Assessing the Survival Benefit of Surgery and Various Types of Radiation Therapy for Treatment of Hepatocellular Carcinoma: Evidence from the Surveillance, Epidemiology, and End Results Registries

Objective

To evaluate the survival benefit of surgery and radiation for hepatocellular carcinoma (HCC) after adjusting for patient-specific and tumor-specific factors.

Methods

This study analyzed HCC patients who enrolled in the Surveillance, Epidemiology, and End Results (SEER) registry between January 2004 and December 2013. Of the 5552 HCC patients, 4597 received surgery and 955 received radiation. Patients who received radiation were further divided into 3 subgroups: 541 who received beam radiation (BR), 197 who received radioactive implants (RI), and 217 who received radioisotopes (RIT). Propensity score weighting analysis derived from generalized boosted models (GBMs) was performed to ensure well-balanced characteristics in all comparison groups.

Results

Overall survival rates and HCC-specific survival rates were higher in those receiving surgery compared with those receiving radiotherapy. This was confirmed by Cox proportional hazard regression both before and after inverse probability of treatment weighting (IPTW). Before IPTW, the RIT group had a better outcome than the BR group in terms of overall and HCC-specific survival rates, but there was no significant difference between the RI and BR groups. After IPTW, Cox proportional hazard regression demonstrated that both the RIT and RI groups had higher survival rates than the BR group.

Conclusion

In HCC patients, surgery was associated with higher survival rates compared with radiotherapy while adjusting for other factors. Among those who received radiotherapy, RIT and RI granted survival benefits.

Mortality and morbidity following postoperative use of short-term, low-dose quetiapine vs risperidone in patients with diabetes: Analysis using a national inpatient database

PURPOSE

Short-term, low-dose quetiapine is used to treat postoperative delirium and insomnia. Quetiapine is contraindicated for patients with diabetes in Japan because there have been several case reports of diabetic ketoacidosis (DKA) in patients receiving long-term, high-dose quetiapine. However, because safety of short-term, low-dose quetiapine remains controversial, it is prescribed for patients with diabetes in real-world clinical practice. The present study aimed to compare in-hospital mortality and morbidity between short-term, low-dose quetiapine and risperidone in postoperative patients with diabetes.

METHODS

We used a national inpatient database in Japan to perform a retrospective cohort study. We identified hospitalized patients with diabetes who underwent scheduled elective surgery and received oral quetiapine 200 mg/d or less or oral risperidone 4 mg/d or less within 7 days of surgery between July 2010 and March 2018. We performed one-to-one propensity score-matched analyses to compare outcomes between patients with quetiapine and risperidone. The primary outcome was in-hospital mortality. The secondary outcome was infectious complications (pneumonia, urinary tract infection, surgical site infection, and sepsis).

RESULTS

Propensity score matching created 665 pairs of patients who received quetiapine or risperidone. The primary outcome was observed in 19 (2.9%) of the quetiapine group and 11 (1.7%) of the risperidone group (relative risk, 1.27; 95% confidence interval, 0.97-1.68; P = .14). The secondary outcome did not differ significantly between the groups.

CONCLUSION

In terms of mortality and infectious outcomes, safety of quetiapine and risperidone may be comparable.

Outcomes of COVID-19 Hospitalized Patients Previously Treated with Renin-Angiotensin System Inhibitors

(1) Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) penetrates respiratory epithelium through angiotensin-converting enzyme-2 binding, raising concerns about the potentially harmful effects of renin-angiotensin system inhibitors (RASi) on Human Coronavirus Disease 2019 (COVID-19) evolution. This study aimed to provide insight into the impact of RASi on SARS-CoV-2 outcomes in patients hospitalized for COVID-19. (2) Methods: This was a retrospective analysis of hospitalized adult patients with SARS-CoV-2 infection admitted to a university hospital in France. The observation period ended at hospital discharge. (3) Results: During the study period, 943 COVID-19 patients were admitted to our institution, of whom 772 were included in this analysis. Among them, 431 (55.8%) had previously known hypertension. The median age was 68 (56-79) years. Overall, 220 (28.5%) patients were placed under mechanical ventilation and 173 (22.4%) died. According to previous exposure to RASi, we defined two groups, namely, "RASi" (n = 282) and "RASi-free" (n = 490). Severe pneumonia (defined as leading to death and/or requiring intubation, high-flow nasal oxygen, noninvasive ventilation, and/or oxygen flow at a rate of ≥5 L/min) and death occurred more frequently in RASi-treated patients (64% versus 53% and 29% versus 19%, respectively). However, in a propensity score-matched cohort derived from the overall population, neither death (hazard ratio (HR) 0.93 (95% confidence interval (CI) 0.57-1.50), p = 0.76) nor severe pneumonia (HR 1.03 (95%CI 0.73-1.44), p = 0.85) were associated with RASi therapy. (4) Conclusion: Our study showed no correlation between previous RASi treatment and death or severe COVID-19 pneumonia after adjustment for confounders.

