Meta-analysis of sex and racial subgroup participation rates and differential treatment effects for trials in solid tumor malignancies leading to US Food and Drug Administration registration between 2010 and 2021.

BACKGROUND: The lack of sociodemographic diversity in clinical trials limits the generalizability of results. The authors examined participation rates and effect modification by sex and race in oncology trials. METHODS: The authors extracted outcome data stratified by sex and race for registration trials supporting US Food and Drug Administration (FDA) approval (2010-2021). Effect modification by race and sex was examined using quantitative and qualitative methods. A random-effects meta-analysis and pairwise comparison of progression-free survival (PFS) and overall survival (OS) outcomes was conducted by sex and race. RESULTS: Ninety-five trials with 123 end points and 54,365 patients provided information on sex. Trial patients were more often male (n = 35,482; 65% vs. 56% male patients in US Surveillance, Epidemiology, and End Results [SEER] data), although the proportion of male patients was similar after adjusting by tumor type (60% in FDA data vs. 58% in SEER data). There was no difference in pooled outcomes among male versus female patients (PFS: hazard ratio, 0.99; 95% confidence interval, 0.92-1.07; p = .89; OS: hazard ratio, 0.99; 95% confidence interval, 0.93-1.07; p = .90). In total, 111 trials including 74,217 patients provided information on race, and 68% of patients identified as White, compared with 72.3% in US SEER incidence data. Black patients were under-represented compared with US SEER incidence data, although ethnicity was poorly reported throughout the data set. In the authors' network meta-analysis by race, there were no statistically significant differences in PFS or OS outcomes. CONCLUSIONS: No significant differences in PFS or OS outcomes were identified when the analyses were stratified by sex or race. Certain racial minorities remain under-represented, and clearer reporting of race and ethnicity is needed. Representation of female patients in FDA trials is similar to that in SEER data after adjusting for tumor type.

Differential treatment effect between younger and older adults for new cancer therapies in solid tumors supporting US Food and Drug Administration approval between 2010 and 2021.

BACKGROUND: Over one half of cancer diagnoses occur in patients aged 65 and older. The authors quantified how treatment effects differ between older and younger patients in oncology registration trials. METHODS: The authors performed a retrospective cohort study of registration trials supporting US Food and Drug Administration approval of cancer drugs (from January 2010 to December 2021). The primary outcome was differential treatment effect by age (younger than 65 years vs. 65 years or older) for progression-free survival and overall survival. Random effects meta-analysis and a pairwise comparison of outcomes by age group also were performed. RESULTS: Among 263 trials that met the inclusion criteria, 120 trials with 153 end points and 83,152 patients presented age-specific outcome data. Among the included randomized patients, 38% were aged 65 years and older compared with an incidence proportion of 55% in data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program. Studies evaluating prostate cancer had the highest representation of patients aged 65 years or older (73%), whereas breast cancer studies had the lowest (20%). There were no changes in the proportion of patients aged 65 years or older over time (p = .86). Only 7% of end points showed a statistically significant interaction between outcome and age group. In a pooled analysis, there was an association between treatment effect and age for progression-free survival that approached but did not meet significance (hazard ratio, 0.95; p = .06), and there was no difference for overall survival (hazard ratio, 0.97; p = .79). CONCLUSIONS: Older adults remain under-represented in oncology registration trials. Significant differences in outcomes by age group were uncommon in individual trials and pooled analyses. However, clinical trial participants differ from real-world patients older than 65 years, and increased enrollment and ongoing research into differential treatment effects by age are needed.

Perceived guideline clarity impacts guideline-concordant care for breast cancer screening in women age 40-49.

