Epidemiology and survival outcomes of synchronous and metachronous brain metastases: a retrospective population-based study

OBJECTIVE

Brain metastases (BMs) are the most common CNS tumors, yet their prevalence is difficult to determine. Most studies only report synchronous metastases, which make up a fraction of all BMs. The authors report the incidence and prognosis of patients with synchronous and metachronous BMs over a decade.

METHODS

Study data were obtained from the TriNetX Research Network. Patients were included if they had a primary cancer diagnosis and a BM diagnosis, with primary cancer occurring between January 1, 2013, and January 1, 2023. Metachronous BM was defined as BM diagnosed more than 2 months after the primary cancer. Cohorts were balanced by propensity score matching for age, extracranial metastasis, and antineoplastic or radiation therapy. Kaplan-Meier plots were used to evaluate survival differences between synchronous and metachronous BMs and associations with clinical conditions. A log-rank test was used to evaluate BM-free survival for metachronous BM and overall survival (OS) for all BMs. Hazard ratios and 95% CIs were calculated.

RESULTS

Of the 11,497,663 patients with 15 primary cancers identified, 300,863 (2.6%) developed BMs. BMs most commonly arose from lung and breast cancers and melanoma. Of all BMs, 113,827 (37.8%) presented synchronously and 187,036 (62.2%) presented metachronously. Lung and bronchial cancer had the highest metastasis rate (11.0%) and the highest synchronous presentation (51.0%). For metachronous presentations, the time from primary diagnosis to metastasis ranged from 1.3 to 2.5 years, averaging 1.8 years. Metachronous BM diagnosis was associated with longer survival over synchronous BM from primary diagnosis (11.54 vs 37.41 months, p < 0.0001), but shorter survival than extracranial metastases without BM (38.75 vs 69.18 months, p < 0.0001). Antineoplastic therapy prior to BM was associated with improved BM-free survival (4.46 vs 17.80 months, p < 0.0001) and OS (25.15 vs 42.26 months, p < 0.0001). Radiotherapy showed a similar effect that was statistically significant but modest for BM-free survival (5.25 vs 11.44 months, p < 0.0001) and OS (30.13 vs 32.82 months, p < 0.0001).

CONCLUSIONS

The majority of BMs present metachronously and arise within 2 years of primary cancer diagnosis. The substantial rate of BMs presenting within 6 months of primary cancer, especially liver, lung, and pancreatic cancer, may guide future recommendations on intracranial staging. Antineoplastic therapy prior to the development of BM may prolong the time before metastasis and improve survival. Further characterization of this population can better inform screening, prevention, and treatment efforts.

What we talk about when we talk about COVID-19 vaccination campaign impact: a narrative review

Background

The lack of precise definitions and terminological consensus about the impact studies of COVID-19 vaccination leads to confusing statements from the scientific community about what a vaccination impact study is.

Objective

The present work presents a narrative review, describing and discussing COVID-19 vaccination impact studies, mapping their relevant characteristics, such as study design, approaches and outcome variables, while analyzing their similarities, distinctions, and main insights.

Methods

The articles screening, regarding title, abstract, and full-text reading, included papers addressing perspectives about the impact of vaccines on population outcomes. The screening process included articles published before June 10, 2022, based on the initial papers' relevance to this study's research topics. The main inclusion criteria were data analyses and study designs based on statistical modelling or comparison of pre- and post-vaccination population.

Results

The review included 18 studies evaluating the vaccine impact in a total of 48 countries, including 32 high-income countries (United States, Israel, and 30 Western European countries) and 16 low- and middle-income countries (Brazil, Colombia, and 14 Eastern European countries). We summarize the main characteristics of the vaccination impact studies analyzed in this narrative review.

Conclusion

Although all studies claim to address the impact of a vaccination program, they differ significantly in their objectives since they adopt different definitions of impact, methodologies, and outcome variables. These and other differences are related to distinct data sources, designs, analysis methods, models, and approaches.

Temporal Trends in Characteristics and Outcomes Associated With In-Hospital Cardiac Arrest: A 20-Year Analysis (1999-2018)

Background

Despite advances in resuscitation medicine, the burden of in‐hospital cardiac arrest (IHCA) remains substantial. The impact of these advances and changes in resuscitation guidelines on IHCA survival remains poorly defined. To better characterize evolving patient characteristics and temporal trends in the nature and outcomes of IHCA, we undertook a 20‐year analysis of a national database.

Methods and Results

We analyzed the National Inpatient Sample (1999–2018) using International Classification of Diseases, Ninth Revision and Tenth Revision, Clinical Modification (ICD‐9‐CM and ICD‐10‐CM) codes to identify all adult patients suffering IHCA. Subgroup analysis was performed based on the type of cardiac arrest (ie, ventricular tachycardia/ventricular fibrillation or pulseless electrical activity‐asystole). An age‐ and sex‐adjusted model and a multivariable risk‐adjusted model were used to adjust for potential confounders. Over the 20‐year study period, a steady increase in rates of IHCA was observed, predominantly driven by pulseless electrical activity‐asystole arrest. Overall, survival rates increased by over 10% after adjusting for risk factors. In recent years (2014–2018), a similar trend toward improved survival is noted, though this only achieved statistical significance in the pulseless electrical activity‐asystole cohort.

Conclusions

Though the ideal quality metric in IHCA is meaningful neurological recovery, survival is the first step toward this. As overall IHCA rates rise, overall survival rates are improving in tandem. However, in more recent years, these improvements have plateaued, especially in the realm of ventricular tachycardia/ventricular fibrillation‐related survival. Future work is needed to better identify characteristics of IHCA nonsurvivors to improve resource allocation and health care policy in this area.