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1.
Stat Methods Med Res ; 33(6): 1069-1092, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38592333

ABSTRACT

For the analysis of time-to-event data, frequently used methods such as the log-rank test or the Cox proportional hazards model are based on the proportional hazards assumption, which is often debatable. Although a wide range of parametric and non-parametric methods for non-proportional hazards has been proposed, there is no consensus on the best approaches. To close this gap, we conducted a systematic literature search to identify statistical methods and software appropriate under non-proportional hazard. Our literature search identified 907 abstracts, out of which we included 211 articles, mostly methodological ones. Review articles and applications were less frequently identified. The articles discuss effect measures, effect estimation and regression approaches, hypothesis tests, and sample size calculation approaches, which are often tailored to specific non-proportional hazard situations. Using a unified notation, we provide an overview of methods available. Furthermore, we derive some guidance from the identified articles.


Subject(s)
Clinical Trials as Topic , Proportional Hazards Models , Humans , Clinical Trials as Topic/statistics & numerical data , Sample Size , Software
2.
Clin Microbiol Infect ; 28(12): 1558-1566, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35788049

ABSTRACT

BACKGROUND: Randomised controlled trials (RCTs) investigated analgesics, herbal formulations, delayed prescription of antibiotics, and placebo to prevent overprescription of antibiotics in women with uncomplicated urinary tract infections (uUTI). OBJECTIVES: To estimate the effect of these strategies and to identify symptoms, signs, or other factors that indicate a benefit from these strategies. DATA SOURCES: MEDLINE, EMBASE, Web of Science, LILACS, Cochrane Database of Systematic Reviews and of Controlled Trials, and ClinicalTrials. STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS: RCTs investigating any strategies to reduce antibiotics vs. immediate antibiotics in adult women with uUTI in primary care. METHODS: We extracted individual participant data (IPD) if available, otherwise aggregate data (AD). Bayesian random-effects meta-analysis of the AD was used for pairwise comparisons. Candidate moderators and prognostic indicators of treatment effects were investigated using generalised linear mixed models based on IPD. RESULTS: We analysed IPD of 3524 patients from eight RCTs and AD of 78 patients. Non-antibiotic strategies increased the rates of incomplete recovery (OR 3.0; 95% credible interval (CrI), 1.7-5.5; Bayesian p-value (pB) = 0.0017; τ = 0.6), subsequent antibiotic treatment (OR 3.5; 95% CrI, 2.1-5.8; pB = 0.0003) and pyelonephritis (OR 5.6; 95% CrI, 2.3-13.9; pB = 0.0003). Conversely, they decreased overall antibiotic use by 63%. Patients positive for urinary erythrocytes and urine culture were at increased risk for incomplete recovery (OR 4.7; 95% CrI, 2.1-10.8; pB = 0.0010), but no difference was apparent where both were negative (OR 0.8; 95% CrI, 0.3-2.0; pB = 0.667). In patients treated using non-antibiotic strategies, urinary erythrocytes and positive urine culture were independent prognostic indicators for subsequent antibiotic treatment and pyelonephritis. CONCLUSIONS: Compared to immediate antibiotics, non-antibiotic strategies reduce overall antibiotic use but result in poorer clinical outcomes. The presence of erythrocytes and tests to confirm bacteria in urine could be used to target antibiotic prescribing.


Subject(s)
Pyelonephritis , Urinary Tract Infections , Female , Adult , Humans , Anti-Bacterial Agents , Urinary Tract Infections/drug therapy , Urinary Tract Infections/prevention & control , Pyelonephritis/drug therapy
3.
BMC Surg ; 22(1): 202, 2022 May 21.
Article in English | MEDLINE | ID: mdl-35597932

ABSTRACT

BACKGROUND: Gastrointestinal stromal tumors (GIST) are rare abdominal tumors. Pretreatment biopsies may be used to diagnose a GIST and enable tailored treatment. Some experts are skeptical about biopsies because they fear tumor cell seeding. The objective of this study was to determine if pretreatment biopsy is associated with increased tumor recurrence. METHODS: We performed a systematic literature search and included studies assessing the oncological outcome of GIST patients who underwent a pre-treatment core needle biopsy or fine needle aspiration. We assessed methodological quality with the Newcastle-Ottawa-Scale for non-randomized studies. This review was registered in the PROSPERO database (CRD42021170290). RESULTS: Three non-randomized studies and eight case reports comprising 350 patients were eligible for inclusion. No prospective study designed to answer the review question was found. One case of needle tract seeding after percutaneous core needle biopsy of GIST was reported. None of the studies reported an increased rate of abdominal recurrence in patients with pretreatment biopsy. CONCLUSIONS: The existing evidence does not indicate a relevant risk of needle tract seeding or abdominal recurrence after pre-treatment biopsy of GIST. Biopsy can safely be done to differentiate GIST from other tumors and to select the most appropriate treatment.