BACKGROUND: Canadian and US Task Forces recommend against routine mammography screening for women age 40-49 at average breast cancer risk as harms outweigh benefits. Both suggest individualized decisions based on the relative value women place on potential screening benefits and harms. Population-based data reveal variation in primary care professionals (PCPs) mammography rates in this age group after adjusting for sociodemographic factors, highlighting the need to explore PCP screening perspectives and how this informs clinical behaviours. Results from this study will inform interventions that can improve guideline concordant breast screening for this age group. METHODS: Qualitative semi-structured interviews were performed with PCPs in Ontario, Canada. Interviews were structured using the theoretical domains framework (TDF) to explore determinants of breast cancer screening best-practice behaviours: (1) risk assessment; (2) discussion regarding benefits and harms; and (3) referral for screening. ANALYSIS: Interviews were transcribed and analyzed iteratively until saturation. Transcripts were coded deductively by behaviour and TDF domain. Data that did not fit within a TDF code were coded inductively. The research team met repeatedly to identify potential themes that influenced or were important consequences of the screening behaviours. The themes were tested against further data, disconfirming cases, and different PCP demographics. RESULTS: Eighteen physicians were interviewed. The theme of perceived guideline clarity (a lack of clarity on guideline-concordant practices) influenced all behaviours and moderated the extent to which the risk assessment and discussion occurred. Many were unaware of how risk-assessment factored into the guidelines and/or did not perceive that a shared-care discussion was guideline-concordant. Deferral to patient preference (screening referral without a complete discussion of benefits and harms) occurred when the PCPs had low knowledge regarding harms and/or if they experienced regret (TDF domain: emotion) resulting from prior clinical experiences. Older providers described patient's influence impacting their decisions and physicians trained outside Canada, practicing in higher-resourced areas, and female physicians described being influenced by beliefs about consequences of benefits of screening. CONCLUSION: Perceived guideline clarity is an important driver of physician behaviour. Improving guideline concordant care should start by clarifying the guideline itself. Thereafter, targeted strategies include building skills in identifying and overcoming emotional factors and communication skills important for evidence-based screening discussions.

Resource stratified guidelines for cancer: Are they all the same? Interguideline concordance for systemic treatment recommendations.

A number of organizations are producing resource stratified guidelines (RSGs) for cancer. Despite using similar definitions of resource levels, systemic treatment recommendations often differ between organizations. We systematically searched for RSGs focusing on solid tumors. We qualitatively compared the methods used to generate guidelines using the AGREE-II appraisal tool. We extracted systemic treatment recommendations and assessed interguideline concordance using the Gwet AC1 coefficient, stratified by resource level, treatment setting and cancer type. We identified 69 RSGs cancer covering 15 solid tumors produced by four organizations. Despite using common resource-level definitions (Basic, Core/Limited, Enhanced and Maximal), recommendations differed between organizations. Concordance for chemotherapy recommendations was poor in Basic (58.3%, Gwet 0.20), fair in Core (58.3%, Gwet 0.32) and excellent in Enhanced (92.4%, Gwet 0.92) and Maximal settings (95.4%, Gwet 0.95). Concordance rates for endocrine therapy were good in Basic (80% Gwet 0.61), and excellent in Core (90%, Gwet 0.87), Enhanced (90%, Gwet 0.89) and Maximal settings (90%, Gwet 0.89). There was moderate to excellent concordance in targeted therapy recommendations across all resource levels. Differences in recommendations appeared driven by different opinions among the chosen panel of experts regarding what is resource appropriate. Overall, we found that countries looking to base treatment and health-policy on RSGs will find conflicting information depending on which guidelines are used, particularly for chemotherapy in Basic and Core settings. Improved transparency regarding the methods used to determine the value of a therapy for a given resource level is needed.

Optimism Bias in the Design of Phase III Randomized Control Trials Evaluating PD-1/PD-L1 Targeting Monoclonal Antibodies.

BACKGROUND: Many randomized control trials (RCTs) evaluating programmed death receptor-1 (PD-1)/programmed death ligand-1 (PD-L1) targeting monoclonal antibodies (mAbs) have been completed or are in progress. We examined hypothesized hazard ratios (HHRs) and observed hazard ratios (OHRs) from published RCTs evaluating these mAbs. METHODS: Publications of RCTs evaluating at least one PD-1/PD-L1 targeting mAbs approved by the US Food and Drug Administration were identified through PubMed searches. The primary reports of RCTs were retrieved. Two investigators extracted HHR, OHR for the primary endpoint among other data elements independently. The differences (∆HR) in HHR and OHR were analyzed statistically. A separate search was conducted for secondary reports after longer follow-ups, the updated OHR was extracted. RESULTS: Forty-nine RCTs enrolling 36 867 patients were included. The mean HHR and OHR were 0.672 and 0.738 respectively. The mean ∆HR was 0.067 (range: -0.300 to 0.895; 95% confidence interval (CI), 0.003-0.130). HHR was met or exceeded in 22 (45%) RCTs. OHR was ≥ 1.0 in 6 RCTs (12%). PD-L1 expression was not associated with the magnitude of effect. Of 18 RCTs with follow-up reports, the magnitude of benefit decreased in 8 RCTs with extended follow-ups. CONCLUSION: The majority of published RCTs evaluating PD-1/PD-L1 targeting mAbs did not achieve their hypothesized magnitude of benefit. The optimism bias requires attention from the cancer clinical research community given the number of these agents in development and the intense interest in evaluating these agents in a variety of disease settings.

Cancer Risk and Mortality in Patients With Kidney Disease: A Population-Based Cohort Study.