Matching-adjusted indirect comparisons: Application to time-to-event data

The Matching-Adjusted Indirect Comparison method (MAIC) is a recent methodology that allows to perform indirect comparisons between two drugs assessed in two different studies, where individual patients data are available in only one of the two studies, the data of the other one being available in an aggregate format only. In this work, we have assessed the properties of the MAIC method and compared, through simulations, several ways of practical implementation of the method. We conclude that it is more efficient to match the treatment arms separately (match the two drugs to compare on one hand, and the control arms on the other hand) and use the Lasso technique to select the covariates for the matching step is better than matching a maximal set of covariates.

Ischemic Stroke Occurs Less Frequently in Patients With COVID-19: A Multicenter Cross-Sectional Study

Supplemental Digital Content is available in the text.

The impact of coronavirus disease 2019 (COVID-19) on the occurrence of ischemic stroke has been the subject of increased speculation but has not been confirmed in large observational studies. We investigated the association between COVID-19 and stroke.

Long-term effect of first-line injectable multiple sclerosis treatments: Input of a time-dependent propensity score

PURPOSE

The long-term effect of beta-interferon and glatiramer acetate on multiple sclerosis (MS) disability progression has resulted in controversial results, probably due to a lack of appropriate control of biases as raised in observational studies. In particular, the time of the therapeutic decision is difficult to define when the controls are not treated.

METHODS

This retrospective observational study was based on a series of patients from the MS expert center in Rennes, France. We used a time-dependent propensity score defined as the linear predictor of a Cox model estimating the hazard of being treated at each time from MS onset. The matching procedure resulted in two groups: patients matched as treated and as not yet treated. The restricted mean times (RMST) to reach a moderate level of disability or worsening of the disability were compared between the two groups in an intention-to-treat analysis.

RESULTS

Of the 2383 patients included in the study, 556 were matched as treated. The matching procedure provided a good balance of both the time-fixed and the time-dependent covariates. A slight difference was observed for the time to reach a moderate level of disability, in favor of the "not yet treated" group (difference in the RMST: -0.62 [-0.91; -0.33]) while no difference was found in terms of worsening of the disability (-0.03 [-0.24; 0.33]).

CONCLUSION

This unexpected result is probably due to unmeasured confounders. However, this time-dependent PS warrants consideration in long-term effectiveness studies.

Common Methods for Handling Missing Data in Marginal Structural Models: What Works and Why

Marginal structural models (MSMs) are commonly used to estimate causal intervention effects in longitudinal nonrandomized studies. A common challenge when using MSMs to analyze observational studies is incomplete confounder data, where a poorly informed analysis method will lead to biased estimates of intervention effects. Despite a number of approaches described in the literature for handling missing data in MSMs, there is little guidance on what works in practice and why. We reviewed existing missing-data methods for MSMs and discussed the plausibility of their underlying assumptions. We also performed realistic simulations to quantify the bias of 5 methods used in practice: complete-case analysis, last observation carried forward, the missingness pattern approach, multiple imputation, and inverse-probability-of-missingness weighting. We considered 3 mechanisms for nonmonotone missing data encountered in research based on electronic health record data. Further illustration of the strengths and limitations of these analysis methods is provided through an application using a cohort of persons with sleep apnea: the research database of the French Observatoire Sommeil de la Fédération de Pneumologie. We recommend careful consideration of 1) the reasons for missingness, 2) whether missingness modifies the existing relationships among observed data, and 3) the scientific context and data source, to inform the choice of the appropriate method(s) for handling partially observed confounders in MSMs.

