J. Wright

Does Locoregional Radiation Therapy Improve Survival in Breast Cancer? A Meta-Analysis

PURPOSE Recent randomized trials in women with node-positive breast cancer who received systemic treatment report that locoregional radiation therapy improves survival. Previous trials failed to detect a difference in survival that results from its use. A systematic review of randomized trials that examine the effectiveness of locoregional radiation therapy in patients treated by definitive surgery and adjuvant systemic therapy was conducted. METHODS Randomized trials published between 1967 and 1999 were identified through MEDLINE database, CancerLit database, and reference lists of relevant articles. Relevant data was abstracted. The results of randomized trials were pooled using meta-analyses to estimate the effect of treatment on any recurrence, locoregional recurrence, and mortality. RESULTS Eighteen trials that involved a total of 6,367 patients were identified. Most trials included both pre- and postmenopausal women with node-positive breast cancer treated with modified radical mastectomy. The type of systemic therapy received, sites irradiated, techniques used, and doses of radiation delivered varied between trials. Data on toxicity were infrequently reported. Radiation was shown to reduce the risk of any recurrence (odds ratio, 0.69; 95% confidence interval [CI], 0.58 to 0.83), local recurrence (odds ratio, 0.25; 95% CI, 0.19 to 0.34), and mortality (odds ratio, 0.83; 95% CI, 0.74 to 0.94). CONCLUSION Locoregional radiation after surgery in patients treated with systemic therapy reduced mortality. Several questions remain on how these results should be translated into current-day clinical practice.

Randomized, Double-Blind, Placebo-Controlled Trial of Erythropoietin in Non–Small-Cell Lung Cancer With Disease-Related Anemia

PURPOSE Previous trials have suggested a quality-of-life (QOL) improvement for anemic cancer patients treated with erythropoietin, but few used QOL as the primary outcome. We designed a trial to investigate the effects of epoetin alfa therapy on the QOL of anemic patients with advanced non-small-cell carcinoma of the lung (NSCLC). PATIENTS AND METHODS A multicenter, randomized, double-blind, placebo-controlled trial was conducted. The proposed sample size was 300 patients. Eligible patients were required to have NSCLC unsuitable for curative therapy and baseline hemoglobin (Hgb) levels less than 121 g/L. Patients were assigned to 12 weekly injections of subcutaneous epoetin alpha or placebo, targeting Hgb levels between 120 and 140 g/L. The primary outcome was the difference in the change in Functional Assessment of Cancer Therapy-Anemia scores between baseline and 12 weeks. RESULTS Reports of thrombotic events in other epoetin trials prompted an unplanned safety analysis after 70 patients had been randomly assigned (33 to the active arm and 37 to the placebo arm). This revealed a significant difference in the median survival in favor of the patients on the placebo arm of the trial (63 v 129 days; hazard ratio, 1.84; P = .04). The Steering Committee closed the trial. Patient numbers compromised the interpretation of the QOL analysis, but a positive Hgb response was noted with epoetin alfa treatment. CONCLUSION An unplanned safety analysis suggested decreased overall survival in patients with advanced NSCLC treated with epoetin alfa. Although infrequent, other similar reports highlight the need for ongoing trials evaluating erythropoietin receptor agonists to ensure that overall survival is monitored closely.

Barriers to participation in clinical trials of cancer: a meta-analysis and systematic review of patient-reported factors.

BACKGROUND Enrolling participants onto clinical trials of cancer presents an important challenge. We aimed to identify the concerns of patients with cancer about, and the barriers to, participation in clinical trials. METHODS We did a systematic review to assess studies of barriers to participation in experimental trials and randomised trials for validity and content. We estimated the frequency with which patients identified particular issues by pooling across studies that presented data for barriers to participation in clinical trials as proportions. FINDINGS We analysed 12 qualitative studies (n=722) and 21 quantitative studies (n=5452). Two qualitative studies inquired of patients who were currently enrolled onto clinical trials, and ten inquired of patients who were eligible for enrolment onto various clinical trials. Barriers to participation in clinical trials were protocol-related, patient-related, or physician-related. The most common reasons cited as barriers included: concerns with the trial setting; a dislike of randomisation; general discomfort with the research process; complexity and stringency of the protocol; presence of a placebo or no-treatment group; potential side-effects; being unaware of trial opportunities; the idea that clinical trials are not appropriate for serious diseases; fear that trial involvement would have a negative effect on the relationship with their physician; and their physicians attitudes towards the trial. Meta-analysis confirmed the findings of our systematic review. INTERPRETATION The identification of such barriers to the participation in clinical trials should help trialists to develop strategies that will keep to a maximum participation and cooperation in cancer trials, while informing and protecting prospective participants adequately.