RATIONALE & OBJECTIVE: Patients with chronic kidney disease (CKD) may be at increased risk for cancer. CKD may also be associated with worse cancer outcomes. This study examined cancer incidence and mortality across the spectrum of CKD. STUDY DESIGN: Population-based cohort study. SETTING & PARTICIPANTS: All adult Ontario residents with data on estimated glomerular filtration rate (eGFR) or who were receiving maintenance dialysis or had received a kidney transplant (2007-2016). EXPOSURE: Patients were categorized as of the first date they had 2 eGFR assessments or were registered as receiving maintenance dialysis or having received a kidney transplant. eGFR levels were further categorized as ≥60, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m2; the latter 4 groups are consistent with KDIGO (Kidney Disease: Improving Global Outcomes) CKD categories G3a, G3b, G4, and G5, respectively. OUTCOMES: Overall and site-specific cancer incidence and mortality. ANALYTICAL APPROACH: Fine and Gray subdistribution hazard models. RESULTS: Among 5,882,388 individuals with eGFR data, 29,809 receiving dialysis, and 4,951 having received a kidney transplant, there were 325,895 cancer diagnoses made during 29,993,847 person-years of follow-up. The cumulative incidence of cancer ranged between 10.8% and 15.3% in patients with kidney disease. Compared with patients with eGFR ≥60 mL/min/1.73 m2, adjusted hazard ratios (AHRs) for a cancer diagnosis among patients with CKD G3a, G3b, G4, and G5 were 1.08 (95% CI, 1.07-1.10), 0.99 (95% CI, 0.97-1.01), 0.85 (95% CI, 0.81-0.88), and 0.81 (95% CI, 0.73-0.90), respectively. The AHRs for patients receiving dialysis and who had received a transplant were 1.01 (95% CI, 0.96-1.07) and 1.25 (95% CI, 1.12-1.39), respectively. Patients with kidney disease had higher proportions of stage 4 cancers at diagnosis. Patients with CKD G3a, G3b, and G4 and transplant recipients had increased risks of cancer-specific mortality (AHRs of 1.27 [95% CI, 1.23-1.32], 1.29 [95% CI, 1.24-1.35], 1.25 [95% CI, 1.18-1.33], and 1.48 [95% CI, 1.18-1.87], respectively). The risks of bladder and kidney cancers and multiple myeloma were particularly increased in CKD, and mortality from these malignancies increased with worsening kidney function. LIMITATIONS: Possible unmeasured confounding and limited ability to infer causal associations. CONCLUSIONS: Cancer incidence in the setting of kidney disease is substantial. Cancer risk was increased in mild to moderate CKD and among transplant recipients, but not in advanced kidney disease. Cancer-related mortality was significantly higher among patients with kidney disease, particularly urologic cancers and myeloma. Strategies to detect and manage these cancers in the CKD population are needed.

Regional Variations in Clinical Trial Outcomes in Oncology.

BACKGROUND: It is unknown how often regional differences in oncology trials are observed. Based on our study findings, we quantified regional variation in registration studies in oncology and developed a question guide to help clinicians evaluate regional differences. METHODS: Using FDA archives, we identified registration studies in solid tumor malignancies from 2010 to 2020. We extracted the baseline study characteristics and participating countries and determined whether the primary publication reported a regional subgroup analysis. For studies presenting outcomes stratified by region, we extracted the stratified hazard ratios (HRs) and extracted or calculated the test for heterogeneity. We performed a random effects meta-analysis and a pairwise comparison to determine whether outcomes differed between high-income versus mixed-income regions. RESULTS: We included 147 studies in our final analysis. Studies supporting FDA drug approval have become increasingly multinational over time (ß = 0.5; P=.04). The median proportion of countries from high-income groups was 81.2% (range, 44%-100%), with no participation from low-income countries in our cohort. Regional subgroup analysis was presented for 78 studies (53%). Regional heterogeneity was found in 17.8% (8/45) and 18% (8/44) of studies presenting an overall survival (OS) and progression-free survival endpoint, respectively. After grouping regions by income level, we found no difference in OS outcomes in high-income regions compared with mixed-income regions (n=20; HR, 0.95; 95% CI, 0.84-1.07). To determine whether regional variation is genuine, clinicians should evaluate the data according to the following 5 questions: (1) Are the regional groupings logical? (2) Is the regional difference on an absolute or relative scale? (3) Is the regional difference consistent and plausible? (4) Is the regional difference statistically significant? (5) Is there a clinical explanation? CONCLUSIONS: As registration studies in oncology become increasingly international, regional variations in trial outcomes may be detected. The question guide herein will help clinicians determine whether regional variations are likely to be clinically meaningful or statistical anomalies.

