Dasatinib is a potent, oral SRC-family kinase inhibitor with preclinical antiproliferative, antimetastatic, and antiosteoclastic activity suggesting dasatinib sensitivity in triple-negative, or ...basal-like, breast cancer cell lines. This phase 2 trial assessed efficacy and safety of single-agent dasatinib in patients with advanced triple-negative breast cancer (TNBC).
Female patients with measurable, locally advanced or metastatic TNBC initially received dasatinib 100 mg twice daily (BID); to improve tolerability, the protocol was amended and subsequent patients received 70 mg BID. Primary endpoint was Response Evaluation Criteria in Solid Tumors-defined objective response rate (ORR); secondary endpoints included progression-free survival (PFS), disease control rate (DCR), safety, and limited pharmacokinetics.
Of the 44 treated patients, 43 were response evaluable. ORR was 4.7%: two patients had confirmed partial responses lasting 14 and 58 weeks, respectively. Of 11 patients with stable disease, two continued for more than 16 weeks, thus protocol-defined DCR was 9.3%. Median PFS was 8.3 weeks (95% CI: 7.3-15.3). Five patients discontinued before first tumor assessment. No grade 4 adverse events (AE) were reported; grade 3 AEs occurring in more than 5% of patients were fatigue (9.1%), diarrhea, pleural effusion, and dyspnea (all 6.8%). Laboratory abnormalities were uncommon. Dasatinib at 100 mg BID was not well tolerated; rates of treatment interruption, dose reduction, and serious AEs were lower with dasatinib 70 mg BID.
Single-agent dasatinib has limited activity in unselected patients with TNBC. Dasatinib 70 mg BID was better tolerated than 100 mg BID. Future studies will investigate dasatinib in other breast cancer settings, including chemotherapy combinations.
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•Patients with breast cancers were treated with tamoxifen or aromatase inhibitors.•Tamoxifen and aromatase inhibitors increased the level of 5,6-epoxycholesterol.•Aromatase inhibitors ...increased the levels of 25- and 27-hydroxycholesterol.
Accumulating evidence indicates that cholesterol oxygenation products, also known as oxysterols (OS), are involved in breast cancer (BC) promotion. The impact of Tam, as well as aromatase inhibitors (AI), an alternative BC endocrine therapy (ET), on OS metabolism in patients is currently unknown. We conducted a prospective clinical study in BC patients receiving Tam (n=15) or AI (n=14) in adjuvant or in metastatic settings. The primary end point was the feasibility of detecting and quantifying 11 different OS in the circulation of patients before and after 28days of treatment with Tam or AI. Key secondary end points were the measurements of variations in the concentrations of OS according to differences between patients and treatments. OS profiling in the serum of patients was determined by gas chromatography coupled to mass spectrometry. OS profiling was conducted in all patients both at baseline and during treatment regimens. An important inter-individual variability was observed for each OS. Interestingly 5,6β-epoxycholesterol relative concentrations significantly increased in the entire population (p=0.0109), while no increase in Cholestane-triol (CT) levels was measured. Interestingly, we found that, in contrast to AI, Tam therapy significantly decreased blood levels of 24-hydroxycholesterol (24-HC), 7α-HC and 25-HC (a tumor promoter) (p=0.0007, p=0.0231 and p=0.0231, respectively), whereas 4β-HC levels increased (p=0.0010). Interestingly, levels of 27-HC (a tumor promoter) significantly increased in response to AI (p=0.0342), but not Tam treatment. According to these results, specific OS are promising candidate markers of Tam and AI efficacy. Thus, further clinical investigations are needed to confirm the use of oxysterols as biomarkers of both prognosis and/or the efficacy of ET.
Altered expression of microRNAs (miRNA), an abundant class of small nonprotein-coding RNAs that mostly function as negative regulators of protein-coding gene expression, is common in cancer. Here, we ...analyze the regulation of miRNA expression in response to estrogen, a steroid hormone that is involved in the development and progression of breast carcinomas and that is acting via the estrogen receptors (ER) transcription factors. We set out to thoroughly describe miRNA expression, by using miRNA microarrays and real-time reverse transcription-PCR (RT-PCR) experiments, in various breast tumor cell lines in which estrogen signaling has been induced by 17beta-estradiol (E(2)). We show that the expression of a broad set of miRNAs decreases following E(2) treatment in an ER-dependent manner. We further show that enforced expression of several of the repressed miRNAs reduces E(2)-dependent cell growth, thus linking expression of specific miRNAs with estrogen-dependent cellular response. In addition, a transcriptome analysis revealed that the E(2)-repressed miR-26a and miR-181a regulate many genes associated with cell growth and proliferation, including the progesterone receptor gene, a key actor in estrogen signaling. Strikingly, miRNA expression is also regulated in breast cancers of women who had received antiestrogen neoadjuvant therapy. Overall, our data indicate that the extensive alterations in miRNA regulation upon estrogen signaling pathway play a key role in estrogen-dependent functions and highlight the utility of considering miRNA expression in the understanding of antiestrogen resistance of breast cancer.
