Assessing real-world representativeness of prospective registry cohorts in oncology: insights from patients with esophagogastric cancer

OBJECTIVES

This study aimed to explore the real-world representativeness of a prospective registry cohort with active accrual in oncology, applying a representativeness metric that is novel to health care.

STUDY DESIGN AND SETTING

We used data from the Prospective Observational Cohort Study of Esophageal-Gastric Cancer Patients (POCOP) registry and from the population-based Netherlands Cancer Registry (NCR). We used Representativeness-indicators (R-indicators) and overall survival to investigate the degree to which the POCOP cohort and clinically relevant subgroups were a representative sample compared to the NCR database. Calibration using inverse propensity score weighting was applied to correct differences between POCOP and NCR.

RESULTS

The R-indicator of the entire POCOP registry was 0.72 95% confidence interval [0.71, 0.73]. Representativeness of palliative patients was higher than that of potentially curable patients (R-indicator 0.88 [0.85, 0.90] and 0.70 [0.68, 0.71], respectively). Stratification to clinically relevant subgroups based on treatment resulted in higher R-indicators of the respective subgroups. Both after stratification and calibration weighting survival estimates in the POCOP registry were more similar to that in the NCR population.

CONCLUSION

This study demonstrated the assessment of real-world representativeness of patients who participated in a prospective registry cohort and showed that real-world representativeness improved when the variability in treatment was accounted for.

Exercise and Nutritional Interventions in Patients with Advanced Gastroesophageal Cancer: A Systematic Review

PURPOSE

The quality of life and survival of patients with advanced gastroesophageal cancer can be improved. Positive effects of exercise and nutritional interventions on quality of life and potential effects on cancer outcomes are found in gastroesophageal cancer in the curative setting, as well as in other cancer types. We therefore systematically reviewed the current literature on the effect of exercise and nutritional interventions on various outcomes in patients with advanced gastroesophageal cancer.

METHODS

We searched on the 11th of June 2021 in Pubmed, Embase and the Cochrane library for publications of randomized trials and observational studies on exercise and nutritional interventions (either combined or as separate intervention) in patients with advanced gastroesophageal cancer. The outcomes of interest were overall survival, progression free survival, quality of life, chemotherapy toxicity, and chemotherapy adherence.

RESULTS

We screened 1,764 records for eligibility and included one study in our analysis. The other 1,763 were excluded for various reasons, most frequently an incorrect study population (e.g. both curable and incurable patients) or an incorrect intervention. One retrospective cohort study of 40 patients with advanced gastric cancer who received first line chemotherapy was included. It was stated that 'no significant differences in terms of overall and progression free survival were reported between the two groups of patients.' No absolute numbers were provided.

CONCLUSION

Our systematic review did not identify any high quality studies on exercise and nutritional interventions in advanced gastroesophageal cancer. We deem a randomized clinical trial on this topic to be highly needed.

Real-world representativeness of patient-reported outcome measures of patients with esophagogastric cancer

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Background: The use of patient reported outcome measures (PROMs) is a popular method to obtain real-world patient data in oncological research. However, PROMs rely on voluntary and active participation of patients and are therefore prone to selection bias. To investigate the suitability of PROMs as real-world data, we investigated the real-world representativeness of the Prospective Observational Cohort Study of Esophageal-Gastric Cancer Patients (POCOP) registry with respect to the Dutch population of patients with esophagogastric cancer. Methods: We identified 2,575 patients in the POCOP registry and 13,702 in the nationwide population-based Netherlands Cancer Registry (NCR) from 2016-2021. We used Representativeness-indicators (R-indicators) to investigate the degree to which the POCOP registry and clinically relevant subgroups thereof, were a representative sample with respect to the population. R-indicators express the representativeness between 0 (not representative) and 1 (perfect representativeness). Calibration methods using inverse propensity weighting were used to correct potential differences between POCOP and the population estimates. Subsequently, median and 5-year overall survival were calculated and compared between patients in the POCOP registry and in the population, to investigate the representativeness in terms of survival. Results: Representativeness of the entire POCOP registry was 0.73 (95% CI: 0.71-0.74). The overall representativeness of palliative patients was higher than that of potentially curable patients (0.89 (0.87-0.90) and 0.70 (0.68-0.71), respectively). Representativeness of most clinical subgroups stratified to treatment was good; R-indicators ranged between 0.8 to 1.0. Median survival of the NCR, POCOP and calibrated POCOP was 19, 32, and 23 months, respectively. The 5-year overall survival of patients in the NCR, POCOP and calibrated POCOP was 26%, 36%, and 27%, respectively. Conclusions: The real-world representativeness of patients who participated in PROMs was good when we accounted for treatment. This shows that in the analysis of PROMs stratification to treatment groups can lead to generalizable results to the population. Using complete non-stratified PROMs, real-world representativeness was lower and calibration methods could be used to correct differences between patients in the PROMs and the population.

