A substantial portion of the older adult population suffers from frequent feelings of loneliness, but a large proportion remains relatively unscathed by loneliness. To date, research examining both ...protective and risk factors for loneliness has not included data from the United States. The present study used the first two waves of data from the National Social Life, Health, and Aging Project to examine sociodemographic, structural, and functional factors thought to be associated with loneliness in older adults. Functional limitations and low family support were associated with an increase in loneliness frequency (as were more strained friendships) and with transitioning from nonlonely to lonely status. Better self-rated health, higher levels of socializing frequency, and lower family strain were associated with transitioning from lonely to nonlonely status. Interventions that target these factors may be effective in preventing and reducing loneliness and its effects on health and well-being in older adults.
Minimally invasive surgery was adopted as an alternative to laparotomy (open surgery) for radical hysterectomy in patients with early-stage cervical cancer before high-quality evidence regarding its ...effect on survival was available. We sought to determine the effect of minimally invasive surgery on all-cause mortality among women undergoing radical hysterectomy for cervical cancer.
We performed a cohort study involving women who underwent radical hysterectomy for stage IA2 or IB1 cervical cancer during the 2010-2013 period at Commission on Cancer-accredited hospitals in the United States. The study used inverse probability of treatment propensity-score weighting. We also conducted an interrupted time-series analysis involving women who underwent radical hysterectomy for cervical cancer during the 2000-2010 period, using the Surveillance, Epidemiology, and End Results program database.
In the primary analysis, 1225 of 2461 women (49.8%) underwent minimally invasive surgery. Women treated with minimally invasive surgery were more often white, privately insured, and from ZIP Codes with higher socioeconomic status, had smaller, lower-grade tumors, and were more likely to have received a diagnosis later in the study period than women who underwent open surgery. Over a median follow-up of 45 months, the 4-year mortality was 9.1% among women who underwent minimally invasive surgery and 5.3% among those who underwent open surgery (hazard ratio, 1.65; 95% confidence interval CI, 1.22 to 2.22; P=0.002 by the log-rank test). Before the adoption of minimally invasive radical hysterectomy (i.e., in the 2000-2006 period), the 4-year relative survival rate among women who underwent radical hysterectomy for cervical cancer remained stable (annual percentage change, 0.3%; 95% CI, -0.1 to 0.6). The adoption of minimally invasive surgery coincided with a decline in the 4-year relative survival rate of 0.8% (95% CI, 0.3 to 1.4) per year after 2006 (P=0.01 for change of trend).
In an epidemiologic study, minimally invasive radical hysterectomy was associated with shorter overall survival than open surgery among women with stage IA2 or IB1 cervical carcinoma. (Funded by the National Cancer Institute and others.).
Competing risks observations, in which patients are subject to a number of potential failure events, are a feature of most clinical cancer studies. With competing risks, several modeling approaches ...are available to evaluate the relationship of covariates to cause-specific failures. We discuss the use and interpretation of commonly used competing risks regression models.
For competing risks analysis, the influence of covariate can be evaluated in relation to cause-specific hazard or on the cumulative incidence of the failure types. We present simulation studies to illustrate how covariate effects differ between these approaches. We then show the implications of model choice in an example from a Radiation Therapy Oncology Group (RTOG) clinical trial for prostate cancer.
The simulation studies illustrate that, depending on the relationship of a covariate to both the failure type of principal interest and the competing failure type, different models can result in substantially different effects. For example, a covariate that has no direct influence on the hazard of a primary event can still be significantly associated with the cumulative probability of that event, if the covariate influences the hazard of a competing event. This is a logical consequence of a fundamental difference between the model formulations. The example from RTOG similarly shows differences in the influence of age and tumor grade depending on the endpoint and the model type used.
Competing risks regression modeling requires that one considers the specific question of interest and subsequent choice of the best model to address it.