PARP inhibitors (PARPi) have demonstrated efficacy in tumors with germline breast cancer susceptibility genes (gBRCA) 1 and 2 mutations, but further factors influencing response to PARPi are poorly ...understood.
Breast cancer tumor tissue from patients with gBRCA1/2 mutations from the phase III EMBRACA trial of the PARPi talazoparib versus chemotherapy was sequenced using FoundationOne CDx.
In the evaluable intent-to-treat population, 96.1% (296/308) had ≥1 tumor BRCA (tBRCA) mutation and there was strong concordance (95.3%) between tBRCA and gBRCA mutational status. Genetic/genomic characteristics including BRCA loss of heterozygosity (LOH; identified in 82.6% of evaluable patients), DNA damage response (DDR) gene mutational burden, and tumor homologous recombination deficiency assessed by genomic LOH (gLOH) demonstrated no association with talazoparib efficacy.
Overall, BRCA LOH status, DDR gene mutational burden, and gLOH were not associated with talazoparib efficacy; however, these conclusions are qualified by population heterogeneity and low patient numbers in some subgroups. Further investigation in larger patient populations is warranted.
To evaluate the efficacy of trastuzumab in patients with node-positive breast cancer treated with surgery, adjuvant chemotherapy, radiotherapy, and hormone therapy if applicable.
Three thousand ten ...patients with operable node-positive breast cancer were randomly assigned to receive adjuvant anthracycline-based chemotherapy with or without docetaxel. Patients who presented human epidermal growth factor receptor 2 (HER2) -overexpressing tumors were secondary randomly assigned to either a sequential regimen of trastuzumab (6 mg/kg every 3 weeks) for 1 year or observation. The primary end point was disease-free survival (DFS).
Overall 528 patients were randomly assigned between trastuzumab (n = 260) and observation (n = 268) arm. Of the 234 patients (90%) who received at least one administration of trastuzumab, 196 (84%) received at least 6 months of treatment, and 41 (18%) discontinued treatment due to cardiac events (any grade). At the date of analysis (October 2007), 129 DFS events were recorded. Random assignment to the trastuzumab arm was associated with a nonsignificant 14% reduction in the risk of relapse (hazard ratio, 0.86; 95% CI, 0.61 to 1.22; P = .41, log-rank stratified on pathologic node involvement). Three-year DFS rates were 78% (95% CI, 72.3 to 82.5) and 81% (95% CI, 75.3 to 85.4) in the observation and trastuzumab arms, respectively.
After a 47-month median follow-up, 1 year of trastuzumab given sequentially after adjuvant chemotherapy was not associated with a statistically significant decrease in the risk of relapse.
The 21-gene Recurrence Score (RS) result predicts outcome and chemotherapy benefit in node-negative and node-positive (N+), estrogen receptor-positive (ER+) patients treated with endocrine therapy. ...The purpose of this study was to evaluate the prognostic impact of RS results in N+, hormone receptor-positive (HR+) patients treated with adjuvant chemotherapy (6 cycles of FEC100 vs. 3 cycles of FEC100 followed by 3 cycles of docetaxel 100 mg/m
) plus endocrine therapy (ET) in the PACS-01 trial (J Clin Oncol 2006;24:5664-5671).
The current study included 530 HR+/N+ patients from the PACS-01 parent trial for whom specimens were available. The primary objective was to evaluate the relationship between the RS result and distant recurrence (DR).
There were 209 (39.4%) patients with low RS (< 18), 159 (30%) with intermediate RS (18-30) and 162 (30.6%) with high RS (≥ 31). The continuous RS result was associated with DR (hazard ratio = 4.14; 95% confidence interval: 2.67-6.43; p < 0.001), adjusting for treatment. In multivariable analysis, the RS result remained a significant predictor of DR (p < 0.001) after adjustment for number of positive nodes, tumor size, tumor grade, Ki-67 (immunohistochemical status), and chemotherapy regimen. There was no statistically significant interaction between RS result and treatment in predicting DR (p = 0.79).
After adjustment for clinical covariates, the 21-gene RS result is a significant prognostic factor in N+/HR+ patients receiving adjuvant chemoendocrine therapy.
Not applicable.
The activity and safety of eribulin mesylate (E7389), a nontaxane microtubule dynamics inhibitor with a novel mechanism of action, were evaluated in patients with locally advanced or metastatic ...breast cancer previously treated with an anthracycline, taxane, and capecitabine.
Eligible patients in this single-arm, open-label phase II study received eribulin mesylate (1.4 mg/m(2)) administered as a 2- to 5-minute intravenous infusion on days 1 and 8 of a 21-day cycle. The primary end point was objective response rate (ORR) assessed by independent review.
Of 299 enrolled patients who had received a median of four prior chemotherapy regimens, 291 received eribulin (for a median of four cycles). Of these, 269 patients met key inclusion criteria for the primary efficacy analysis. The primary end point of ORR by independent review was 9.3% (95% CI, 6.1% to 13.4%; all partial responses PRs), the stable disease (SD) rate was 46.5%, and clinical benefit rate (complete response + PR + SD > or = 6 months) was 17.1%. The investigator-reported ORR was 14.1% (95% CI, 10.2% to 18.9%). Median duration of response was 4.1 months, and progression-free survival was 2.6 months. Median overall survival was 10.4 months. The most common treatment-related grade 3 or 4 toxicities were neutropenia (54%; febrile neutropenia, 5.5%), leukopenia (14%), and asthenia/fatigue (10%; no grade 4); grade 3 neuropathy occurred in 6.9% of patients (no grade 4).
