Immortal time bias in pharmacoepidemiological studies on cancer patient survival: empirical illustration for beta-blocker use in four cancers with different prognosis

Comparative effectiveness of treatment approaches for early invasive breast cancer

BACKGROUND

Randomized controlled trials (RCTs) suggested breast conserving therapy (BCT) and mastectomy have similar survival for early-stage breast cancer, whereas observational studies reported survival advantage for BCT. We aimed to address biases in observational studies to compare the effect of BCT and mastectomy on survival.

METHODS

We emulated a target trial using institutional cancer registry. We included adult women diagnosed with early invasive first primary breast tumors ≤ 5 cm between July 2011 and December 2017. We used cloning, censoring, and weighting to estimate risk differences (RDs) and risk ratios (RRs) for all-cause mortality and recurrence or all-cause mortality between BCT and mastectomy (reference).

RESULTS

Our study population comprised 534 observations with breast cancer. Median age was 56 years and 65 % were racial/ethnic minorities. The 8-year RD was 1.5 % (95 % confidence limits [CL]: -7.0 %, 9.8 %) and RR was 1.1 (95 % CL: 0.57, 2.2) for all-cause mortality. Results for recurrence or mortality were similar.

CONCLUSIONS

Our results suggest that target trial emulation to mitigate selection and immortal-time biases in observational studies may generate estimates that are more compatible with RCTs when comparing the effects of BCT and mastectomy on survival. Studies with longer follow-up and more events are needed to confirm our findings.

Beta-blocker exposure and survival outcomes in patients with advanced pancreatic ductal adenocarcinoma: a retrospective cohort study (BETAPANC)

Introduction: Preclinical studies have demonstrated the possible role of beta-adrenergic receptors in pancreatic ductal adenocarcinoma (PDAC) tumor invasion and migration. The current study aimed to explore the possible association between survival outcomes and beta-blocker (BB) exposure in patients with advanced PDAC. Methods: This retrospective single-center study included 182 patients with advanced PDAC. Clinical [age, sex, BMI, cardiovascular condition, presence (SBB) or absence (NSBB) of beta-1 selectivity of BB, exposure duration, and multimorbidity], oncological (stage and anticancer treatment regimen), and biological (renal and liver function) data were collected. The endpoints were overall survival (OS) and progression-free survival (PFS). Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for survival outcomes associated with BB exposure were estimated using Cox regression model and propensity score (PS) methods. Results: Forty-one patients (22.5%) were exposed to BB. A total of 104 patients progressed (57.1%) to PDAC and 139 (76.4%) patients died at the end of follow-up (median, 320 days; IQR, 438.75 days). When compared to the non-exposed group, there was no increase in survival outcomes associated with BB use (OS: HR = 1.38, 95% CI = 0.80-2.39, p = 0.25; PFS: adjusted HR = 0.95, 95% CI = 0.48-1.88, p = 0.88). Similar results were obtained using the PS method. Compared to no BB usage, SBB use was associated with a significant decrease in OS (HR = 1.80, 95% CI = 1.16-2.80, p < 10^-2). Conclusion: BB exposure was not associated with improved PDAC survival outcomes. Beta-1-selectivity was not independently associated with any differences.

Immune changes over time and survival in patients with cirrhosis treated with non-selective beta-blockers: A prospective longitudinal study

BACKGROUND

Treatment with non-selective beta-blockers (NSBB) has been associated with anti-inflammatory and anti-cancer effects in patients with cirrhosis. This study aims to analyze the impact of chronic NSBB treatment on immune activation and disease progression in stable outpatients with cirrhosis.

METHODS

In this prospective follow-up of 150 patients with cirrhosis, 39 received treatment with NSBB. Blood samples were taken every 6-9 months, and immune and adrenergic variables were measured. Mixed linear models were used to assess the effect of NSBB on these variables over time. Multivariate Cox regression was used to study associations with adverse clinical events (hepatocellular carcinoma, death, or liver transplant).

RESULTS

Median follow-up was 1635 days. NSBB treatment was associated with significantly lower levels of IL-6 (β - 4.7; 95% confidence interval [CI] -6.9, -2.6) throughout the study. During follow-up, 11 patients developed hepatocellular carcinoma, 32 died, and 4 underwent liver transplant. Patients with higher concentrations of IL-10, IL-6 and IFN-γ developed more clinical events. Event-free survival was significantly better in patients treated with NSBB (hazard ratio 0.36, 95% CI 0.18, 0.71) in a multivariate Cox regression adjusted for Child-Pugh-Score, esophageal varices, and platelets.

CONCLUSION

Chronic treatment with NSBB in patients with stable cirrhosis gives rise to a different state of immune activation, characterized by lower concentrations of IL-6 over time, and it is associated with a reduced risk of adverse event (death, hepatocellular carcinoma, or transplant), after controlling for disease severity.

The influence of immortal time bias in observational studies examining associations of antifibrotic therapy with survival in idiopathic pulmonary fibrosis: A simulation study

Background

Immortal time bias (ITB) has been overlooked in idiopathic pulmonary fibrosis (IPF). We aimed to identify the presence of ITB in observational studies examining associations between antifibrotic therapy and survival in patients with IPF and illustrate how ITB may affect effect size estimates of those associations.