Patient and provider determinants of breast cancer screening among Ontario women aged 40-49: a population-based retrospective cohort study.

PURPOSE: Canadian breast cancer screening guidelines state that mammography screening for women 40-49 should be individualized based on risk assessment and preferences. This retrospective cohort study describes the frequency of screening in women aged 40-49 and identifies patient and provider-level associations with screening. METHODS: Administrative databases were linked. The overall cohort included Ontario women aged 40-49 between April 1, 2009 and March 31, 2019. Subgroups were created: the "screen" group included women who received a mammogram defined as screening (using a set of exclusion criteria) and the "routine screen" group included women with three or more screening mammograms. A multivariable multilevel logistic regression model accounting for patient and provider characteristics was fit to determine characteristics associated with routine screening. The intracluster correlation co-efficient was used to quantify the degree of variation across providers. RESULTS: Of approximately 2 million eligible women, there were 532,596 (25.5%) in the screen group and 90,651 (4.3%) the routine screen group. There was an average of 0.30 and 0.52 screening mammograms per woman year, in the screen and routine screen groups, respectively. Routine screening was associated with periodic health exams (OR 1.21, 95% CI 1.20-1.22), receiving pap smears (OR 1.38, 95% CI 1.37-1.39), and fee-for-service models of care (OR 1.32, 95% CI 1.27-1.36). Over 20% of the variation in screening was due to systematic between-provider differences. CONCLUSIONS: Approximately 4.3% of women aged 40-49 in Ontario received routine breast cancer screening with substantial variation across providers. Routine screening is associated with periodic health examinations, receipt of pap smears, and fee-for-service models of care.

Quantifying Withdrawal of Consent, Loss to Follow-Up, Early Drug Discontinuation, and Censoring in Oncology Trials.

BACKGROUND: Censoring due to early drug discontinuation (EDD) or withdrawal of consent or loss to follow-up (WCLFU) can result in postrandomization bias. In oncology, censoring rules vary with no defined standards. In this study, we sought to describe the planned handling and transparency of censoring data in oncology trials supporting FDA approval and to compare EDD and WCLFU in experimental and control arms. METHODS: We searched FDA archives to identify solid tumor drug approvals and their associated trials between 2015 and 2019, and extracted the planned handling and reporting of censored data. We compared the proportion of WCLFU and EDD between the experimental and control arms by using generalized estimating equations, and performed logistic regression to identify trial characteristics associated with WCLFU occurring more frequently in the control group. RESULTS: Censoring rules were defined adequately in 48 (59%) of 81 included studies. Only 14 (17%) reported proportions of censored participants clearly. The proportion of WCLFU was higher in the control group than in the experimental group (mean, 3.9% vs 2.5%; ß-coefficient, -2.2; 95% CI, -3.1 to -1.3; P<.001). EDD was numerically higher in the experimental arm in 61% of studies, but there was no statistically significant difference in the proportion of EDD between the experimental and control groups (mean, 21.6% vs 19.9%, respectively; ß-coefficient, 0.27; 95% CI, -0.32 to 0.87; P=.37). The proportion of EDD due to adverse effects (AEs) was higher in the experimental group (mean, 13.2% vs 8.5%; ß-coefficient, 1.5; 95% CI, 0.57-2.45; P=.002). WCLFU was higher in the control group in studies with an active control group (odds ratio [OR], 10.1; P<.001) and in open label studies (OR, 3.00; P=.08). CONCLUSIONS: There are significant differences in WCLFU and EDD for AEs between the experimental and control arms in oncology trials. This may introduce postrandomization bias. Trials should improve the reporting and handling of censored data so that clinicians and patients are fully informed regarding the expected benefits of a treatment.

Associations With Definitive Outcomes and Clinical Benefit of Cancer Drugs at the Time of Marketing Approval and in the Postmarketing Period.

