Real-world outcomes from use of CDK4/6 inhibitors in the management of advanced/metastatic breast cancer in Asia.

Background: Oestrogen receptor positive, human epidermal growth factor receptor-2 (HER2) negative breast cancer (BC) is the most frequently diagnosed BC subtype. Combinations of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) with anti-oestrogen therapy have led to improved survival compared with anti-oestrogen therapy alone for advanced/metastatic BC. The evaluation of CDK4/6i in the real-world facilitates treatment planning, insights into the incidence of drug toxicities, dose modifications including dose delays (DDs) and dose reductions (DRs) and improves prognostic accuracy in subgroups, for example geriatric patients, who are under-represented in clinical trials. Methods: This multi-centre study analysed retrospective and prospective data from 456 patients treated with CDK4/6i between January 2015 and December 2020. We examined patient characteristics, variation in prescribing practices, efficacy and toxicity outcomes. Results: In all, 456 patients were included in this study. The median age was 59 (range: 24-92). In total, 85 (19%) were ⩾70 years old. In all, 122 (27%) and 119 (26%) of patients were treated in the first-line and second-line settings, respectively. In total, 25 (5%), 31 (7%) and 145 (32%) of patients had brain, peritoneum and liver metastasis, respectively, at the time of CDK4/6i initiation. On univariate analysis, heavily pre-treated patients and those with distant metastases, involving the liver, brain or peritoneum, had significantly shorter progression-free survival (PFS) and 24-month overall survival (OS). Elderly patients (⩾70) had a shorter PFS; OS results were not mature. Majority of patients (n = 362, 80%) initiated treatment with the United States FDA-approved starting dose of CDK4/6i. In all, 330 (72%) had at least one DD and 217 (48%) patients required at least one DR, but these dose modifications were not associated with poorer survival outcomes. Patients age ⩾70 were more likely to require dose modifications leading to a lower treatment dose. The most common reason for DD/DR was neutropenia (60%) and the incidence of febrile neutropenia was only 2%. Conclusions: Our study indicates CDK4/6i is effective and safe. Age ⩾ 70, distant metastases to liver, peritoneal or brain were negative prognostic factors. Age ⩾ 70 was associated with significantly increased requirement for dose modification; however, this did not impact survival outcomes. These findings provide reassurance that survival outcomes are not adversely affected in elderly patients when DD/DR is indicated.

Beliefs about medicines and adherence in women with breast cancer on adjuvant endocrine therapy.

The Beliefs about Medicines Questionnaire (BMQ) and Adherence Starts with Knowledge (ASK-12) questionnaire were originally developed and validated in Western populations to assess beliefs and barriers to medication adherence. The study aim is to validate the BMQ and ASK-12 questionnaire for use in a Singapore population with early stage breast cancer. English-speaking women on adjuvant endocrine therapy (n = 157) were recruited. The BMQ-Specific showed good internal consistency with structural validity. The internal consistency of BMQ-General and ASK-12 Behaviour scale improved with the new factor structure obtained from exploratory factor analysis. Further studies are needed to confirm these factor structures.

Immunohistochemistry study of tumor vascular normalization and anti-angiogenic effects of sunitinib versus bevacizumab prior to dose-dense doxorubicin/cyclophosphamide chemotherapy in HER2-negative breast cancer.

PURPOSE: Tumor angiogenesis controlled predominantly by vascular endothelial growth factor and its receptor (VEGF-VEGFR) interaction plays a key role in the growth and propagation of cancer cells. However, the newly formed network of blood vessels is disorganized and leaky. Pre-treatment with anti-angiogenic agents can "normalize" the tumor vasculature allowing effective intra-tumoral delivery of standard chemotherapy. Immunohistochemistry (IHC) analysis was applied to investigate and compare the vascular normalization and anti-angiogenic effects of two commonly used anti-angiogenic agents, Sunitinib and Bevacizumab, administered prior to chemotherapy in HER2-negative breast cancer patients. METHODS: This prospective clinical trial enrolled 38 patients into a sunitinib cohort and 24 into a bevacizumab cohort. All received 4 cycles of doxorubicin/cyclophosphamide chemotherapy and pre-treatment with either sunitinib or bevacizumab. Tumor biopsies were obtained at baseline, after cycle 1 (C1) and cycle 4 (C4) of chemotherapy. IHC was performed to assess the tumor vascular normalization index (VNI), lymphatic vessel density (LVD), Ki67 proliferation index and expression of tumor VEGFR2. RESULTS: In comparison to Bevacizumab, Sunitinib led to a significant increase in VNI post-C1 and C4 (p < 0.001 and 0.001) along with decrease in LVD post-C1 (p = 0.017). Both drugs when combined with chemotherapy resulted in significant decline in tumor proliferation after C1 and C4 (baseline vs post-C4 Ki67 index p = 0.006 for Sunitinib vs p = 0.021 for Bevacizumab). Bevacizumab resulted in a significant decrease in VEGFR2 expression post-C1 (p = 0.004). CONCLUSION: Sunitinib, in comparison to Bevacizumab showed a greater effect on tumor vessel modulation and lymphangiogenesis suggesting that its administration prior to chemotherapy might result in improved drug delivery. TRIAL REGISTRY: ClinicalTrials.gov: NCT02790580 (first posted June 6, 2016).