Methods

Immortal time bias was identified in observational studies using the ITB Study Assessment Checklist. We used a simulation study to illustrate how ITB may affect effect size estimates of antifibrotic therapy on survival in patients with IPF based on four statistical techniques including time-fixed, exclusion, time-dependent and landmark methods.

Results

Of the 16 included IPF studies, ITB was detected in 14 studies, while there were insufficient data for assessment in two others. Our simulation study showed that use of time-fixed [hazard ratio (HR) 0.55, 95% confidence interval (CI) 0.47-0.64] and exclusion methods (HR 0.79, 95% CI 0.67-0.92) overestimated the effectiveness of antifibrotic therapy on survival in simulated subjects with IPF, in comparison of the time-dependent method (HR 0.93, 95% CI 0.79-1.09). The influence of ITB was mitigated using the 1 year landmark method (HR 0.69, 95% CI 0.58-0.81), compared to the time-fixed method.

Conclusion

The effectiveness of antifibrotic therapy on survival in IPF can be overestimated in observational studies, if ITB is mishandled. This study adds to the evidence for addressing the influence of ITB in IPF and provides several recommendations to minimize ITB. Identifying the presence of ITB should be routinely considered in future IPF studies, with the time-dependent method being an optimal approach to minimize ITB.

Timing of adjuvant chemotherapy initiation and mortality among colon cancer patients at a safety-net health system

Background

Prior studies reported survival benefits from early initiation of adjuvant chemotherapy for stage III colon cancer, but this evidence was derived from studies that may be sensitive to time-related biases. Therefore, we aimed to estimate the effect of initiating adjuvant chemotherapy ≤8 or ≤ 12 weeks on overall and disease-free survival among stage III colon cancer patients using a study design that helps address time-related biases.

Methods

We used institutional registry data from JPS Oncology and Infusion Center, a Comprehensive Community Cancer Program. Eligible patients were adults aged < 80 years, diagnosed with first primary stage III colon cancer between 2011 and 2017, and received surgical resection with curative intent. We emulated a target trial with sequential eligibility. We subsequently pooled the trials and estimated risk ratios (RRs) along with 95% confidence limits (CL) for all-cause mortality and recurrence or death at 5-years between initiators and non-initiators of adjuvant chemotherapy ≤8 or ≤ 12 weeks using pseudo-observations and a marginal structural model with stabilized inverse probability of treatment weights.

Results

Our study population comprised 222 (for assessing initiation ≤8 weeks) and 310 (for assessing initiation ≤12 weeks) observations, of whom the majority were racial/ethnic minorities (64–65%), or uninsured with or without enrollment in our hospital-based medical assistance program (68–71%). Initiation of adjuvant chemotherapy ≤8 weeks of surgical resection did not improve overall survival (RR for all-cause mortality = 1.04, 95% CL: 0.57, 1.92) or disease-free survival (RR for recurrence or death = 1.07, 95% CL: 0.61, 1.88). The results were similar for initiation of adjuvant chemotherapy ≤12 weeks of surgical resection.

Conclusions

Our results suggest that the overall and disease-free survival benefits of initiating adjuvant chemotherapy ≤8 or ≤ 12 weeks of surgical resection may be overestimated in prior studies, which may be attributable to time-related biases. Nevertheless, our estimates were imprecise and differences in population characteristics are an alternate explanation. Additional studies that address time-related biases are needed to clarify our findings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09688-w.

Calcium Channel Blockers and the Risk of Sensorineural Hearing Loss

OBJECTIVE

To evaluate calcium channel blockers as a potential prophylactic agent for sensorineural hearing loss (SNHL).Patients: We used a retrospective cohort of US veterans treated by the Veteran's Affairs healthcare system. Patients were included in the study if 1) they were diagnosed with high blood pressure; 2) had no previous diagnosis of SNHL; 3) were prescribed a calcium channel blocker after diagnosis or as a control cohort, patients who had no antihypertensive medication use.

INTERVENTION

Patients were categorized into mutually exclusive cohorts by their antihypertensive medication exposure: calcium channel blocker exposed and no antihypertensive medication exposure.

MAIN OUTCOME MEASURE

Incident SNHL was defined as an inpatient or outpatient record with diagnosis codes international classification of diseases (ICD)-9-CM 389.1 or ICD-10-CM H90, H90.41, H90.42, H90.A21, H90.A22. An audiology or otolaryngology clinic visit was required for patients with an outpatient diagnosis of SNHL.

RESULTS

A total of 1,338,409 patients met the inclusion criteria consisting of 292,981 patients with CCBs (25,614 with verapamil and 267,367 with other CCBs) and 1,045,428 patients with no antihypertensive medication. On average, patients were middle-aged, White men with a body mass index (BMI) of 30+. Cox proportional hazards model estimates from propensity score matched data revealed CCB users had a 23.6% decreased risk of SNHL compared with those with no antihypertensive medication use (hazard ratios [HR] = 0.764; 95% confidence interval = [0.752-0.777]).

CONCLUSION

This analysis found evidence supporting the theory that calcium channel blockers might be a potential prophylactic agent for sensorineural hearing loss. Additional research is warranted.

