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Women with hormone receptor positive breast cancer may receive 5 years of treatment with aromatase inhibitors but the magnitude of benefit was relatively small. Our goal was to develop a tool for identification of women with limited treatment benefit. Regression analyses were applied to women treated by placebo in CCTG MA.17R trial (NCT00754845) to identify important prognostic factors associated with distant recurrence and develop a nomogram for predicting 5-year likelihood of distant recurrence, which was internally validated using bootstrap resampling method. Differential treatment effects between risk categories derived from the nomogram were evaluated among all women enrolled through interaction test between treatment and risk category. A total of 1735 women were included and the final model from 866 women treated by placebo identified the following three factors associate with distant recurrence: tumor size, nodal status, and presence of cardiovascular disease. The nomogram derived from the final model exhibited good discrimination power with a bootstrap-corrected concordance index of 0.71 and, importantly, identified 64% of low risk patients in whom extended treatment has limited benefit. Interaction between treatment and risk category derived from the nomogram was significant (p = 0.04). A nomogram with good performance may be used to accurately predict distant recurrence risk and also benefits with extended treatment after 5 years of aromatase inhibitors. Future independent validation of the proposed nomogram is warranted. NCT00754845

Women with hormone receptor positive breast cancer may receive 5 years of treatment with aromatase inhibitors but the magnitude of benefit was relatively small. Our goal was to develop a tool for identification of women with limited treatment benefit.Regression analyses were applied to women treated by placebo in CCTG MA.17R trial (NCT00754845) to identify important prognostic factors associated with distant recurrence and develop a nomogram for predicting 5-year likelihood of distant recurrence, which was internally validated using bootstrap resampling method. Differential treatment effects between risk categories derived from the nomogram were evaluated among all women enrolled through interaction test between treatment and risk category.A total of 1735 women were included and the final model from 866 women treated by placebo identified the following three factors associate with distant recurrence: tumor size, nodal status, and presence of cardiovascular disease. The nomogram derived from the final model exhibited good discrimination power with a bootstrap-corrected concordance index of 0.71 and, importantly, identified 64% of low risk patients in whom extended treatment has limited benefit. Interaction between treatment and risk category derived from the nomogram was significant (p = 0.04).A nomogram with good performance may be used to accurately predict distant recurrence risk and also benefits with extended treatment after 5 years of aromatase inhibitors. Future independent validation of the proposed nomogram is warranted.NCT00754845.

PURPOSE: To examine associations between the UGT2B17 gene deletion and exemestane metabolites, and commonly reported side-effects (fatigue, hot flashes, and joint pain) among postmenopausal women participating in the MAP.3 chemoprevention trial. METHODS: The analytical samples for the UGT2B17 analysis comprised 1,752 women on exemestane and 1,721 women on placebo; the exemestane metabolite analysis included 1,360 women on exemestane with one-year serum samples. Both the UGT2B17 gene deletion and metabolites were measured in blood. The metabolites were conceptualized as a ratio (17-DHE-Gluc:17-DHE). Symptoms were assessed using the CTCAE v4.0 at approximately 1-year intervals. Log-binomial regression was used to examine the associations between UGT2B17 deletion, exemestane metabolites and each side effect at 1 and up to 5 year follow-up, adjusting for potential confounders. RESULTS: Among individuals on exemestane with the UGT2B17 gene deletion (i.e. lower detoxification), a higher risk of severe fatigue (RR=2.59 95% CI: 1.14–5.89) was observed at up to 5-year follow-up. Among individuals on placebo, those with the UGT2B17 gene deletion had a higher risk of any fatigue (RR=1.39, 95% CI: 1.02–1.89) at year 1. A lower metabolite ratio (poor detoxification) was associated with a higher risk of any fatigue, hot flashes and joint pain at year 1 (fatigue: RR=1.89, 95% CI: 1.16–3.09; hot flashes: RR=1.77, 95% CI: 1.40–2.24; joint pain: RR=2.05, 95% CI: 1.35–3.12); similar associations were observed at 5-year follow-up. CONCLUSION: Variation in the metabolism of exemestane through the UGT2B17-mediated pathway is associated with subsequent risk of commonly reported symptoms in MAP.3.