Subject(s)
Gastrointestinal Stromal Tumors , Abdomen/pathology , Biopsy, Fine-Needle , Gastrointestinal Stromal Tumors/diagnosis , Gastrointestinal Stromal Tumors/pathology , Humans , Prospective Studies
4.
ERJ Open Res ; 8(1)2022 Jan.
Article in English | MEDLINE | ID: mdl-35265703

ABSTRACT

A decreasing trend in exacerbation rates has been observed in COPD. Because mortality is linked to exacerbations, it is of interest to investigate whether a similar time trend is also present in mortality rates. We performed a systematic review of placebo groups in published randomised controlled trials. Mortality rate was modelled based on a Poisson distribution for the event counts. Adding information on mortality as well as on newly published studies on a previous database, we performed a meta-regression. Among the 56 included studies representing 14 166 patients, an annual decrease in mortality rates of 6.1% (-0.6%, 12.6%) (p=0.073) was observed. Consistent results were obtained in subgroups as well as when adjusting for potential confounders. The correlation between exacerbation rate and mortality rate was positive but weak as well as insignificant. In summary, analysis of randomised controlled trials in COPD patients showed a decrease in mortality in the placebo arms over the last two decades. This effect is comparable to the previously observed decrease in annual exacerbation rate. Albeit insignificant, our results suggest that care is needed in the design of new trials or when comparing results from trials published many years apart.

5.
Eur Heart J Digit Health ; 2(3): 424-436, 2021 Sep.
Article in English | MEDLINE | ID: mdl-36713608

ABSTRACT

Aims: Artificial intelligence (AI) and machine learning (ML) promise vast advances in medicine. The current state of AI/ML applications in cardiovascular medicine is largely unknown. This systematic review aims to close this gap and provides recommendations for future applications. Methods and results: Pubmed and EMBASE were searched for applied publications using AI/ML approaches in cardiovascular medicine without limitations regarding study design or study population. The PRISMA statement was followed in this review. A total of 215 studies were identified and included in the final analysis. The majority (87%) of methods applied belong to the context of supervised learning. Within this group, tree-based methods were most commonly used, followed by network and regression analyses as well as boosting approaches. Concerning the areas of application, the most common disease context was coronary artery disease followed by heart failure and heart rhythm disorders. Often, different input types such as electronic health records and images were combined in one AI/ML application. Only a minority of publications investigated reproducibility and generalizability or provided a clinical trial registration. Conclusions: A major finding is that methodology may overlap even with similar data. Since we observed marked variation in quality, reporting of the evaluation and transparency of data and methods urgently need to be improved.

6.
BMJ Open ; 10(10): e035883, 2020 10 01.
Article in English | MEDLINE | ID: mdl-33004385

ABSTRACT

INTRODUCTION: Uncomplicated urinary tract infection (UTI) in women is a common reason to present in general practice and is usually treated with antibiotics to reduce symptom severity and duration. Results of recent clinical trials indicate that non-antibiotic treatment approaches can also be effective. However, it remains unclear which patients would benefit from antibiotic treatment and which can effectively and safely be treated without antibiotics. This systematic review and meta-analysis aims to estimate the effect of treatment strategies to reduce antibiotic use in comparison with immediate antibiotic treatment and to identify prognostic factors and moderators of treatment effects. A further aim is to identify subgroups of patients benefiting from a specific therapy. METHODS AND ANALYSIS: A systematic literature search will be performed to identify randomised controlled trials which investigated the effect of treatment strategies to reduce antibiotic use in female adults with uncomplicated UTI compared with immediate antibiotic treatment. Therefore, the primary outcome of the meta-analysis is incomplete recovery. Anonymised individual patient data (IPD) will be collected. Aggregate data will be used for pairwise comparisons of treatment strategies using meta-analysis models with random effects accounting for potential between-study heterogeneity. Potential effect moderators will be explored in meta-regressions. For IPD, generalised linear mixed models will be used, which may be adjusted for baseline characteristics. Interactions of baseline variables with treatment effects will be explored. These models will be used to assess direct comparisons of treatment, but might be extended to networks. ETHICS AND DISSEMINATION: The local institutional review and ethics board judged the project a secondary analysis of existing anonymous data which meet the criteria for waiver of ethics review. Dissemination of the results will be via published scientific papers and presentations. Key messages will be promoted for example, via social media or press releases. PROSPERO REGISTRATION NUMBER: CRD42019125804.


Subject(s)
Anti-Bacterial Agents , Urinary Tract Infections , Adult , Anti-Bacterial Agents/therapeutic use , Female , Humans , Meta-Analysis as Topic , Primary Health Care , Systematic Reviews as Topic , Urinary Tract Infections/drug therapy
7.
Am J Kidney Dis ; 76(6): 826-841.e1, 2020 12.
Article in English | MEDLINE | ID: mdl-32679151