The effect of a constraint on the maximum number of controls matched to each treated subject on the performance of full matching on the propensity score when estimating risk differences

Many observational studies estimate causal effects using methods based on matching on the propensity score. Full matching on the propensity score is an effective and flexible method for utilizing all available data and for creating well-balanced treatment and control groups. An important component of the full matching algorithm is the decision about whether to impose a restriction on the maximum ratio of controls matched to each treated subject. Despite the possible effect of this restriction on subsequent inferences, this issue has not been examined. We used a series of Monte Carlo simulations to evaluate the effect of imposing a restriction on the maximum ratio of controls matched to each treated subject when estimating risk differences. We considered full matching both with and without a caliper restriction. When using full matching with a caliper restriction, the imposition of a subsequent constraint on the maximum ratio of the number of controls matched to each treated subject had no effect on the quality of inferences. However, when using full matching without a caliper restriction, the imposition of a constraint on the maximum ratio of the number of controls matched to each treated subject tended to result in an increase in bias in the estimated risk difference. However, this increase in bias tended to be accompanied by a corresponding decrease in the sampling variability of the estimated risk difference. We illustrate the consequences of these restrictions using observational data to estimate the effect of medication prescribing on survival following hospitalization for a heart attack.

A pilot design for observational studies: Using abundant data thoughtfully

Observational studies often benefit from an abundance of observational units. This can lead to studies that-while challenged by issues of internal validity-have inferences derived from sample sizes substantially larger than randomized controlled trials. But is the information provided by an observational unit best used in the analysis phase? We propose the use of a "pilot design," in which observations are expended in the design phase of the study, and the posttreatment information from these observations is used to improve study design. In modern observational studies, which are data rich but control poor, pilot designs can be used to gain information about the structure of posttreatment variation. This information can then be used to improve instrumental variable designs, propensity score matching, doubly robust estimation, and other observational study designs. We illustrate one version of a pilot design, which aims to reduce within-set heterogeneity and improve performance in sensitivity analyses. This version of a pilot design expends observational units during the design phase to fit a prognostic model, avoiding concerns of overfitting. In addition, it enables the construction of "assignment-control plots," which visualize the relationship between propensity and prognostic scores. We first show some examples of these plots, then we demonstrate in a simulation setting how this alternative use of the observations can lead to gains in terms of both treatment effect estimation and sensitivity analyses of unobserved confounding.

Rectal cancer in young patients: incidence and outcome disparities

Background

There is an alarming rise in incidence among young patients with rectal cancer. The National Cancer Database (NCDB) and Surveillance, Epidemiology, and End Results Analysis (SEER) databases may help identify population level disparities in incidence and cancer-related outcomes.

Methods

A total of 197,178 patients within the SEER 18 registry and 221,886 patients from the NCDB database with rectal cancer were evaluated in this retrospective cohort study. The analyzed cohort consisted of young (<50), white or African American patients. Indication bias was mitigated by conducting inverse probability of treatment weighted analysis using binary logistic regression modeling to determine propensity score for being white or African American.

Results

A total of 6,144 young patients were identified from the SEER 18 registry and a total of 17,819 young patients were identified from the NCDB. From 1990 to 2016, there was a significant change in rectal cancer incidence, with a steadily increasing APC of 3.06 (P<0.05). The was no overall change in age-adjusted APC among young African American patients (APC 0.00, P=1); however, there was a significant increase among young white patients (APC 2.97, P<0.05). There was an increased incidence for both stage III and IV among young rectal cancer patients, with an age-adjusted APC of 5.35 and 3.83, respectively (P<0.05). After propensity score matching and inverse probability of treatment weighting, young African Americans had worse overall survival in both the NCDB and SEER (HR 1.1-1.3, P<0.05) databases. This disparity was also seen for cancer-specific survival (HR 1.5, P=0.002).

Conclusions

The current study adds to the growing body of literature demonstrating an alarming increase in incidence of rectal cancer among young patients. Moreover, the incidence appears to be increasing particularly among young white patients and driven by stage III disease.

The impact of routine Edmonton Symptom Assessment System (ESAS) use on overall survival in cancer patients: Results of a population-based retrospective matched cohort analysis

BACKGROUND

The Edmonton Symptom Assessment System (ESAS) is a validated instrument whose use has been standardized in the Ontario cancer system to measure symptoms among ambulatory cancer patients. The objective was to examine the effect of ESAS exposure on overall survival. We hypothesized, a priori, that patients exposed to ESAS would have higher rates of overall survival than those who were not exposed.

METHODS

This was a retrospective matched cohort study of adults diagnosed with cancer between 2007 and 2015. Patients were considered exposed if they were screened with ESAS at least once during the study period. Their first ESAS screening date defined the index date. Each exposed patient was matched randomly to a cancer patient without ESAS using a combination of hard matching (4 variables) and propensity score matching (14 variables). Kaplan-Meier curves and multivariable Cox regression were used to evaluate the impact of ESAS exposure on survival.