Use of Palliative Chemotherapy and ICU Admissions in Gastric and Esophageal Cancer Patients in the Last Phase of Life: A Nationwide Observational Study

Simple Summary

This is the first nationwide study on chemotherapy use and intensive care unit (ICU) admission in the last three months before death in patients with cancer of the stomach or esophagus. Chemotherapy use and ICU admission shortly before death were relatively infrequent in the Netherlands. Chemotherapy was used less often in hospitals that treat many patients compared to hospitals that treat fewer patients. In patients that received chemotherapy before their final three months before death, chemotherapy was prescribed four times more often in the last three months before death compared to patients without previous chemotherapy use.

Abstract

Since intensive care unit (ICU) admission and chemotherapy use near death impair the quality of life, we studied the prevalence of both and their correlation with hospital volume in incurable gastroesophageal cancer patients as both impair the quality of life. We analyzed all Dutch patients with incurable gastroesophageal cancer who died in 2017–2018. National insurance claims data were used to determine the prevalence of ICU admission and chemotherapy use (stratified on previous chemotherapy treatment) at three and one month(s) before death. We calculated correlations between hospital volume (i.e., the number of included patients per hospital) and both outcomes. We included 3748 patients (mean age: 71.4 years; 71.4% male). The prevalence of ICU admission and chemotherapy use were, respectively, 5.6% and 21.2% at three months and 4.2% and 8.0% at one month before death. Chemotherapy use at three and one months before death was, respectively, 4.3 times (48.0% vs. 11.2%) and 3.7 times higher (15.7% vs. 4.3%), comparing patients with previous chemotherapy treatment to those without. Hospital volume was negatively correlated with chemotherapy use in the final month (r_weighted = −0.23, p = 0.04). ICU admission and chemotherapy use were relatively infrequent. Oncologists in high-volume hospitals may be better equipped in selecting patients most likely to benefit from chemotherapy.

Selection of individuals for genetic testing for familial hypercholesterolaemia: development and external validation of a prediction model for the presence of a mutation causing familial hypercholesterolaemia

Aims

Familial hypercholesterolaemia (FH) is an autosomal dominant disease that warrants early diagnosis to prevent premature cardiovascular disease (CVD). However, genetic testing to make a definite diagnosis is costly, and careful selection of eligible subjects is important. Unfortunately, accuracy of current diagnostic criteria is poor, especially in young individuals. We therefore developed and validated a model to predict the presence of an FH causing mutation in persons referred by general practitioners.

Methods and results

All participants in the Dutch FH screening programme from 1994 to 2014 were included in the development cohort. The validation cohort consisted of consecutive patients, suspected for FH, attending the outpatient lipid clinic in Saguenay (Quebec) from 1993 to 2014. Cross-sectional data were available on medical history, lipid profile, and DNA analysis. Multivariable logistic regression analysis was used for model development. The primary outcome was the presence of a deleterious FH mutation. The development cohort comprised 26 167 FH patients and 37 939 unaffected relatives. Our final model included age; sex; levels of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, and triglycerides; history and age of CVD; use of statins; smoking; alcohol; and presence of hypertension. The area under the receiver operating characteristic curve (AUC) was 85.4% (95% CI: 85.0-85.9). The calibration slope was 1.02 (where 1.00 is optimal). In the validation cohort (1436 FH patients and 1767 unaffected persons), the AUC was 95.4% (95% CI: 94.7-96.1%) and the calibration slope 1.06.

