], 0.78 to 1.53; P=0.59). The addition of zoledronic acid to endocrine therapy, as compared with endocrine therapy without zoledronic acid, resulted in an absolute reduction of 3.2 percentage points and a relative reduction of 36% in the risk of disease progression (hazard ratio, 0.64; 95% CI, 0.46 to 0.91; P=0.01); the addition of zoledronic acid did not significantly reduce the risk of death (hazard ratio, 0.60; 95% CI, 0.32 to 1.11; P=0.11). Adverse events were consistent with known drug-safety profiles. CONCLUSIONS The addition of zoledronic acid to adjuvant endocrine therapy improves disease-free survival in premenopausal patients with estrogen-responsive early breast cancer. (ClinicalTrials.gov number, NCT00295646.)

Adjuvant denosumab in breast cancer (ABCSG-18): a multicentre, randomised, double-blind, placebo-controlled trial

BACKGROUND Adjuvant endocrine therapy compromises bone health in patients with breast cancer, causing osteopenia, osteoporosis, and fractures. Antiresorptive treatments such as bisphosphonates prevent and counteract these side-effects. In this trial, we aimed to investigate the effects of the anti-RANK ligand antibody denosumab in postmenopausal, aromatase inhibitor-treated patients with early-stage hormone receptor-positive breast cancer. METHODS In this prospective, double-blind, placebo-controlled, phase 3 trial, postmenopausal patients with early hormone receptor-positive breast cancer receiving treatment with aromatase inhibitors were randomly assigned in a 1:1 ratio to receive either denosumab 60 mg or placebo administered subcutaneously every 6 months in 58 trial centres in Austria and Sweden. Patients were assigned by an interactive voice response system. The randomisation schedule used a randomly permuted block design with block sizes 2 and 4, stratified by type of hospital regarding Hologic device for DXA scans, previous aromatase inhibitor use, and baseline bone mineral density. Patients, treating physicians, investigators, data managers, and all study personnel were masked to treatment allocation. The primary endpoint was time from randomisation to first clinical fracture, analysed by intention to treat. As an additional sensitivity analysis, we also analysed the primary endpoint on the per-protocol population. Patients were treated until the prespecified number of 247 first clinical fractures was reached. This trial is ongoing (patients are in follow-up) and is registered with the European Clinical Trials Database, number 2005-005275-15, and with ClinicalTrials.gov, number NCT00556374. FINDINGS Between Dec 18, 2006, and July 22, 2013, 3425 eligible patients were enrolled into the trial, of whom 3420 were randomly assigned to receive denosumab 60 mg (n=1711) or placebo (n=1709) subcutaneously every 6 months. Compared with the placebo group, patients in the denosumab group had a significantly delayed time to first clinical fracture (hazard ratio [HR] 0·50 [95% CI 0·39-0·65], p<0·0001). The overall lower number of fractures in the denosumab group (92) than in the placebo group (176) was similar in all patient subgroups, including in patients with a bone mineral density T-score of -1 or higher at baseline (n=1872, HR 0·44 [95% CI 0·31-0·64], p<0·0001) and in those with a bone mineral density T-score of less than -1 already at baseline (n=1548, HR 0·57 [95% CI 0·40-0·82], p=0·002). The patient incidence of adverse events in the safety analysis set (all patients who received at least one dose of study drug) did not differ between the denosumab group (1366 events, 80%) and the placebo group (1334 events, 79%), nor did the numbers of serious adverse events (521 vs 511 [30% in each group]). The main adverse events were arthralgia and other aromatase-inhibitor related symptoms; no additional toxicity from the study drug was reported. Despite proactive adjudication of every potential osteonecrosis of the jaw by an international expert panel, no cases of osteonecrosis of the jaw were reported. 93 patients (3% of the full analysis set) died during the study, of which one death (in the denosumab group) was thought to be related to the study drug. INTERPRETATION Adjuvant denosumab 60 mg twice per year reduces the risk of clinical fractures in postmenopausal women with breast cancer receiving aromatase inhibitors, and can be administered without added toxicity. Since a main side-effect of adjuvant breast cancer treatment can be substantially reduced by the addition of denosumab, this treatment should be considered for clinical practice. FUNDING Amgen.