Facilitators and barriers to medication adherence with adjuvant endocrine therapy in women with breast cancer: a structural equation modelling approach.

PURPOSE: To identify a structure to explain the relationship between socio-clinico factors, necessity-concerns beliefs, and perceived barriers to adherence with adjuvant endocrine therapy (AET) amongst women with breast cancer. METHODS: Participants were 244 patients with early-stage breast cancer recruited from two tertiary hospitals from May 2015 to December 2018 who completed questionnaires on medication adherence (Simplified Medication Adherence Questionnaire), necessity-concerns beliefs (Beliefs about Medicine Questionnaire), and barriers to adherence (Adherence Starts with Knowledge Questionnaire). Socio-clinico variables were collected via interview and medical records review. Structural equation modelling was applied to examine the relationships between these variables and possible mediating effects of necessity-concerns beliefs on adherence to AET. RESULTS: The median age of the study participants was 61 (range 32-80) years and the median duration on AET was 1.6 (IQR 1.2-2.6) years. Adherence was positively associated with age (ß = 0.145, 95% CI: 0.011 to 0.279, p = 0.034) and negatively associated with barriers (ß = - 0.381, 95% CI: - 0.511 to - 0.251, p < 0.001). There was no effect of Necessity (ß = 0.006, 95% CI: - 0.145 to 0.158, p = 0.933) or Concerns (ß = 0.041, 95% CI: - 0.117 to 0.199, p = 0.614) on adherence. Necessity-concerns beliefs were also not significant mediators in the relationship between socio-clinico factors and medication adherence. CONCLUSIONS: Older age and lower barriers to adherence were associated with higher adherence scores. Necessity-concerns beliefs did not have a significant effect on adherence as majority of the patients identified forgetfulness as a reason for non-adherence.

A randomized phase II trial evaluating the addition of low dose, short course sunitinib to docetaxel in advanced solid tumours.

BACKGROUND: We previously reported that low-dose, short-course sunitinib prior to neoadjuvant doxorubicin-cyclophosphamide (AC) normalised tumour vasculature and improved perfusion, but resulted in neutropenia and delayed subsequent cycles in breast cancer patients. This study combined sunitinib with docetaxel, which has an earlier neutrophil nadir than AC. METHODS: Patients with advanced solid cancers were randomized 1:1 to 3-weekly docetaxel 75 mg/m2, with or without sunitinib 12.5 mg daily for 7 days prior to docetaxel, stratified by primary tumour site. Primary endpoints were objective-response (ORR:CR + PR) and clinical-benefit rate (CBR:CR + PR + SD); secondary endpoints were toxicity and progression-free-survival (PFS). RESULTS: We enrolled 68 patients from 2 study sites; 33 received docetaxel-sunitinib and 35 docetaxel alone, with 33 breast, 25 lung and 10 patients with other cancers. There was no difference in ORR (30.3% vs 28.6%, p = 0.432, odds-ratio [OR] 1.10, 95% CI 0.38-3.18); CBR was lower in the docetaxel-sunitinib arm (48.5% vs 71.4%, p = 0.027 OR 0.37, 95% CI 0.14-1.01). Median PFS was shorter in the docetaxel-sunitinib arm (2.9 vs 4.9 months, hazard-ratio [HR] 2.00, 95% CI 1.15-3.48, p = 0.014) overall, as well as in breast (4.2 vs 5.6 months, p = 0.048) and other cancers (2.0 vs 5.3 months, p = 0.009), but not in lung cancers (2.9 vs 4.1 months, p = 0.597). Median OS was similar in both arms overall (9.9 vs 10.5 months, HR 0.92, 95% CI 0.51-1.67, p = 0.789), and in the breast (18.9 vs 25.8 months, p = 0.354), lung (7.0 vs 6.7 months, p = 0.970) and other cancers (4.5 vs 8.8 months, p = 0.449) subgroups. Grade 3/4 haematological toxicities were lower with docetaxel-sunitinib (18.2% vs 34.3%, p = 0.132), attributed to greater discretionary use of prophylactic G-CSF (90.9% vs 63.0%, p = 0.024). Grade 3/4 non-haematological toxicities were similar (12.1% vs 14.3%, p = 0.792). CONCLUSIONS: The addition of sunitinib to docetaxel was well-tolerated but did not improve outcomes. The possible negative impact in metastatic breast cancer patients is contrary to results of adding sunitinib to neoadjuvant AC. These negative results suggest that the intermittent administration of sunitinib in the current dose and schedule with docetaxel in advanced solid tumours, particularly breast cancers, is not beneficial. TRIAL REGISTRATION: The study was registered ( NCT01803503 ) prospectively on clinicaltrials.gov on 4th March 2013.