ABSTRACT

RATIONALE & OBJECTIVE: The usefulness of measures of neutrophil gelatinase-associated lipocalin (NGAL) in urine or plasma obtained on clinical laboratory platforms for predicting acute kidney injury (AKI) and AKI requiring dialysis (AKI-D) has not been fully evaluated. We sought to quantitatively summarize published data to evaluate the value of urinary and plasma NGAL for kidney risk prediction. STUDY DESIGN: Literature-based meta-analysis and individual-study-data meta-analysis of diagnostic studies following PRISMA-IPD guidelines. SETTING & STUDY POPULATIONS: Studies of adults investigating AKI, severe AKI, and AKI-D in the setting of cardiac surgery, intensive care, or emergency department care using either urinary or plasma NGAL measured on clinical laboratory platforms. SELECTION CRITERIA FOR STUDIES: PubMed, Web of Science, Cochrane Library, Scopus, and congress abstracts ever published through February 2020 reporting diagnostic test studies of NGAL measured on clinical laboratory platforms to predict AKI. DATA EXTRACTION: Individual-study-data meta-analysis was accomplished by giving authors data specifications tailored to their studies and requesting standardized patient-level data analysis. ANALYTICAL APPROACH: Individual-study-data meta-analysis used a bivariate time-to-event model for interval-censored data from which discriminative ability (AUC) was characterized. NGAL cutoff concentrations at 95% sensitivity, 95% specificity, and optimal sensitivity and specificity were also estimated. Models incorporated as confounders the clinical setting and use versus nonuse of urine output as a criterion for AKI. A literature-based meta-analysis was also performed for all published studies including those for which the authors were unable to provide individual-study data analyses. RESULTS: We included 52 observational studies involving 13,040 patients. We analyzed 30 data sets for the individual-study-data meta-analysis. For AKI, severe AKI, and AKI-D, numbers of events were 837, 304, and 103 for analyses of urinary NGAL, respectively; these values were 705, 271, and 178 for analyses of plasma NGAL. Discriminative performance was similar in both meta-analyses. Individual-study-data meta-analysis AUCs for urinary NGAL were 0.75 (95% CI, 0.73-0.76) and 0.80 (95% CI, 0.79-0.81) for severe AKI and AKI-D, respectively; for plasma NGAL, the corresponding AUCs were 0.80 (95% CI, 0.79-0.81) and 0.86 (95% CI, 0.84-0.86). Cutoff concentrations at 95% specificity for urinary NGAL were>580ng/mL with 27% sensitivity for severe AKI and>589ng/mL with 24% sensitivity for AKI-D. Corresponding cutoffs for plasma NGAL were>364ng/mL with 44% sensitivity and>546ng/mL with 26% sensitivity, respectively. LIMITATIONS: Practice variability in initiation of dialysis. Imperfect harmonization of data across studies. CONCLUSIONS: Urinary and plasma NGAL concentrations may identify patients at high risk for AKI in clinical research and practice. The cutoff concentrations reported in this study require prospective evaluation.


Subject(s)
Acute Kidney Injury/diagnosis , Lipocalin-2/blood , Renal Dialysis , Acute Kidney Injury/metabolism , Acute Kidney Injury/therapy , Biomarkers/blood , Biomarkers/urine , Humans , Predictive Value of Tests
8.
Anticancer Res ; 39(9): 4603-4612, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31519557

ABSTRACT

BACKGROUND/AIM: Sarcopenia describes the loss of skeletal muscle mass. While this condition is associated with a high mortality in cancer patients, its influence on survival is still underestimated. PATIENTS AND METHODS: A systematic review for articles was performed using the PubMed database, Cochrane Library, Biomed Central, Science Direct and by manual search. We used data of overall survival in sarcopenic patients for assessing the death risk. We extracted hazard ratio estimates from univariate and multivariate Cox proportional hazards models for meta-analysis. RESULTS: A total of 15 studies were eligible for meta-analysis including a total of 2,521 lung cancer patients. Univariate meta-analysis revealed a two-fold increased death risk in sarcopenic patients; multivariate meta-analysis yielded a significant, three-fold elevated risk of death. This higher mortality is independent of tumour stage. CONCLUSION: Muscle loss is an independent risk factor for increased death risk in lung cancer patients independent of cancer stage. This argues for implementing screening for sarcopenia into cancer care.


Subject(s)
Lung Neoplasms/complications , Lung Neoplasms/mortality , Sarcopenia/etiology , Humans , Lung Neoplasms/diagnosis , Lung Neoplasms/epidemiology , Muscle, Skeletal/pathology , Neoplasm Staging , Organ Size , Prognosis , Proportional Hazards Models , Sarcopenia/diagnosis , Sarcopenia/epidemiology
9.
Respir Res ; 20(1): 186, 2019 Aug 16.
Article in English | MEDLINE | ID: mdl-31420040