The PAM50 Risk-of-Recurrence Score Predicts Risk for Late Distant Recurrence after Endocrine Therapy in Postmenopausal Women with Endocrine-Responsive Early Breast Cancer

Purpose: To assess the prognostic value of the PAM50 risk-of-recurrence (ROR) score on late distant recurrence (beyond 5 years after diagnosis and treatment) in a large cohort of postmenopausal, endocrine-responsive breast cancer patients. Experimental Design: The PAM50 assay was performed on formalin-fixed paraffin-embedded whole-tumor sections of patients who had been enrolled in the Austrian Breast and Colorectal Cancer Study Group Trial 8 (ABCSG-8). RNA expression levels of the PAM50 genes were determined centrally using the nCounter Dx Analysis System. Late distant recurrence-free survival (DRFS) was analyzed using Cox models adjusted for clinical and pathologic parameters. Results: PAM50 analysis was successfully performed in 1,246 ABCSG-8 patients. PAM50 ROR score and ROR-based risk groups provided significant additional prognostic information with respect to late DRFS compared with a combined score of clinical factors alone (ROR score: ΔLRχ2 15.32, P < 0.001; ROR-based risk groups: ΔLRχ2 14.83, P < 0.001). Between years 5 and 15, we observed an absolute risk of distant recurrence of 2.4% in the low ROR-based risk group, as compared with 17.5% in the high ROR-based risk group. The DRFS differences according to the PAM50 ROR score were observed for both node-positive and node-negative disease. Conclusion: PAM50 ROR score and ROR-based risk groups can differentiate patients with breast cancer with respect to their risk for late distant recurrence beyond what can be achieved with established clinicopathologic risk factors. Clin Cancer Res; 20(5); 1298–305. ©2014 AACR.

Proteomic Profiling Identifies Afamin as a Potential Biomarker for Ovarian Cancer

Purpose: To discover and validate serum glycoprotein biomarkers in ovarian cancer using proteomic-based approaches. Experimental Design: Serum samples from a “discovery set” of 20 patients with ovarian cancer or benign ovarian cysts or healthy volunteers were compared by fluorescence two-dimensional differential in-gel electrophoresis and parallel lectin-based two-dimensional profiling. Validation of a candidate biomarker was carried out with Western blotting and immunoassay (n = 424). Results: Twenty-six proteins that changed significantly were identified by mass spectrometric sequencing. One of these, confirmed by Western blotting, was afamin, a vitamin E binding protein, with two isoforms decreasing in patients with ovarian cancer. Validation using cross-sectional samples from 303 individuals (healthy controls and patients with benign, borderline, or malignant ovarian conditions and other cancers) assayed by ELISA showed significantly decreased total afamin concentrations in patients with ovarian cancer compared with healthy controls (P = 0.002) and patients with benign disease (P = 0.046). However, the receiver operating characteristic areas for total afamin for the comparison of ovarian cancer with healthy controls or benign controls were only 0.67 and 0.60, respectively, with comparable figures for CA-125 being 0.92 and 0.88 although corresponding figures for a subgroup of samples analyzed by isoelectric focusing for afamin isoform 2 were 0.85 and 0.79. Analysis of a further 121 samples collected prospectively from 9 patients pretreatment through to relapse indicated complementarity of afamin with CA-125, including two cases in whom CA-125 was noninformative. Conclusions: Afamin shows potential complementarity with CA-125 in longitudinal monitoring of patients with ovarian cancer, justifying prospective larger-scale investigation. Changes in specific isoforms may provide further information.

MeCP2 and MBD2 expression in human neoplastic and non-neoplastic breast tissue and its association with oestrogen receptor status

This study analysed mRNA expression of two members of the methyl-CpG-binding protein family – MeCP2 and MBD2 – in human non-neoplastic (n=11) and neoplastic (n=57) breast tissue specimens using a quantitative real-time PCR method. We observed higher expression levels of MeCP2 mRNA in neoplastic tissues than in non-neoplastic tissues (P=0.001), whereas no significant differences for MBD2 were detected. When studying the relations between the most important clinicopathologic features of breast cancer and the mRNA expression level of both MBDs, we found that oestrogen receptor (OR)-positive breast cancer specimens contained higher levels of MeCP2 mRNA than did OR-negative cancers (P=0.005). Furthermore, we observed statistically significantly higher levels of MeCP2 in non-neoplastic tissues expressing high levels of OR as compared to those expressing low levels (P=0.017). Finally, using a linear regression model, we identified a statistically significant association between OR expression and MeCP2 mRNA expression in neoplastic and non-neoplastic breast tissue specimens (P=0.003). In conclusion, we were able to demonstrate for the first time that there exists a strong association between OR status and MeCP2 mRNA expression. Furthermore, we speculate that MeCP2, regulated by OR, plays a key role in the differentiation processes in human breast tissues.