Pelareorep, a serotype 3 reovirus, has demonstrated preclinical and early clinical activity in breast cancer and synergistic cytotoxic activity with microtubule targeting agents. This multicentre, randomized, phase II trial was undertaken to evaluate the efficacy and safety of adding pelareorep to paclitaxel for patients with metastatic breast cancer (mBC). Following a safety run-in of 7 patients, 74 women with previously treated mBC were randomized either to paclitaxel 80 mg/m2 intravenously on days 1, 8, and 15 every 4 weeks plus pelareorep 3 × 1010 TCID50 intravenously on days 1, 2, 8, 9, 15, and 16 every 4 weeks (Arm A) or to paclitaxel alone (Arm B). Primary endpoint was progression-free survival (PFS). Secondary endpoints were objective response rate, overall survival (OS), circulating tumour cell counts, safety, and exploratory correlative analyses. All comparisons used a two-sided test at an alpha level of 20%. Survival analyses were adjusted for prior paclitaxel. Final analysis was performed after a median follow-up of 29.5 months. Pelareorep was well tolerated. Patients in Arm A had more favourable baseline prognostic variables. Median adjusted PFS (Arm A vs B) was 3.78 mo vs 3.38 mo (HR 1.04, 80% CI 0.76–1.43, P = 0.87). There was no difference in response rate between arms (P = 0.87). Median OS (Arm A vs B) was 17.4 mo vs 10.4 mo (HR 0.65, 80% CI 0.46–0.91, P = 0.1). This first, phase II, randomized study of pelareorep and paclitaxel in previously treated mBC did not show a difference in PFS (the primary endpoint) or RR. However, there was a significantly longer OS for the combination. Further exploration of this regimen in mBC may be of interest.

In murine models, overexpression of the MET receptor transgene induces tumors with human basal gene expression characteristics supporting MET inhibition as a treatment strategy for triple-negative breast cancer (TNBC). Foretinib is an oral multi-kinase inhibitor of MET, RON, AXL, TIE-2, and VEGF receptors with anti-tumor activity in advanced HCC and papillary renal cell cancer. Patients with centrally reviewed primary TNBC and 0–1 prior regimens for metastatic disease received daily foretinib 60 mg po in a 2-stage single-arm trial. Primary endpoints were objective response and early progression rates per RECIST 1.1. In stage 2, correlative studies of MET, PTEN, EGFR, and p53 on archival and fresh tumor specimens were performed along with enumeration of CTCs. 45 patients were enrolled with 37 patients having response evaluable and centrally confirmed primary TNBC (cTNBC). There were 2 partial responses (ITT 4.7 % response evaluable cTNBC 5.4 %) with a median duration of 4.4 months (range 3.7–5 m) and 15 patients had stable disease (ITT 33 %, response evaluable cTNBC 40.5 %) with a median duration of 5.4 months (range 2.3–9.7 m). The most common toxicities (all grades/grade 3) were nausea (64/4 %), fatigue (60/4 %), hypertension (58/49 %), and diarrhea (40/7 %). Six serious adverse events were considered possibly related to foretinib and 4 patients went off study due to adverse events. There was no correlation between MET positivity and response nor between response and PTEN, EGFR, p53, or MET expression in CTCs. Although CCTG IND 197 did not meet its primary endpoint, the observation of a clinical benefit rate of 46 % in this cTNBC population suggests that foretinib may have clinical activity as a single, non-cytotoxic agent in TNBC (ClinicalTrials.gov number, NCT01147484).