ABSTRACT

BACKGROUND: An important goal of chronic obstructive pulmonary disease (COPD) treatment is to reduce the frequency of exacerbations. Some observations suggest a decline in exacerbation rates in clinical trials over time. A more systematic understanding would help to improve the design and interpretation of COPD trials. METHODS: We performed a systematic review and meta-regression of the placebo groups in published randomized controlled trials reporting exacerbations as an outcome. A Bayesian negative binomial model was developed to accommodate results that are reported in different formats; results are reported with credible intervals (CI) and posterior tail probabilities (pB). RESULTS: Of 1114 studies identified by our search, 55 were ultimately included. Exacerbation rates decreased by 6.7% (95% CI (4.4, 9.0); pB <  0.001) per year, or 50% (95% CI (36, 61)) per decade. Adjusting for available study and baseline characteristics such as forced expiratory volume in 1 s (FEV1) did not alter the observed trend considerably. Two subsets of studies, one using a true placebo group and the other allowing inhaled corticosteroids in the "placebo" group, also yielded consistent results. CONCLUSIONS: In conclusion, this meta-regression indicates that the rate of COPD exacerbations decreased over the past two decades to a clinically relevant extent independent of important prognostic factors. This suggests that care is needed in the design of new trials or when comparing results from older trials with more recent ones. Also a considerable effect of adjunct therapy on COPD exacerbations can be assumed. REGISTRATION: PROSPERO 2018 CRD4218118823.


Subject(s)
Clinical Trials as Topic/methods , Disease Progression , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/epidemiology , Humans
10.
Int J Med Robot ; 13(4)2017 Dec.
Article in English | MEDLINE | ID: mdl-28660682

ABSTRACT

BACKGROUND: The purpose of this study was to analyze all relevant comparative studies comparing robot-assisted minimally invasive thymectomy (RATS) and video-assisted thoracic surgery thymectomy (VATS) in terms of surgical and short-term outcomes. METHODS: A systematic search for articles describing robot-assisted and video-assisted thymectomy and addressing surgical outcomes, operation time, length of hospitalization, intra-operative blood loss, conversion to sternotomy and post-operative complications was performed using the medical databases. RESULTS: Of the 478 studies from preliminary screening, five articles were included. By pooling these studies, we found no significant differences between the RATS and VATS (odds ratio 1.24 (95% CI 0.51, 3.03; p = 0.63)).There were no significant differences in comparison of conversion rates, operation time (26.29 min (95% CI -2.57, 55.35; p = 0.07)) and length of hospitalization (-1.58 days (95% CI -4.78, 1.62; p = 0.33)). There was a slightly higher blood loss in the RATS group. CONCLUSION: Our meta-analysis did not detect any statistically significant differences in surgery outcomes between the two groups.


Subject(s)
Minimally Invasive Surgical Procedures/methods , Postoperative Complications , Robotic Surgical Procedures/methods , Robotics , Thoracic Surgery, Video-Assisted/methods , Thymectomy/methods , Adult , Hospitalization , Humans , Length of Stay , Lung Neoplasms/surgery , Middle Aged , Operative Time , Retrospective Studies , Sternotomy/methods , Thoracic Surgical Procedures , Treatment Outcome , Video Recording
11.
Medicine (Baltimore) ; 96(24): e7161, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28614249

ABSTRACT

BACKGROUND: Robot-assisted minimally invasive surgery (RVATS) is a relatively new technique applied for thymectomies. Only few studies directly compare RVATS to the mainstay therapy, open surgery (sternotomy). METHODS: A systematic search of the literature was performed in October 2016. The meta-analysis includes studies comparing robotassisted and open thymectomy regarding operation time, length of hospitalization, intraoperative blood loss, and chest-in-tube days, postoperative complications, reoperation, arrhythmic events, pleural effusion, and postoperative bleeding. RESULTS: Of 626 studies preliminary screened, 7 articles were included. There were no significant differences in comparison of operation time (-3.19 minutes [95% confidence interval, 95% CI -112.43 to 106.05]; P = .94), but patients undergoing RVATS spent significantly less time in hospital (-4.06 days [95% CI -7.98 to -0.13], P = .046). There were fewer chests-in-tube days (-2.50 days [95% CI -15.01 to 10.01]; P = .24) and less intraoperative blood loss (-256.84 mL [95% CI -627.47 to 113.80]; P = .10) observed in the RVATS group; due to a small number of studies, these results were not statistically significant. There were also less post-operative complications in the RVATS group (12 complications in 209 patients vs 51 complications in 259 patients); however, this difference was not statistical significant (odds ratio 0.27, 95% CI 0.07-1.12; P = .06). CONCLUSIONS: Patients undergoing RVATS spent less time in hospital than patients treated by open surgery (sternotomy). These patients tended to have less postoperative complications, less intraoperative blood loss, and fewer chest-in-tube days. We found evidence for the safety and feasibility of RVATS compared with open surgery, which has to be further confirmed in randomised controlled trials.