Metformin inhibits growth and enhances radiation response of non-small cell lung cancer (NSCLC) through ATM and AMPK.

Background:We examined the potential of metformin (MET) to enhance non-small cell lung cancer (NSCLC) responses to ionising radiation (IR).Methods:Human NSCLC cells, mouse embryonic fibroblasts from wild-type and AMP-activated kinase (AMPK) α1/2-subunit−/− embryos (AMPKα1/2−/−-MEFs) and NSCLC tumours grafted into Balb/c-nude mice were treated with IR and MET and subjected to proliferation, clonogenic, immunoblotting, cell cycle and apoptosis assays and immunohistochemistry (IHC).Results:Metformin (2.5 μM–5 mM) inhibited proliferation and radio-sensitised NSCLC cells. Metformin (i) activated the ataxia telengiectasia-mutated (ATM)–AMPK–p53/p21cip1 and inhibited the Akt–mammalian target of rapamycin (mTOR)–eIF4E-binding protein 1 (4EBP1) pathways, (ii) induced G1 cycle arrest and (iii) enhanced apoptosis. ATM inhibition blocked MET and IR activation of AMPK. Non-small cell lung cancer cells with inhibited AMPK and AMPKα1/2−/−-MEFs were resistant to the antiproliferative effects of MET and IR. Metformin or IR inhibited xenograft growth and combined treatment enhanced it further than each treatment alone. Ionising radiation and MET induced (i) sustained activation of ATM–AMPK–p53/p21cip1 and inhibition of Akt–mTOR–4EBP1 pathways in tumours, (ii) reduced expression of angiogenesis and (iii) enhanced expression of apoptosis markers.Conclusion:Clinically achievable MET doses inhibit NSCLC cell and tumour growth and sensitise them to IR. Metformin and IR mediate their action through an ATM–AMPK-dependent pathway. Our results suggest that MET can be a clinically useful adjunct to radiotherapy in NSCLC.

Ionizing radiation activates AMP-activated kinase (AMPK): a target for radiosensitization of human cancer cells.

PURPOSE Adenosine monophosphate (AMP)-activated kinase (AMPK) is a molecular energy sensor regulated by the tumor suppressor LKB1. Starvation and growth factors activate AMPK through the DNA damage sensor ataxia-telangiectasia mutated (ATM). We explored the regulation of AMPK by ionizing radiation (IR) and its role as a target for radiosensitization of human cancer cells. METHODS AND MATERIALS Lung, prostate, and breast cancer cells were treated with IR (2-8 Gy) after incubation with either ATM or AMPK inhibitors or the AMPK activator metformin. Then, cells were subjected to either lysis and immunoblotting, immunofluorescence microscopy, clonogenic survival assays, or cell cycle analysis. RESULTS IR induced a robust phosphorylation and activation of AMPK in all tumor cells, independent of LKB1. IR activated AMPK first in the nucleus, and this extended later into cytoplasm. The ATM inhibitor KU-55933 blocked IR activation of AMPK. AMPK inhibition with Compound C or anti-AMPK alpha subunit small interfering RNA (siRNA) blocked IR induction of the cell cycle regulators p53 and p21(waf/cip) as well as the IR-induced G2/M arrest. Compound C caused resistance to IR, increasing the surviving fraction after 2 Gy, but the anti-diabetic drug metformin enhanced IR activation of AMPK and lowered the surviving fraction after 2 Gy further. CONCLUSIONS We provide evidence that IR activates AMPK in human cancer cells in an LKB1-independent manner, leading to induction of p21(waf/cip) and regulation of the cell cycle and survival. AMPK appears to (1) participate in an ATM-AMPK-p21(waf/cip) pathway, (2) be involved in regulation of the IR-induced G2/M checkpoint, and (3) may be targeted by metformin to enhance IR responses.

Phase III Trial of an Emulsion Containing Trolamine for the Prevention of Radiation Dermatitis in Patients With Advanced Squamous Cell Carcinoma of the Head and Neck: Results of Radiation Therapy Oncology Group Trial 99-13

PURPOSE This multicentered phase III trial was designed to compare an emulsion containing trolamine against the usual supportive care within each participating institution for patients with head and neck cancer undergoing radiation therapy. PATIENTS AND METHODS Patients with biopsy-proven squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx were randomly assigned to one of the following treatments: prophylactic trolamine emulsion, interventional trolamine emulsion, or declared institutional preference. The primary outcome was the reduction in grade 2 or higher skin toxicity, as per National Cancer Institute Common Toxicity Criteria version 2.0. Secondary outcomes included patient-reported quality of life (QOL). RESULTS From October 2000 to April 2002, 547 patients from 51 institutions were entered onto the trial. The average age was 59 years. Patients were predominately male (79%) and most continued to use tobacco products (52%). The rates of grade 2 or higher radiation dermatitis were 79%, 77%, and 79% in the prophylactic, interventional, and institutional preference arms of the study, respectively. No significant differences in QOL were found. CONCLUSION The results of this trial demonstrate no advantage for the use of trolamine in reducing the incidence of grade 2 or higher radiation dermatitis or improving patient-reported QOL. The use of 15 different local standards of care highlights the need to continue research that will result in evidence-based recommendations to reduce the burden of radiation dermatitis.

