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1.
Clin Infect Dis ; 74(7): 1275-1278, 2022 04 09.
Article in English | MEDLINE | ID: mdl-34363462

ABSTRACT

The impact of coronavirus disease 2019 vaccination on viral characteristics of breakthrough infections is unknown. In this prospective cohort study, incidence of severe acute respiratory syndrome coronavirus 2 infection decreased following vaccination. Although asymptomatic positive tests were observed following vaccination, the higher cycle thresholds, repeat negative tests, and inability to culture virus raise questions about their clinical significance.


Subject(s)
COVID-19 , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Health Personnel , Humans , Incidence , Prospective Studies , SARS-CoV-2 , Vaccination
2.
Stat Med ; 41(24): 4745-4755, 2022 10 30.
Article in English | MEDLINE | ID: mdl-35818331

ABSTRACT

Longitudinal clinical trials are often designed to compare treatments on the basis of multiple outcomes. For example in the case of cardiac trials, the outcomes of interest include mortality as well as cardiac events and hospitalization. For a COVID-19 trial, the outcomes of interest include mortality, time on ventilator, and time in hospital. Earlier work by these authors proposed a non-parametric test based on a composite of multiple endpoints referred to as the Finkelstein-Schoenfeld (FS) test (Finkelstein and Schoenfeld. Stat Med. 1999;18(11):1341-1354.). More recently, an estimate of the treatment comparison based on multiple endpoints (related to the FS test) was proposed (Pocock et al. Eur Heart J. 2011;33(2):176-182.). This estimate, which summarized the ratio of the number of patients who fared better vs worse on the experimental arm was coined the win ratio. The aim of this article is to provide guidance in the design of a trial that will use the FS test or the win ratio. The issues that will be considered are the sample size, sequential monitoring, and adaptive designs.


Subject(s)
COVID-19 , Hospitalization , Humans , Research Design , Sample Size
3.
Lancet Oncol ; 21(1): 60-72, 2020 01.
Article in English | MEDLINE | ID: mdl-31806543

ABSTRACT

BACKGROUND: Denosumab is a fully human monoclonal antibody that binds to, and inhibits, the receptor activator of RANKL (TNFSF11) and might affect breast cancer biology, as shown by preclinical evidence. We aimed to assess whether denosumab combined with standard-of-care adjuvant or neoadjuvant systemic therapy and locoregional treatments would increase bone metastasis-free survival in women with breast cancer. METHOD: In this international, double-blind, randomised, placebo-controlled, phase 3 study (D-CARE), patients were recruited from 389 centres in 39 countries. We enrolled women (aged ≥ 18 years) with histologically confirmed stage II or III breast cancer and an Eastern Cooperative Oncology Group performance status of 0 or 1. On eligibility confirmation, investigators at each site telephoned an interactive voice response system to centrally randomly assign patients (1:1) based on a fixed stratified permuted block randomisation list (block size 4) to receive either denosumab (120 mg) or matching placebo subcutaneously every 3-4 weeks, starting with neoadjuvant or adjuvant chemotherapy, for about 6 months and then every 12 weeks for a total duration of 5 years. Stratification factors were breast cancer therapy, lymph node status, hormone receptor and HER2 status, age, and geographical region. The primary endpoint was the composite endpoint of bone metastasis-free survival. This trial is registered with ClinicalTrials.gov, NCT01077154. FINDINGS: Between June 2, 2010, and Aug 24, 2012, 4509 women were randomly assigned to receive denosumab (n=2256) or placebo (n=2253) and included in the intention-to-treat analysis. The primary analysis of the study was done when all patients had the opportunity to complete 5 years of follow-up with an analysis data cutoff date of Aug 31, 2017. The primary endpoint of bone metastasis-free survival was not significantly different between the groups (median not reached in either group; hazard ratio 0·97, 95% CI 0·82-1·14; p=0·70). The most common grade 3 or worse treatment-emergent adverse events, reported in patients who had at least one dose of the investigational product (2241 patients with denosumab vs 2218 patients with placebo), were neutropenia (340 [15%] vs 328 [15%]), febrile neutropenia (112 [5%] vs 142 [6%]), and leucopenia (62 [3%] vs 61 [3%]). Positively adjudicated osteonecrosis of the jaw occurred in 122 (5%) of 2241 patients treated with denosumab versus four (<1%) of 2218 patients treated with placebo; treatment-emergent hypocalcaemia occurred in 152 (7%) versus 82 (4%). Two treatment-related deaths occurred in the placebo group due to acute myeloid leukaemia and depressed level of consciousness. INTERPRETATION: Despite preclinical evidence suggesting RANKL inhibition might delay bone metastasis or disease recurrence in patients with early-stage breast cancer, in this study, denosumab did not improve disease-related outcomes for women with high-risk early breast cancer. FUNDING: Amgen.