Improving medication adherence with adjuvant aromatase inhibitor in women with breast cancer: A randomised controlled trial to evaluate the effect of short message service (SMS) reminder.

BACKGROUND: Medication adherence is crucial for improving clinical outcomes in the treatment of patients. We evaluate the effect of short message service (SMS) reminder on medication adherence and serum hormones in patients with breast cancer on aromatase inhibitors. METHODS: An open-label, multi-centre, prospective randomised controlled trial of SMS versus Standard Care was conducted. Medication adherence was assessed via self-report using the Simplified Medication Adherence Questionnaire at baseline, 6 month, and 1 year. Androstenedione, estradiol, and estrone were measured at baseline and 1 year. The χ2 test and mixed effects logistic regression was performed to compare medication adherence between groups. Difference in androstenedione and estrone levels were assessed using analysis of covariance, whereas χ2 test and logistic regression was used for estradiol. Analysis was based on intention-to-treat. RESULTS: A total of 244 patients were randomised to receive weekly SMS reminder (n = 123) or Standard Care (n = 121) between May 2015 and December 2018. The odds of adherence was higher at 6-month in SMS (OR = 1.78, 95% CI 1.04-3.05, p = 0.034), and not significantly different at 1-year (OR = 1.15, 95% CI: 0.67-1.96 p = 0.617). Mixed effects logistic regression analysis showed higher odds of adherence in SMS over the 1-year period (OR = 2.35, 95% CI: 1.01-5.49, p = 0.048). There was no difference in serum hormone levels between groups. CONCLUSION: SMS reminder improved medication adherence in the short-term but had no effect on serum hormones levels in the longer term. Future studies could investigate the use of tailored SMS intervention according to patient preference to improve its sustainability.

Phase I Trial of Expanded, Activated Autologous NK-cell Infusions with Trastuzumab in Patients with HER2-positive Cancers.

PURPOSE: Natural killer (NK) cells exert antibody-dependent cell cytotoxicity (ADCC). We infused expanded, activated autologous NK cells to potentiate trastuzumab-mediated ADCC in patients with HER2-positive malignancies. PATIENTS AND METHODS: In a phase I trial, patients with treatment-refractory HER2-positive solid tumors received trastuzumab, with or without bevacizumab, and autologous NK cells expanded by 10-day coculture with K562-mb15-41BBL cells. Primary objectives included safety and recommended phase II dose determination; secondary objectives included monitoring NK-cell activity and RECIST antitumor efficacy. RESULTS: In 60 cultures with cells from 31 subjects, median NK-cell expansion from peripheral blood was 340-fold (range, 91-603). NK cells expressed high levels of CD16, the mediator of ADCC, and exerted powerful killing of trastuzumab-targeted cells. In the 22 subjects enrolled in phase I dose escalation, trastuzumab plus NK cells were well tolerated; MTD was not reached. Phase IB (n = 9) included multiple cycles of NK cells (1 × 107/kg) and addition of bevacizumab. Although no objective response was observed, 6 of 19 subjects who received at least 1 × 107/kg NK cells at cycle 1 had stable disease for ≥6 months (median, 8.8 months; range 6.0-12.0). One patient, the only one with the high-affinity F158V CD16 variant, had a partial response. Peripheral blood NK cells progressively downregulated CD16 postinfusion; paired tumor biopsies showed increased NK cells, lymphocytic infiltrates, and apoptosis posttreatment. CONCLUSIONS: NK-cell therapy in combination with trastuzumab was well tolerated, with target engagement and preliminary antitumor activity, supporting continued assessment of this approach in phase II trials.