RESULTS

There were 128,893 pairs well matched on all baseline characteristics. The probability of survival within the first 5 years was higher among those exposed to ESAS compared to those who were not (81.9% vs. 76.4% at 1 year, 68.3% vs. 66.1% at 3 years, 61.9% vs. 61.4% at 5 years, P-value < .0001). In the multivariable Cox regression model, ESAS was significantly associated with a decreased mortality risk (HR: 0.48, 95% CI: 0.47-0.49).

CONCLUSIONS

Our results show that ESAS exposure is associated with improved survival in cancer patients. This provides real world evidence of the impact of routine symptom assessment in cancer care.

Empirical use of causal inference methods to evaluate survival differences in a real-world registry vs those found in randomized clinical trials

With heighted interest in causal inference based on real-world evidence, this empirical study sought to understand differences between the results of observational analyses and long-term randomized clinical trials. We hypothesized that patients deemed "eligible" for clinical trials would follow a different survival trajectory from those deemed "ineligible" and that this factor could partially explain results. In a large observational registry dataset, we estimated separate survival trajectories for hypothetically trial-eligible vs ineligible patients under both coronary artery bypass surgery (CABG) and percutaneous coronary intervention (PCI). We also explored whether results would depend on the causal inference method (inverse probability of treatment weighting vs optimal full propensity matching) or the approach to combine propensity scores from multiple imputations (the "across" vs "within" approaches). We found that, in this registry population of PCI/CABG multivessel patients, 32.5% would have been eligible for contemporaneous RCTs, suggesting that RCTs enroll selected populations. Additionally, we found treatment selection bias with different distributions of propensity scores between PCI and CABG patients. The different methodological approaches did not result in different conclusions. Overall, trial-eligible patients appeared to demonstrate at least marginally better survival than ineligible patients. Treatment comparisons by eligibility depended on disease severity. Among trial-eligible three-vessel diseased and trial-ineligible two-vessel diseased patients, CABG appeared to have at least a slight advantage with no treatment difference otherwise. In conclusion, our analyses suggest that RCTs enroll highly selected populations, and our findings are generally consistent with RCTs but less pronounced than major registry findings.

iDPPIV-SCM: A Sequence-Based Predictor for Identifying and Analyzing Dipeptidyl Peptidase IV (DPP-IV) Inhibitory Peptides Using a Scoring Card Method

The inhibition of dipeptidyl peptidase IV (DPP-IV, E.C.3.4.14.5) is well recognized as a new avenue for the treatment of Type 2 diabetes (T2D). Until now, peptide-like DDP-IV inhibitors have been shown to normalize the blood glucose concentration in T2D subjects. To the best of our knowledge, there is yet no computational model for predicting and analyzing DPP-IV inhibitory peptides using sequence information. In this study, we present for the first time a simple and easily interpretable sequence-based predictor using the scoring card method (SCM) for modeling the bioactivity of DPP-IV inhibitory peptides (iDPPIV-SCM). Particularly, the iDPPIV-SCM was developed by employing the SCM method together with the propensity scores of amino acids. Rigorous independent test results demonstrated that the proposed iDPPIV-SCM was found to be superior to those of well-known machine learning (ML) classifiers (e.g., k-nearest neighbor, logistic regression, and decision tree) with demonstrated improvements of 2-11, 4-22, and 7-10% for accuracy, MCC, and AUC, respectively, while also achieving comparable results to that of the support vector machine. Furthermore, the analysis of estimated propensity scores of amino acids as derived from the iDPPIV-SCM was performed so as to provide a more in-depth understanding on the molecular basis for enhancing the DPP-IV inhibitory potency. Taken together, these results revealed that iDPPIV-SCM was superior to those of other well-known ML classifiers owing to its simplicity, interpretability, and validity. For the convenience of biologists, the predictive model is deployed as a publicly accessible web server at http://camt.pythonanywhere.com/iDPPIV-SCM. It is anticipated that iDPPIV-SCM can serve as an important tool for the rapid screening of promising DPP-IV inhibitory peptides prior to their synthesis.

Four versus six chemotherapy cycles in endometrial carcinoma with a high risk of recurrence: a retrospective study

OBJECTIVE

This study compared the survival outcomes and the incidence of chemotherapy-related adverse events in endometrial cancer patients who received four and six cycles of adjuvant chemotherapy to examine the optimal number of adjuvant chemotherapy cycles.