Effects of Antihypertensive Drugs Use on Risk and Prognosis of Colorectal Cancer: A Meta-Analysis of 37 Observational Studies

Background: Antihypertensive drugs might play a key role in the risk and poor prognosis of colorectal cancer. However, current epidemiologic evidence remains inconsistent. The aim of this study is to quantify the association between antihypertensive drugs and colorectal cancer. Methods: To identify available studies, we systematically searched electronic databases: PubMed, Web of Science, Embase, Cochrane Library. The risk estimates and their corresponding 95% confidence intervals (CIs) were collected and analyzed by using random-effects models. Heterogeneity test and sensitivity analysis were also performed. Results: Overall, 37 observational studies were included in this analysis (26 studies with cohort design, three studies with nested case-control design, and 8 studies with case-control design). Antihypertensive drugs did not present a significant effect on the risk or overall survival of patients with colorectal cancer [Risk ratio (RR) = 1.00, 95% CI: 0.95-1.04; Hazard ratio (HR) = 0.93, 95% CI: 0.84-1.02]. In the subgroup analysis, diuretics use was significantly associated with a worse overall survival of patients with colorectal cancer (HR = 1.27; 95% CI: 1.14-1.40). However, use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers was associated with improved progression-free survival of patients who suffered from colorectal cancer (HR = 0.83; 95% CI: 0.72-0.95). Conclusion: Antihypertensive drug usage did not influence the risk and overall survival of patients with colorectal cancer in general. Further investigation reminded us that diuretics use might reduce the overall survival time in colorectal cancer patients, whereas those who took Angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers had a longer progression-free survival.

Deep Learning-based Propensity Scores for Confounding Control in Comparative Effectiveness Research: A Large-scale, Real-world Data Study

BACKGROUND

Due to the non-randomized nature of real-world data, prognostic factors need to be balanced, which is often done by propensity scores (PSs). This study aimed to investigate whether autoencoders, which are unsupervised deep learning architectures, might be leveraged to compute PS.

METHODS

We selected patient-level data of 128,368 first-line treated cancer patients from the Flatiron Health EHR-derived de-identified database. We trained an autoencoder architecture to learn a lower-dimensional patient representation, which we used to compute PS. To compare the performance of an autoencoder-based PS with established methods, we performed a simulation study. We assessed the balancing and adjustment performance using standardized mean differences, root mean square errors (RMSE), percent bias, and confidence interval coverage. To illustrate the application of the autoencoder-based PS, we emulated the PRONOUNCE trial by applying the trial's protocol elements within an observational database setting, comparing two chemotherapy regimens.

RESULTS

All methods but the manual variable selection approach led to well-balanced cohorts with average standardized mean differences <0.1. LASSO yielded on average the lowest deviation of resulting estimates (RMSE 0.0205) followed by the autoencoder approach (RMSE 0.0248). Altering the hyperparameter setup in sensitivity analysis, the autoencoder approach led to similar results as LASSO (RMSE 0.0203 and 0.0205, respectively). In the case study, all methods provided a similar conclusion with point estimates clustered around the null (e.g., HRautoencoder 1.01 [95% confidence interval = 0.80, 1.27] vs. HRPRONOUNCE 1.07 [0.83, 1.36]).

CONCLUSIONS

Autoencoder-based PS computation was a feasible approach to control for confounding but did not perform better than some established approaches like LASSO.

Beta-blockers have no impact on survival in pancreatic ductal adenocarcinoma prior to cancer diagnosis

Previous studies have suggested that β-adrenergic signaling may regulate the growth of various cancers. The aim of our study is to investigate the association between the incidental use of beta-blockers for various conditions on the overall survival of patients with pancreatic ductal adenocarcinoma (PDAC). Patients with histologically-confirmed PDAC between 2007 and 2011 were extracted from Surveillance, Epidemiology, and End Results registry (SEER)-Medicare linked database. Kaplan Meier and multivariable Cox Proportional-Hazard models were used to examine the association between beta-blocker usage before diagnosis and overall survival adjusting for appropriate confounders. As an additional analysis we also examined continuous beta-blocker use before and after diagnosis. From 2007 to 2011, 13,731 patients were diagnosed with PDAC. Of these, 7130 patients had Medicare Part D coverage in the 6-month period before diagnosis, with 2564 (36%) of these patients using beta-blockers in this period. Patients receiving beta-blockers had a mean survival time of 5.1 months compared to 6 months for non-users (p < 0.01). In multivariable analysis, beta-blockers usage was not associated with improved survival (Hazard Ratio (HR) 1.04, 95%, Confidence Interval (CI) 0.98–1.1, p = 0.2). When patients were stratified by conditions with indications for beta-blocker usage, such as hypertension, coronary artery disease and cardiac arrhythmia, differences in survival were insignificant compared to non-users in all groups (p > 0.05). After stratification by receptor selectivity, this lack of association with survival persisted (p > 0.05 for all). As a subgroup analysis, looking at patients with continuous Medicare Part D coverage who used beta-blockers in the 6-month period before and after cancer diagnosis, we identified 7085 patients, of which 1750 (24.7%) had continuous beta blocker use. In multivariable analysis, continuous beta-blockers usage was associated with improved survival (Hazard Ratio (HR) 0.86, 95%, Confidence Interval (CI) 0.8–0.9, p < 0.01). Beta-blocker usage before diagnosis does not confer a survival advantage in patients with PDAC, though continuous use before and after diagnosis did confer a survival advantage. Prospective studies into the mechanism for this advantage are needed.