Subject(s)
Robotic Surgical Procedures , Thoracic Surgery, Video-Assisted , Thymectomy/methods , Humans , Minimally Invasive Surgical Procedures/adverse effects , Minimally Invasive Surgical Procedures/methods , Robotic Surgical Procedures/adverse effects , Robotic Surgical Procedures/methods , Thoracic Surgery, Video-Assisted/adverse effects , Thoracic Surgery, Video-Assisted/methods , Thymectomy/adverse effects
12.
Am J Epidemiol ; 183(4): 325-34, 2016 Feb 15.
Article in English | MEDLINE | ID: mdl-26823437

ABSTRACT

We employed a semi-Markov multistate model for the simultaneous analysis of various endpoints describing the course of breast cancer. Results were compared with those from standard analyses using a Cox proportional hazards model. We included 3,012 patients with invasive breast cancer newly diagnosed between 2001 and 2005 who were recruited in Germany for a population-based study, the Mamma Carcinoma Risk Factor Investigation (MARIE Study), and prospectively followed up until the end of 2009. Locoregional recurrence and distant metastasis were included as intermediate states, and deaths from breast cancer, secondary cancer, and other causes were included as competing absorbing states. Tumor characteristics were significantly associated with all breast cancer-related endpoints. Nodal involvement was significantly related to local recurrence but more strongly related to distant metastases. Smoking was significantly associated with mortality from second cancers and other causes, whereas menopausal hormone use was significantly associated with reduced distant metastasis and death from causes other than cancer. The presence of cardiovascular disease at diagnosis was solely associated with mortality from other causes. Compared with separate Cox models, multistate models allow for dissection of prognostic factors and intermediate events in the analysis of cause-specific mortality and can yield new insights into disease progression and associated pathways.


Subject(s)
Breast Neoplasms/epidemiology , Carcinoma/epidemiology , Models, Theoretical , Aged , Female , Germany/epidemiology , Humans , Life Style , Mammography , Middle Aged , Prospective Studies , Risk Factors
13.
Int J Cancer ; 138(9): 2098-108, 2016 May 01.
Article in English | MEDLINE | ID: mdl-26649645

ABSTRACT

Cohort studies of breast cancer (BC) patients, but not of disease-free women at inclusion, have found menopausal hormone therapy (MHT) to be associated with decreased BC specific mortality (BCM). Here, the German population-based MARIEplus BC cohort was analyzed to further elucidate associations of prediagnostic MHT with BCM (and modification by tumor characteristics), recurrence, and secondarily with other cause and overall mortality. Enrolled 2002-2005, incident invasive BC cases (N = 3,321) were followed up for a median of 6.1 years. Cox proportional hazards models adjusted for tumor characteristics, mammography and lifestyle were applied. Compared with never users of MHT, current users at date of diagnosis had significantly lower BCM (Hazard ratio (HR) 0.72, 95% CI 0.53-0.97) and risk of recurrence (HR 0.61, 95% CI 0.46-0.82). The MHT related reduced BCM was confined to patients with low grade tumors (HR 0.44, 95% CI 0.28-0.70; phet = 0.01) and not modified by estrogen receptor or nodal status. BCM decreased with MHT duration in current and increased in past users (phet = 0.015). Mortality due to causes other than BC and overall mortality were also reduced in current MHT users (HR 0.51, 95% CI 0.32-0.81, HR 0.66, 95% CI 0.52-0.86, respectively). Favorable tumor characteristics and mammographic surveillance could not fully explain associations of current MHT use with BCM and recurrence risk. Thus, the study contributes to the evidence that prediagnostic MHT does not have a negative impact on prognosis after BC. The restriction of a reduced BCM to low grade tumors should be confirmed in independent studies.


Subject(s)
Breast Neoplasms/mortality , Breast Neoplasms/pathology , Estrogen Replacement Therapy/adverse effects , Aged , Cohort Studies , Female , Humans , Middle Aged , Neoplasm Recurrence, Local/epidemiology , Prognosis , Proportional Hazards Models , Prospective Studies , Risk Factors
14.
Psychooncology ; 24(1): 40-6, 2015 Jan.
Article in English | MEDLINE | ID: mdl-24839264

ABSTRACT

OBJECTIVE: Fatigue is among the most distressing symptoms across the breast cancer continuum. However, little is known about the factors contributing to long-term persisting fatigue. Therefore, we explored determinants of long-term physical, affective, and cognitive fatigue in a prospective cohort of breast cancer patients. METHODS: Breast cancer patients recruited in a population-based case-control study (MARIE study) provided comprehensive data on sociodemographics, lifestyle, and preexisting medical conditions. At follow-up (median 6.3 years post-diagnosis, MARIEplus), disease-free cancer survivors (N = 1928) reported current fatigue using a validated multidimensional questionnaire. Additionally, survivors retrospectively rated their fatigue levels before diagnosis, during the treatment phase, and 1 year post-surgery. Linear regression analyses were performed. RESULTS: As major determinants of long-term physical, affective, and cognitive fatigue, multiple regression analyses revealed preexisting psychological or depressive disorders, migraine, analgesic use, peripheral arterial obstructive disease (PAOD), and arthritis. A physically inactive lifestyle and obesity were associated with persisting physical fatigue. Aromatase inhibitors were also associated with long-term fatigue, especially cognitive fatigue. Chemotherapy and, to a lower extent, radiotherapy were major contributors to the development of fatigue during the treatment phase, yet were not associated with long-term fatigue. CONCLUSIONS: Although the development of fatigue in breast cancer patients seems largely impacted by cancer therapy, for the long-term persistence of fatigue, preexisting medical or psychological conditions related to depression or pain and lifestyle factors appear to be more relevant. Physicians, psycho-oncologists, and researchers may need to distinguish between acute fatigue during therapy and long-term persisting fatigue with regard to its pathophysiology and treatment.