Oncologist-patient-caregiver decision-making discussions in the context of advanced cancer in an Asian setting.

OBJECTIVE: Patient involvement in treatment decisions is recommended in clinician-patient encounters. Little is known about how oncologists engage patients in shared decision making in non-Western countries. We assessed the prevalence of shared decision making among Singaporean oncologists and analysed how they discussed prognosis. METHODS: We audio-recorded 100 consultations between advanced cancer patients and their oncologists. We developed a coding system to assess oncologist encouragement of patient participation in decision making and disclosure of an explicit prognosis. We assessed patient and oncologist characteristics that predicted these behaviours. RESULTS: Forty-one consultations involved treatment discussions. Oncologists almost always listed more than one treatment option (90%). They also checked patient understanding (34%), discussed pros and cons (34%) and addressed uncertainty (29%). Oncologists discussed prognosis mostly qualitatively (34%) rather than explicitly (17%). They were more likely to give an explicit prognosis when patients/caregivers asked questions related to prognosis. CONCLUSION: Oncologists in our sample engaged their patients in decision making. They have areas in which they can improve to involve patients at a deeper level to ensure shared decision making. Findings will be used to develop an intervention targeting oncologists and patients to promote patient involvement in decision making.

Oncologists' responses to patient and caregiver negative emotions and patient perception of quality of communication: results from a multi-ethnic Asian setting.

PURPOSE: Patients with advanced cancer and their caregivers experience many negative emotions. Empathic responses from oncologists can help alleviate their distress. We aimed to assess expressions of negative emotions among patients with advanced cancer and their caregivers and oncologists' empathic responses during consultations in an Asian setting. We also assessed the association between oncologists' expression of empathy and patients' and caregivers' perception of communication quality. METHODS: We surveyed 100 patients with advanced cancer and their caregivers and audio recorded consultations with their oncologists. We coded expressions of negative emotions by patients and caregivers and oncologists' empathic responses. We also surveyed participating oncologists (n = 30) about their confidence in expressing empathy and perceived communication behavior outcomes. RESULTS: About 52% of patients and 49% of caregivers expressed at least one negative emotion during the consultation, though 59% of patients and 48% of caregivers reported not wanting to discuss negative emotions. Oncologists responded empathically to 12% of patients' negative emotions and 9% of caregivers' negative emotions, despite 92% of them reporting confidence in expressing empathy. Oncologists' expression of empathy did not vary significantly by patient, caregiver, or their own demographic characteristics. It also did not differ based on their confidence in expressing empathy and positive outcome expectations. When oncologists responded empathically just one time, patients perceived communication more favorably. CONCLUSIONS: In this Asian setting, patients and caregivers commonly expressed negative emotions. Oncologists' expressed empathy infrequently, although when they were empathic, it was related to improved patient perception of communication quality.

Accelerated partial breast irradiation in an Asian population: dosimetric findings and preliminary results of a multicatheter interstitial program.

