Considerations for observational research using large data sets in radiation oncology

Big Data in Oncology: The Electronic Patient Record Transformation Program

OBJECTIVES

There is a vast amount of real-world data collected daily in oncology through diagnostic, therapeutic, and patient-reported outcome measures. The challenge arises with linking data together to create structured and meaningful databases, which are representative of the general population, free of bias, and of good quality to be able to draw meaningful conclusions. Real-world data that are linked together within trusted cancer research environments could represent the next generation of big data strategy in cancer.

DATA SOURCES

Patient and public involvement initiatives and expert opinion.

CONCLUSION

Collaboration among specialist cancer data analysts, academic researchers, and clinicians within cancer institutions is key to standardizing the design and evaluation of real-world databases. Digital transformation efforts must include implementation of integrated care records and patient-facing portals, in combination with training and education of clinicians in digital skills and health leadership. As part of the Electronic Patient Record Transformation Program, our experience with patient and public involvement in the development of a cancer patient-facing portal linked to an oncology electronic health record at University Hospitals Coventry and Warwickshire has given us useful insights into patient needs and priorities.

IMPLICATIONS FOR NURSING PRACTICE

The growth of electronic health records and patient portals is an opportunity to gather big data in oncology at a population level to help clinicians and researchers with the development of predictive and preventive algorithms and new models for personalized care.

Population-level and individual-level explainers for propensity score matching in observational studies

Precis

The exclusion of unmatched observations in propensity score matching has implications for the generalizability of causal effects. Machine learning methods can help to identify how the study population differs from the unmatched subpopulation.

Background

There has been widespread use of propensity scores in evaluating the effect of cancer treatments on survival, particularly in administrative databases and cancer registries. A byproduct of certain matching schemes is the exclusion of observations. Borrowing an analogy from clinical trials, one can view these exclusions as subjects that do not satisfy eligibility criteria.

Methods

Developing identification rules for these “data-driven eligibility criteria” in observational studies on both population and individual levels helps to ascertain the population on which causal effects are being made. This article presents a machine learning method to determine the representativeness of causal effects in two different datasets from the National Cancer Database.

Results

Decision trees reveal that groups with certain features have a higher probability of inclusion in the study population than older patients. In the first dataset, younger age categories had an inclusion probability of at least 0.90 in all models, while the probability for the older category ranged from 0.47 to 0.65. Most trees split once more on an even higher age at a lower node, suggesting that the oldest patients are the least likely to be matched. In the second set of data, both age and surgery status were associated with inclusion.

Conclusion

The methodology presented in this paper underscores the need to consider exclusions in propensity score matching procedures as well as complementing matching with other propensity score adjustments.

Development of an Electronic Health Record Registry to Facilitate Collection of Commission on Cancer Metrics for Patients Undergoing Surgery for Breast Cancer

PURPOSE

Accurate and efficient data collection is a challenge for quality improvement initiatives and clinical research. We describe the development of a custom electronic health record (EHR)–based registry to automatically extract structured Commission on Cancer axillary surgery-specific metrics from a custom synoptic note template included in the operative reports for patients with breast cancer undergoing surgery.

METHODS

The smart functionality of our enterprise-based EHR system was leveraged to create a custom smart phrase to capture axillary surgery-specific variables. A multidisciplinary team developed structured data elements correlating to each axillary surgery-specific variable. These data elements were then included in a note template for the operative report. Each variable could be aggregated and converted into a single flat database through the EHR's reporting workbench and serve as a live, prospective registry for all users within the EHR.

RESULTS

The final axillary surgery-specific note template in a synoptic format allowed for efficient and easy entry and automatic collection of breast cancer–specific metrics. From initial adoption in February 2021-December 2021, there were 1,254 patients who underwent breast surgery with axillary surgery. The operative notes allowed for automatic capture of metrics from 60.5% (n = 759) of patients. Data capture improved from 37.6% in the initial adoption period of 6 months to 86.2% in the last 5 months.

CONCLUSION

We were able to demonstrate successful implementation of provider-driven structured data entry into EHR systems that permits automatic data capture. The end result is a custom synoptic note template and a real-time, prospective registry of breast cancer–specific Commission on Cancer metrics that are robust enough to use for quality improvement initiatives and clinical research.

Comparative Effectiveness Analysis of 3D-Conformal Radiation Therapy Versus Intensity Modulated Radiation Therapy (IMRT) in a Prospective Multicenter Cohort of Patients With Breast Cancer

PURPOSE

Simple intensity modulation of radiation therapy reduces acute toxicity compared with 2-dimensional techniques in adjuvant breast cancer treatment, but it remains unknown whether more complex or inverse-planned intensity modulated radiation therapy (IMRT) offers an advantage over forward-planned, 3-dimensional conformal radiation therapy (3DCRT).

METHODS AND MATERIALS

Using prospective data regarding patients receiving adjuvant whole breast radiation therapy without nodal irradiation at 23 institutions from 2011 to 2018, we compared the incidence of acute toxicity (moderate-severe pain or moist desquamation) in patients receiving 3DCRT versus IMRT (either inverse planned or, if forward-planned, using ≥5 segments per gantry angle). We evaluated associations between technique and toxicity using multivariable models with inverse-probability-of-treatment weighting, adjusting for treatment facility as a random effect.

