Validating Restricted Mean Survival Time Estimates From Reconstructed Kaplan-Meier Data Against Original Trial Individual Patient Data From Trials Conducted by the Canadian Cancer Trials Group

Adult Internal Cerebrospinal Fluid Shunt Overall Survival: A Meta-Analysis of Restricted Mean Survival Times from Reconstructed Kaplan-Meier Data

OBJECTIVE

To assess the overall survival (OS) of internal cerebrospinal fluid shunt (ICSFS) in the adult population.

METHODS

MEDLINE database was searched from 2000 to 2023 to identify studies reporting on ICSFS OS. Only articles reporting on adult ICSFS OS by a Kaplan-Meier (KM) OS curve were included. Numerical data were extracted from KM curves and were then reconstructed to estimate 3, 6, 9, 12, 18, 24, 36, 48, and 60 months restricted mean survival times (RMSTs). RMSTs of ICSFS and its SE at each time of interest were used as summary measure and primary outcome across studies. To account for the effect of between-study heterogeneity, RMSTs were pooled using a random effects model.

RESULTS

Out of 421 screened studies, only 6 were included in the meta-analysis. Calculated ICSFS OS at 3, 6, 9, 12, 18, 24, 36, 48, and 60 months were 92.4% (95% CI, 89.6-95.2), 89.5% (95% CI, 86.3-92.8), 87.5% (95% CI, 83.9-91.1), 85.2% (95% CI, 80.4-90.0), 83.4% (95% CI, 79.0-87.9), 81.6% (95% CI, 76.7-86.5), 78.8% (95% CI, 72.9-84.6), 76.7% (95% CI, 70.3-83.1), and 74.5% (95% CI, 67.8-81.1), respectively. There was a significant heterogeneity as indicated by a high I2 value of 82.5% (95% CI, 63.1-91.7). Heterogeneity test of Q = 28.63 was also significant (P < 0.001).

CONCLUSIONS

On contrary to what one might think, there are few available studies assessing adult ICSFS OS. We used a novel technique to meta-analyze adult ICSFS OS. ICSFS failure rate is maximal within the 3 to 6 postoperative months. Afterward, the risk slowly decreases over time. At 5 years, less than three quarters of the patients still have a naïve functional ICSFS never revised.

Tissue mapping by cardiac magnetic resonance imaging for the prognostication of cardiac amyloidosis: A systematic review and meta-analysis

BACKGROUND

Cardiac amyloidosis is increasingly recognized as a significant contributor to cardiovascular morbidity and mortality. With the emergence of novel therapies, there is a growing interest in prognostication of patients with cardiac amyloidosis using cardiac magnetic resonance imaging (CMR). In this systematic review and meta-analysis, we aimed to examine the prognostic significance of myocardial native T1 and T2, and extracellular volume (ECV).

METHODS

Observational cohort studies or single arms of clinical trials were eligible. MEDLINE, EMBASE and CENTRAL were systematically searched from their respective dates of inception to January 2023. No exclusions were made based on date of publication, study outcomes, or study language. The study populations composed of adult patients (≥18 years old) with amyloid cardiomyopathy. All studies included the use of CMR with and without intravenous gadolinium contrast administration to assess myocardial native T1 mapping, T2 mapping, and ECV in association with the pre-specified primary outcome of all-cause mortality. Data were extracted from eligible primary studies by two independent reviewers and pooled via the inverse variance method using random effects models for meta-analysis.

RESULTS

A total of 3852 citations were reviewed. A final nine studies including a total of 955 patients (mean age 65 ± 10 years old, 32% female, mean left ventricular ejection fraction (LVEF) 59 ± 12% and 24% had NYHA class III or IV symptoms) with cardiac amyloidosis [light chain amyloidosis (AL) 50%, transthyretin amyloidosis (ATTR) 49%, other 1%] were eligible for inclusion and suitable for data extraction. All included studies were single centered (seven with 1.5 T MRI scanners, two with 3.0 T MRI scanners) and non-randomized in design, with follow-up spanning from 8 to 64 months (median follow-up = 25 months); 320 patients died during follow-up, rendering a weighted mortality rate of 33% across studies. Compared with patients with AL amyloid, patients with ATTR amyloid had significantly higher mean left ventricular mass index (LVMi) (102 ± 34 g/m2 vs 127 ± 37 g/m2, p = 0.02). N-terminal pro-brain natriuretic peptide (NT-proBNP), troponin T levels, mean native T1 values, ECV and T2 values did not differ between patients with ATTR amyloid and AL amyloid (all p > 0.25). Overall, the hazard ratios for mortality were 1.33 (95% CI = [1.10, 1.60]; p = 0.003; I2 = 29%) for every 60 ms higher T1 time, 1.16 (95% CI = [1.09, 1.23], p < 0.0001; I2 = 76%) for every 3% higher ECV, and 5.23 (95% CI = [2.27, 12.02]; p < 0.0001; I2 = 0%) for myocardial-to-skeletal T2 ratio below the mean (vs above the mean).

CONCLUSION

Higher native T1 time and ECV, and lower myocardial to skeletal T2 ratio, on CMR are associated with worse mortality in patients with cardiac amyloidosis. Therefore, tissue mapping using CMR may offer a useful non-invasive technique to monitor disease progression and determine prognosis in patients with cardiac amyloidosis.

Efficacy of Immune Checkpoint Inhibitors vs. Tyrosine Kinase Inhibitors/Everolimus in Adjuvant Renal Cell Carcinoma: Indirect Comparison of Disease-Free Survival

BACKGROUND

The proven efficacy of mTOR inhibitors (mTORIs), tyrosine kinase inhibitors (TKIs) or immune checkpoint inhibitors (ICIs) in metastatic renal cell carcinoma (RCC) suggests that these agents should be investigated as adjuvant therapy with the aim of eliminating undetectable microscopic residual disease after curative resection. The aim of our study was to compare the efficacy of these treatments using an innovative method of reconstructing individual patient data.

METHODS

Nine phase III trials describing adjuvant RCC treatments were selected. The IPDfromKM method was used to reconstruct individual patient data from Kaplan-Meier (KM) curves. The combination treatments were compared with the control arm (placebo) for disease-free survival (DFS). Multi-treatment KM curves were used to summarize the results. Standard statistical tests were performed. These included hazard ratio and likelihood ratio tests for heterogeneity.

RESULTS

In the overall population, the study showed that two ICIs (nivolumab plus ipilimumab and pembrolizumab) and one TKI (sunitinib) were superior to the placebo, whereas both TKIs and mTORIs were inferior. As we assessed DFS as the primary endpoint for the adjuvant comparison, the overall survival benefit remains unknown.

CONCLUSIONS

This novel approach to investigating survival has allowed us to conduct all indirect head-to-head comparisons between these agents in a context where no "real" comparative trials have been conducted.