INTRODUCTION: Accelerated partial breast irradiation (APBI) using the multicatheter method has excellent cosmesis and low rates of long-term toxicity. However, there are few studies looking at the feasibility of this procedure and the outcomes in an Asian population. This study aims to look at outcomes at our hospital. METHODS: We identified 121 patients treated with APBI at our center between 2008 and 2014. The median follow-up for our patient group was 30 months (range 3.7-66.5). The prescribed dose per fraction was 3.4 Gy in 10 fractions. In this study population, 71% of the patients were Chinese while 15% (n=19) were of other Asian ethnicity. RESULTS: In this study, the median breast volume was 850 cc (range 216-2,108) with 59.5% (n=72) patients with a breast volume of <1,000 cc. The average planning target volume was 134 cc (range 28-324). The number of catheters used ranged from 8 to 25 with an average of 18 catheters used per patient. We achieved an average dose homogeneity index of 0.76 in our patients. The average D90(%) was 105% and the average D90(Gy) was 3.6 Gy per fraction. The median volume receiving 100% of the prescribed dose (V100) was 161.7 cc (range 33.9-330.1), 150% of the prescribed dose (V150) and 200% of the prescribed dose (V200) was 39.4 cc (range 14.6-69.6) and 14.72 cc (range 6.48-22.25), respectively. Our dosimetric outcomes were excellent even in patients with breast volume under 1,000 cc. There were no cases of grade 3 skin toxicity or acute pneumonitis. Two patients had a postoperative infection and two patients had fat necrosis postprocedure. CONCLUSION: Multicatheter high dose rate APBI is a safe and feasible procedure that can be carried out with minimal toxicity in Asian patients with breast volumes under 1,000 cc.

Phase Ib/II randomized, open-label study of doxorubicin and cyclophosphamide with or without low-dose, short-course sunitinib in the pre-operative treatment of breast cancer.

BACKGROUND: Prolonged anti-angiogenic therapy destroys tumor vasculature, whereas vascular-normalizing doses may enhance intra-tumoral drug delivery. We hypothesize that low-dose, short-course sunitinib normalizes vasculature, enhancing chemotherapy efficacy. PATIENTS AND METHODS: In phase Ib, treatment-naïve breast cancer patients received four cycles of pre-operative doxorubicin/cyclophosphamide, with sunitinib before each cycle. The optimal dose of sunitinib leading to tumor vessel normalization on immunohistochemistry was identified. In phase II, subjects were randomized to chemotherapy alone or chemotherapy plus sunitinib at the recommended phase II dose (RP2D). Primary endpoint was pathological complete response (pCR) rate. Tumor and functional imaging biomarkers were evaluated serially. RESULTS: In phase Ib (n=9), sunitinib 12.5 mg daily for 7 days before each chemotherapy was established as RP2D. In phase II, patients receiving chemotherapy plus sunitinib (n=24) had similar pCR rates (5.0% versus 4.3%, p=1.00), but a higher incidence of chemotherapy dose delays (33.3% versus 8.7%, p=0.04), compared to those receiving chemotherapy alone (n=25). The addition of sunitinib to chemotherapy significantly increased vascular normalization index (VNI) and decreased lymphatic vessel density (D2-40) on immunohistochemistry [VNI:25.50±27.94% versus 49.29±31.84%, p=0.034; D2-40:3.29±2.70 versus 1.29±1.54, p=0.014, baseline versus post-cycle 1], and improved perfusion on DCE-MRI (Ktrans:12.6±9.6 mL/100 g/min versus 16.3±10.7 mL/100 g/min, baseline versus post-cycle 1, p=0.015). Conversely, immunohistochemical and DCE-MRI parameters were not significantly altered by chemotherapy alone. CONCLUSION: Low-dose, short-course sunitinib prior to anthracycline-based chemotherapy in breast cancer patients did not improve pCR and increased chemotherapy dose delays. However, the addition of sunitinib induced compelling pharmacodynamic evidence of vascular normalization. Further studies with alternative cytotoxic regimens should be explored.

High expression of intratumoral stromal proteins is associated with chemotherapy resistance in breast cancer.

We studied the changes of intratumoral stromal proteins including THBS1, TNC, FN, SPARC and α-SMA, following neoadjuvant chemotherapy. The underlying mechanisms by which THBS1 and TNC regulated resistance to docetaxel were further studied using functional studies. 100 patients with newly diagnosed breast cancer were treated with alternating sequential doxorubicin and docetaxel. Immunohistochemistry (IHC) staining for stromal proteins was performed on pre- and post-treatment core biopsies respectively. THBS1 and TNC were further validated with IHC in an independent cohort of 31 patients. A high baseline combined expression score of the 5 stromal proteins predicted independently for poor progression-free (HRadjusted 2.22, 95% CI 1.06-4.64) and overall survival (HRadjusted 5.94, 95% CI 2.25-15.71). After 1-2 cycles of chemotherapy, increased expression of THBS1, TNC, FN, SPARC and α-SMA was seen in patients with subsequent pathological lymph node involvement at surgery. Increased expression of THBS1 and TNC compared to baseline was also seen in intrinsically resistant tumors, but not in sensitive ones. Both THBS1 and TNC-associated chemoresistance were confirmed in an independent validation cohort. Exogenous THBS1 and TNC protected MCF-7 cells against proliferation inhibition induced by docetaxel through activating integrin ß1/mTOR pathway. Thus, up-regulation of THBS1, TNC, FN, SPARC and α-SMA following neoadjuvant chemotherapy was associated with chemotherapy resistance in breast cancer patients. Functional studies showed THBS1 and TNC to mediate chemoresistance through the integrin ß1/mTOR pathway, suggesting that therapies targeting integrin ß1/mTOR pathway may be a promising strategy to overcome chemotherapy resistance.