Subject(s)
Bone Density Conservation Agents/therapeutic use , Bone Neoplasms/drug therapy , Breast Neoplasms/drug therapy , Chemotherapy, Adjuvant/mortality , Denosumab/therapeutic use , Neoadjuvant Therapy/mortality , Neoplasm Recurrence, Local/drug therapy , Adult , Biomarkers, Tumor/metabolism , Bone Neoplasms/metabolism , Bone Neoplasms/secondary , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Double-Blind Method , Female , Follow-Up Studies , Humans , Middle Aged , Neoplasm Recurrence, Local/metabolism , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Receptor, ErbB-2/metabolism , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Survival Rate
4.
Lifetime Data Anal ; 26(1): 1-20, 2020 01.
Article in English | MEDLINE | ID: mdl-30386969

ABSTRACT

The accelerated failure time (AFT) model is a common method for estimating the effect of a covariate directly on a patient's survival time. In some cases, death is the final (absorbing) state of a progressive multi-state process, however when the survival time for a subject is censored, traditional AFT models ignore the intermediate information from the subject's most recent disease state despite its relevance to the mortality process. We propose a method to estimate an AFT model for survival time to the absorbing state that uses the additional data on intermediate state transition times as auxiliary information when a patient is right censored. The method extends the Gehan AFT estimating equation by conditioning on each patient's censoring time and their disease state at their censoring time. With simulation studies, we demonstrate that the estimator is empirically unbiased, and can improve efficiency over commonly used estimators that ignore the intermediate states.


Subject(s)
Models, Statistical , Survival Analysis , Computer Simulation , Disease Progression , Humans , Time Factors
5.
BMC Cancer ; 19(1): 166, 2019 Feb 21.
Article in English | MEDLINE | ID: mdl-30791872

ABSTRACT

BACKGROUND: Although rare cancers account for 27% of cancer diagnoses in the US, there is insufficient research on survivorship issues in these patients. An important issue cancer survivors face is an elevated risk of being diagnosed with new primary cancers. The primary aim of this analysis was to assess whether a history of rare cancer increases the risk of subsequent cancer compared to survivors of common cancers. METHODS: This was a prospective cohort study of 16,630 adults with personal and/or family history of cancer who were recruited from cancer clinics at 14 geographically dispersed US academic centers of the NIH-sponsored Cancer Genetics Network (CGN). Participants' self-reported cancer histories were collected at registration to the CGN and updated annually during follow-up. At enrollment, 14% of participants reported a prior rare cancer. Elevated risk was assessed via the cause-specific hazard ratio on the time to a subsequent cancer diagnosis. RESULTS: After a median follow-up of 7.9 years, relative to the participants who were unaffected at enrollment, those with a prior rare cancer had a 23% higher risk of subsequent cancer (95% CI: -1 to 52%), while those with a prior common cancer had no excess risk. Patients having two or more prior cancers were at a 53% elevated risk over those with fewer than two (95% CI: 21 to 94%) and if the multiple prior cancers were rare cancers, risk was further elevated by 47% (95% CI: 1 to 114%). CONCLUSION: There is evidence suggesting that survivors of rare cancers, especially those with multiple cancer diagnoses, are at an increased risk of a subsequent cancer. There is a need to study this population more closely to better understand cancer pathogenesis.


Subject(s)
Cancer Survivors , Neoplasms, Second Primary/epidemiology , Neoplasms/epidemiology , Adult , Cohort Studies , Female , Follow-Up Studies , Humans , Incidence , Male , Medical History Taking , Middle Aged , Prospective Studies , Risk , United States/epidemiology
6.
Stat Med ; 38(1): 53-61, 2019 01 15.
Article in English | MEDLINE | ID: mdl-30206956

ABSTRACT

Clinical trials are often designed to compare treatments on the basis of multiple outcomes. For the analysis of the treatment comparison from such a trial, in 1999, the Finkelstein-Schoenfeld test was proposed, which was a generalization of the Gehan-Wilcoxon test based on pairwise comparison of patients on a primary outcome when possible but otherwise on a secondary outcome. In 2012, Pocock and colleagues suggested an estimate based on this concept, the Win Ratio, which summarized the ratio of the number of patients who fared better versus worse on the experimental arm. However, in 2016, Oakes noted that the Win Ratio could be a function of the distribution of follow-up times of the trial. The aim of this paper is to propose an approach to representing the Win Ratio graphically in such a way that the effect of time on the estimate would be apparent. In addition, the methods are used to display the contribution of each endpoint to the composite. We apply the methods to clinical trials in cancer, cardiology, and neurology. Software is available named winRatioAnalysis in CRAN.