Therapy with anti-PD-L1 immune check-point inhibitors is approved for several cancers, including advanced urothelial carcinomas. PD-L1 prevalence estimates vary widely in bladder cancer, and lack of ...correlation between expression and clinical outcomes and immunotherapy response may be attributed to methodological differences of the immunohistochemical reagents and procedures. We characterized PD-L1 expression in 235 urothelial carcinomas including 79 matched pairs of primary and metastatic cancers using a panel of four PD-L1 immunoassays in comparison with RNAscope assay using PD-L1-specific probe (CD274). The antibody panel included three FDA-approved clones (22C3 for pembrolizumab, 28.8 for nivolumab, SP142 for atezolizumab), and a commonly used clone E1L3N. Manual scoring of tissue microarrays was performed in each of 235 tumors (624 tissue cores) and compared to an automated image analysis. Expression of PD-L1 in tumor cells by ≥1 marker was detected in 41/142 (28.9%) primary tumors, 13/77 (16.9%) lymph nodes, and 2/16 (12.5%) distant metastases. In positive cases, high PD-L1 expression (>50% cells) was detected in 34.1% primary and 46.7% metastases. Concordant PD-L1 expression status was present in 71/79 (89.9%) cases of matched primary and metastatic urothelial carcinomas. PD-L1 sensitivity ranked from highest to lowest as follows: RNAscope, clone 28.8, 22C3, E1L3N, and SP142. Pairwise concordance correlation coefficients between the four antibodies in 624 tissue cores ranged from 0.76 to 0.9 for tumor cells and from 0.30 to 0.85 for immune cells. RNA and protein expression levels showed moderate to high agreement (0.72-0.87). Intra-tumor expression heterogeneity was low for both protein and RNA assays (interclass correlation coefficients: 0.86-0.94). Manual scores were highly concordant with automated Aperio scores (0.94-0.97). A significant subset of 56/235 (23.8%) urothelial carcinomas stained positive for PD-L1 with high concordance between all four antibodies and RNA ISH assay. Despite some heterogeneity in staining, the overall results are highly concordant suggesting diagnostic equivalence of tested assays.
We sought to define the lower and upper limits of cerebral blood flow autoregulation and the optimal blood pressure during cardiopulmonary bypass. We further sought to identify variables predictive ...of these autoregulation end points.
Cerebral autoregulation was monitored continuously with transcranial Doppler in 614 patients during cardiopulmonary bypass enrolled in 3 investigations. A moving Pearson's correlation coefficient was calculated between cerebral blood flow velocity and mean arterial pressure to generate the variable mean velocity index. Optimal mean arterial pressure was defined as the mean arterial pressure with the lowest mean velocity index indicating the best autoregulation. The lower and upper limits of cerebral blood flow autoregulation were defined as the mean arterial pressure at which mean velocity index was increasingly pressure passive (ie, mean velocity index ≥0.4) with declining or increasing blood pressure, respectively.
The mean (± standard deviation) lower and upper limits of cerebral blood flow autoregulation, and optimal mean arterial pressure were 65 ± 12 mm Hg, 84 ± 11 mm Hg, and 78 ± 11 mm Hg, respectively, after adjusting for study enrollment. In 17% of patients, though, the lower limit of cerebral autoregulation was above this optimal mean arterial pressure, whereas in 29% of patients the upper limit of autoregulation was below the population optimal mean arterial pressure. Variables associated with optimal mean arterial pressure based on multivariate regression analysis were nonwhite race (increased 2.7 mm Hg; P = .034), diuretics use (decreased 1.9 mm Hg; P = .049), prior carotid endarterectomy (decreased 5.5 mm Hg; P = .019), and duration of cardiopulmonary bypass (decreased 1.28 per 60 minutes of cardiopulmonary bypass). The product of the duration and magnitude that mean arterial pressure during cardiopulmonary bypass was below the lower limit of cerebral autoregulation was associated with the risk for stroke (P = .02).
Real-time monitoring of autoregulation may improve individualizing mean arterial pressure during cardiopulmonary bypass and improving patient outcomes.
Background:
Restricted mean survival time is a measure of average survival time up to a specified time point. There has been an increased interest in using restricted mean survival time to compare ...treatment arms in randomized clinical trials because such comparisons do not rely on proportional hazards or other assumptions about the nature of the relationship between survival curves.
Methods:
This article addresses the question of whether covariate adjustment in randomized clinical trials that compare restricted mean survival times improves precision of the estimated treatment effect (difference in restricted mean survival times between treatment arms). Although precision generally increases in linear models when prognostic covariates are added, this is not necessarily the case in non-linear models. For example, in logistic and Cox regression, the standard error of the estimated treatment effect does not decrease when prognostic covariates are added, although the situation is complicated in those settings because the estimand changes as well. Because estimation of restricted mean survival time in the manner described in this article is also based on a model that is non-linear in the covariates, we investigate whether the comparison of restricted mean survival times with adjustment for covariates leads to a reduction in the standard error of the estimated treatment effect relative to the unadjusted estimator or whether covariate adjustment provides no improvement in precision. Chen and Tsiatis suggest that precision will increase if covariates are chosen judiciously. We present results of simulation studies that compare unadjusted versus adjusted comparisons of restricted mean survival time between treatment arms in randomized clinical trials.
Results:
We find that for comparison of restricted means in a randomized clinical trial, adjusting for covariates that are associated with survival increases precision and therefore statistical power, relative to the unadjusted estimator. Omitting important covariates results in less precision but estimates remain unbiased.
Conclusion:
When comparing restricted means in a randomized clinical trial, adjusting for prognostic covariates can improve precision and increase power.