Pharmacogenetics-Guided Phase I Study of Capecitabine on an Intermittent Schedule in Patients with Advanced or Metastatic Solid Tumours.

The FDA-approved starting dosage of capecitabine is 1,250 mg/m(2), and market research indicates that U.S. physicians routinely prescribe 1,000 mg/m(2). Retrospective analyses however report reduced toxicity and efficacy in a subset of patients with the 3R/3R genotype of the thymidylate synthase gene enhancer region (TSER). This study sought to develop TSER genotype-specific guidelines for capecitabine dosing. Capecitabine was dose-escalated in advanced and/or metastatic cancer patients with TSER 3R/3R (Group A; N = 18) or 2R/2R + 2R/3R (Group B; N = 5) from 1,250 to 1,625 mg/m(2) b.i.d., every 2 weeks on/1 week off for up to 8 cycles. Parent and metabolites pharmacokinetics, adverse events, and tumour response were assessed. The maximum tolerated and recommended doses in 3R/3R patients are 1,625 mg/m(2) and 1,500 mg/m(2). At 1,500 mg/m(2), one in nine 3R/3R patients experienced a dose-limiting toxicity. Dosing guidelines for 2R/2R + 2R/3R remain undetermined due to poor accrual. The results indicate that 3R/3R patients may be amenable to 1,500 mg/m(2) b.i.d. on an intermittent schedule, and is the first to prospectively validate the utility of TSER pharmacogenetic-testing before capecitabine treatment.

Dose modifications in Asian cancer patients with hepatic dysfunction receiving weekly docetaxel: A prospective pharmacokinetic and safety study.

Hepatic dysfunction may modify the safety profile and pharmacokinetics of docetaxel in cancer patients, but no validated guideline exists to guide dose modification necessitated by this uncommon comorbidity. We carried out the first prospective study of a personalized dosage regimen for cancer patients with liver dysfunction treated with docetaxel. Weekly dosages were stratified by hepatic dysfunction classification as such: Category 1, normal; Category 2, mild--alkaline phosphatase, aspartate aminotransferase, and/or alanine aminotransferase ≤5× upper limit of normal (ULN), and total bilirubin within normal range; and Category 3, moderate--any alkaline phosphatase, and aspartate aminotransferase or alanine aminotransferase ≤5-10× ULN, and/or total bilirubin ≤1-1.5× ULN. Category 1, 2 and 3 patients received starting dosages of 40, 30, and 20 mg/m(2) docetaxel, respectively. Pharmacokinetics were evaluated on day 1 and 8 of the first treatment cycle, and entered into a multilevel model to delineate interindividual and interoccasion variability. Adverse event evaluation was carried out weekly for two treatment cycles. We found that docetaxel clearance was significantly different between patient categories (P < 0.001). Median clearance was 22.8, 16.4, and 11.3 L/h/m(2) in Categories 1, 2, and 3, respectively, representing 28% and 50% reduced clearance in mild and moderate liver dysfunction patients, respectively. However, docetaxel exposure (area under the concentration-time curve) and docetaxel-induced neutropenia (nadir and the maximum percentage decrease in neutrophil count) were not significantly different between categories. Median area under the concentration-time curve was 1.74, 1.83, and 1.77 mg·h/L in Categories 1, 2, and 3, respectively. The most common Grade 3/4 toxicity was neutropenia (30.0%). An unplanned comparison with the Child-Pugh and National Cancer Institute Organ Dysfunction Working Group grouping systems suggests that the proposed classification system appears to more effectively discriminate patients by docetaxel clearance and dose requirements. (ClinicalTrials.gov registration no. NCT00703378).