Observational study on time on treatment with abiraterone and enzalutamide

Introduction

The aim of this study was to assess time on treatment with abiraterone and enzalutamide, two androgen receptor targeted (ART) drugs, the impact on time on treatment of time interval without drug supply between prescription fillings, and adherence to treatment.

Material and methods

By use of data from The National Prostate Cancer Register, The Prescribed Drug Registry and the Patient Registry, time on treatment with the abiraterone and enzalutamide was analyzed in all men with castration resistant prostate cancer (CRPC) in Sweden 2015–2019. Three time intervals between consecutive fillings, i.e. time without drug supply, were assessed. Adherence to the treatment was evaluated by use of the Medication Possession Ratio. Kaplan Meier analysis and multivariable Cox regression model were used to assess factors affecting time on treatment.

Results

Between January 2015 and October 2019, 1803 men filled a prescription for abiraterone and 4 534 men filled a prescription for enzalutamide. With a time interval of 30 days or less between two fillings, median time on treatment was 4.9 months (IQR 2.6–11.7) for abiraterone and 8.0 months (IQR 3.6–16.4) for enzalutamide. In sensitivity analyses, allowing for no more than 14 days without drug supply between fillings, median time on treatment was 3.9 months (IQR 2.1–9.0) for abiraterone and 5.9 months (IQR 2.8–12.1) for enzalutamide. Allowing for any time period without drug between fillings, median time on treatment was 5.7 months (IQR 2.7–14.0) for abiraterone and 9.8 months (IQR 4.4–21.0) for enzalutamide. Adherence to treatment was above 90% for both drugs.

Conclusion

Time on treatment with abiraterone and enzalutamide was shorter in clinical practice than in randomized controlled trials and varied almost two-fold with time interval without drug. Adherence to treatment was high. The main limitation of our study was the lack of data on use of chemotherapy.

Risk of Cancer in Association with Ranitidine and Nizatidine vs Other H2 Blockers: Analysis of the Japan Medical Data Center Claims Database 2005-2018

INTRODUCTION

In September 2019, ranitidine and nizatidine were suggested to contain N-nitrosodimethylamine, a carcinogenic substance. People have since been concerned about the potential impact of ranitidine/nizatidine use on the risk of cancer.

OBJECTIVE

The objective of this study was to investigate the risk of cancer among people receiving ranitidine or nizatidine compared with other histamine 2 receptor antagonists (H2 blockers) [cimetidine, famotidine, roxatidine, and lafutidine].

METHODS

In the Japan Medical Data Center claims database (comprising people aged < 75 years) from 2005 to 2018, we identified new adult users of H2 blockers and classified them into ranitidine/nizatidine users and other H2 blocker users. We estimated the incidence of cancer diagnosis in each group and conducted a multivariable Cox regression analysis.

RESULTS

We identified 113,745 new users of ranitidine/nizatidine (median age 41.2 years [interquartile range 31.7-51.1]; 49.1% men; median follow-up 2.4 years [1.1-4.5]) and 503,982 new users of other H2 blockers (median age 40.9 years [31.1-51.2]; 51.0% men; median follow-up 2.3 years [0.9-4.2]). The incidence rate of cancer diagnosis was 6.39 (95% confidence interval 6.13-6.66) cases per 1000 person-years (top three sites: breast 14.8%; colorectal 14.6%; and stomach 11.5%) in the ranitidine/nizatidine group and 6.17 (6.05-6.30) cases per 1000 person-years (colorectal 14.7%; breast 13.5%; and stomach 11.2%) in the other H2 blockers group. The adjusted hazard ratio (ranitidine/nizatidine users vs other H2 blocker users) was 1.02 (0.98-1.07). The results were similar by follow-up length, by cancer site, and when ranitidine and nizatidine users were separately compared with the other H2 blockers group. By cumulative dose, the adjusted hazard ratio (95% confidence interval) was 1.03 (0.98-1.08) from 1 to 180 defined daily doses (DDDs), 1.00 (0.73-1.39) from 181 to 365 DDDs, 0.95 (0.61-1.48) from 366 to 730 DDDs, and 0.83 (0.45-1.55) at > 730 DDDs.

CONCLUSIONS

We found no evidence that ranitidine/nizatidine is associated with an increased risk of cancer, although further studies with more accurate measurement of exposure, inclusion of older people, and longer follow-up may be needed.

Does sympathetic nervous system modulate tumor progression? A narrative review of the literature

Objective

The role of the sympathetic nervous system (SNS) in tumor development, progression and metastasis is studied for more than half a century and is attracting more attention during the last years. In this narrative review, we aim to a chronological and methodological presentation of the most interesting and pioneering studies on the subject.