Subject(s)
Clinical Trials as Topic/methods , Data Interpretation, Statistical , Data Display , Endpoint Determination/methods , Humans , Models, Statistical , Treatment Outcome
7.
Clin Trials ; 16(5): 531-538, 2019 10.
Article in English | MEDLINE | ID: mdl-31256630

ABSTRACT

BACKGROUND/AIMS: For single arm trials, a treatment is evaluated by comparing an outcome estimate to historically reported outcome estimates. Such a historically controlled trial is often analyzed as if the estimates from previous trials were known without variation and there is no trial-to-trial variation in their estimands. We develop a test of treatment efficacy and sample size calculation for historically controlled trials that considers these sources of variation. METHODS: We fit a Bayesian hierarchical model, providing a sample from the posterior predictive distribution of the outcome estimand of a new trial, which, along with the standard error of the estimate, can be used to calculate the probability that the estimate exceeds a threshold. We then calculate criteria for statistical significance as a function of the standard error of the new trial and calculate sample size as a function of difference to be detected. We apply these methods to clinical trials for amyotrophic lateral sclerosis using data from the placebo groups of 16 trials. RESULTS: We find that when attempting to detect the small to moderate effect sizes usually assumed in amyotrophic lateral sclerosis clinical trials, historically controlled trials would require a greater total number of patients than concurrently controlled trials, and only when an effect size is extraordinarily large is a historically controlled trial a reasonable alternative. We also show that utilizing patient level data for the prognostic covariates can reduce the sample size required for a historically controlled trial. CONCLUSION: This article quantifies when historically controlled trials would not provide any sample size advantage, despite dispensing with a control group.


Subject(s)
Control Groups , Randomized Controlled Trials as Topic/methods , Sample Size , Amyotrophic Lateral Sclerosis/therapy , Bayes Theorem , Clinical Trials, Phase II as Topic/methods , Clinical Trials, Phase II as Topic/statistics & numerical data , Humans , Randomized Controlled Trials as Topic/statistics & numerical data
8.
Am J Gastroenterol ; 111(2): 285-93, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26856748

ABSTRACT

OBJECTIVES: Individuals whose families meet the Amsterdam II clinical criteria for hereditary non-polyposis colorectal cancer are recommended to be referred for genetic counseling and to have colonoscopic screening every 1-2 years. To assess the uptake and knowledge of guideline-based genetic counseling and colonoscopic screening in unaffected members of families who meet Amsterdam II criteria and their treating endoscopists. METHODS: Participants in the Family Health Promotion Project who met the Amsterdam II criteria were surveyed regarding their knowledge of risk-appropriate guidelines for genetic counseling and colonoscopy screening. Endoscopy/pathology reports were obtained from patients screened during the study to determine the follow-up recommendations made by their endoscopists. Survey responses were compared using Fisher's Exact and the χ(2) test. Concordance in participant/provider-reported surveillance interval was assessed using the kappa statistic. RESULTS: Of the 165 participants, the majority (98%) agreed that genetics and family history are important predictors of CRC, and 63% had heard of genetic testing for CRC, although only 31% reported being advised to undergo genetic counseling by their doctor, and only 7% had undergone genetic testing. Only 26% of participants reported that they thought they should have colonoscopy every 1-2 years and 30% of endoscopists for these participants recommended 1-2-year follow-up colonoscopy. There was a 65% concordance (weighted kappa 0.42, 95% CI 0.24-0.61) between endoscopist recommendations and participant reports regarding screening intervals. CONCLUSIONS: A minority of individuals meeting Amsterdam II criteria in this series have had genetic testing and reported accurate knowledge of risk-appropriate screening, and only a small percentage of their endoscopists provided them with the appropriate screening recommendations. There was moderate concordance between endoscopist recommendations and participant knowledge suggesting that future educational interventions need to target both health-care providers and their patients.