Eribulin demonstrated antitumor activity in extensively pretreated patients who had previously received an anthracycline, taxane, and capecitabine, with a manageable tolerability profile.
PURPOSE The indications of adjuvant chemotherapy for patients with estrogen receptor (ER) -positive breast cancer are controversial. We analyzed the predictive value of Ki67, HER2, and progesterone ...receptor (PR) expression for the efficacy of docetaxel in patients with ER-positive, node-positive breast cancer. PATIENTS AND METHODS Expression of Ki67, HER2, and PR was measured by immunohistochemistry in tumor samples from 798 patients with ER-positive breast cancer who participated in PACS01, a randomized trial that evaluated the efficacy of docetaxel. Risk reduction was evaluated using a Cox model adjusted for age, tumor size, nodal involvement, treatment arm, and biomarkers. The predictive value of biomarkers was assessed by an interaction test. Disease-free survival (DFS) was the primary end point. Results Ki67, HER2, and PR were expressed in 21%, 9%, and 62% of samples, respectively. Hazard ratios for relapse associated with docetaxel were 0.51 (95% CI, 0.26 to 1.01) in ER-positive/Ki67-positive tumors and 1.03 (95% CI, 0.69 to 1.55) in ER-positive/Ki67-negative tumors (ratio for interaction: 0.53; 95% CI, 0.24 to 1.16; P = .11). Five-year DFS rates were 81% (95% CI, 76% to 86%) and 84% (95% CI, 75% to 93%) in patients with ER-positive/Ki67-negative and ER-positive/Ki67-positive tumors treated with docetaxel and 81% (95% CI, 76% to 86%) and 62% (95% CI, 52% to 72%) in patients with ER-positive/Ki67-negative and ER-positive/Ki67-positive tumors treated with fluorouracil, epirubicin, and cisplatin. No trend for interaction was observed between docetaxel and HER2 (ratio for interaction: 0.83; 95% CI, 0.35 to 1.94; P = .66), nor between docetaxel and PR (ratio for interaction: 0.89; 95% CI, 0.47 to 1.66; P = .71). CONCLUSION Ki67 expression identifies a subset of patients with ER-positive breast cancer who could be sensitive to docetaxel treatment in the adjuvant setting.
In addition to the effect of cytochrome P450 (CYP) 2D6 genetic polymorphisms, the metabolism of tamoxifen may be impacted by other factors with possible consequences on therapeutic outcome (efficacy ...and toxicity). This analysis focused on the pharmacokinetic (PK)‐pharmacogenetic evaluation of tamoxifen in 730 patients with adjuvant breast cancer included in a prospective multicenter study. Plasma concentrations of tamoxifen and six major metabolites, the genotype for 63 single‐nucleotide polymorphisms, and comedications were obtained 6 months after treatment initiation. Plasma concentrations of endoxifen were significantly associated with CYP2D6 diplotype (P < 0.0001), CYP3A4*22 genotype (P = 0.0003), and concomitant intake of potent CYP2D6 inhibitors (P < 0.001). Comparison of endoxifen levels showed that the CYP2D6 phenotype classification could be improved by grouping intermediate metabolizer (IM)/IM and IM/poor metabolizer diplotype into IM phenotype for future use in tamoxifen therapy optimization. Finally, the multivariable regression analysis showed that formation of tamoxifen metabolites was independently impacted by CYP2D6 diplotype and CYP3A4*22, CYP2C19*2, and CYP2B6*6 genetic polymorphisms.
There is a need for new agents to treat metastatic breast cancer (MBC) in patients for whom anthracycline therapy has failed or is contraindicated. This study was conducted to assess the efficacy and ...safety of the novel antineoplastic, the epothilone B analog ixabepilone, in patients with MBC previously treated with an adjuvant anthracycline.
Patients were age >or= 18 years and had received a prior anthracycline-based regimen as adjuvant treatment. Ixabepilone as first-line metastatic chemotherapy was administered as a 40 mg/m(2) intravenous infusion during 3 hours every 3 weeks. The primary efficacy end point was objective response rate (ORR). Secondary efficacy end points included duration of response, time to response, time to progression, and survival.
All 65 patients were assessable for response. Their median age was 52 years (range, 33 to 80 years). ORR was 41.5% (95% CI, 29.4% to 54.4%), median duration of response was 8.2 months (95% CI, 5.7 to 10.2 months), and median time to response was 6 weeks (range, 5 to 17 weeks). Median survival was 22.0 months (95% CI, 15.6 to 27.0 months). Treatment-related adverse events were manageable and mostly grades 1/2: the most common of these (other than alopecia) was mild to moderate neuropathy, which was primarily sensory and mostly reversible in nature.
Ixabepilone is efficacious and has a predictable and manageable safety profile in women with MBC previously treated with an adjuvant anthracycline.
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