John Hilton

Novel Methodology for Comparing Standard-of-Care Interventions in Patients With Cancer

PURPOSE The current clinical trials development and conduct process is cumbersome and expensive, with the majority of studies focusing on either the development of new agents or new indications for established agents. Unfortunately, research comparing standard-of-care interventions is rarely performed, leaving many important and practical patient-centered questions unanswered. Novel clinical trial methodologies and approaches are needed. METHODS We have identified simple key components that, when combined, enhance the ability to both perform and increase accrual for studies that compare standard-of-care interventions. These include selection of clinically relevant and practical questions, demonstration of clinical equipoise through surveys of knowledge users and completion of systematic reviews, appropriate study design and simply defined study end points, use of an integrated consent model incorporating oral consent, efficient research ethics board approval, Web-based randomization in the clinic, real-time electronic data capture and management, and regular formal team feedback. RESULTS We have demonstrated the feasibility of this model in a pragmatic trial comparing two standard-of-care interventions (growth factor support or ciprofloxacin) for the primary prophylaxis of febrile neutropenia in patients with breast cancer receiving adjuvant docetaxel with cyclophosphamide chemotherapy. Research ethics board approval took 3 months, and 110 (72%) of 153 potentially eligible patients have agreed to participate in the study. When surveyed, 81 (85%) of 95 patients were completely satisfied with the integrated consent model process. CONCLUSION Our proposed model contains elements that, when used alone or in combination, may allow efficient and cost-effective comparison of standard-of-care interventions.

Detection of PIK3CA Mutations in Breast Cancer Bone Metastases

Background. An important goal of personalized cancer therapy is to tailor specific therapies to the mutational profile of individual patients. However, whole genome sequencing studies have shown that the mutational profiles of cancers evolve over time and often differ between primary and metastatic sites. Activating point mutations in the PIK3CA gene are common in primary breast cancer tumors, but their presence in breast cancer bone metastases has not been assessed previously. Results. Fourteen patients with breast cancer bone metastases were biopsied by three methods: CT-guided bone biopsies; bone marrow trephine biopsies; and bone marrow aspiration. Samples that were positive for cancer cells were obtained from six patients. Three of these patients had detectable PIK3CA mutations in bone marrow cancer cells. Primary tumor samples were available for four of the six patients assessed for PIK3CA status in their bone metastases. For each of these, the PIK3CA mutation status was the same in the primary and metastatic sites. Conclusions. PIK3CA mutations occur frequently in breast cancer bone metastases. The PIK3CA mutation status in bone metastases samples appears to reflect the PIK3CA mutation status in the primary tumour. Breast cancer patients with bone metastases may be candidates for treatment with selective PIK3CA inhibitors.

Optimal Management of Leptomeningeal Carcinomatosis in Breast Cancer Patients—A Systematic Review

The incidence of leptomeningeal carcinomatosis in breast cancer patients (LC-BC) is increasing. Despite significantly affecting patient quality of life (QoL) and overall survival (OS), little is known about its optimal management. A systematic review of treatment strategies for LC-BC was performed. EMBASE, Ovid Medline, Pubmed, and the Cochrane Central Register of Controlled Trials were searched from 1946 to 2015 for trials reporting on treatments for LC-BC. All treatment modalities and study types were considered. The outcome measures of interest included OS, time to neurologic progression (TTNP), QoL, and treatment toxicity. Of 718 unique citations, 173 studies met the prespecified eligibility criteria. Most were not specific to LC-BC patients. Of 4 identified randomized controlled trials (RCTs), 1 was specific to LC-BC patients and compared systemic therapy and involved-field radiotherapy with or without intrathecal (IT) methotrexate (35 patients), and the remaining 3 had compared different IT chemotherapy regimens (58 of 157 with LC-BC). Of the remaining studies, 19 were nonrandomized interventional studies (225 LC-BC patients), 148 were observational studies (3230 LC-BC patients), and 2 systematic reviews. Minimal prospective data were available on OS, TTNP, QoL, and toxicity. Owing to study heterogeneity, meta-analyses of the endpoint data could not be performed. Limited high-quality evidence exists regarding optimal treatment of LC-BC. The identified studies were heterogeneous and often methodologically poor. The only RCT that specifically assessed the role of IT chemotherapy showed no benefit, and, if anything, harm. Further prospective, tumor-specific trials with improved interstudy methodologic consistency and transparently reported data on OS, TTNP, QoL, and toxicity are urgently needed.