Subject(s)
Clinical Competence , Colonoscopy/statistics & numerical data , Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis , Early Detection of Cancer/statistics & numerical data , Gastroenterology/methods , Genetic Counseling/statistics & numerical data , Genetic Testing/statistics & numerical data , Health Knowledge, Attitudes, Practice , Adult , Aged , Colonoscopy/psychology , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , Colorectal Neoplasms, Hereditary Nonpolyposis/psychology , Early Detection of Cancer/psychology , Female , Genetic Counseling/psychology , Health Promotion , Humans , Male , Middle Aged , Risk
9.
Biometrics ; 72(3): 926-35, 2016 09.
Article in English | MEDLINE | ID: mdl-26812695

ABSTRACT

Clinical trials often collect multiple outcomes on each patient, as the treatment may be expected to affect the patient on many dimensions. For example, a treatment for a neurological disease such as ALS is intended to impact several dimensions of neurological function as well as survival. The assessment of treatment on the basis of multiple outcomes is challenging, both in terms of selecting a test and interpreting the results. Several global tests have been proposed, and we provide a general approach to selecting and executing a global test. The tests require minimal parametric assumptions, are flexible about weighting of the various outcomes, and are appropriate even when some or all of the outcomes are censored. The test we propose is based on a simple scoring mechanism applied to each pair of subjects for each endpoint. The pairwise scores are then reduced to a summary score, and a rank-sum test is applied to the summary scores. This can be seen as a generalization of previously proposed nonparametric global tests (e.g., O'Brien, 1984). We discuss the choice of optimal weighting schemes based on power and relative importance of the outcomes. As the optimal weights are generally unknown in practice, we also propose an adaptive weighting scheme and evaluate its performance in simulations. We apply the methods to analyze the impact of a treatment on neurological function and death in an ALS trial.


Subject(s)
Data Interpretation, Statistical , Statistics, Nonparametric , Treatment Outcome , Amyotrophic Lateral Sclerosis/drug therapy , Amyotrophic Lateral Sclerosis/mortality , Amyotrophic Lateral Sclerosis/physiopathology , Clinical Trials as Topic , Computer Simulation , Humans , Nervous System/physiopathology , Survival Analysis
10.
Clin Trials ; 13(3): 352-7, 2016 06.
Article in English | MEDLINE | ID: mdl-26908538

ABSTRACT

BACKGROUND: For a potentially lethal chronic disease like cancer, it is often infeasible to compare treatments on the basis of overall survival, so a combined outcome such as progression-free survival (which is the time from randomization to progression or death) has become an acceptable primary endpoint. The rationale of using an efficacy measure that is dominated by the time to progression is that an effective treatment will delay progression and when treatment is stopped at progression, the effect of treatment after this time is small. However, often trials that show a significant benefit for delaying progression but not on overall survival are not universally viewed as providing convincing evidence that the drug should become the standard of care. METHODS: We propose that when there is a significant treatment effect of delaying progression, a Bayesian analysis of overall survival should be undertaken. We suggest using a joint piecewise exponential model, where the treatment effect on the hazard for progression and for death after progression is captured through two distinct parameters. We develop a plot of the overall survival advantage of the new therapy versus the prior distribution of the relative hazard for death after progression. This plot can augment the discussion about whether the new treatment is beneficial on survival. RESULTS: In the example of an early breast cancer trial for which a new treatment significantly delayed disease recurrence, our Bayesian analysis showed that with very reasonable assumptions on the effects of treatment after recurrence, there is a high probability that the new treatment improves overall survival. CONCLUSION: For a clinical trial for which treatment delays progression, the proposed method can improve the interpretability of the survival comparison using data from the study.


Subject(s)
Aromatase Inhibitors/therapeutic use , Breast Neoplasms/drug therapy , Disease-Free Survival , Nitriles/therapeutic use , Survival Rate , Triazoles/therapeutic use , Bayes Theorem , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Chemotherapy, Adjuvant , Disease Progression , Female , Humans , Letrozole , Mastectomy , Neoplasm Staging , Proportional Hazards Models , Randomized Controlled Trials as Topic
11.
Breast Cancer Res ; 17: 56, 2015 Apr 16.
Article in English | MEDLINE | ID: mdl-25888246