Methods

The complexity of the autonomic nervous system’s interaction with the immune system, its direct and indirect effects on tumors and their surrounding tissues, plus the diversity and heterogeneity in the design and methodology of the studies, provide hard-to-interpret data and, at times, controversial findings. Studies are categorized into four main groups regarding the distribution of sympathetic nerve fibers inside the tumor, the effect of sympathectomy on cancer progression, the role of neurotransmitters on tumor growth and the impact of sympathetic adrenergic signaling on the anti-tumor immune response.

Results

Studies from all four categories converge to a common point. There is strong evidence that SNS function plays a role in the development and progression of tumors and subsequently the modification of SNS function, locally or diffusely, can affect the course of tumor growth.

Conclusion

The impact of SNS function on cancer behavior may be exerted in two ways, directly via the sympathetic nerve fibers or through widely distributed neurotransmitters. Modification of them, combined or not with treatments altering the immune function, could be the target for future therapeutic implications.

The Suggested Unique Association Between the Various Statin Subgroups and Prostate Cancer

BACKGROUND

The chemopreventive effect of various medications in prostate cancer (PCa) has gained interest. Specifically, the potential impact of statins on PCa incidence has been studied, but solely as a "drug family" overlooking the distinctive pharmacological properties of its two main subgroups: hydrophilic and hydrophobic statins.

OBJECTIVE

To assess the impact of statin subgroups on PCa-specific mortality (PCSM), PCa diagnosis, and undergoing another prostate biopsy.

DESIGN, SETTING, AND PARTICIPANTS

This is a population-based cohort study in Ontario identifying all men aged ≥66 yr with a history of a single negative prostate biopsy (representing healthy men at risk for PCa) between 1994 and 2016, who were not on any of the analyzed medications prior to the study, with a median follow-up of 9.42 yr (interquartile range 8.03 yr).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Using multivariable cause-specific hazard models with time-dependent covariates, the association of hydrophobic and hydrophilic statins with all study outcomes was analyzed. Other putative chemopreventive medications (including alpha-blockers, 5-alpha-reductase inhibitors, and proton-pump inhibitors), age, rurality, comorbidities, and study inclusion year were included in the models.

RESULTS AND LIMITATIONS

Overall, 21 512 men were identified. Statins were taken by 11 401 patients (50.3%), 5184 men (24.1%) were diagnosed with PCa, and 805 (3.7%) died from it. Overall, 7556 patients (35.1%) underwent another biopsy. Any use of hydrophilic statins was associated with a 32.4% (95% confidence interval [CI] 12.9-47.5%), a 20% (95% CI 10-28%), and an 18% (95% CI 6.1-27.3%) decreased risk of PCSM, undergoing another prostate biopsy, and being diagnosed with PCa, respectively. Hydrophobic statins were associated with 17% (95% CI 2-31%) decreased PCSM. The study is limited by its retrospective nature, selection bias, and accompanying health-administrative database inaccuracies.

CONCLUSIONS

Use of any statin may be associated with a lower hazard of PCSM, with hydrophilic statins showing a greater association with decreased PCa diagnosis rates. Preferentially prescribing one statin subgroup over another in men needs further exploration.

PATIENT SUMMARY

Use of any statin may be associated with a lower probability of dying from prostate cancer. Hydrophilic statins (rosuvastatin and pravastatin) may also be more positively associated with a lower risk of undergoing an additional prostate biopsy and being diagnosed with prostate cancer in men aged ≥66 yr.

Beta-adrenergic receptor blockers and liver cancer mortality in a national cohort of hepatocellular carcinoma patients

Background: β-adrenergic signaling has been implicated in the pathology of hepatocellular carcinoma (HCC), but the evidence from clinical studies is limited. In this national population-based cohort study, we investigated the possible association of β-adrenergic receptor blockers and cancer-specific mortality among patients with primary HCC diagnosed in Sweden between 2006 and 2014.Methods: Patients were identified from the Swedish Cancer Register (n = 2104) and followed until 31 December 2015. We used Cox regression to evaluate the association of β-blockers dispensed within 90 days prior to cancer diagnosis, ascertained from the national Prescribed Drug Register, with liver cancer mortality identified from the Cause of Death Register, while controlling for socio-demographic factors, tumor characteristics, comorbidity, other medications and treatment procedures.Results: Over a median follow-up of 9.9 months, 1601 patients died (of whom 1309 from liver cancer). Compared with non-use, β-blocker use at cancer diagnosis [n = 714 (predominantly prevalent use, 93%)] was associated with lower liver cancer mortality [0.82 (0.72-0.94); p = .005]. Statistically significant associations were observed for non-selective [0.71 (0.55-0.91); p = .006], β1-receptor selective [0.86 [0.75-1.00); p = .049] and lipophilic [0.78 (0.67-0.90); p = .001] β-blockers. No association was observed for hydrophilic β-blockers [1.01 (0.80-1.28); p = .906] or other antihypertensive medications. Further analysis suggested that the observed lower liver cancer mortality rate was limited to patients with localized disease at diagnosis [0.82 (0.67-1.01); p = .062].Conclusion: β-blocker use was associated with lower liver cancer mortality rate in this national cohort of patients with HCC. A higher-magnitude inverse association was observed in relation to non-selective β-blocker use.