Cyclin E dysregulation and chromosomal instability in endometrial cancer.

Deregulation of cyclin E, an activator of cyclin-dependent kinase 2 (Cdk2), has been associated with a broad spectrum of human malignancies. Yet the mechanism linking abnormal cyclin E expression to carcinogenesis is largely unknown. The gene encoding the F-box protein hCdc4, a key component of the molecular machinery that targets cyclin E for degradation, is frequently mutated in endometrial cancer, leading to deregulation of cyclin E expression. Here we show that hCDC4 gene mutation and hyperphosphorylation of cyclin E, a parameter that usually correlates with hCDC4 mutation, have a strong statistically significant association with polypoidy and aneuploidy in endometrial cancer. On the contrary, elevated expression of cyclin E by itself was not significantly correlated with polyploidy or aneuploidy when tumors of similar grade are evaluated. These data suggest that impairment of cell cycle regulated proteolysis of cyclin E may be linked to carcinogenesis by promoting genomic instability.

HE4 is an independent prognostic marker in endometrial cancer patients

OBJECTIVE To evaluate the prognostic value of pretherapeutic serum HE4 in endometrial cancer in comparison to CA125. METHODS HE4 and CA125 serum levels were analyzed by means of chemiluminescent microparticle immunoassays in 183 patients with endometrial cancer treated at the Department of Obstetrics and Gynecology, Innsbruck Medical University, between 1999 and 2009. The Kaplan-Meier method and Coxs proportional hazards analysis were performed to determine the prognostic significance of HE4, CA125 and the combination of both markers. RESULTS In univariate analysis both markers, HE4 and CA125, were of prognostic value for overall survival (p<0.001 and p=0.028) and disease-free survival (p=0.015 and p=0.045). In multivariate analysis HE4 was seen to have independent prognostic value in overall survival (HR 2.407, p=0.017) in contrast to CA125. The combination of both markers showed a higher hazard ratio (HR 4.04, p=0.023) for overall survival in comparison to HE4 alone. In the subgroup endometrioid histological type (n=132) only HE4 was of prognostic value for overall survival in univariate (p=0.001) and multivariate analysis (p=0.023). CONCLUSIONS Pretherapeutic serum HE4 levels alone and in combination with CA125 are an independent prognostic marker in endometrial cancer patients.

Epirubicin and docetaxel with or without capecitabine as neoadjuvant treatment for early breast cancer: final results of a randomized phase III study (ABCSG-24)

BACKGROUND This randomized phase III trial compared pathologic complete response (pCR) rates of early breast cancer (EBC) following neoadjuvant epirubicin-docetaxel (ED)±capecitabine (C), and evaluated the addition of trastuzumab in HER2-positive tumors. PATIENTS AND METHODS Patients with invasive breast cancer (except T4d) were randomly assigned to receive six 3-weekly cycles of ED (both 75 mg/m2)±C (1000 mg/m2, twice daily, days 1-14). Patients with HER2-positive disease were further randomized to receive trastuzumab (8 mg/kg, then 6 mg/kg every 3 weeks) or not. Primary end point: pCR rate at the time of surgery. RESULTS Five hundred thirty-six patients were randomized to ED (n=266) or EDC (n=270); 93 patients were further randomized to trastuzumab (n=44) or not (n=49). pCR rate was significantly increased with EDC (23.0% versus 15.4% ED, P=0.027), and nonsignificantly further increased with trastuzumab (38.6% EDC versus 26.5% ED, P=0.212). Rates of axillary node involvement at surgery and breast conservation were improved with EDC versus ED, but not significantly; the addition of trastuzumab had no further impact. Hormone receptor status, tumor size, grade, and C (all P≤0.035) were independent prognostic factors for pCR. Trastuzumab added to ED±C significantly increased the number of serious adverse events (35 versus 18; P=0.020), mainly due to infusion-related reactions. CONCLUSION These findings show that the integration of C into a neoadjuvant taxane-/anthracycline-based regimen is a feasible, safe, and effective treatment option, with incorporation of trastuzumab in HER2-positive disease. CLINICAL TRIAL NUMBER NCT00309556, www.clinicaltrials.gov.