6mer seed toxicity is a novel cell death mechanism that kills cancer cells by triggering death induced by survival gene elimination (DISE). It is based on si- or shRNAs with a specific G-rich ...nucleotide composition in position 2-7 of their guide strand. An arrayed screen of 4096 6mer seeds on two human and two mouse cell lines identified G-rich 6mers as the most toxic seeds. We have now tested two additional cell lines, one human and one mouse, identifying the GGGGGC consensus as the most toxic average 6mer seed for human cancer cells while slightly less significant for mouse cancer cells. RNA Seq and bioinformatics analyses suggested that an siRNA containing the GGGGGC seed (siGGGGGC) is toxic to cancer cells by targeting GCCCCC seed matches located predominantly in the 3' UTR of a set of genes critical for cell survival. We have identified several genes targeted by this seed and demonstrate direct and specific targeting of GCCCCC seed matches, which is attenuated upon mutation of the GCCCCC seed matches in these 3' UTRs. Our data show that siGGGGGC kills cancer cells through its miRNA-like activity and points at artificial miRNAs, si- or shRNAs containing this seed as a potential new cancer therapeutics.
High-grade serous ovarian cancer (HGSOC) is characterized by a complex genomic landscape, with both genetic and epigenetic diversity contributing to its pathogenesis, disease course, and response to ...treatment. To better understand the association between genomic features and response to treatment among 370 patients with newly diagnosed HGSOC, we utilized multi-omic data and semi-biased clustering of HGSOC specimens profiled by TCGA. A Cox regression model was deployed to select model input features based on the influence on disease recurrence. Among the features most significantly correlated with recurrence were the promotor-associated probes for the NFRKB and DPT genes and the TREML1 gene. Using 1467 transcriptomic and methylomic features as input to consensus clustering, we identified four distinct tumor clusters-three of which had noteworthy differences in treatment response and time to disease recurrence. Each cluster had unique divergence in differential analyses and distinctly enriched pathways therein. Differences in predicted stromal and immune cell-type composition were also observed, with an immune-suppressive phenotype specific to one cluster, which associated with short time to disease recurrence. Our model features were additionally used as a neural network input layer to validate the previously defined clusters with high prediction accuracy (91.3%). Overall, our approach highlights an integrated data utilization workflow from tumor-derived samples, which can be used to uncover novel drivers of clinical outcomes.
Accelerometry measures older adult (in)activity with high resolution. Most studies summarize activity over the entire wear time. We extend prior work by analyzing hourly activity data to determine ...how frailty and other characteristics relate to activity among older adults.
Using wrist accelerometry data collected from the National Social Life, Health and Aging Project (n = 651), a nationally-representative probability sample of older adults, we used mixed effects linear regression to model the logarithm of hourly counts per minute as a function of an adapted phenotypic frailty score, adjusting for demographic and health characteristics, season, day of week and time of day.
Higher frailty scores were associated with modestly lower activity; each frailty point (0-4) corresponded to a 7% lower mean hourly counts per minute. Older age, more comorbidities, male gender, and higher BMI were also associated with lower activity, though the latter was not evident among frail respondents. After adjusting for differences associated with frailty and other covariates, a substantial amount of between-individual variability in activity remained, as well as within-individual variability across days.
Our findings indicate that frail elders, men, those who are older, overweight or have multiple comorbidities are most likely to have low activity. However, residual differences between individuals remain larger than the differences associated with frailty and other covariates. We suggest defining individual-specific activity goals and further research to identify the sources of between-individual variability to better understand how activity reflects health status and to permit the development of more effective interventions.
Allogeneic hematopoietic cell transplantation is increasingly utilized in older adults. This study prospectively evaluated the prognostic utility of geriatric assessment domains prior to allogeneic ...transplantation in recipients aged 50 years and over. Geriatric assessment was performed prior to transplant, and included validated measures across domains of function and disability, comorbidity, frailty, mental health, nutritional status, and systemic inflammation. A total of 203 patients completed geriatric assessment and underwent transplant. Median age was 58 years (range 50-73). After adjusting for established prognostic factors, limitations in instrumental activities of daily living (HR 2.38, 95%CI: 1.59-3.56; P<0.001), slow walk speed (HR 1.80, 95%CI: 1.14-2.83; P=0.01), high comorbidity by hematopoietic cell transplantation-specific comorbidity index (HR 1.56, 95%CI: 1.07-2.28; P=0.02), low mental health by short-form-36 mental component summary (HR 1.67, 95%CI: 1.13-2.48; P=0.01), and elevated serum C-reactive protein (HR 2.51, 95%CI: 1.54-4.09; P<0.001) were significantly associated with inferior overall survival. These associations were more pronounced in the cohort 60 years and over. Geriatric assessment measures confer independent prognostic utility in older allogeneic transplant recipients. Implementation of geriatric assessment prior to allogeneic transplantation may aid appropriate selection of older adults.
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