BACKGROUND: Most anticancer drugs are approved by regulatory agencies based on surrogate measures. This article explores the variables associated with overall survival (OS), quality of life (QoL), and substantial clinical benefit among anticancer drugs at the time of approval and in the postmarketing period. METHODS: Anticancer drugs approved by the FDA between January 2006 and December 2015 and with postmarketing follow-up until April 2019 were identified. We evaluated trial-level data supporting approval and any updated OS and/or QoL data. We applied the ESMO-Magnitude of Clinical Benefit Scale (ESMO-MCBS) and the ASCO Value Framework (ASCO-VF) to initial and follow-up studies. RESULTS: We found that 58 drugs were approved for 96 indications based on 96 trials. At registration, approval was based on improved OS in 39 trials (41%) and improved QoL in 16 of 45 indications (36%). Postmarketing data showed an improvement in OS for 28 of 59 trials (47%) and in QoL for 22 of 48 indications (46%). At the time of approval, 25 of 94 (27%) and 26 of 80 scorable trials (33%) met substantial benefit thresholds using the ESMO-MCBS and ASCO-VF, respectively. In the postmarketing period, 37 of 69 (54%) and 35 of 65 (54%) trials met the substantial benefit thresholds. Drugs with companion diagnostics and immune checkpoint inhibitors were associated significantly with substantial clinical benefit. CONCLUSIONS: Compared with the time of approval, more anticancer drugs showed improved OS and QoL and met the ESMO-MCBS or ASCO-VF thresholds for substantial benefit over the course of postmarketing time. However, only approximately half of the trials met the threshold for substantial benefit. Companion diagnostic drugs and immunotherapy seemed to be associated with greater clinical benefit.

A prospective multi-centre, randomized study comparing the addition of tapering dexamethasone to other standard of care therapies for taxane-associated pain syndrome (TAPS) in breast cancer patients.

PURPOSE: Taxane-associated pain syndrome (TAPS) is common with docetaxel and is characterised by myalgias and arthralgias starting 2-3 days after treatment and can last for up to 7 days. Anecdotal evidence suggests that corticosteroids can reduce TAPS. This multicentre, randomized trial evaluated the effect of additional tapering dexamethasone on TAPS. METHODS: 130 breast cancer patients commencing docetaxel were randomized to dexamethasone premedication (8 mg/twice daily for 3 days) or dexamethasone premedication followed by tapering dexamethasone (4 mg/daily for 2 days followed by 2 mg/daily for 2 days). The primary endpoint was absolute change in FACT-Taxane questionnaire during the first chemotherapy cycle. Secondary endpoints: proportion of patients with clinically significant TAPS, QoL, pain and toxicity. RESULTS: 110/130 patients had complete data included in the primary analysis. The fall in FACT-Taxane scores was lower in the experimental group on day 5 (p = 0.05), but not on day 7 (p = 0.21). There was no difference in FACT-Taxane scores over the entire study duration (p = 0.59). Fewer patients in the experimental arm reported TAPS on day 5 (30 vs. 47%). There was a borderline significant attenuation of impairment of QoL with experimental treatment on day 5 (p = 0.06), but not day 7 (p = 0.53). Tapered schedule was associated with more dyspepsia and insomnia. CONCLUSION: A tapering schedule of dexamethasone was associated with a brief reduction in docetaxel-associated symptoms which was observed only during dexamethasone exposure and did not persist after discontinuation of the drug. TRIAL REGISTRATION: ClinicalTrials.gov NCT03348696.

HER2 heterogeneity and resistance to anti-HER2 antibody-drug conjugates.

BACKGROUND: There has been substantial interest in HER2 intratumoral heterogeneity as an explanation for the development of resistance to anti-HER2 therapies in breast cancer, particularly to trastuzumab emtansine (T-DM1). METHODS: Through a literature-based approach, we discuss mechanisms of resistance to HER2-targeting antibody-drug conjugates (ADCs) in breast cancer. RESULTS: We describe results from clinical studies reporting the effect of anti-HER2 strategies particularly ADCs and their mechanistic effect. We review biological findings underlying HER2 heterogeneity and its implication in the development of novel anti-HER2 drugs including new ADCs in clinical development like trastuzumab deruxtecan (DS-8201). CONCLUSIONS: We suggest potential mechanisms to optimize these compounds and their future clinical implementation.

Clinical benefit and cost of breakthrough cancer drugs approved by the US Food and Drug Administration.