To evaluate changes in serum lipid parameters (cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, and lipoprotein(a) [Lp(a)]), in postmenopausal women receiving letrozole after tamoxifen therapy. MA.17L is a sub-study of MA.17, a double-blind, placebo-controlled trial of extended adjuvant letrozole. Eligible postmenopausal women were non-hyperlipidemic and not on lipid-lowering drugs. This analysis considers the 183 patients on the letrozole arm. Lipid parameters evaluated at baseline, 6 months, 12 months, and yearly thereafter until completion of 5 years of letrozole. The median duration of letrozole treatment was 5.0 years with a range from 0.03 to 6.05 years. After 5 year tamoxifen, patients on letrozole experienced significant increases from baseline in total cholesterol, LDL cholesterol, and Lp(a) at all study time points but no statistically significant changes in triglycerides. Specifically, a statistically significant increase was found at 60 months in total cholesterol [mean percentage change from baseline (PC) 5.27; p = 0.003], HDL cholesterol (mean PC 6.75; p = 0.003), LDL cholesterol (mean PC 10.02; p = 0.001), Lp(a) (mean PC 105.95; p < 0.0001). 103 (56 %) women in the study had clinically significantly elevated levels of Lp(a) (106 % above baseline) after 5 years of therapy. The results were similar after excluding the 21 % of patients who had ever received anti-lipid treatment. Significant increases in total cholesterol, HDL cholesterol, LDL cholesterol, and, most notably, Lp(a) in postmenopausal women were observed following 5 years of adjuvant letrozole treatment and after 5 years of tamoxifen therapy and such patients should have monitoring of their lipid levels in clinical practice.

HER2 amplification, TOP2A aberrations, and absence of tissue inhibitor of metalloproteinase (TIMP-1) expression in breast carcinomas have been shown to be associated with incremental benefit from anthracycline-containing adjuvant chemotherapy, and this study was undertaken to validate these findings in a similar, but independent, randomized clinical trial. TIMP-1 was examined by immunohistochemistry in archival tumor tissue from 403 of 716 premenopausal high-risk patients with known HER2 and TOP2A status who were randomized to cyclophosphamide, epirubicin, and fluorouracil (CEF) or cyclophosphamide, methotrexate, and fluorouracil (CMF) in the MA.5 trial. Ninety-eight (24%) patients had no TIMP-1 staining of tumor cells, 27% were HER2 amplified, and 18% were TOP2A aberrant. Forty-four percentage was classified as HT responsive (HER2 amplified and/or TIMP-1 negative) and 37% as 2T responsive (TOP2A aberrant and/or TIMP-1 negative). There was no heterogeneity in treatment effect of CEF versus CMF according to TIMP-1. In HT-responsive patients, CEF was superior to CMF with an improved RFS (adjusted HR, 0.64; 95% CI, 0.42-0.97), but this was not significant for OS (adjusted HR, 0.66; 95% CI, 0.42-1.04). A significant HT profile versus treatment interaction was detected for OS (P = 0.03). In 2T-responsive patients, CEF seemed to improve RFS compared to CMF (adjusted HR, 0.67; 95% CI, 0.43-1.03) and improved OS (adjusted HR, 0.58; 95% CI, 0.36-0.93). A significant 2T profile versus treatment interaction was detected for OS (P = 0.01). With this study, we validate a more substantial reduction in mortality by CEF compared to CMF in patients with an HT- or 2T-responsive profile; however, we could not show a similarly significant reduction in RFS events, where a benefit of CEF over CMF was found irrespective of TIMP-1 status. Further studies are necessary before the HT and 2T profiles may be used to direct the use of anthracyclines.