Primary endocrine therapy as an approach for patients with localized breast cancer deemed not to be surgical candidates.

Purpose of reviewFor women diagnosed with localized hormone-receptor-positive breast cancer who have a poor performance status or who have medical conditions precluding aggressive treatment with chemotherapy or surgery, primary endocrine therapy has been proposed as a therapeutic alternative. Given that society is rapidly aging overall, this subset of patients will likely become a greater proportion of the patient population seen by breast cancer specialists. Recent findingsOn the basis of the results from randomized trials in patients whose health does not permit surgery, it appears that tamoxifen achieves a similar overall survival compared with surgery plus tamoxifen, supporting the use of primary endocrine therapy. In the neoadjuvant setting, aromatase inhibitors appear superior to tamoxifen, suggesting that these agents may be the best choice in the primary endocrine therapy setting. In addition, new breakthroughs for the management of hormone-receptor-positive disease in the metastatic setting have recently been reported. SummaryThis review will discuss the rationale and evidence for primary endocrine therapy; which agents could be selected for use; and how recent advances for the management of hormone-receptor-positive disease may potentially apply to this population.

Dual Blockade of HER2 — Twice as Good or Twice as Toxic?

With about 20% of breast cancers overexpressing HER2, the implementation of trastuzumab and, more recently, lapatinib has revolutionised the care of these patients. Despite these successes, de novo and acquired resistance to these agents represent significant barriers that need to be overcome if further progress is to be achieved. Given that resistance can involve interplay between different members of the HER family multi-targeted inhibition of HER receptors represents an interesting therapeutic strategy. To date, clinical trials have shown that a number of targeted drugs can be combined with trastuzumab and lead to improved overall response rates and potentially also survival. However, such progress leads to an increased burden of toxicity. This review will discuss the mechanisms behind HER2 resistance, the preclinical basis for combining different agents with trastuzumab and the available results from clinical studies evaluating these combinations.

Filgrastim use in patients receiving chemotherapy for early-stage breast cancer—a survey of physicians and patients

PurposeDespite its widespread use as primary febrile neutropenia (FN) prophylaxis during chemotherapy for early-stage breast cancer, the optimal duration of daily filgrastim is unknown. Using the minimum effective duration may improve patient comfort and acceptability while reducing costs. Yet, suboptimal dosing may also negatively impact patient care. A survey was performed to obtain information regarding current practices for granulocyte colony-stimulating factor (G-CSF) use.MethodsCanadian oncologists involved in the treatment of breast cancer patients, as well as patients who had received neo/adjuvant chemotherapy for breast cancer, were surveyed. Standardized surveys were designed to collect information on perceived reasons for G-CSF use and current practices.ResultsThe surveys were completed by 38/50 (76%) physicians and 95/97 (98%) patients. For physicians, there was variability in the choice of chemotherapy regimens that required G-CSF support, the dose of filgrastim prescribed and the number of days prescribed. The majority of physicians reported using 5 (31.6%), 7 (47.4%), or 10 (13.2%) days of therapy. Nearly half of the patients (46.3%) recalled having experienced at least one of the chemotherapy-related complications including chemotherapy delays, dose reductions, and FN. While on filgrastim, 66.3% of patients reported myalgia and bone pain. Both physicians and patients expressed interest in participating in clinical trials designed to optimize the duration of filgrastim administration.ConclusionsSignificant variability in practice exists with respect to filgrastim administration. Definitive studies are therefore required to standardize and improve care, as this has the potential to impact treatment outcomes, patient quality of life, and cost savings.