BACKGROUND: The clinical benefit and pricing of breakthrough-designated cancer drugs are uncertain. This study compares the magnitude of the clinical benefit and monthly price of new and supplemental breakthrough-designated and non-breakthrough-designated cancer drug approvals. METHODS: A cross-sectional cohort comprised approvals of cancer drugs for solid tumors from July 2012 to December 2017. For each indication, the clinical benefit from the pivotal trials was scored via validated frameworks: the American Society of Clinical Oncology Value Framework (ASCO-VF), the American Society of Clinical Oncology Cancer Research Committee (ASCO-CRC), the European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS), and the National Comprehensive Cancer Network (NCCN) Evidence Blocks. A high clinical benefit was defined as scores ≥ 45 for the ASCO-VF, overall survival gains ≥ 2.5 months or progression-free survival gains ≥ 3 months for all cancer types for the ASCO-CRC criteria, a grade of A or B for trials of curative intent and a grade of 4 or 5 for trials of noncurative intent for the ESMO-MCBS, and scores of 4 and 5 and a combined score ≥ 16 for the NCCN Evidence Blocks. Monthly Medicare drug prices were calculated with Medicare prices and DrugAbacus. RESULTS: This study identified 106 trials supporting approval of 52 drugs for 96 indications. Forty percent of these indications received the breakthrough designation. Among the included trials, 33 (43%), 46 (73%), 35 (34%), and 67 (69%) met the thresholds established by the ASCO-VF, ASCO-CRC, ESMO-MCBS, and NCCN, respectively. In the metastatic setting, there were higher odds of clinically meaningful grades in trials supporting breakthrough drugs with the ASCO-VF (odds ratio [OR], 3.69; P = .022) and the NCCN Evidence Blocks (OR, 5.80; P = .003) but not with the ASCO-CRC (OR, 3.54; P = .11) or version 1.1 (v1.1) of the ESMO-MCBS (OR, 1.22; P = .70). The median costs of breakthrough therapy drugs were significantly higher than those of nonbreakthrough therapies (P = .001). CONCLUSIONS: In advanced solid cancers, drugs that received the breakthrough therapy designation were more likely than nonbreakthrough therapy drugs to be scored as providing a high clinical benefit with the ASCO-VF and the NCCN Evidence Blocks but not with the ESMO-MCBS v1.1 or the ASCO-CRC scale.

Evolution in the risk of adverse events of adjuvant endocrine therapy in postmenopausal women with early-stage breast cancer.

BACKGROUND: Adjuvant endocrine therapy is a gold standard in early-stage, hormone receptor positive breast cancer. In postmenopausal women, aromatase inhibitors (AIs) are associated with improved outcome compared to tamoxifen monotherapy. Differences in the toxicity profiles of these drugs are described; however, little is known about whether the risk of adverse events changes over time. METHODS: Sequential reports of large, randomized, adjuvant endocrine therapy trials comparing AIs to tamoxifen were reviewed. Data on pre-specified adverse events were extracted including cardiovascular events, bone fractures, cerebrovascular disease, endometrial cancer, secondary malignancies excluding breast cancer, venous thrombosis and death without recurrence. Odds ratios (ORs) were calculated for each adverse event at each time over the course of follow-up. The change in the ORs for adverse events over time was evaluated using weighted linear regression. RESULTS: Analysis included 21 reports of 7 trials comprising 30,039 patients and reporting outcomes between 28 and 128 months of follow-up. Compared to tamoxifen, AIs use was associated with a significant reduction in the magnitude of increased odds of bone fracture over time (ß = - 0.63, p = 0.013). There was a non-significant decrease in the magnitude of reduced odds of secondary malignancies over time (ß = 0.448, p = 0.094). The differences in other toxicity profiles between AIs and tamoxifen did not change significantly over time. CONCLUSIONS: The increased risk of bone fractures associated with adjuvant AIs falls over time and after discontinuation of treatment. Differences in other toxicities between AIs and tamoxifen do not change significantly over time including a persistently elevated risk of cardiovascular events.

Development and validation of a multivariable prediction model for major adverse cardiovascular events after early stage breast cancer: a population-based cohort study.

AIMS: Develop a score to predict the risk of major adverse cardiovascular events (MACE) after early stage breast cancer (EBC) to facilitate personalized decision-making about potentially cardiotoxic treatments and interventions to reduce cardiovascular risk. METHODS AND RESULTS: Using administrative databases, we assembled a cohort of women diagnosed with EBC in Ontario between 2003 and 2014, with follow-up through 2015. Two-thirds of the cohort were used for risk score derivation; the remainder were reserved for its validation. The outcome was a composite of hospitalizations for acute myocardial infarction, unstable angina, transient ischaemic attack, stroke, peripheral vascular disease, heart failure (HF), or cardiovascular death. We developed the score by regressing MACE incidence against candidate predictors in the derivation sample using a Fine-Gray model. Discrimination was assessed in the validation sample using Wolber's c-index for prognostic models with competing risks, while calibration was assessed by comparing predicted and observed MACE incidence. The risk score was derived in 60 294 women and validated in 29 810 women. Age, hypertension, diabetes, ischaemic heart disease, atrial fibrillation, HF, cerebrovascular disease, peripheral vascular disease, chronic obstructive pulmonary disease, and chronic kidney disease were significantly associated with MACE incidence and incorporated into the score. Ten-year MACE incidence was >40-fold higher for patients in the highest score decile compared to the lowest. The c-index was 81.9% (95% confidence interval 80.9-82.9%) at 5 years and 79.8% (78.8-80.8%) at 10 years in the validation cohort, with good agreement between predicted and observed MACE incidence. CONCLUSION: Cardiovascular prognosis after EBC can be estimated using patients' pre-treatment characteristics.