Conclusion

Our model showed good discrimination and calibration. We specifically expect our model to be of added value for young persons set against current diagnostic criteria, since LDL-C and age are now used as continuous predictors. The equation will be available as an online calculator to estimate the probability of the presence of an FH mutation in individual patients. This tool might aid physicians in the decision for referral of patients for molecular testing.

The impact of LDLR function on fibroblast growth factor 21 levels

CONTEXT

Fibroblast growth factor 21 (FGF21) has been described to have beneficial effects on glucose and lipid metabolism, and FGF21 analogs are currently evaluated in phase 1 trials. However, the complete spectrum of effects and regulators of FGF21 is yet partly elucidated. Recent studies have shown that FGF21 plays a role in transmembrane cholesterol transport.

OBJECTIVE

We set out to examine the association between FGF21 and LDLR mediated transmembrane cholesterol transport, by comparing FGF21 levels in patients with genetically impaired LDLR function and unaffected relatives. Secondly, we explored whether the severity of the LDLR mutation was associated with FGF21 levels.

METHODS

We performed a cross-sectional study in carriers of an LDLR mutation and their unaffected relatives. Subjects were eligible if they participated in the Dutch national screening program for familial hypercholesterolemia (FH), were 18-55 years old, and were carrier of a pathogenic LDLR mutation with an untreated LDL-C level below the 75(th) or above the 90(th) percentile of the general population, or did not carry an FH mutation. The outcome measure was the level of FGF21, which was assessed using ELISA.

RESULTS

We included 224 carriers of an LDLR mutation and 148 unaffected relatives. FGF21 levels were lower in LDLR mutation carriers compared to unaffected relatives (median [interquartile range]: 96.92 [60.80-174.05] versus 136.98 [77.34-219.47] pg/mL, respectively; p = 0.08), but after adjusting for potential confounders, there was no association between LDLR mutations and FGF21 levels (p = 0.70). Neither, did we find a relationship between the severity of LDLR mutations and FGF21 levels (p = 0.51, after adjustment for potential confounders).

CONCLUSIONS

We showed that levels of FGF21 are not different in patients with and without LDLR mutations, which suggests that decreased LDLR expression does not have a negative effect on FGF21 levels. Given the potential beneficial effects of FGF21 analogs on lipids and lipoproteins in a phase 1 study, we deem this of great interest for future treatment options for FH patients.

Screening and treatment of familial hypercholesterolemia - Lessons from the past and opportunities for the future (based on the Anitschkow Lecture 2014)

In this review, we discuss the screening and treatment of familial hypercholesterolemia (FH), an autosomal dominant inherited disease, characterized by severely increased levels of low-density lipoprotein cholesterol (LDL-C) and increased risk for premature coronary heart disease (CHD). Genetic family based cascade screening for FH was shown to be cost-effective and a screening program with such an approach was carried out in the Netherlands from 1994 to 2014. Over 64,000 persons have participated in this program of whom 40.3% were found to carry an FH causing mutation. We will discuss the results of this screening program, as well as the scientific opportunities it has provided. Currently, statins and ezetimibe are the only registered LDL-C lowering treatment options for FH patients. Many of them do not attain the treatment goals that are recommended by treatment guidelines. In this review, we will also provide a comprehensive overview of promising new modalities that could lower LDL-C in FH patients.

Anacetrapib as lipid-modifying therapy in patients with heterozygous familial hypercholesterolaemia (REALIZE): a randomised, double-blind, placebo-controlled, phase 3 study

BACKGROUND

Present guidelines emphasise the importance of low concentrations of LDL cholesterol (LDL-C) in patients with familial hypercholesterolaemia. In most patients with the disease, however, these concentrations are not achieved with present treatments, so additional treatment is therefore warranted. Inhibition of cholesteryl ester transfer protein has been shown to reduce LDL-C concentrations in addition to regular statin treatment in patients with hypercholesterolaemia or at high risk of cardiovascular disease. We aimed to investigate the safety and efficacy of anacetrapib, a cholesteryl ester transfer protein inhibitor, in patients with heterozygous familial hypercholesterolaemia.