ABSTRACT

INTRODUCTION: Worldwide, many patients with HER2+ (human epidermal growth factor receptor 2-positive) early breast cancer (BC) do not receive adjuvant trastuzumab. Hazards of recurrence of these patients with respect to hormone receptor status of the primary tumor have not been described. METHODS: Using data from 1,260 patients randomized to placebo in the adjuvant TEACH trial, we report 10-year annual hazards of recurrence in HER2+ patients not treated with anti-HER2 therapy. RESULTS: Disease-free survival (DFS) was 75% after 5 and 61% after 10 years, respectively. Patients with HER2+ hormone receptor-positive (HR+ (hormone receptor-positive); ER+ (estrogen receptor-positive) or PR+ (progesterone receptor-positive)) disease had a significantly better DFS than patients with HER2+ HR- (ER-/PR-) disease (hazard ratio 0.72, P=0.02). This difference was explainable by a significantly higher hazard of recurrence in years 1 to 5 in HER2+ HR- compared to HER2+ HR+ patients, with a mean risk of recurrence of 9%/year for HR- versus 5%/year in HR+ patients (hazard ratio 0.59, P=0.002 for years 1 to 5). The high early risk of recurrence of HER2+ HR- patients declined sharply over time, so that it was similar to that seen in HER2+ HR+ patients in years 6 to 10 (hazard ratio 0.97, P=0.92 for years 6 to 10). CONCLUSIONS: Our results show that outcomes in HER2+ patients with early BC not receiving anti-HER2 therapy strongly depend on HR expression. The very high early risk of relapse seen in HER2+ HR- patients is particularly relevant in health care settings with limited access to adjuvant anti-HER2 treatment. The event rates shown for subpopulations of HER2+ BC patients suggest that in resource-constrained environments patients with HER2+ HR- early BC should be prioritized for consideration of adjuvant anti-HER2 therapy.


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/mortality , Receptor, ErbB-2/metabolism , Adult , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Chemotherapy, Adjuvant , Female , Follow-Up Studies , Humans , Middle Aged , Molecular Targeted Therapy , Neoplasm Recurrence, Local , Prognosis , Proportional Hazards Models , Receptor, ErbB-2/antagonists & inhibitors , Receptor, ErbB-2/genetics , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Treatment Outcome , Young Adult
12.
Stat Med ; 34(9): 1454-66, 2015 Apr 30.
Article in English | MEDLINE | ID: mdl-25582933

ABSTRACT

The generalized Wilcoxon and log-rank tests are commonly used for testing differences between two survival distributions. We modify the Wilcoxon test to account for auxiliary information on intermediate disease states that subjects may pass through before failure. For a disease with multiple states where patients are monitored periodically but exact transition times are unknown (e.g. staging in cancer), we first fit a multi-state Markov model to the full data set; when censoring precludes the comparison of survival times between two subjects, we use the model to estimate the probability that one subject will have survived longer than the other given their censoring times and last observed status, and use these probabilities to compute an expected rank for each subject. These expected ranks form the basis of our test statistic. Simulations demonstrate that the proposed test can improve power over the log-rank and generalized Wilcoxon tests in some settings while maintaining the nominal type 1 error rate. The method is illustrated on an amyotrophic lateral sclerosis data set.


Subject(s)
Biometry/methods , Disease Progression , Markov Chains , Survival Analysis , Amyotrophic Lateral Sclerosis , Computer Simulation , Humans , Models, Statistical , Sensitivity and Specificity , Severity of Illness Index
13.
Lancet Oncol ; 15(7): e279-89, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24872111

ABSTRACT

The health burden of cancer is increasing in China, with more than 1·6 million people being diagnosed and 1·2 million people dying of the disease each year. As in most other countries, breast cancer is now the most common cancer in Chinese women; cases in China account for 12·2% of all newly diagnosed breast cancers and 9·6% of all deaths from breast cancer worldwide. China's proportional contribution to global rates is increasing rapidly because of the population's rising socioeconomic status and unique reproductive patterns. In this Review we present an overview of present control measures for breast cancer across China, and emphasise epidemiological and socioeconomic diversities and disparities in access to care for various subpopulations. We describe demographic differences between China and high-income countries, and also within geographical and socioeconomic regions of China. These disparities between China and high-income countries include younger age at onset of breast cancer; the unique one-child policy; lower rates of provision and uptake for screening for breast cancer; delays in diagnosis that result in more advanced stage of disease at presentation; inadequate resources; and a lack of awareness about breast cancer in the Chinese population. Finally, we recommend key measures that could contribute to improved health outcomes for patients with breast cancer in China.


Subject(s)
Breast Neoplasms/epidemiology , Adult , Aged , Breast Neoplasms/etiology , Breast Neoplasms/mortality , Breast Neoplasms/therapy , China/epidemiology , Delayed Diagnosis , Early Detection of Cancer , Female , Humans , Incidence , Middle Aged , Precision Medicine , Risk Factors
14.
Breast Cancer Res Treat ; 145(1): 233-43, 2014 May.
Article in English | MEDLINE | ID: mdl-24696430