Resistance to HER2-targeted therapy: mechanisms of trastuzumab resistance and possible strategies to overcome unresponsiveness to treatment

ZusammenfassungTrastuzumab ist eine hocheffektive Waffe in der Behandlung des HER2-positiven Mammakarzinoms. Dieser monoklonale Antikörper ist sowohl in der metastasierten als auch adjuvanten Situation zur Behandlung zugelassen. Trotzdem bleiben viele Fragen über den optimalen Einsatz weitgehend offen. Insbesondere die Tatsache, dass ein signifikanter Anteil HER-2 positiver Mammakarzinome primär nicht auf eine Trastuzumab-Therapie ansprechen oder nach etwa einem Jahr eine Resistenz gegenüber diesem Antikörper entwickeln, bedarf intensiver Forschungsarbeit. In dieser Zusammenfassung des aktuellen Wissenstands über die Resistenzmechanismen gegenüber Trastuzumab werden als mögliche Ursachen der extrazelluläre trunkierte HER2-Rezeptor, der Verlust des Tumor-Suppressors PTEN, die Aktivierung alternativer Signalwege (z. B. IGFR etc.) und der Verlust der Rezeptor-Antikörper-Interaktion diskutiert. Die Entwicklung von Strategien zur Aufhebung der Resistenzentwicklung stellt ein wichtiges Betätigungsfeld bei der Behandlung des HER2-neu positiven Mammakarzinoms dar.SummaryTrastuzumab has shown significant efficacy in HER2-overexpressing breast cancers and is approved for patients whose tumors carry this abnormality, both in the metastatic and in the adjuvant settings. However, several issues about its optimal use remain unresolved. Many breast cancer patients with HER2 overexpression do not respond to initial therapy with trastuzumab (Herceptin®), and a vast majority of these develop resistance to this monoclonal antibody within one year. This review discusses the molecular mechanisms leading to the development of trastuzumab resistance, including circulating HER2 extracellular domain, loss of PTEN, activation of alternative pathways (e.g. IGFR), and receptor-antibody interaction block. Additionally, the possibility of exploring these aberrations as therapeutic targets that potentially overcome resistance to trastuzumab is highlighted.

Regulation of transcription factor E2F3a and its clinical relevance in ovarian cancer

Recently we showed an integral epidermal growth factor receptor (EGFR)–E2F3a signaling path, in which E2F3a was found to be essential in EGFR-mediated proliferation in ovarian cancer cells. The present work evaluates the clinical relevance of this novel axis and of E2F3a itself in a large set of 130 ovarian cancer specimens. For this purpose E2F3a and its counterpart, E2F3b, were measured by RT–PCR and activated EGFR was assessed by immunohistochemistry. When compared with healthy control tissue, both E2F3 isoforms were overexpressed in the cancers, but only E2F3a expression correlated with tumor stage (ρ=0.349, P=0.0001) and residual disease (ρ=0.254, P=0.004). Univariate survival analyses showed E2F3a and activated EGFR to be associated with poor PFS and OS. Furthermore, a strong, positive correlation between activated EGFR and E2F3a expression was shown (P=0.0001). We further identified two EGFR-independent mechanisms that regulate E2F3a expression, namely one, acting by promoter methylation of miR-34a, which by its physical interaction with E2F3a transcripts causes their degradation, and the second based on 6p22 gene locus amplification. MiRIDIAN-based knockdown and induction of miR-34a evidenced a direct regulatory link between miR-34a and E2F3a, and the tumor-suppressive character of miR-34a was documented by its association with improved survival. Although, 6p22 gene locus amplification was detected in a significant number of ovarian cancer specimens, 6p22 ploidy was not relevant in predicting survival. In Cox regression analysis, E2F3a, but not activated EGFR or miR-34a expression, retained independent prognostic significance (PFS: hazards ratio 3.785 (1.326–9.840), P=0.013; OS: hazards ratio 4.651 (1.189–15.572), P=0.013). These clinical findings highlight the relevance of E2F3a in the biology of ovarian cancer. Moreover, identification of EGFR-independent mechanisms in E2F3a control can be helpful in explaining the non-responsiveness of therapeutic EGFR targeting in ovarian cancer.