METHODS

In this multicentre, randomised, double-blind, placebo-controlled, phase 3 study, patients aged 18-80 years with a genotype-confirmed or clinical diagnosis of heterozygous familial hypercholesterolaemia, on optimum lipid-lowering treatment for at least 6 weeks, and with an LDL-C concentration of 2·59 mmol/L or higher without cardiovascular disease or 1·81 mmol/L or higher with cardiovascular disease from 26 lipid clinics across nine countries were eligible. We randomly allocated participants with a computer-generated allocation schedule (2:1; block size of six; no stratification) to oral anacetrapib 100 mg or placebo for 52 weeks, with a 12 week post-treatment follow-up afterwards. We masked patients, care providers, and those assessing outcomes to treatment groups throughout the study. The primary outcome was percentage change from baseline in LDL-C concentration. We did analysis using a constrained longitudinal repeated measures model. This trial is registered with ClinicalTrials.gov, number NCT01524289.

FINDINGS

Between Feb 10, 2012, and Feb 12, 2014, we randomly allocated 204 patients to anacetrapib and 102 to placebo. One patient in the anacetrapib group did not receive the drug. At week 52, anacetrapib reduced mean LDL-C concentration from 3·3 mmol/L (SD 0·8) to 2·1 mmol/L (0·8; percentage change 36·0% [95% CI -39·5 to -32·5] compared with an increase with placebo from 3·4 mmol/L (1·2) to 3·5 mmol/L (1·6; percentage change 3·7% [-1·2 to 8·6], with a difference in percentage change between anacetrapib and placebo of -39·7% (95% CI -45·7 to -33·7; p<0·0001). The number of cardiovascular events was increased in patients given anacetrapib compared with those given placebo (4 [2%] of 203 vs none [0%] of 102; p=0·1544), but the proportion with adverse events leading to discontinuation was similar (12 [6%] of 203 vs five [5%] of 102).

INTERPRETATION

In patients with heterozygous familial hypercholesterolaemia, treatment with anacetrapib for 1 year was well tolerated and resulted in substantial reductions in LDL-C concentration. Whether this change leads to a reduction of cardiovascular events will be answered in an outcome study.

FUNDING

Merck & Co, Inc.

Association between familial hypercholesterolemia and prevalence of type 2 diabetes mellitus

IMPORTANCE

Familial hypercholesterolemia is characterized by impaired uptake of cholesterol in peripheral tissues, including the liver and the pancreas. In contrast, statins increase the cellular cholesterol uptake and are associated with increased risk for type 2 diabetes mellitus. We hypothesize that transmembrane cholesterol transport is linked to the development of type 2 diabetes.

OBJECTIVE

To assess the association between type 2 diabetes prevalence and familial hypercholesterolemia.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study in all individuals (n = 63,320) who underwent DNA testing for familial hypercholesterolemia in the national Dutch screening program between 1994 and 2014.

EXPOSURES

Deleteriousness and nondeleteriousness of familial hypercholesterolemia mutations were based on literature or laboratory function testing. Low-density lipoprotein (LDL) receptor mutations were considered more severe than apolipoprotein B gene (APOB) mutations, and receptor-negative LDL receptor mutations were considered more severe than receptor-deficient mutations.

MAIN OUTCOMES AND MEASURES

Prevalence of type 2 diabetes.

RESULTS

The prevalence of type 2 diabetes was 1.75% in familial hypercholesterolemia patients (n = 440/25,137) vs 2.93% in unaffected relatives (n = 1119/38,183) (P < .001; odds ratio [OR], 0.62 [95% CI, 0.55-0.69]). The adjusted prevalence of type 2 diabetes in familial hypercholesterolemia, determined using multivariable regression models, was 1.44% (difference, 1.49% [95% CI, 1.24%-1.71%]) (OR, 0.49 [95% CI, 0.41-0.58]; P < .001). The adjusted prevalence of type 2 diabetes by APOB vs LDL receptor gene was 1.91% vs 1.33% (OR, 0.65 [95% CI, 0.48-0.87] vs OR, 0.45 [95% CI, 0.38-0.54]), and the prevalence for receptor-deficient vs receptor-negative mutation carriers was 1.44% vs 1.12% (OR, 0.49 [95% CI, 0.40-0.60] vs OR, 0.38 [95% CI, 0.29-0.49]), respectively (P for trend <.001 in both comparisons).