ABSTRACT

Early and late effects of cancer treatment are of increasing concern with growing survivor populations, but relevant data are sparse. We sought to determine the prevalence and hazard ratio of such effects in breast cancer cases. Women with invasive breast cancer and women with no cancer history recruited for a cancer research cohort completed a mailed questionnaire at a median of 10 years post-diagnosis or matched reference year (for the women without cancer). Reported medical conditions including lymphedema, osteopenia, osteoporosis, and heart disease (congestive heart failure, myocardial infarction, coronary heart disease) were assessed in relation to breast cancer therapy and time since diagnosis using Cox regression. The proportion of women currently receiving treatment for these conditions was calculated. Study participants included 2,535 women with breast cancer and 2,428 women without cancer (response rates 66.0 % and 50.4 %, respectively) Women with breast cancer had an increased risk of lymphedema (Hazard ratio (HR) 8.6; 95 % confidence interval (CI) 6.3-11.6), osteopenia (HR 2.1; 95 % CI 1.8-2.4), and osteoporosis (HR 1.5; 95 % CI 1.2-1.9) but not heart disease, compared to women without cancer Hazard ratios varied by treatment and time since diagnosis. Overall, 49.3 % of breast cancer cases reported at least one medical condition, and at 10 or more years post-diagnosis, 37.7 % were currently receiving condition-related treatment. Responses from survivors a decade following cancer diagnosis demonstrate substantial treatment-related morbidity, and emphasize the need for continued medical surveillance and follow-up care into the second decade post-diagnosis.


Subject(s)
Bone Diseases, Metabolic/epidemiology , Breast Neoplasms/therapy , Heart Diseases/epidemiology , Lymphedema/epidemiology , Osteoporosis/epidemiology , Adult , Aged , Antineoplastic Agents/adverse effects , Bone Diseases, Metabolic/etiology , Female , Heart Diseases/etiology , Humans , Lymph Node Excision/adverse effects , Lymphedema/etiology , Middle Aged , Osteoporosis/etiology , Prevalence , Radiotherapy/adverse effects , Risk Factors , Surveys and Questionnaires , Survivors/statistics & numerical data
15.
BMC Cancer ; 14: 658, 2014 Sep 09.
Article in English | MEDLINE | ID: mdl-25199766

ABSTRACT

BACKGROUND: Despite recently implemented access to care programs, Mexican breast cancer (BC) mortality rates remain substantially above those in the US. We conducted a survey among Mexican Oncologists to determine whether practice patterns may be responsible for these differences. METHODS: A web-based survey was sent to 851 oncologists across Mexico using the Vanderbilt University REDCap database. Analyses of outcomes are reported using exact and binomial confidence bounds and tests. RESULTS: 138 participants (18.6% of those surveyed) from the National capital and 26 Mexican states, responded. Respondents reported that 58% of newly diagnosed BC patients present with stage III-IV disease; 63% undergo mastectomy, 52% axillary lymph node dissection (ALND) and 48% sentinel lymph node biopsy (SLNB). Chemotherapy is recommended for tumors > 1 cm (89%), positive nodes (86.5%), triple-negative (TN) (80%) and HER2 positive tumors (58%). Trastuzumab is prescribed in 54.3% and 77.5% for HER2 < 1 cm and > 1 cm tumors, respectively. Tamoxifen is indicated for premenopausal hormone receptor (HR) positive tumors in 86.5% of cases and aromatase inhibitors (AI's) for postmenopausal in 86%. 24% of physicians reported treatment limitations, due to delayed or incomplete pathology reports and delayed or limited access to medications. CONCLUSIONS: Even though access to care programs have been recently applied nationwide, women commonly present with advanced BC, leading to increased rates of mastectomy and ALND. Mexican physicians are dissatisfied with access to appropriate medical care. Our survey detects specific barriers that may impact BC outcomes in Mexico and warrant further investigation.


Subject(s)
Breast Neoplasms/pathology , Breast Neoplasms/therapy , Health Services Accessibility , Practice Patterns, Physicians' , Adult , Aged , Data Collection , Female , Humans , Mexico , Middle Aged , Physicians , Socioeconomic Factors , Young Adult
16.
Stat Med ; 33(12): 1981-9, 2014 May 30.
Article in English | MEDLINE | ID: mdl-24500790

ABSTRACT

Clinical trials often assess efficacy by comparing treatments on the basis of two or more event-time outcomes. In the case of cancer clinical trials, progression-free survival (PFS), which is the minimum of the time from randomization to progression or to death, summarizes the comparison of treatments on the hazards for disease progression and mortality. However, the analysis of PFS does not utilize all the information we have on patients in the trial. First, if both progression and death times are recorded, then information on death time is ignored in the PFS analysis. Second, disease progression is monitored at regular clinic visits, and progression time is recorded as the first visit at which evidence of progression is detected. However, many patients miss or have irregular visits (resulting in interval-censored data) and sometimes die of the cancer before progression was recorded. In this case, the previous progression-free time could provide additional information on the treatment efficacy. The aim of this paper is to propose a method for comparing treatments that could more fully utilize the data on progression and death. We develop a test for treatment effect based on of the joint distribution of progression and survival. The issue of interval censoring is handled using the very simple and intuitive approach of the Conditional Expected Score Test (CEST). We focus on the application of these methods in cancer research.