HER2 gene amplification and topoisomerase IIα gene (TOP2A) alteration have been associated with increased benefit from anthracycline compared to non-anthracycline containing adjuvant breast cancer chemotherapy in some but not other studies. Chromosome 17 centromere (CEP17) duplication was measured on TMAs from formalin-fixed paraffin-embedded specimens obtained from 639 of 716 premenopausal women with node positive breast cancer who received cyclophosphamide, epirubicin and fluorouracil (CEF) or cyclophosphamide, methotrexate and fluorouracil (CMF) in the randomized controlled mammary 5 (MA.5) adjuvant trial. The prognostic impact of CEP17 duplication and its interactions with treatment were studied for relapse-free survival (RFS) and overall survival (OS). Overall, CEP17 duplication was not significantly associated with RFS or OS in multivariate analysis. For patients whose tumours had normal CEP17 copy number there were no apparent benefits for CEF compared to CMF for RFS (HR 0.98; 95% CI 0.68–1.42) or OS (HR 1.10; 95% CI 0.72–1.69). For patients whose tumours had CEP17 duplication, there was significant benefit for CEF compared to CMF for RFS (HR 0.54; CI 0.33–0.89) and a trend towards significance for OS (HR 0.64; CI 0.37–1.09). The adjusted P values for interaction between treatment and CEP17 duplication were 0.09 for RFS and 0.13 for OS. This study suggests that CEP17 duplication has a borderline association with clinical responsiveness to anthracycline containing chemotherapy similar to previous results seen with HER2 amplification and TOP2A alteration in MA.5. An appropriately powered meta-analysis is required to discriminate the predictive value of these three candidate markers.

We hypothesized that exemestane (EXE) would reduce mammographic breast density and have unique effects on biomarkers of bone and lipid metabolism. Healthy postmenopausal women were randomized to EXE (25 mg daily) or placebo (PLAC) for 12 months and followed for a total of 24 months. The primary endpoint was change in percent breast density (PD) between the baseline and 12-month mammograms and secondary endpoints were changes in serum lipid levels, bone biomarkers, and bone mineral density (BMD). Ninety-eight women were randomized (49 to EXE; 49 to PLAC) and 65 had PD data at baseline and 12 months. Among women treated with EXE, PD was not significantly changed from baseline at 6, 12, or 24 months and was not different from PLAC. EXE was associated with significant percentage increase from baseline in N-telopeptide at 12 months compared with PLAC. No differences in percent change from baseline in BMD (lumbar spine and femoral neck) were observed between EXE and PLAC at either 12 or 24 months. Patients on EXE had a significantly larger percent decrease in total cholesterol than in the PLAC arm at 6 months and in HDL cholesterol at 3, 6, and 12 months. No significant differences in percent change in LDL or triglycerides were noted at any time point between the two treatment arms. EXE administered for 1 year to healthy postmenopausal women did not result in significant changes in mammographic density. A reversible increase in the bone resorption marker N-telopeptide without significant change in bone specific alkaline phosphatase or BMD during the 12 months treatment period and 1 year later was noted. Changes in lipid parameters on this trial were modest and reversible.

Overexpression of topoisomerase II protein (topo 2α) is postulated to be more closely associated with responsiveness to anthracycline-containing chemotherapy than human epidermal growth factor receptor type 2 (HER2) gene amplification or alterations in the topoisomerase II alpha gene (TOP2A). The authors used tissue microarrays from 477 of 710 premenopausal women with node-positive breast cancer randomized to CEF or CMF adjuvant chemotherapy in the NCIC Clinical Trials Group Mammary 5 (MA.5) trial. No significant interaction was found between treatment and continuous topo 2α level in either relapse-free (RFS) or overall survival (OS). In 136 patients (28.5%) whose tumors showed topo 2α overexpression by immunohistochemistry based on a cut-off of 13%, CEF was superior to CMF for RFS (adjusted HR 0.45; 95% CI 0.25–0.82; P = 0.009) and OS (adjusted HR 0.50; 95% CI 0.26–0.96; P = 0.04). When tumors lacked topo 2α overexpression, CEF was not superior for RFS (adjusted HR 0.88; 95% CI 0.64–1.22; P = 0.46) or OS (adjusted HR 0.95; 95% CI 0.66–1.38; P = 0.80). Interaction between topo 2α and treatment was borderline significant for RFS (P = 0.04) and OS (P = 0.05) and not substantially more significant than between TOP2A gene alteration (P interaction = 0.09 for RFS and 0.02 for OS) or HER2 overexpression (P interaction = 0.002 for RFS and 0.009 for OS). Topo 2α protein overexpression based on the cut-off identified in this study, TOP2A gene alterations and HER2 protein overexpression were each associated with responsiveness to anthracycline-containing chemotherapy. The topo 2α protein analysis was exploratory and will require further validation.