Subject(s)
Analgesics/therapeutic use , Aromatase Inhibitors/therapeutic use , Breast Neoplasms/epidemiology , Depressive Disorder/epidemiology , Fatigue/epidemiology , Peripheral Arterial Disease/epidemiology , Survivors , Aged , Antineoplastic Agents/therapeutic use , Arthritis/epidemiology , Breast Neoplasms/therapy , Cohort Studies , Comorbidity , Female , Humans , Linear Models , Longitudinal Studies , Mental Fatigue/epidemiology , Middle Aged , Migraine Disorders/epidemiology , Obesity/epidemiology , Prospective Studies , Radiotherapy , Risk Factors , Sedentary Behavior
15.
Cancer Epidemiol ; 38(4): 419-26, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24950597

ABSTRACT

BACKGROUND: Inconsistent associations of smoking and breast cancer-specific mortality might be explained by subgroups of patients with different susceptibility to harmful effects of smoking. METHODS: We used a prospective cohort of 3340 postmenopausal breast cancer patients aged 50-74 and diagnosed with invasive tumours 2001-2005 in Germany, with a median follow-up time of 6 years. The effect of pre-diagnostic smoking behaviour on mortality outcomes and risk of recurrence was investigated using delayed entry Cox regression analysis. Differential effects according to N-acetyltransferase (NAT2) status, BMI, alcohol consumption, and tumour subtypes were assessed. RESULTS: Overall, smoking at time of breast cancer diagnosis versus never/former smoking was non-significantly associated with increased breast cancer-specific mortality and risk of recurrence (HR 1.23, 95% CI 0.93-1.64, and HR 1.29, 95% CI 0.95-1.75, respectively). Associations were consistently stronger in NAT2 slow than in fast acetylators for all mortality outcomes. Breast cancer-specific mortality was significantly increased in smokers with NAT2 slow acetylating status (HR 1.77, 95% CI 1.13-2.79) but not in those with fast acetylating status (HR 1.09, 95% CI 0.60-1.98; Pheterogeneity=0.19). Smoking was associated with significantly poorer outcomes for triple negative and luminal A-like tumours (e.g. all-cause mortality: HR 1.93, 95% CI 1.02-3.65, and HR 2.08, 95% CI 1.40-3.10, respectively). Risk of recurrence was significantly increased for women with HER2 positive tumours (HR 3.64, 95% CI 1.22-10.8). There was significant heterogeneity by BMI for non-breast cancer-specific mortality (<25 kg/m(2): HR 2.52, 95% CI 1.52-4.15 vs. ≥25 kg/m(2): HR 0.94, 95% CI 0.38-2.36; Pheterogeneity=0.04). CONCLUSION: The harmful effects of smoking may be particularly relevant for certain subgroups of breast cancer patients. This may include patients with NAT2 slow acetylation status or with tumour subtypes other than luminal B, such as luminal A tumours who usually have a rather good prognosis. Emphasis on smoking cessation programmes for all cancer patients should be strengthened.


Subject(s)
Arylamine N-Acetyltransferase/metabolism , Breast Neoplasms/pathology , Smoking/adverse effects , Aged , Alcohol Drinking/adverse effects , Arylamine N-Acetyltransferase/genetics , Body Mass Index , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Cohort Studies , Female , Genotype , Germany , Humans , Kaplan-Meier Estimate , Middle Aged , Neoplasm Recurrence, Local/epidemiology , Polymorphism, Single Nucleotide , Prognosis , Proportional Hazards Models , Prospective Studies , Risk Factors , White People
16.
J Cancer Surviv ; 8(3): 384-93, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24570215

ABSTRACT

PURPOSE: Comorbid conditions have become increasingly relevant for breast cancer care given the large numbers of long-term survivors. Our aim was to identify potential determinants associated with the development of comorbidities after breast cancer. METHODS: Self-reported comorbidities and lifestyle were assessed at recruitment and after a median follow up of 69.4 months from diagnosis in a population-based cohort of breast cancer cases aged 50 to 74 years at diagnosis (MARIEplus study). Tumor and therapy data were extracted from medical records. Determinants potentially associated with incident diagnoses of hypertension, cardiovascular diseases (CVD), and osteoporosis were assessed using multivariable Cox proportional hazard regression models. RESULTS: Follow-up interview was completed by 2,542 women (76.4 % of eligible patients). A diagnosis of hypertension was significantly associated with age, higher education (hazard ratio (HR) 0.54, CI 0.37-0.79), baseline body mass index (BMI; ≥30 kg/m(2); HR, 1.90; CI, 1.24-2.90), and trastuzumab medication (HR, 2.16; CI, 1.09-4.33). An increased risk for CVD was associated with age, BMI, and intake of aromatase inhibitors (AI; HR, 1.42; CI, 1.09-1.84). Risk of osteoporosis was also positively associated with AI treatment (HR, 2.15; CI, 1.64-2.82) but inversely associated with a higher BMI (≥30 kg/m(2); HR, 0.50; CI, 0.31-0.79). CONCLUSION: In breast cancer survivors, treatment with AI constituted a risk factor for incident CVD and osteoporosis. Besides known risk factors, patients who were treated with trastuzumab may have an increased risk for hypertension. IMPLICATIONS FOR CANCER SURVIVORS: Reducing overweight and regular sport/cycling activities may help to prevent CVD after breast cancer. Patients should be monitored for risk factors and advised on possible cardiac side effects of AI and trastuzumab.