High-Throughput Mutation Profiling Changes before and 3 Weeks after Chemotherapy in Newly Diagnosed Breast Cancer Patients.

BACKGROUND: Changes in tumor DNA mutation status during chemotherapy can provide insights into tumor biology and drug resistance. The purpose of this study is to analyse the presence or absence of mutations in cancer-related genes using baseline breast tumor samples and those obtained after exposure to one cycle of chemotherapy to determine if any differences exist, and to correlate these differences with clinical and pathological features. METHODS: Paired breast tumor core biopsies obtained pre- and post-first cycle doxorubicin (n = 18) or docetaxel (n = 22) in treatment-naïve breast cancer patients were analysed for 238 mutations in 19 cancer-related genes by the Sequenom Oncocarta assay. RESULTS: Median age of patients was 48 years (range 32-64); 55% had estrogen receptor-positive tumors, and 60% had tumor reduction ≥25% after cycle 1. Mutations were detected in 10/40 (25%) pre-treatment and 11/40 (28%) post-treatment samples. Four mutation pattern categories were identified based on tumor mutation status pre- → post-treatment: wildtype (WT)→WT, n = 24; mutant (MT)→MT, n = 5; MT→WT, n = 5; WT→MT, n = 6. Overall, the majority of tumors were WT at baseline (30/40, 75%), of which 6/30 (20%) acquired new mutations after chemotherapy. Pre-treatment mutations were predominantly in PIK3CA (8/10, 80%), while post-treatment mutations were distributed in PIK3CA, EGFR, PDGFRA, ABL1 and MET. All 6 WT→MT cases were treated with docetaxel. Higher mutant allele frequency in baseline MT tumors (n = 10; PIK3CA mutations n = 8) correlated with less tumor reduction after cycle 1 chemotherapy (R = -0.667, p = 0.035). No other associations were observed between mutation pattern category with treatment, clinicopathological features, and tumor response or survival. CONCLUSION: Tumor mutational profiles can change as quickly as after one cycle of chemotherapy in breast cancer. Understanding of these changes can provide insights on potential therapeutic options in residual resistant tumors. TRIAL REGISTRATION: ClinicalTrials.gov NCT00212082.

An update on chemotherapy and tumor gene expression profiles in breast cancer.

INTRODUCTION: Various trials have attempted to develop gene expression profiles (GEPs) that may provide a better predictor of clinical outcome over traditional clinicopathological criteria. AREAS COVERED: The review focuses on two main areas: trials examining chemotherapy-induced GEP changes pre- and post-treatment, and studies correlating baseline signatures with chemosensitivity. In the first part of the article, the authors specifically cover areas pertaining to general/drug-specific tumor GEP changes and GEP changes between responders versus non-responders in specific molecular subclasses. The authors also discuss non-tumor-specific signatures, and provide a comparison of different biopsy methods. The authors also discuss the challenges that must be overcome in this area, looking at the clinical application of gene expression profiling and some of the multigene assays which have gained clinical utility. EXPERT OPINION: Current studies are challenged by a number of issues including: small sample sizes, retrospective analyses, varying chemotherapy regimens and response end points, the need for fresh frozen samples, distinct gene signatures in multiple platforms with minimal overlap and inherent microarray technological complexities. To date, no pharmacogenomic drug-specific predictor has been implemented clinically. Future studies should focus on distinct molecular subgroups by pooling resources and validation in well-powered randomized trials. Incorporating GEPs with newer biotechnological modalities may provide a more robust predictive model.

Clinical implications of chemotherapy-induced tumor gene expression in human breast cancers.