METHODS

A total of 112 patients with endometrial cancer with a high risk of recurrence were retrospectively enrolled; 46 patients received four cycles and 66 received six cycles of adjuvant chemotherapy. Between-group differences of overall survival, disease-free survival, hematological and non-hematological toxicities were analyzed. Baseline patient's background differences were assessed with inverse probability of treatment weighting using propensity score.

RESULTS

Overall and disease-free survivals between the two groups were not significantly different. Paclitaxel + carboplatin, every 3-4 weeks was the most frequently used chemotherapy regimen in both groups. Patients in the six-cycle chemotherapy group developed neutropenia G4 or febrile neutropenia more frequently than those in the four-cycle group; odds ratio (95% confidence interval) is 4.07 (1.51-10.96). Peripheral sensory neuropathy was the most frequently observed non-hematological toxicity; the incidence of peripheral sensory neuropathy was not significantly different between four- and six-cycle chemotherapy group, P = 0.832. The result was same in the subgroup analysis in patients who received TC regimen, P = 0.455.

CONCLUSION

This study implies a possible benefit of fewer cycles of adjuvant chemotherapy in endometrial cancer patients with a high risk of recurrence because of the lower incidence of hematological toxicities without impairing survival outcomes.

Causal Mediation Analysis in the Presence of Post-treatment Confounding Variables: A Monte Carlo Simulation Study

In many disciplines, mediating processes are usually investigated with randomized experiments and linear regression to determine if the treatment affects the outcome through a mediator. However, randomizing the treatment will not yield accurate causal direct and indirect estimates unless certain assumptions are satisfied since the mediator status is not randomized. This study describes methods to estimate causal direct and indirect effects and reports the results of a large Monte Carlo simulation study on the performance of the ordinary regression and modern causal mediation analysis methods, including a previously untested doubly robust sequential g-estimation method, when there are confounders of the mediator-to-outcome relation. Results show that failing to measure and incorporate potential post-treatment confounders in a mediation model leads to biased estimates, regardless of the analysis method used. Results emphasize the importance of measuring potential confounding variables and conducting sensitivity analysis.

Local Anesthesia Without Sedation During Thrombectomy for Anterior Circulation Stroke Is Associated With Worse Outcome

BACKGROUND AND PURPOSE

The best anesthetic management for mechanical thrombectomy of large vessel occlusion strokes is still uncertain and could impact the quality of reperfusion and clinical outcome. We aimed to compare the efficacy and safety outcomes between local anesthesia (LA) and conscious sedation in a large cohort of acute ischemic stroke patients with anterior circulation large vessel occlusion strokes treated with mechanical thrombectomy in current, everyday clinical practice.

METHODS

Patients undergoing mechanical thrombectomy for anterior large vessel occlusion strokes at 4 comprehensive stroke centers in France between January 1, 2018, and December 31, 2018, were pooled from the ongoing prospective multicenter observational Endovascular Treatment in Ischemic Stroke Registry in France. Intention-to-treat and per-protocol analyses were used.

RESULTS

Among the included 1034 patients, 762 were included in the conscious sedation group and 272 were included in the LA group. In the propensity score matched cohort, the rate of favorable outcome (90-day modified Rankin Scale score 0-2) was significantly lower in the LA group than in the conscious sedation group (40.0% versus 52.0%, matched relative risk=0.76 [95% CI, 0.60-0.97]), as well as the rate of successful reperfusion (modified Thrombolysis in Cerebral Infarction grade 2b-3; 76.6% versus 87.1%; matched relative risk=0.88 [95% CI, 0.79-0.98]). There was no difference in procedure time between the 2 groups. In the inverse probability of treatment weighting-propensity score-adjusted cohort, similar significant differences were found for favorable outcomes and successful reperfusion. In inverse probability of treatment weighting-propensity score-adjusted cohort, a higher rate of 90-day mortality and a lower parenchymal hematoma were observed after LA. The sensitivity analysis restricted to our per-protocol sample provided similar results in the matched- and inverse probability of treatment weighting-propensity cohorts.

CONCLUSIONS

In the Endovascular Treatment in Ischemic Stroke registry mainly included patients in early time window (<6 hours), LA was associated with lower odds of favorable outcome, successful reperfusion, and higher odds of mortality compared with conscious sedation for mechanical thrombectomy of large vessel occlusion.