Repurposing of drugs approved for cardiovascular diseases: Opportunity or mirage?

Drug repurposing is a promising way in drug discovery to identify new therapeutic uses -different from the original medical indication- for existing drugs. It has many advantages over traditional approaches to de novo drug discovery, since it can significantly reduce healthcare costs and development timeline. In this review, we discuss the possible repurposing of drugs approved for cardiovascular diseases, such as β-blockers, angiotensin converting enzyme inhibitors (ACE-Is), angiotensin II receptor blockers (ARBs), statins, aspirin, cardiac glycosides and low-molecular-weight heparins (LMWHs). Indeed, numerous experimental and epidemiological studies have reported promising anti-cancer activities for these drugs. It is worth mentioning, however, that the results of these studies are often controversial and very few data were obtained by controlled prospective clinical trials. Therefore, no final conclusion has yet been reached in this area and no final recommendations can be made. Moreover, β-blockers, ARBs and statins showed promising results in randomised controlled trials (RCTs) where pathological conditions other than cancer were considered. The results obtained have led or may lead to new indications for these drugs. For each drug or class of drugs, the potential molecular mechanisms of action justifying repurposing, results obtained in vitro and in animal models and data from epidemiological and randomized studies are described.

Tumour innervation and neurosignalling in prostate cancer

Prostate cancer progression has been shown to be dependent on the development of autonomic nerves into the tumour microenvironment. Sympathetic nerves activate adrenergic neurosignalling that is necessary in early stages of tumour progression and for initiating an angiogenic switch, whereas parasympathetic nerves activate cholinergic neurosignalling resulting in tumour dissemination and metastasis. The innervation of prostate cancer seems to be initiated by neurotrophic growth factors, such as the precursor to nerve growth factor secreted by tumour cells, and the contribution of brain-derived neural progenitor cells has also been reported. Current experimental, epidemiological and clinical evidence shows the stimulatory effect of tumour innervation and neurosignalling in prostate cancer. Using nerves and neurosignalling could have value in the management of prostate cancer by predicting aggressive disease, treating localized disease through denervation and relieving cancer-associated pain in bone metastases.

Beta-Blocker Use and Lung Cancer Mortality in a Nationwide Cohort Study of Patients with Primary Non-Small Cell Lung Cancer

BACKGROUND

β-Adrenergic receptor blockers have been associated with improved survival among patients with different types of malignancies, but available data for patients with non-small cell lung cancer (NSCLC) are contradictory and limited to small hospital-based studies. We therefore aimed to investigate whether β-blocker use at the time of cancer diagnosis is associated with lung cancer mortality in the largest general population-based cohort of patients with NSCLC to date.

METHODS

For this retrospectively defined nationwide cohort study, we used prospectively collected data from Swedish population and health registers. Through the Swedish Cancer Register, we identified 18,429 patients diagnosed with a primary NSCLC between 2006 and 2014 with follow-up to 2015. Cox regression was used to estimate the association between β-blocker use at time of cancer diagnosis ascertained from the Prescribed Drug Register and cancer-specific mortality identified from the Cause of Death Register.

RESULTS

Over a median follow-up of 10.2 months, 14,994 patients died (including 13,398 from lung cancer). Compared with nonuse, β-blocker use (predominantly prevalent use, 93%) was not associated with lung cancer mortality [HR (95% confidence interval): 1.01 (0.97-1.06)]. However, the possibility that diverging associations for specific β-blockers and some histopathologic subtypes exist cannot be excluded.

CONCLUSIONS

In this nationwide cohort of patients with NSCLC, β-blocker use was not associated with lung cancer mortality when assessed in aggregate in the total cohort, but evidence for some β-blockers is less conclusive.

IMPACT

Our results do not indicate that β-blocker use at lung cancer diagnosis reduces the cancer-specific mortality rate in patients with NSCLC.

Use of Antihypertensive Medications and Survival Rates for Breast, Colorectal, Lung, or Stomach Cancer

Using time-dependent Cox regression models, we examined associations of common antihypertensive medications with overall cancer survival (OS) and disease-specific survival (DSS), with comprehensive adjustment for potential confounding factors. Participants were from the Shanghai Women's Health Study (1996-2000) and Shanghai Men's Health Study (2002-2006) in Shanghai, China. Included were 2,891 incident breast, colorectal, lung, and stomach cancer cases. Medication use was extracted from electronic medical records. With a median 3.4-year follow-up after diagnosis (interquartile range, 1.0-6.3), we found better outcomes among users of angiotensin II receptor blockers with colorectal cancer (OS: adjusted hazard ratio (HR) = 0.62, 95% confidence interval (CI): 0.44, 0.86; DSS: adjusted HR = 0.61, 95% CI: 0.43, 0.87) and stomach cancer (OS: adjusted HR = 0.62, 95% CI: 0.41, 0.94; DSS: adjusted HR = 0.63, 95% CI: 0.41, 0.98) and among users of β-adrenergic receptor blockers with colorectal cancer (OS: adjusted HR = 0.50, 95% CI: 0.35, 0.72; DSS: adjusted HR = 0.50, 95% CI: 0.34, 0.73). Better survival was also found for calcium channel blockers (DSS: adjusted HR = 0.67, 95% CI: 0.47, 0.97) and diuretics (OS: adjusted HR = 0.66, 95% CI: 0.45, 0.96; DSS: adjusted HR = 0.57, 95% CI: 0.38, 0.85) with stomach cancer. Our findings suggest angiotensin II receptor blockers, β-adrenergic receptor blockers, and calcium channel blockers might be associated with improved survival outcomes of gastrointestinal cancers.