Undisclosed financial conflicts of interest among authors of American Society of Clinical Oncology clinical practice guidelines.

BACKGROUND: Clinical practice guidelines (CPGs) are crucial to the practice of evidence-based medicine. Declared author financial conflicts of interest (FCOIs) are common in CPGs and have been associated with endorsement of treatment. Less is known about undeclared FCOIs. METHODS: The American Society of Clinical Oncology (ASCO) website was searched to identify all CPGs for systemic therapy published between August 2013 and June 2018. Data on self-reported author FCOIs and funding sources were extracted. The Open Payments database was then searched to identify compensation to CPG authors. Concordance between declared and undeclared but verified FCOIs was assessed with Cohen's κ. RESULTS: For 26 CPGs, 314 nonduplicate authors were identified; 184 of these authors (59%) disclosed FCOIs. Among the remaining 130 authors, data in Open Payments were unavailable for 71 authors (non-US residents or authors affiliated with a nonprofit organization). Among the 59 authors who declared no FCOIs and for whom Open Payments data were available, 55 (93%) had received payment from industry. The κ value for agreement between disclosed and verified FCOIs was 0.092. Among the 243 authors with FCOIs verifiable via Open Payments, 239 (98%) received payment from industry. Thirty-four authors (62%) received more than $1000 in nonresearch funding, and 19 (35%) received more than $5000. Among the 52 first and last authors, 44 (85%) received payment from industry; 14 of these payments (32%) were not declared. CONCLUSIONS: FCOIs among authors of ASCO CPGs are common and are not disclosed by a substantial proportion of authors with Open Payments data. Improved transparency of FCOIs should become standard practice among CPG authors. Professional societies and journal editors need to create a mechanism to verify self-reported FCOIs.

A Phase Ib Trial of Durvalumab in Combination with Trastuzumab in HER2-Positive Metastatic Breast Cancer (CCTG IND.229).

BACKGROUND: Immune checkpoint inhibitors are active in a broad range of cancers, including programmed death ligand 1 (PD-L1)-positive, triple-negative, metastatic breast cancer (MBC). Antibody-dependent cell-mediated cytotoxicity is a mechanism of action of trastuzumab. We performed a phase Ib trial of durvalumab and trastuzumab in HER2-positive MBC previously treated with chemotherapy and anti-HER2 antibodies to assess safety, efficacy, and correlative endpoints. PATIENTS AND METHODS: Patients with HER2-positive MBC were enrolled on a standard 3 + 3 design. Dose level 1 was durvalumab (1,125 mg intravenously day 1) and trastuzumab (8 mg/kg intravenously loading, then 6 mg/kg day 1) on a q3 weekly cycle. An expansion cohort at the recommended phase II dose (RP2D) performed tumor biopsies at baseline and after cycle 1. The primary endpoint was to establish the RP2D. RESULTS: Fifteen patients were accrued from April to December 2016, of which 14 were evaluable for response. Median age was 54 years (range 40-86); the majority had visceral disease (87%) and at least three prior (adjuvant and/or metastatic) lines of chemotherapy (73%), including trastuzumab (93%), pertuzumab (60%), and trastuzumab-emtansine (93%) for MBC. No dose-limiting toxicities were observed at dose level 1 (n = 6) or dose expansion (n = 9) during cycle 1. One patient developed a grade ≥3 immune-related adverse event (grade 4 diabetes mellitus). No responses by RECIST were seen, with 4 of 14 patients (29%) demonstrating stable disease as best response at week 6 (median duration, 2.7 months). All patients had <1% PD-L1 expression on either archival tissue (7/15) or prestudy biopsy (8/15). In the dose expansion cohort, evaluable pretreatment and on-treatment tumor biopsies (n = 5) showed minimal CD8 cell infiltration. CONCLUSION: The RP2D of durvalumab and trastuzumab is standard full doses of both agents. No significant clinical activity was observed in patients with heavily pretreated HER2-positive PD-L1-negative MBC. IMPLICATIONS FOR PRACTICE: This phase Ib trial with associated correlative endpoints provides insights into the lack of activity of the combination of durvalumab and trastuzumab in heavily pretreated HER2-positive metastatic breast cancer (MBC). No significant clinical activity was observed in patients with heavily pretreated HER2-positive programmed death ligand 1 (PD-L1)-negative MBC with evidence of cytotoxic T-cell exhaustion. Furthermore, all patients had no expression of PD-L1 in the tumor cells. These data support the importance of PD-L1 as an important selection biomarker and the need to assess the tumor microenvironment for immune regulatory cells. Further work is needed to understand how to activate the "cold" tumors to be able to combine current immune-oncology agents.