Enhancing accrual to chemotherapy trials for patients with early stage triple-negative breast cancer: a survey of physicians and patients

PurposeThe optimal chemotherapy regimen for patients with early stage triple-negative breast cancer (TNBC) remains unknown. The purpose of the study is to survey physicians and breast cancer patients about preferred chemotherapy regimens for early stage TNBC and clinical trial strategies.MethodsA standardised online questionnaire was developed and circulated to medical oncologists known to treat breast cancer. A separate questionnaire was given to patients who had received chemotherapy for breast cancer.ResultsThe questionnaire was completed by 41/84 medical oncologists (48.8% response rate) and 74 patients. The most commonly used neoadjuvant and adjuvant chemotherapy regimens for TNBC were dose-dense doxorubicin and cyclophosphamide (AC)–paclitaxel (P), dose-dense AC followed by weekly P and fluorouracil, epirubicin, cyclophosphamide–docetaxel (FEC-D). The majority of medical oncologists (80%) would be willing to enrol patients in trials evaluating the most effective chemotherapy regimen for TNBC. Oncologists favoured a three arm trial design comparing currently available standard of care treatments (36%) and trials of novel or non-standard of care agents 22% (9/41). Sixty percent (41/74) of patients indicated that they would be willing to be enrolled in trials evaluating various adjuvant regimens for TNBC. Both oncologists and patients were interested in novel consent approaches such as using the integrated consent model.ConclusionOptimisation of chemotherapy for TNBC is an important and unmet clinical need. It is apparent that various chemotherapy regimens are used for patients with early stage TNBC. The majority of medical oncologists and patients are interested in entering trials to optimise chemotherapy choices.

Feasibility of using a pragmatic trials model to compare two primary febrile neutropenia prophylaxis regimens (ciprofloxacin versus G-CSF) in patients receiving docetaxel-cyclophosphamide chemotherapy for breast cancer (REaCT-TC)

PurposeOptimal primary febrile neutropenia (FN) prophylaxis (i.e. ciprofloxacin or granulocyte-colony stimulating factors [G-CSF]) for patients receiving docetaxel-cyclophosphamide (TC) chemotherapy is unknown. We assessed the feasibility of using a novel pragmatic comparative effectiveness trial to compare these standard-of-care options.MethodsEarly-stage breast cancer patients receiving TC chemotherapy were randomised to either ciprofloxacin or G-CSF. Trial methodology consists of broad eligibility criteria, simply-defined endpoints, integrated consent model incorporating oral consent, and web-based randomisation in the clinic. Primary feasibility endpoints included patient and physician engagement (if > 50% of patients approached agree to participate and if > 50% of physicians approached patients for the study). Secondary clinical endpoints included the following: first occurrence rates of FN, treatment-related hospitalisation, or chemotherapy dose reduction/delay/discontinuation, as well as patient satisfaction with the oral consent process.ResultsOf 204 patients approached, 91.2% (186/204) agreed to randomisation. Sixteen of twenty (80%) participating medical oncologists randomised patients. Median patient age was 57.7 (range 31.8–84.1). The 186 patients received 557 cycles of chemotherapy. Overall incidences of first events by patient (n = 186) were as follows: FN (18/186, 21.43%), treatment-related hospitalisation (11/186, 13.10%), chemotherapy reduction (19/186, 22.62%), chemotherapy discontinuation (16/186, 19.05%), and chemotherapy delays (5/186, 5.95%). A total of 37.77% (69/186) of patients and 12.39% (69/557) of chemotherapy cycles had at least one of these first events. Patients were highly satisfied with the oral consent process.ConclusionThis study met its feasibility endpoints. This model offers a means of comparing standard-of-care treatments in a practical and cost-efficient manner.Trial registrationTrial registration: ClinicalTrials.gov: NCT02173262

Effects on bone resorption markers of continuing pamidronate or switching to zoledronic acid in patients with high risk bone metastases from breast cancer