CONCLUSIONS AND RELEVANCE

In a cross-sectional analysis in the Netherlands, the prevalence of type 2 diabetes among patients with familial hypercholesterolemia was significantly lower than among unaffected relatives, with variability by mutation type. If this finding is confirmed in longitudinal analysis, it would raise the possibility of a causal relationship between LDL receptor-mediated transmembrane cholesterol transport and type 2 diabetes.

Intestinal cholesterol secretion: future clinical implications

Together with the liver, the intestine serves as a homeostatic organ in cholesterol metabolism. Recent evidence has substantiated the pivotal role of the intestine in reverse cholesterol transport (RCT). RCT is a fundamental antiatherogenic pathway, mediating the removal of cholesterol from tissues in the body to the faeces. In humans, faecal cholesterol elimination via the RCT pathway is considered to be restricted to excretion via the hepatobiliary route. Recently, however, direct trans-intestinal excretion of plasma-derived cholesterol (TICE) was shown to contribute substantially to faecal neutral sterol (FNS) excretion in mice. TICE was found to be amenable to stimulation by various pharmacological and dietary interventions in mice, offering new options to target the intestine as an inducible, cholesterol-excretory organ. The relevance of TICE for cholesterol elimination in humans remains to be established. There is, however, emerging evidence for the presence of TICE in human (patho) physiology. This review discusses our current understanding of TICE and its novel therapeutic potential for individuals at increased risk of cardiovascular disease.

Efficacy and safety of mipomersen sodium (Kynamro)

INTRODUCTION

Mipomersen is a first-in-class drug indicated as an adjunct to lipid-lowering medications and diet to reduce low-density lipoprotein-cholesterol (LDL-C), apolipoprotein B (apoB), total cholesterol (TC) and non-high density lipoprotein-cholesterol (non-HDL-C) in patients with homozygous familial hypercholesterolemia (HoFH).

AREAS COVERED

This article summarizes the efficacy and safety profile of mipomersen based on literature, public materials available from the Endocrinologic and Metabolic Drugs Advisory Committee meeting (FDA) in review of the New Drug Application (NDA 203568) and the recent product label.

EXPERT OPINION

Patients suffering from HoFH are characterized by elevated levels of LDL-C and are, therefore, at severely increased risk for cardiovascular disease (CVD). Currently available lipid-lowering therapies (LLT), such as statins, have been shown to lower LDL-C levels and CVD risk. However, in patients suffering from HoFH, additional therapy is urgently needed to further decrease LDL-C levels and CVD risk. Mipomersen (Kynamro) has recently been approved by the FDA as a novel LLT modality in patients with HoFH. Mipomersen has been show to result in highly relevant absolute LDL-C reductions in HoFH patients, and given the undisputed causal relationship between LDL-C levels and CVD risk, this additional LDL-C lowering is expected to result in a robust CVD risk reduction.

Antisense oligonucleotides in the treatment of lipid disorders: pitfalls and promises

Dyslipidaemia is one of the pivotal risk factors for cardiovascular disease (CVD), and lipid-lowering therapy is therefore the cornerstone in cardiovascular risk management. With the currently available treatment options the relative risk reduction in CVD is approximately 30%, leaving a large residual risk. This calls for the development of additional therapeutic moieties and antisense oligonucleotides (ASOs) have proven to be such a new and effective treatment. ASOs are short single strands of DNA that intracellularly bind mRNA of specific proteins. This induces the degradation of the mRNA through which the protein cannot be produced. Based on knowledge of lipid metabolism several targets of ASO therapy can be identified. This review offers a summary of current developments in ASO therapy regarding lipid disorders.