Sorafenib with Transarterial Chemoembolization Achieves Improved Survival vs. Sorafenib Alone in Advanced Hepatocellular Carcinoma: A Nationwide Population-Based Cohort Study

We hypothesized that sorafenib plus transarterial chemoembolization (TACE) would confer survival benefits over sorafenib alone for advanced hepatocellular carcinoma (aHCC). We investigated this while using the population-based All-Cancer Dataset to assemble a cohort (n = 3674; median age, 60; 83% men) of patients receiving sorafenib for aHCC (Child-Pugh A) with macro-vascular invasion or nodal/distant metastases. The patients were classified into the sorafenib-TACE group (n = 426) or the propensity score-matched sorafenib-alone group (n = 1686). All of the participants were followed up until death or the end of the study. Time-dependent Cox model and the Mantel-Byar test were used for survival analysis. During the median follow-ups of 221 and 133 days for the sorafenib-TACE and sorafenib-alone groups, 164 (39%) and 916 (54%) deaths occurred, respectively; the corresponding median overall survivals (OS) were 381 and 204 days, respectively (hazard ratio, HR: 0.74; 95% confidence interval, CI, 0.63-0.88; p = 0.021). The one-year and six-month OS were 53.5% and 80.3% in the sorafenib-TACE group and 32.4% and 54.4% in the sorafenib-alone group, respectively. The major complications were comparable between the two groups. The addition of TACE to sorafenib improves survival, with a 26% reduction in mortality. These findings provide strong real-world evidence that supports this combination strategy for eligible Child-Pugh A aHCC patients.

Outcome of Bevacizumab Therapy in Patients with Recurrent Glioblastoma Treated with Angiotensin System Inhibitors

PURPOSE

Antihypertensive therapy may improve bevacizumab efficacy in cancer patients. We examined efficacy and toxicity of angiotensin system inhibitors (ASI) and other antihypertensive drugs in bevacizumab treated recurrent glioblastoma patients.

METHODS

We retrospectively combined a national prescription registry with a clinical database with recurrent glioblastoma patients (n = 243).

RESULTS

Patients who initiated ASI after bevacizumab (n = 26) showed a tendency towards improved progression-free survival and overall survival (OS) with hazard rate (HR) reductions (HR = 0.70 and HR = 0.79, respectively). Calcium antagonists during bevacizumab therapy significantly improved OS (HR = 0.57).

CONCLUSIONS

Overall the study supports a potential beneficial effect of antihypertensive treatment on prognosis of bevacizumab treated glioblastoma patients.

Use of N-nitrosodimethylamine (NDMA) contaminated valsartan products and risk of cancer: Danish nationwide cohort study

OBJECTIVE

To perform an expedited assessment of cancer risk associated with exposure to N-nitrosodimethylamine (NDMA) through contaminated valsartan products.

DESIGN

Nationwide cohort study.

SETTING

Danish health registries on individual level prescription drug use, cancer occurrence, and hospital diagnoses.

PARTICIPANTS

5150 Danish patients with no history of cancer, aged 40 years or older, and using valsartan at 1 January 2012 or initiating use between 1 January 2012 and 30 June 2017. Participants were followed from one year after cohort entry (lag time period) until experiencing a cancer outcome, death, migration, or end of study period (30 June 2018). Each participant's exposure to NDMA (ever exposure and predefined categories of cumulative valsartan exposure) was mapped out as a time varying variable while also applying a one year lag.

MAIN OUTCOME MEASURES

Association between NDMA exposure and a primary composite endpoint comprising all cancers except non-melanoma skin cancer, estimated using Cox regression. In supplementary analyses, the risk of individual cancers was determined.

RESULTS

The final cohort comprised 5150 people followed for a median of 4.6 years. In total, 3625 cohort participants contributed 7344 person years classified as unexposed to NDMA, and 3450 participants contributed 11 920 person years classified as ever exposed to NDMA. With 104 cancer outcomes among NDMA unexposed participants and 198 among exposed participants, the adjusted hazard ratio for overall cancer was 1.09 (95% confidence interval 0.85 to 1.41), with no evidence of a dose-response relation (P=0.70). For single cancer outcomes, increases in risk were observed for colorectal cancer (hazard ratio 1.46, 95% confidence interval 0.79 to 2.73) and for uterine cancer (1.81, 0.55 to 5.90), although with wide confidence intervals that included the null.

CONCLUSIONS

The results do not imply a markedly increased short term overall risk of cancer in users of valsartan contaminated with NDMA. However, uncertainty persists about single cancer outcomes, and studies with longer follow-up are needed to assess long term cancer risk.