Subject(s)
Bias , Breast Neoplasms/drug therapy , Data Interpretation, Statistical , Disease Progression , Disease-Free Survival , Antineoplastic Agents/therapeutic use , Clinical Trials as Topic , Female , Humans , Letrozole , Models, Statistical , Nitriles/therapeutic use , Triazoles/therapeutic use
17.
Lancet Oncol ; 14(1): 88-96, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23234763

ABSTRACT

BACKGROUND: Worldwide, many patients with HER2-positive early stage breast cancer do not receive trastuzumab-the standard adjuvant treatment. We investigated the efficacy and safety of adjuvant lapatinib for patients with trastuzumab-naive HER2-positive early-stage breast cancer, started at any time after diagnosis. METHODS: This study was a placebo-controlled, multicentre, randomised phase 3 trial. Women outpatients from 405 [corrected] centres in 33 countries [corrected] with HER2-positive early-breast cancer who had previously received adjuvant chemotherapy but not trastuzumab were randomly assigned (1:1) to receive daily lapatinib (1500 mg) or daily placebo for 12 months. Randomisation was done with a computer-generated sequence, stratified by time since diagnosis, lymph node involvement at diagnosis, and tumour hormone-receptor status. Investigators, site staff, and patients were masked to treatment assignment. The primary endpoint was disease-free survival in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT00374322. FINDINGS: Between August, 2006, and May, 2008, 3161 women were enrolled and 3147 were assigned to lapatinib (n=1571) or placebo (n=1576). After a median follow-up of 47·4 months (range 0·4-60·0) in the lapatinib group and 48·3 (0·7-61·3) in the placebo group, 210 (13%) disease-free survival events had occurred in the lapatinib group versus 264 (17%) in the placebo group (hazard ratio [HR] 0·83, 95% CI 0·70-1·00; p=0·053). Central review of HER2 status showed that only 2490 (79%) of the randomised women were HER2-positive. 157 (13%) of 1230 confirmed HER2-positive patients in the lapatinib group and in 208 (17%) of 1260 in the placebo group had a disease-free survival event (HR 0·82, 95% 0·67-1·00; p=0·04). Serious adverse events occurred in 99 (6%) of 1573 patients taking lapatinib and 77 (5%) of 1574 patients taking placebo, with higher incidences of grade 3-4 diarrhoea (97 [6%] vs nine [<1%]), rash (72 [5%] vs three [<1%]), and hepatobiliary disorders (36 [2%] vs one [<1%]). INTERPRETATION: Our data show that there was no significant difference in disease-free survival between groups when analysed in the intention-to-treat population. However, exploratory analyses restricted to patients who had HER2-positive disease confirmed by central fluorescence in-situ hybridisation review suggested marginal benefit with lapatinib in terms of disease-free survival. Thus lapatinib might be an option for women with HER2-positive breast cancer who do not or cannot receive adjuvant trastuzumab. FUNDING: GlaxoSmithKline.


Subject(s)
Breast Neoplasms/drug therapy , Disease-Free Survival , Quinazolines/administration & dosage , Receptor, ErbB-2/metabolism , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized/administration & dosage , Breast Neoplasms/pathology , Chemotherapy, Adjuvant/adverse effects , Drug-Related Side Effects and Adverse Reactions/classification , Female , Humans , Lapatinib , Lymph Nodes/pathology , Middle Aged , Neoplasm Staging , Quinazolines/adverse effects , Trastuzumab
18.
Breast Cancer Res Treat ; 140(3): 485-94, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23912961