Toxicity and clinical outcomes of partial breast irradiation compared to whole breast irradiation for early-stage breast cancer: a systematic review and meta-analysis.

PURPOSE: There is uncertainty about outcomes differences between partial breast irradiation (PBI) and whole breast irradiation (WBI) for early-stage breast cancer. METHODS: Prospective randomized trials comparing adjuvant PBI to WBI in early-stage invasive breast cancer were identified using PubMed. Odds ratios (OR), 95% confidence intervals and absolute risks were computed for pre-specified efficacy and toxicity outcomes including cosmesis. Subgroup analysis evaluated the effect of PBI modality (external beam radiation treatment [EBRT], intraoperative radiation treatment [IORT] or brachytherapy) on efficacy. Meta-regression analysis explored the influence of median follow-up, patient and tumor characteristics on results. RESULTS: Nine trials comprising 14514 patients were included. While PBI was associated with increased odds of local recurrence compared to WBI (OR 1.69, P < 0.001), it was associated with reduced odds of death without breast cancer recurrence (OR 0.55, P < 0.001) and with improvement in overall survival (OS) that approached, but did not meet statistical significance (OR 0.84, P = 0.06). Subgroup analysis for PBI modality showed significant differences in the odds of local recurrence, based on method of PBI with EBRT showing the lowest magnitude of inferiority. Nodal involvement was associated with higher local recurrence risk, while larger tumors were associated with lesser improvement in death without breast cancer recurrence and OS. PBI was associated with higher odds of fat necrosis (OR 1.72, P = 0.002). Worse cosmetic outcome with PBI approached statistical significance (OR 1.23, P = 0.06). CONCLUSIONS: Compared to WBI, PBI is associated with higher odds for local recurrence and toxicity, but less death without breast cancer recurrence. The balance between benefit and risk of PBI appears optimal for women with smaller hormone receptor positive tumors, without nodal involvement and treated with EBRT.

Adjuvant chemotherapy and outcomes in patients with nodal and resection margin-negative pancreatic ductal adenocarcinoma: A systematic review and meta-analysis.

Adjuvant chemotherapy (AC) following pancreatic carcinoma (PC) resection improves overall survival (OS). A systematic review identified 10 phase-2/3 studies investigating AC in 3644 patients looking at the influence of nodal and resection status. AC significantly improved disease free survival, OS and 5-year odds of death risk. There was greater survival benefit in patients PS 0 and with body/tail tumors. There was a nonsignificant effect in N - /N + patients on OS and no difference between R0/R1 patients.

Role of Bisphosphonates in Breast Cancer Therapy.

Opinion statement Bisphosphonates are utilized routinely in breast cancer. In metastatic disease with bone involvement, bisphosphonates prevent or delay skeletal-related events and can improve pain control. Different agents have shown benefit compared with placebo or no treatment. While in unselected patients, comparison between zoledronic acid and pamidronate did not show a significant difference, exploratory analyses showed that in patients with osteolytic lesions or hypercalcemia, zoledronic acid is superior to pamidronate. De-escalating treatment with zoledronic acid from every 4 to every 12 weeks has been shown to provide similar control of skeletal morbidity and may result in less toxicity and reduced cost. While available data support bisphosphonate treatment for 2 years in metastatic disease, typical treatment duration is influenced by performance status with treatment discontinued only once patients are not well enough to continue receiving systemic therapy or developed treatment-related adverse events. In early-stage breast cancer, individual trials of adjuvant bisphosphonates have reported inconsistent results. However, the Early Breast Cancer Trialists' Collaborative Group showed that bisphosphonates significantly reduce distant recurrence, bone recurrence, and breast cancer mortality, an effect observed in postmenopausal women only. The relative benefit of bisphosphonates was not influenced by receptor status, tumor grade, nodal involvement, or administration of adjuvant chemotherapy. Current guidelines support consideration of adjuvant zoledronic acid or oral clodronate for 3-5 years in postmenopausal women with early-stage disease. Although bisphosphonates are tolerated well, serious adverse events, including osteonecrosis of the jaw and renal impairment, can occur, especially for higher dose density schedules utilized in metastatic disease. Decision to include bisphosphonates in the treatment plan should be based on the anticipated absolute benefit and potential for adverse effects. In some patients with both early-stage and metastatic disease, omission of bisphosphonates is reasonable as the potential benefit from this treatment is not likely to outweigh its risks.