Distinct Clinical Characteristics in Young-Onset Pancreatic Neuroendocrine Tumor

BACKGROUND

We aimed to study the effect of socioeconomic differences and molecular characteristics on survival in patients with young-onset pancreatic neuroendocrine tumors (YOPNET) and typical-onset PNET (TOPNET).

METHODS

We identified the patients with YOPNET (<50 years) and TOPNET (≥50 years) who underwent definitive surgery diagnosed between 2004 and 2016 using the National Cancer Database. We evaluated overall survival (OS) using the Kaplan-Meier and Cox regression methods before and after propensity score matching. A publicly available genomic dataset was used to compare mutation frequencies among the two groups.

RESULTS

A total of 6259 patients with PNET were included, of which 27% were YOPNET. Patients with YOPNET were more likely to be Black, Hispanic, female, and have private insurance versus patients with TOPNET (all p < 0.001). Patients with YOPNET had a lower comorbidity score, but higher stage and tumor size (all p < 0.001). YOPNET was associated with a greater improved OS than TOPNET before and after propensity score matching (p < 0.001). On multivariable analysis, this survival difference persisted for YOPNET as an independent prognostic factor (unmatched p = 0.008; matched p = 0.01). For genomic analysis, patients with YOPNET had a lower rate of multiple endocrine neoplasia type-1 (MEN-1) mutation than patients with TOPNET (26% vs. 56%, p < 0.001).

CONCLUSIONS

YOPNET represents a disease with distinct clinical features. Patients with YOPNET who underwent definitive surgery had better OS than patients with TOPNET despite having higher stage and tumor size. YOPNET also had lower rate of MEN-1 mutation.

Mortality due to hospital-acquired infection after cardiac surgery

PURPOSE

Hospital-acquired infections have been associated with significant morbidity and mortality in critically ill surgical patients. However, little is known about mortality due to hospital-acquired infections in cardiac surgery.

METHODS

We conducted a retrospective analysis of prospectively collected data from the cardiac surgery unit of a university hospital. All patients who underwent cardiac surgery over a 7-year period were included. Patients with hospital-acquired infections were matched 1:1 with patients with nonhospital-acquired infections based on risk factors for hospital-acquired infections and death after cardiac surgery using propensity score matching. We performed a competitive risk analysis to study the mortality fraction due to hospital-acquired infections.

RESULTS

Of 8853 patients who underwent cardiac surgery, 370 (4.2%) developed 500 postoperative infections (incidence density rate 4.2 hospital-acquired infections per 1000 patient-days). Crude hospital mortality was significantly higher in patients with hospital-acquired infections than in matched patients who did not develop hospital-acquired infections, 15.4% and 5.7%, respectively (P < .001). The in-hospital mortality fraction due to hospital-acquired infections in our cohort was 17.1% (12.3%-22.8%). Pseudomonas aeruginosa infection (hazard ratio, 2.09; 95% confidence interval, 1.23-3.49; P = .005), bloodstream infection (hazard ratio, 2.08; 95% confidence interval, 1.19-3.63; P = .010), and pneumonia (hazard ratio, 1.68; 95% confidence interval, 1.02-2.77; P = .04) were each independently associated with increased hospital mortality.

CONCLUSIONS

Although hospital-acquired infections are relatively uncommon after cardiac surgery (4.2%), these infections have a major impact on postoperative mortality (attributable mortality fraction, 17.1%).

Long-Term Outcomes of Laparoscopic Versus Open Surgery for Colon Cancer in Noncancer-Specific Hospital: Propensity Score Analysis

Background: Noninferiority of the laparoscopic approach compared with open surgery for colon cancer treatment has remained controversial. In this study, we aimed to evaluate the long-term outcomes of laparoscopic surgery (LS) versus open surgery (OPS). Methods: A total of 418 patients with Stage I-III colon cancer, who received radical surgery at the Tokyo Medical University Hospital from 2000 to 2014 were included. Propensity score analysis with overall survival (OS) and relapse-free survival (RFS) as the primary endpoints was performed retrospectively to reduce the effects of confounding factors between groups, including age, sex, body mass index, tumor size, clinical T stage, and clinical N stage. Results: After case matching, the 5-year OS rate was 87.8% in the OPS group (n = 97) and 90.1% in the LS group (n = 97; P = .59), indicating no significant difference. The 5-year RFS rate was 79.0% in the OPS group (n = 97) and 84.1% in the LS group (n = 97; P = .29), indicating no significant difference. Five-year cumulative local recurrence (LR) rates were 7.6% and 0% in the OPS group and the LS group, respectively, indicating a significant difference (P = .007). Five-year cumulative distant metastasis rates were 9.2% and 12.7% in the OPS group and the LS group, respectively (P = .49). Conclusion: Laparoscopic surgery appears to be a reasonable option with similar long-term outcomes and to have low LR rate to open surgery in colon cancer patients.