Factors that influence the recruitment of patients to Phase III studies in oncology: the perspective of the clinical research associate.

The multiple determinants of a patients decision to enter into a clinical trial have been explored largely from the perspectives of patients and their physicians. Little research has involved clinical research associates (CRAs) formally, despite their central role in the process of recruitment. The current study was initiated to explore the factors that influence the decision of patients with cancer regarding clinical trial entry, specifically from the perspective of the CRA.

Multiple treatment comparison meta-analyses: a step forward into complexity

The use of meta-analysis has become increasingly useful for clinical and policy decision making. A recent development in meta-analysis, multiple treatment comparison (MTC) meta-analysis, provides inferences on the comparative effectiveness of interventions that may have never been directly evaluated in clinical trials. This new approach may be confusing for clinicians and methodologists and raises specific challenges relevant to certain areas of medicine. This article addresses the methodological concepts of MTC meta-analysis, including issues of heterogeneity, choice of model, and adequacy of sample sizes. We address domain-specific challenges relevant to disciplines of medicine, including baseline risks of patient populations. We conclude that MTC meta-analysis is a useful tool in the context of comparative effectiveness and requires further study, as its utility and transparency will likely predict its uptake by the research and clinical community.

Three-year outcomes of a Canadian multicenter study of accelerated partial breast irradiation using conformal radiation therapy.

PURPOSE To report 3-year toxicity, cosmesis, and efficacy of a multicenter study of external beam, accelerated partial breast irradiation (APBI) for early-stage breast cancer. METHODS AND MATERIALS Between March 2005 and August 2006, 127 women aged ≥40 years with ductal carcinoma in situ or node-negative invasive breast cancer ≤3 cm in diameter, treated with breast-conserving surgery achieving negative margins, were accrued to a prospective study involving five Canadian cancer centers. Women meeting predefined dose constraints were treated with APBI using 3 to 5 photon beams, delivering 35 to 38.5 Gy in 10 fractions, twice a day, over 1 week. Patients were assessed for treatment-related toxicities, cosmesis, and efficacy before APBI and at specified time points for as long as 3 years after APBI. RESULTS 104 women had planning computed tomography scans showing visible seromas, met dosimetric constraints, and were treated with APBI to doses of 35 Gy (n=9), 36 Gy (n=33), or 38.5 Gy (n=62). Eighty-seven patients were evaluated with minimum 3-year follow-up after APBI. Radiation dermatitis, breast edema, breast induration, and fatigue decreased from baseline levels or stabilized by the 3-year follow-up. Hypopigmentation, hyperpigmentation, breast pain, and telangiectasia slightly increased from baseline levels. Most toxicities at 3 years were Grade 1. Only 1 patient had a Grade 3 toxicity with telangiectasia in a skin fold inside the 95% isodose. Cosmesis was good to excellent in 86% (89/104) of women at baseline and 82% (70/85) at 3 years. The 3-year disease-free survival was 97%, with only one local recurrence that occurred in a different quadrant away from the treated site and two distant recurrences. CONCLUSIONS At 3 years, toxicity and cosmesis were acceptable, and local control and disease-free survival were excellent, supporting continued accrual to randomized APBI trials.

The Importance of Reporting Patient Recruitment Details in Phase III Trials

James R. Wright, Juravinski Cancer Centre at Hamilton Health Sciences, and Department of Medicine, McMaster University, Hamilton, ON, Canada Sarah Bouma, Juravinski Cancer Centre at Hamilton Health Sciences, Hamilton, ON, Canada Ian Dayes and Jonathan Sussman, Juravinski Cancer Centre at Hamilton Health Sciences, and Department of Medicine, McMaster University, Hamilton, ON, Canada Marko R. Simunovic, Juravinski Cancer Centre at Hamilton Health Sciences, and Department of Surgery, McMaster University, Hamilton, ON, Canada Mark N. Levine, Juravinski Cancer Centre at Hamilton Health Sciences, and Departments of Medicine and Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada Tim J. Whelan, Juravinski Cancer Centre at Hamilton Health Sciences, and Department of Medicine, McMaster University, Hamilton, ON, Canada