Comparative performance of a modified landmark approach when no time of treatment data are available within oncological databases: exemplary cohort study among resected pancreatic cancer patients

Purpose

The Mantel-Byar method is the gold standard analytical approach to avoid immortal time bias, but requires information on the time between start of follow-up and exposure initiation. Alternatively, a modified landmark approach might be used to mitigate the amount of immortal time bias, which assumes exposure initiation at a predefined landmark time. In the context of an expected positive association between adjuvant chemotherapy (ACT) and overall survival among resected pancreatic cancer (PCa) patients, this study aims to empirically assess the performance of this approach relative to the Mantel-Byar method.

Patients and methods

Data from resected PCa patients diagnosed between 2003 and 2014 and registered in the national cancer registries of Belgium, the Netherlands, and Slovenia were used to estimate the association between ACT and overall survival using a Cox proportional hazards model by country and overall. Results derived from the immortal time bias (misclassifying the time to ACT initiation), Mantel-Byar method, and conventional and modified landmark analyses with assumed cutoff times of ACT initiation at 9, 12 and 15 weeks post-diagnosis were compared.

Results

In total, 5,668 patients with a total of 10,921 person-years of follow-up were eligible. All analytical approaches showed a significant survival benefit for resected PCa patients who received ACT, but immortal time bias analyses led to strong overestimation of ACT benefits compared to the Mantel-Byar method (immortal time bias: overall HR [95% CI] 0.68 [0.62-0.75] vs Mantel-Byar method: 0.82 [0.71-0.93]), whereas the conventional landmark approach generally provided rather conservative estimates (0.86 [0.75-1.00], 15 weeks landmark). HRs derived from modified landmark analyses depended on the cutoff time, but were similar compared to the Mantel-Byar method at 15 weeks (0.81 [0.70-0.94]).

Conclusion

A modified landmark approach might be a valid alternative to the Mantel-Byar method if no time of treatment information is available. The performance depends on the chosen cutoff time.

Use of prescription drugs among women diagnosed with epithelial ovarian cancer in Denmark

INTRODUCTION

Epithelial ovarian cancer patients often suffer from chronic diseases requiring drug treatment. We assessed temporal patterns of drug use among women with ovarian cancer.

MATERIAL AND METHODS

We identified all postmenopausal women with epithelial ovarian cancer in Denmark 2005-2012 and a comparison cohort of age-matched women without cancer. We calculated rates of new drug treatment and total drug use and examined use of new and prevalent drugs before and after diagnosis. Analyses were stratified by histological type and stage of epithelial ovarian cancer.

RESULTS

We identified 2742 patients. The rate of new drug treatment increased from 3 to 5 months before diagnosis and peaked in the first month after diagnosis at 99 new types of drug therapy per 100 individuals (mainly antiemetics, proton-pump inhibitors, hypnotics, and opioids). Although declining, the rate of new drug use remained substantially higher among epithelial ovarian cancer patients than among controls throughout the 3-year postdiagnosis follow-up period. The number of prevalent drugs increased slightly from a median of 4 drugs (interquartile range 2-7) before diagnosis to 5 drugs (interquartile range 2-8) shortly after the diagnosis. The use of preventive drugs decreased only slightly after diagnosis. In stratified analyses, we found limited variation according to histological type, whereas patterns were slightly more pronounced among women with nonlocalized disease compared with localized disease.

CONCLUSIONS

Drug use among postmenopausal women with epithelial ovarian cancer was substantial and varied considerably in relation to the time of cancer diagnosis, although only limited changes were seen in the use of preventive medicines.

Effect of beta-blockers on cancer recurrence and survival: a meta-analysis of epidemiological and perioperative studies

BACKGROUND

The biological perturbation associated with psychological and surgical stress is implicated in cancer recurrence. Preclinical evidence suggests that beta-blockers can be protective against cancer progression. We undertook a meta-analysis of epidemiological and perioperative clinical studies to investigate the association between beta-blocker use and cancer recurrence (CR), disease-free survival (DFS), and overall survival (OS).

METHODS

Databases were searched until September 2017, reported hazard ratios (HRs) pooled, and 95% confidence intervals (CIs) calculated. Comparative studies examining the effect of beta-blockers (selective and non-selective) on cancer outcomes were included. The Newcastle Ottawa Scale was used to assess methodological quality and bias.

RESULTS

Of the 27 included studies, nine evaluated the incidental use of non-selective beta-blockers, and ten were perioperative studies. Beta-blocker use had no effect on CR. Within subgroups of cancer, melanoma was associated with improved DFS (HR 0.03, 95% CI 0.01-0.17) and OS (HR 0.04, 95% CI 0.00-0.38), while endometrial cancer had an associated reduction in DFS (HR 1.40, 95% CI 1.10-1.80) and OS (HR 1.50, 95% CI 1.12-2.00). There was also reduced OS seen with head and neck and prostate cancer. Non-selective beta-blocker use was associated with improved DFS and OS in ovarian cancer, improved DFS in melanoma, but reduced OS in lung cancer. Perioperative studies showed similar variable effects across cancer types, albeit from a limited data pool.

CONCLUSION

Beta-blocker use had no evident effect on CR. The beneficial effect of beta-blockers on DFS and OS in the epidemiological or perioperative setting remains variable, tumour-specific, and of low-level evidence at present.