ABSTRACT

The purpose of this study is to evaluate arm volume measurements and clinico-pathologic characteristics of breast cancer patients to define a threshold for intervention in breast cancer-related lymphedema. We prospectively performed arm volume measurements on breast cancer patients using a Perometer. Arm measurements were performed pre- and post-operatively, and change in arm volume was quantified using a relative volume change (RVC) equation. Patient and treatment risk factors were evaluated. Cox proportional hazards models with time-dependent covariates for RVC were used to evaluate whether RVC elevations of ≥3 to <5 % or ≥5 to <10 % occurring ≤3 months or >3 months after surgery were associated with progression to ≥10 % RVC. 1,173 patients met eligibility criteria with a median of 27 months post-operative follow-up. The cumulative incidence of ≥10 % RVC at 24 months was 5.26 % (95 % CI 4.01-6.88 %). By multivariable analysis, a measurement of ≥5 to <10 % RVC occurring >3 months after surgery was significantly associated with an increased risk of progression to ≥10 % RVC (HR 2.97, p < 0.0001), but a measurement of ≥3 to <5 % RVC during the same time period was not statistically significantly associated (HR 1.55, p = 0.10). Other significant risk factors included a measurement ≤3 months after surgery with RVC of ≥3 to <5 % (p = 0.007), ≥5 to <10 % (p < 0.0001), or ≥10 % (p = 0.023), axillary lymph node dissection (ALND) (p < 0.0001), and higher BMI at diagnosis (p = 0.0028). Type of breast surgery, age, number of positive or number of lymph nodes removed, nodal radiation, chemotherapy, and hormonal therapy were not significant (p > 0.05). Breast cancer patients who experience a relative arm volume increase of ≥3 to <5 % occurring >3 months after surgery do not have a statistically significant increase in risk of progression to ≥10 %, a common lymphedema criterion. Our data support utilization of a ≥5 to <10 % threshold for close monitoring or intervention, warranting further assessment. Additional risk factors for progression to ≥10 % include ALND, higher BMI, and post-operative arm volume elevation.


Subject(s)
Breast Neoplasms/complications , Breast Neoplasms/surgery , Lymphedema/etiology , Adult , Aged , Aged, 80 and over , Arm/physiopathology , Breast Neoplasms/pathology , Breast Neoplasms/therapy , Disease Progression , Female , Humans , Lymph Node Excision/adverse effects , Lymphedema/epidemiology , Lymphedema/pathology , Mastectomy/adverse effects , Middle Aged , Multivariate Analysis , Postoperative Period , Proportional Hazards Models , Prospective Studies , Time Factors , Young Adult
19.
Lancet Oncol ; 13(3): e95-e102, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22381937

ABSTRACT

Breast cancer is the most common cancer in women worldwide and 70% of breast cancer deaths occur in women from low-income and middle-income countries. Latin America has about 115,000 new cases of disease every year, with about 50,000 arising in Brazil. We examined the present status of breast cancer in Brazil as an example of the health effects of geographical, ethnic, and socioeconomic diversities on delivery of care. Our goal was to identify deficiencies that could be responsible for disparities in survival from breast cancer. We searched the English and Portuguese published work and reviewed national databases and Brazilian publications. Although the availability of publications specific to Brazil is low in general, we identified several factors that could account for disparities: delays in diagnosis due to low cancer awareness and implementation of mammography screening, unknown quality of surgery, and restricted access to radiotherapy and modern systemic therapies.


Subject(s)
Breast Neoplasms/diagnosis , Breast Neoplasms/therapy , Delivery of Health Care, Integrated/statistics & numerical data , Health Services Accessibility/statistics & numerical data , Healthcare Disparities/statistics & numerical data , Aged , Antineoplastic Agents/therapeutic use , Brazil/epidemiology , Breast Neoplasms/ethnology , Breast Neoplasms/mortality , Early Detection of Cancer , Female , Humans , Incidence , Mammography/statistics & numerical data , Mass Screening/methods , Mass Screening/statistics & numerical data , Mastectomy/statistics & numerical data , Middle Aged , Predictive Value of Tests , Radiotherapy , Residence Characteristics , Socioeconomic Factors , Treatment Outcome
20.
Lancet Oncol ; 13(8): e335-43, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22846838

ABSTRACT

Breast cancer is a major public health issue in low-income and middle-income countries. In Mexico, incidence and mortality of breast cancer have risen in the past few decades. Changes in health-care policies in Mexico have incorporated programmes for access to early diagnosis and treatment of this disease. This Review outlines the status of breast cancer in Mexico, regarding demographics, access to care, and strategies to improve clinical outcomes. We identify factors that contribute to the existing disease burden, such as low mammography coverage, poor quality control, limited access to diagnosis and treatment, and insufficient physical and human resources for clinical care.


Subject(s)
Breast Neoplasms/diagnosis , Breast Neoplasms/therapy , Delivery of Health Care, Integrated , Health Services Accessibility , Quality of Health Care , Women's Health Services , Adult , Aged , Breast Neoplasms/economics , Breast Neoplasms/mortality , Delivery of Health Care, Integrated/economics , Early Detection of Cancer , Female , Health Care Costs , Health Services Accessibility/economics , Humans , Incidence , Mammography , Mass Screening/methods , Mexico/epidemiology , Middle Aged , Preventive Health Services , Prognosis , Quality of Health Care/economics , Risk Assessment , Risk Factors , Women's Health Services/economics
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