Subject(s)
Breast Neoplasms/mortality , Survivors , Aged , Antibodies, Monoclonal, Humanized/adverse effects , Aromatase Inhibitors/adverse effects , Body Mass Index , Breast Neoplasms/complications , Cardiovascular Diseases/etiology , Cohort Studies , Comorbidity , Female , Humans , Middle Aged , Osteoporosis/etiology , Proportional Hazards Models , Prospective Studies , Risk Factors , Trastuzumab
17.
Int J Cancer ; 135(4): 923-33, 2014 Aug 15.
Article in English | MEDLINE | ID: mdl-24436155

ABSTRACT

We previously reported that high concentrations of enterolactone, a lignan metabolite, are associated with lower mortality in 1,140 breast cancer patients from Germany. Using an extended set of 2,182 patients aged 50-74 years at diagnosis (2001-2005) and prospectively followed up until 2009, we investigated whether the association with mortality differs by lifestyle factors and tumor characteristics. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using multivariable Cox regression. Potential differential effects by tumor characteristics and lifestyle factors were assessed and a meta-analysis of five studies addressing lignan exposure and breast cancer prognosis was performed to summarize evidence. Median enterolactone concentrations were 17.4 (± 30.5 standard deviation) and 22.9 nmol L(-1) (± 44.8), respectively, for 269 deceased and 1,913 patients still alive. High enterolactone concentrations were significantly associated with lower all-cause mortality (per 10 nmol L(-1) : HR 0.94, 95% CI 0.90-0.98), breast cancer-specific mortality (HR 0.94, 0.89-0.99), and distant disease-free survival (HR 0.94, 0.90-0.98). Associations were found for stage 0-IIIA but not for stage IIIB-IV disease (p(het) = 0.01) and were stronger in patients with BMI <25 kg m(-2) than those with BMI ≥ 25 (p(het) = 0.04). In patients with healthy lifestyle (BMI <25, nonsmoker, physically active), the inverse association with all-cause mortality was still apparent (HR 0.92, 0.85-0.99). The meta-analysis yielded significant associations both for all-cause (HR 0.57, 0.42-0.78) and breast cancer-specific mortality (HR 0.54, 0.39-0.75). Our findings show that high lignan exposure is associated with reduced mortality in breast cancer patients. The inverse association observed in this study cannot be entirely explained by a healthy lifestyle.


Subject(s)
4-Butyrolactone/analogs & derivatives , Breast Neoplasms/blood , Diet , Lignans/blood , 4-Butyrolactone/blood , Aged , Biomarkers, Tumor/blood , Body Mass Index , Breast Neoplasms/diagnosis , Breast Neoplasms/mortality , Disease Progression , Disease-Free Survival , Female , Germany , Humans , Life Style , Middle Aged , Postmenopause , Prognosis , Proportional Hazards Models , Prospective Studies , Risk Factors
18.
Int J Cancer ; 134(12): 2972-83, 2014 Jun 15.
Article in English | MEDLINE | ID: mdl-24272459

ABSTRACT

We previously reported that lower post-diagnostic circulating 25-hydroxyvitamin D [25(OH)D] concentrations were associated with higher risk of overall mortality and distant disease in stage I-IV postmenopausal breast cancer survivors. This association was now re-examined in an extended dataset to investigate potential effect modification by tumor characteristics and lifestyle factors. A prospective cohort study was conducted in Germany including 2,177 incident stage I-IV postmenopausal breast cancer patients aged 50-74 years. Patients were diagnosed between 2001 and 2005 and median follow-up time was 5.3 years. Cox proportional hazards models were stratified by age at diagnosis, study center and season of blood collection and adjusted for other prognostic factors. A meta-analysis of studies on circulating 25(OH)D and mortality in breast cancer patients was performed to summarize evidence. Lower concentrations of 25(OH)D were significantly associated with higher risk of overall mortality [hazard ratio (HR) lowest vs. highest tertile = 1.86; 95% confidence interval (CI): 1.22, 2.82; p-trend = 0.002] and distant disease (HR = 1.76; 95% CI: 1.24, 2.49; p-trend = 0.003) in stage I-IIIa but not in stage IIIb-IV breast cancer patients. No significant interaction by lifestyle factors was observed (all p-interaction > 0.05). The meta-analysis yielded significant associations with overall and breast cancer-specific mortality (lowest vs. highest quantile: HR = 1.52; 95% CI: 1.22, 1.88 and HR = 1.74; 95% CI: 1.23, 2.40, respectively). In conclusion, post-diagnostic circulating 25(OH)D concentrations were associated with overall mortality and distant disease in stage I-IIIa postmenopausal breast cancer patients. This association was not strongly modified by lifestyle factors.