Artificial urinary sphincter significantly better than fixed sling for moderate post-prostatectomy stress urinary incontinence: a propensity score-matched study

OBJECTIVE

To compare the efficacy of artificial urinary sphincter (AUS) vs retrourethral transobturator sling (RTS) in men with moderate post-prostatectomy urinary incontinence (PPI) using propensity score-matching analysis to enhance the validity of the comparison (Canadian Task Force classification II-2).

PATIENTS AND METHODS

Consecutive men with moderate (3-5 pads/day) stress-prevalent PPI were included if implanted with a RTS (TiLOOP^® Male; pfm medical, Köln, Germany) or AUS (AMS800^® ; Boston Scientific, Boston, MA, USA) since July 2011 to December 2017 and with ≥12 months of follow-up. Preoperative assessment included 24-h pad usage, International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), urethrocystoscopy, and urodynamics if indicated. Propensity score-matching analysis was based on age, body mass index, Charlson Comorbidity Index, pad usage, previous radiotherapy, and urethrotomy. The primary outcome was at least 'much improved' response at 12-months according to the Patient Global Impression of Improvement questionnaire, without additional PPI surgery or prosthesis explantation.

RESULTS

Of 109 included patients, 70 patients were matched and the study groups were well balanced for the baseline matched variables. The median baseline 24-h pad usage was four in both groups (P = 0.10), and median follow-up was 51.2 months for AUS and 47.2 months (P = 0.5) for RTS patients. In the AUS and RTS cohorts, respectively, 33 (94.3%) and 24 (68.6%) patients achieved the primary outcome (P < 0.001), the 0-1 pad/day rates was 94.3% vs 68.6% (P = 0.012) at 12 months, and 91.4% vs 68.6% (P = 0.034) at last follow-up. At the last follow-up, the median 24-h leakage volumes, median ICIQ-SF scores and satisfaction rates were 0 vs 15 mL (P = 0.017), 4 vs 10 (P = 0.001), and 94.3% vs 68.6% (P = 0.012) in the AUS and RTS cohorts, respectively. There were no significant differences in overall rates of complications and re-interventions, although Clavien-Dindo Grade III complications (n = 3) occurred only in the AUS group. At sensitivity analysis, the study was reasonably robust to hidden bias.

CONCLUSION

We found that AUS implantation significantly outperformed RTS in patients with moderate PPI for both subjective and objective outcomes.

Surgical left atrial appendage occlusion in patients with atrial fibrillation undergoing mechanical heart valve replacement

BACKGROUND

Surgical left atrial appendage occlusion (SLAAO) may be associated with a lower risk of thromboembolism in patients with atrial fibrillation undergoing cardiac surgery. However, evidence regarding the effectiveness of SLAAO in patients undergoing mechanical heart valve replacement (MHVR) is lacking. Therefore, we aimed to evaluate the association between SLAAO and the cardiovascular outcomes in patients with atrial fibrillation undergoing MHVR.

METHODS

We retrospectively analyzed data for 497 patients with atrial fibrillation; 27.6% of the patients underwent SLAAO, and the remainder of the patients did not (No-SLAAO group). The primary outcome was a composite of ischemic stroke, systemic embolism, and all-cause mortality. Cumulative event-free survival rates were estimated using Kaplan-Meier curves, and we performed multivariate Cox analyses to evaluate the association between SLAAO and outcomes. We used one-to-one propensity score matching to balance patients' baseline characteristics, and analyzed 120 matching pairs.

RESULTS

Five patients died within 30 days postoperatively, and there were no significant differences between the two groups regarding in-hospital complications (all P > 0.05). After a median follow-up of 14 months, 14 primary events occurred. Kaplan-Meier curves showed no difference in the cumulative incidence of freedom from the primary outcome (log-rank P = 0.830), hemorrhagic events (log-rank P = 0.870), and the secondary outcome (log-rank P = 0.730), between the two groups. Multivariable Cox proportional hazards regression analysis showed no association between SLAAO and any outcome (all P > 0.05). After propensity score matching, cardiopulmonary bypass time and aortic cross-clamp time, and the postoperative length of stay were significantly longer in the SLAAO group (all P < 0.05); results were similar to the unadjusted analyses.