Background Switching patients who remain at high risk of skeletal related events (SREs) despite pamidronate to the more potent bisphosphonate zoledronate, may be an effective treatment strategy. As part of a previously reported clinic study in this setting, we evaluated whether biomarkers for bone resorption, such as Bone-Specific Alkaline Phosphatase (BSAP), bone sialoprotein (BSP), and N-terminal telopeptide (NTX) correlated with subsequent SRE risk. Methods Breast cancer patients who remained at high risk of SREs despite at least 3 months of q.3–4 weekly pamidronate were randomized to either continue on pamidronate or to switch to zoledronate (4 mg) once every 4 weeks for 12-weeks. High risk bone metastases were defined by either: occurrence of a prior SRE, bone pain, radiologic progression of bone metastases and/or serum C-terminal telopeptide (CTx) levels > 400 ng/L despite pamidronate use. Serum samples were collected at baseline and weeks 1, 4, 8 and 12 (CTx and BSAP) and baseline and week 12 (NTx and BSP), and all putative biomarkers were measured by ELISA. Follow up was extended to 2 years post trial entry for risk of subsequent SREs. The Kaplan-Meier method was used to estimate time-to-event outcomes. Generalized estimating equations (GEE) were used to evaluate if laboratory values over time or the change in laboratory values from baseline were associated with having a SRE within the time frame of this study. Results From March 2012 to May 2014, 76 patients were screened, with 73 eligible for enrolment. All 73 patients were available for biochemical analysis, with 35 patients receiving pamidronate and 38 patients receiving zoledronate. The GEE analysis found that no laboratory value was associated with having a subsequent SRE. Interaction between visit and laboratory values was also investigated, but no interaction effect was statistically significant. Only increased number of lines of prior hormonal treatment was associated with subsequent SRE risk. Conclusion Our analysis failed to find any association between serum BSAP, BSP, CTx or NTx levels and subsequent SRE risk in this cohort of patients. This lack of correlation between serum biomarkers and clinical outcomes could be due to influences of prior bisphosphonate treatment or presence of extra-osseous metastases in a significant proportion of enrolled patients. As such, caution should be used in biomarker interpretation and use to direct decision making regarding SRE risk for high risk patients in this setting.

Optimal sequence of adjuvant endocrine and radiation therapy in early-stage breast cancer – A systematic review

IMPORTANCE Clinical equipoise exists around the optimal time to start adjuvant endocrine therapy in patients who will receive post-operative radiotherapy for breast cancer. Concerns continue to exist regarding potential reduced efficacy, or increased toxicity, when radiation, and endocrine therapy are administered concurrently. OBJECTIVE To perform a systematic review of studies comparing outcomes between sequential and concurrent adjuvant radiation and endocrine therapy in early-stage breast cancer. All modalities of radiation therapy were considered, and endocrine therapy could be either tamoxifen or an aromatase inhibitor. Outcomes of interest included; local, regional or distant recurrence, overall survival and treatment-related toxicities. EVIDENCE REVIEWED PubMed, Ovid Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from 1946 to December 2017. Two reviewers independently assessed each citation using the criteria outlined above. Study quality was assessed using the Cochrane Collaborations tool for prospective studies, and the Newcastle-Ottawa scale for retrospective studies. FINDINGS Of 2137 unique citations identified, 13 met eligibility criteria. Eleven were unique studies (7569 patients), while 2 of the studies were updated analyses of previous studies. Studies evaluated the timing of adjuvant radiation, and tamoxifen (5 studies, 1550 patients), or aromatase inhibitors (6 studies, 6019 patients). We identified 1 complete randomized clinical trial (150 patients), and 5 retrospective studies (1580 patients), in addition to conference abstracts (5 studies, 5839 patients). Overall, none of the studies showed a significant difference in efficacy, or toxicity, with concurrent versus sequential treatment. However, given the significant heterogeneity of the study populations, it was not possible to conduct a meta-analysis. CONCLUSIONS AND RELEVANCE In the absence of high quality data, adequately powered randomized trials are required to answer this important clinical question.