IMPORTANCE OF THE FIELD: There has been much interest in generating gene signatures to predict treatment response in breast cancer. AREAS COVERED IN THIS REVIEW: There are at least 15 published studies that describe baseline tumor gene signatures predicting chemotherapy sensitivity. As an extension of these baseline studies, there have been at least 8 published studies evaluating chemotherapy-induced tumor genomic changes over time in human breast cancers. WHAT THE READER WILL GAIN: Studies on chemotherapy-induced gene expression changes were reviewed in detail. Drug-induced biological changes within the tumor shed light on mechanisms of drug resistance and provided valuable insights regarding genes and pathways that were regulated by different drugs, including therapeutic targets that could be exploited to overcome resistance. One study also suggested post-chemotherapy gene signatures to be more predictive of response and survival than the unchallenged baseline signatures. TAKE HOME MESSAGE: Studies on chemotherapy-induced changes, although informative, are logistically demanding to execute, often with significant attrition of collected samples resulting in small datasets. They are further limited by heterogeneity of study population, chemotherapy regimens used, timing of the post-therapy sample and definition of response endpoint, making cross-comparisons of studies and data interpretation difficult. Future studies should address these limitations, and should involve larger sample sets and prospective studies for validation.

Phase II study of gemcitabine and carboplatin in metastatic breast cancers with prior exposure to anthracyclines and taxanes.

BACKGROUND: Patients with metastatic breast cancer (MBC) are usually exposed to both anthracyclines and taxanes during neoadjuvant or adjuvant treatment of primary breast cancer or during initial therapy of MBC. We investigate the combination of gemcitabine and carboplatin in MBC with prior exposure to both anthracyclines and taxanes. PATIENTS AND METHODS: MBC patients previously treated with anthracyclines and taxanes were enrolled in a single tertiary center phase II study. Treatment consisted of gemcitabine (1,000 mg/m(2) I.V on days 1 and 8) and carboplatin (AUC 5 I.V on day 1) administered every 3 weeks. Results 41 patients were recruited. Objective response rate was 39% including 1 complete response (2%) and 15 partial responses (37%). Twelve patients (29%) had stable disease. Median time to progression was 4.6 months (95% CI 3.3-5.9 months) and median overall survival 10.5 months (95% CI 7.6-13.4 months). Grade 3 & 4 hematological toxicities included neutropenia (58%), febrile neutropenia (15%), anemia (12%) and thrombocytopenia (49%), including 7% who required platelet transfusions. Non-hematological toxicity was rarely severe. 56% of patients required at least one dose reduction; the mean relative dose intensity for gemcitabine and carboplatin were 0.82 (range 0.5-1.0) and 0.95 (range 0.75-1.00) respectively, with no difference in dose intensity between responders and non-responders. CONCLUSION: Gemcitabine combined with carboplatin has promising efficacy in MBC with prior treatment with anthracyclines and taxanes but has significant haematological toxicities requiring dose modifications. The regimen may be modified to gemcitabine 800 mg/m(2) days 1 and 8 to improve tolerability.

Chemotherapy-induced tumor gene expression changes in human breast cancers.

OBJECTIVE: Studying chemotherapy-induced gene expression changes in vivo, which could provide insights into mechanisms of chemotherapy resistance. METHODS: We analyzed and compared tumor gene expression changes of about 38 500 genes before and 3 weeks after doxorubicin or docetaxel treatment in 47 breast cancer patients. RESULTS: By using the median expression level of each probe set as the parameter, less than 5% of genes were upregulated or downregulated by more than 50% after treatment with either drug. Doxorubicin and docetaxel concordantly induced 251 genes predominantly involved in protein and macromolecule metabolism (upregulated), and cell cycle and DNA/RNA metabolism (downregulated). Doxorubicin treatment resulted in coregulation of a cluster of 345 probe sets involved in focal adhesion, Jak-Stat signaling pathway, cell adhesion molecules, and natural killer cell mediated cytotoxicity, whereas docetaxel treatment resulted in coregulation of a cluster of 448 probe sets involved in focal adhesion, neurodegenerative disorders, sphingolipid metabolism, and cell cycle. Tumors that were intrinsically sensitive or resistant to doxorubicin or docetaxel evoked distinct gene expression changes in response to the drug; doxorubicin-resistant tumors upregulated genes that were enriched for ErbB signaling, ubiquitin-mediated proteolysis, TGF-beta signaling, and MAP-kinase signaling pathways, whereas docetaxel-resistant tumors upregulated genes that were enriched for focal adhesion and regulation of actin cytoskeleton. The drug-specific tumor gene expression changes were validated in independent in-vitro and in-vivo datasets. CONCLUSION: Gene expression alterations of breast cancer were specific to doxorubicin and docetaxel treatment, and yielded mechanistic insights into resistance to either drug. Gene expression analysis provides more global perspectives on resistance pathways that could be exploited for therapeutic selection.