Decision-making regarding early closure and reporting of clinical trial results became a topic of intense debate following the reporting of the MA.17 adjuvant endocrine therapy trial. This trial was terminated at the first planned interim analysis when a highly significant improvement in disease free survival (DFS) was found. It has been suggested that the criterion for early stopping be made stricter when DFS is the primary study endpoint by ensuring that the targeted effect size is excluded. Our purpose is to examine this approach and to determine whether applying such a criterion would have affected the decision to terminate MA17. The sample size assumptions and the interim analysis of MA17 were reviewed and an appropriate method employed to convert hazard ratios (HR) to absolute differences. Expressed in relative terms, the effect size of MA17 was an HR of 0.78, and the upper boundary (0.75) of the confidence limits around the observed HR (0.57) excluded this value. In absolute terms, the lower confidence limit (3.1%) of best estimate of the 4 year difference in DFS (5.4%) excludes the difference (2.5%) used in the calculation of the targeted HR. We conclude that although the decision to release the results of the interim analysis of MA17 and allow patients on placebo to take letrozole was justified, methods for analyzing and interpreting interim results can be improved.

DPPE (tesmilifene) plus doxorubicin (DOX) demonstrated a significant improvement in survival versus DOX in a phase III clinical trial in advanced breast cancer. However, DPPE is associated with unusual toxicity in the form of hallucinations, nausea and vomiting which were anticipated to impact on short-term quality of life (QOL). Standard National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) approaches were applied as the primary method to analyze the QOL data from this trial. This includes cross-sectional comparisons, together with a global test for the QOL response rate. Sensitivity analyses were also performed for selected QOL domains and items, using other types of summary measures and statistics. Two hundred seventy one patients (89% of randomized) submitted the baseline QOL questionnaires and were included in the QOL analysis. No statistically significant difference in QOL response between treatment arms was found for any domain or item except nausea and vomiting (P = 0.04). Cross-sectional comparisons showed statistically significant differences for some domains/items at specific assessment times with all differences favoring the DOX alone arm. Patients on DPPE/DOX arm were significantly worse in terms of average and median pain change scores. Different analyses yielded slightly different conclusions but, in general, the QOL analyses were concordant and showed that patients on DOX alone had fewer disease and treatment related adverse events and␣better QOL. Interestingly, the QOL response analysis also showed that aggressive premedication regimens appear to ameliorate potential negative effects of DPPE on emesis and nausea as measured by patient assessed QOL.

MA.17 was a double-blind placebo-controlled trial involving 5187 postmenopausal women that established letrozole to be of value in reducing recurrence of breast cancer when given in the extended adjuvant therapy setting after about 5 years of tamoxifen. Analyses were conducted to examine the relationships between duration of treatment on MA.17 and outcomes.The final MA.17 database that included all events up to the date of unblinding of the study was interrogated. A non-parametric kernel smoothing method was used to estimate the hazard rates for disease-free survival (DFS), distant DFS (DDFS) and overall survival (OS) at 6, 12, 24, 36 and 48 months of follow-up and the hazard ratios (HRs) of letrozole to placebo were determined. The trend in HRs over time was tested based on a Cox model with a time-dependent covariate.Considering all patients, HRs for events in DFS and DDFS progressively decreased over time, favoring letrozole, with the trend being significant (p0.0001 and p = 0.0013, respectively) whereas the trend for OS was not significant. Considering the 2360 patients with node-positive status, the HRs for DFS, DDFS and OS all decreased over time with tests for trend all showing significance (p = 0.0004, 0.0005 and 0.038, respectively). Considering the 2568 patients with node-negative status, the HRs for DFS decreased over time with the test for trend being significant (p = 0.027) whereas the HRs for DDFS and OS showed no significant change over time.These analyses suggest that, at least out to about 48 months, longer duration of letrozole treatment is associated with greater benefit in the extended adjuvant therapy setting.