Subject(s)
Breast Neoplasms/blood , Breast Neoplasms/mortality , Vitamin D/analogs & derivatives , Aged , Cohort Studies , Female , Germany/epidemiology , Humans , Life Style , Middle Aged , Neoplasm Staging , Postmenopause/blood , Prospective Studies , Risk , Risk Factors , Survival , Vitamin D/blood
19.
PLoS One ; 8(9): e75088, 2013.
Article in English | MEDLINE | ID: mdl-24086446

ABSTRACT

Lipid-lowering drugs are used for the prevention of cardiovascular diseases. Statins are the most commonly used lipid-lowering drugs. Evidence from preclinical and observational studies suggests that statins might improve the prognosis of breast cancer patients. We analyzed data from the German MARIEplus study, a large prospective population-based cohort of patients aged 50 and older, who were diagnosed with breast cancer between 2001 and 2005. For overall mortality, breast-cancer specific mortality, and non-breast-cancer mortality, we included 3189 patients with invasive breast cancer stage I-IV, and for recurrence risk 3024 patients with breast cancer stage I-III. We used Cox proportional hazards models to assess the association with self-reported lipid-lowering drug use at recruitment. We stratified by study region, tumor grade, and estrogen/progesterone receptor status, and adjusted for age, tumor size, nodal status, metastases (stage I-IV only), menopausal hormone treatment, mode of detection, radiotherapy, and smoking. Mortality analyses were additionally adjusted for cardiovascular disease, diabetes mellitus and body-mass index. During a median follow-up of 5.3 years, 404 of 3189 stage I-IV patients died, and 286 deaths were attributed to breast cancer. Self-reported use of lipid-lowering drugs was non-significantly associated with increased non-breast cancer mortality (Hazard ratio (HR) 1.49, 95% confidence interval (CI) 0.88-2.52) and increased overall mortality (HR 1.21, 95% CI 0.87-1.69) whereas no association with breast cancer-specific mortality was found (HR 1.04, 0.67-1.60). Restricted to stage I-III breast cancer patients, 387 recurrences occurred during a median follow-up of 5.4 years. We found lipid-lowering drug use to be non-significantly associated with a reduced risk of recurrence (HR 0.83, 95% CI 0.54-1.24) and of breast cancer-specific mortality (HR 0.89, 95% CI 0.52-1.49). Although compatible with previous findings of an improved prognosis associated with statin use, our results do not provide clear supportive evidence for an association with lipid-lowering drug use due to imprecise estimates.


Subject(s)
Breast Neoplasms/drug therapy , Breast Neoplasms/epidemiology , Breast Neoplasms/physiopathology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Neoplasm Recurrence, Local/prevention & control , Age Factors , Aged , Cohort Studies , Female , Germany/epidemiology , Humans , Middle Aged , Proportional Hazards Models , Prospective Studies , Receptors, Steroid/metabolism , Risk Assessment
20.
Int J Cancer ; 133(6): 1431-40, 2013 Sep 15.
Article in English | MEDLINE | ID: mdl-23444048

ABSTRACT

Evidence is emerging that physical activity (PA) may improve overall survival after breast cancer diagnosis. However, the effect of PA on breast cancer recurrence and on cause-specific mortality is less investigated. We assessed the association of pre-diagnosis PA with recurrence, overall and cause-specific survival in a prospective cohort study in Germany including 3,393 non-metastatic breast cancer patients aged 50-74 years. Cox proportional hazards models were calculated adjusted for relevant prognostic factors. During a median follow-up of 5.6 years, 367 patients deceased. Overall mortality was significantly inversely associated with pre-diagnosis recreational PA. However, this effect was mainly attributed to deaths due to causes other than breast cancer. Multiple fractional polynomial analyses yielded a nonlinear association with markedly increased non-breast cancer mortality for women who did not engage in any sports or cycling in the years before the breast cancer diagnosis with a hazard ratio (HR, none vs. any) of 1.71, 95% confidence interval (1.16, 2.52). There were no further risk reductions with increasing activity levels. The association with breast cancer-specific mortality showed a similar dose-response but was far less pronounced with HR (none vs. any) = 1.22 (0.91, 1.64). In contrast, regarding cancer recurrence the dose-response was linear. However, this association was restricted to estrogen/progesterone receptor-negative (ER-/PR-) cases (p interaction = 0.033) with HR (highest vs. no recreational PA) = 0.53 (0.24, 1.16), p trend = 0.0045. Thus, breast cancer patients with a physically inactive lifestyle pre-diagnosis may decease prematurely irrespective of their cancer prognosis. Higher levels of exercise may reduce the risk of recurrence of ER-/PR- breast tumors.


Subject(s)
Breast Neoplasms/mortality , Exercise , Neoplasm Recurrence, Local/epidemiology , Aged , Breast Neoplasms/chemistry , Cohort Studies , Female , Humans , Kaplan-Meier Estimate , Middle Aged , Proportional Hazards Models , Prospective Studies , Receptors, Estrogen/analysis , Receptors, Progesterone/analysis
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