CONCLUSIONS

Concomitant SLAAO and MHVR was associated with longer length of stay, and cardiopulmonary bypass time and aortic cross-clamp time, but was not associated with additional protective effects against thromboembolic events and mortality during the 14-month follow-up.

Comparison of diagnostic efficacy between transrectal and transperineal prostate biopsy: A propensity score-matched study

This study compared the diagnostic efficacy of transrectal ultrasound (TRUS)-guided prostate biopsy (TRBx) and transperineal prostate biopsy (TPBx) in patients with suspected prostate cancer (PCa). We enrolled 2962 men who underwent transrectal (n = 1216) or transperineal (n = 1746) systematic 12-core prostate biopsy. Clinical data including age, prostate-specific antigen (PSA) level, and prostate volume (PV) were recorded. To minimize confounding, we performed propensity score-matching analysis. We measured and compared PCa detection rates between TRBx and TPBx, which were stratified by clinical characteristics and Gleason scores. The effects of clinical characteristics on PCa detection rate were assessed by logistic regression. For all patients, TPBx detected a higher proportion of clinically significant PCa (P < 0.001). Logistic regression analyses illustrated that PV had a smaller impact on PCa detection rate of TPBx compared with TRBx. Propensity score-matching analysis showed that the detection rates in TRBx were higher than those in TPBx for patients aged >- 80 years (80.4% vs 56.5%, P = 0.004) and with PSA level 20.1-100.0 ng ml^-1 (80.8% vs 69.1%, P = 0.040). In conclusion, TPBx was associated with a higher detection rate of clinically significant PCa than TRBx was; however, because of the high detection rate at certain ages and PSA levels, biopsy approaches should be optimized according to patents' clinical characteristics.

Vertebral body fracture rates after stereotactic body radiation therapy compared with external-beam radiation therapy for metastatic spine tumors

OBJECTIVE

Stereotactic body radiation therapy (SBRT) is utilized to deliver highly conformal, dose-escalated radiation to a target while sparing surrounding normal structures. Spinal SBRT can allow for durable local control and palliation of disease while minimizing the risk of damage to the spinal cord; however, spinal SBRT has been associated with an increased risk of vertebral body fractures. This study sought to compare the fracture rates between SBRT and conventionally fractionated external-beam radiation therapy (EBRT) in patients with metastatic spine tumors.

METHODS

Records from patients treated at the University of California, San Francisco, with radiation therapy for metastatic spine tumors were retrospectively reviewed. Vertebral body fracture and local control rates were compared between SBRT and EBRT. Ninety-six and 213 patients were identified in the SBRT and EBRT groups, respectively. Multivariate analysis identified the need to control for primary tumor histology (p = 0.003 for prostate cancer, p = 0.0496 for renal cell carcinoma). The patient-matched EBRT comparison group was created by matching SBRT cases using propensity scores for potential confounders, including the Spinal Instability Neoplastic Score (SINS), the number and location of spine levels treated, sex, age at treatment, duration of follow-up (in months) after treatment, and primary tumor histology. Covariate balance following group matching was confirmed using the Student t-test for unequal variance. Statistical analysis, including propensity score matching and multivariate analysis, was performed using R software and related packages.

RESULTS

A total of 90 patients met inclusion criteria, with 45 SBRT and 45 EBRT matched cases. Balance of the covariates, SINS, age, follow-up time, and primary tumor histology after the matching process was confirmed between groups (p = 0.062, p = 0.174, and 0.991, respectively, along with matched tumor histology). The SBRT group had a higher 5-year rate of vertebral body fracture at 22.22% (n = 10) compared with 6.67% (n = 3) in the EBRT group (p = 0.044). Survival analysis was used to adjust for uneven follow-up time and showed a significant difference in fracture rates between the two groups (p = 0.044). SBRT also was associated with a higher rate of local control (86.67% vs 77.78%).

CONCLUSIONS

Patients with metastatic cancer undergoing SBRT had higher rates of vertebral body fractures compared with patients undergoing EBRT, and this difference held up after survival analysis. SBRT also had higher rates of initial local control than EBRT but this difference did not hold up after survival analysis, most likely because of a high percentage of radiosensitive tumors in the EBRT cohort.