RESULTS

Of 1185 patients treated with 3DCRT and conventional fractionation, 650 (54.9%) experienced acute toxicity; of 774 treated with highly segmented forward-planned IMRT, 458 (59.2%) did; and of 580 treated with inverse-planned IMRT, 245 (42.2%) did. Of 1296 patients treated with hypofractionation and 3DCRT, 432 (33.3%) experienced acute toxicity; of 709 treated with highly segmented forward-planned IMRT, 227 (32.0%) did; and of 623 treated with inverse-planned IMRT, 164 (26.3%) did. On multivariable analysis with inverse-probability-of-treatment weighting, the odds ratio for acute toxicity after inverse-planned IMRT versus 3DCRT was 0.64 (95% confidence interval, 0.45-0.91) with conventional fractionation and 0.41 (95% confidence interval, 0.26-0.65) with hypofractionation.

CONCLUSIONS

This large, prospective, multicenter comparative effectiveness study found a significant benefit from inverse-planned IMRT compared with 3DCRT in reducing acute toxicity of breast radiation therapy. Future research should identify the dosimetric differences that mediate this association and evaluate cost-effectiveness.

Impact of Social Determinants of Health on Stereotactic Radiotherapy for Vestibular Schwannoma

OBJECTIVES/HYPOTHESIS

Linear accelerator (LINAC) and Gamma Knife (GK) are common stereotactic radiation therapies for treating vestibular schwannoma (VS). There is currently limited literature examining specific demographic and socioeconomic factors, which influence the type of stereotactic radiation therapy a patient with VS receives.

STUDY DESIGN

Retrospective database review.

METHODS

The National Cancer Database was queried for cases of VS between 2004 and 2016. Patient demographic characteristics were compared using chi-squared and t-tests between GK and LINAC treated groups. Multivariate regression analysis was performed to assess predictors of stereotactic radiation therapy received.

RESULTS

Of the 6,208 included patients, 5,306 (85.5%) received GK and 902 (14.5%) received LINAC. The mean age of GK patients was significantly lower than that of LINAC patients (58.0 vs. 59.7, P < .001). Individuals treated with GK had greater proportions of private insurance (P < .001) and incomes greater than $63,332 (P = .003). A greater proportion of GK patients were treated in academic centers (P < .001), in high-volume facilities (P < .001), in metropolitan areas (P < .001), and in the Northeastern United States (P < .001). On multivariate logistic regression analysis, region, metropolitan area, facility type, tumor size, and distance traveled by patients independently predict receipt of GK versus LINAC.

CONCLUSION

Differences in patient demographics and other social determinants of health influence choice of GK versus LINAC therapy for VS patients. Future studies focused on addressing barriers to care, which may influence postprocedural quality of life and clinical outcomes associated with these two treatments are necessary to better understand the impact of these social differences.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Effectiveness and Safety of Oral Anticoagulants Among Nonvalvular Atrial Fibrillation Patients With Active Cancer

Background

Patients with cancer are more likely to develop nonvalvular atrial fibrillation (NVAF). Currently there are no definitive clinical trials or treatment guidelines for NVAF patients with concurrent cancer.

Objectives

This subgroup analysis of the ARISTOPHANES study compared the risk of stroke/systemic embolism (stroke/SE) and major bleeding (MB) among NVAF patients with active cancer who were prescribed non–vitamin K antagonist oral anticoagulants (NOACs) or warfarin.

Methods

A retrospective observational study was conducted in NVAF patients with active cancer who newly initiated apixaban, dabigatran, rivaroxaban, or warfarin from January 1, 2013, through September 30, 2015, with the use of Medicare and 4 U.S. commercial claims databases. Cox models were used to estimate the risk of stroke/SE and MB in the pooled propensity score–matched cohorts.

Results

A total of 40,271 patients were included, with main cancer types of prostate (29%), female breast (17%), genitourinary (14%), and lung (13%). Compared with warfarin, apixaban was associated with a lower risk of stroke/SE (hazard ratio [HR]: 0.59; 95% confidence interval [CI]: 0.45-0.78) and MB (HR: 0.58; 95% CI: 0.50-0.68); dabigatran and rivaroxaban had similar risks of stroke/SE (dabigatran: HR: 0.88 [95% CI: 0.54-1.41]; rivaroxaban: HR: 0.82 [95% CI: 0.62-1.08]) and MB (dabigatran: HR: 0.76 [95% CI: 0.57-1.01]; rivaroxaban: HR: 0.95 [95% CI: 0.85-1.06]). Risks of stroke/SE and MB varied among NOAC-NOAC comparisons, while consistent treatment effects were seen for all treatment comparisons across key cancer types.

Conclusions

Among this cohort of NVAF patients with active cancer, the risk of stroke/SE and MB varied among oral anticoagulants and were consistent across cancer types.

Impact of Treatment Parameters on Racial Survival Differences in Oropharyngeal Cancer: National Cancer Database Study

OBJECTIVE

To investigate how differences in treatment parameters account for survival differences between races of patients with oropharyngeal squamous cell carcinoma (OPSCC).

STUDY DESIGN

Retrospective cohort study.

SETTING

National Cancer Database.

METHODS

Data of patients with OPSCC undergoing radiation therapy (RT) or concurrent chemoradiation therapy as primary treatment were obtained from the National Cancer Database from 2004 to 2016. We analyzed 4 treatment-related time intervals to determine their impact on survival between races when controlling for human papilloma virus (HPV) status. Cox proportional hazards models, stepwise logistic regressions, covariate adjustments, and propensity score matching were performed.

RESULTS

A total of 3152 patients were identified (2877 White, 275 Black). In HPV- cases, Black patients with prolonged radiation duration had a significantly worse overall survival as compared with White patients (hazard ratio, 1.77; 95% CI, 1.03-3.05; P = .039). In a logistic regression model, the only covariate that was significantly associated with prolonged RT was facility type. When further adjusted for facility type, the survival difference between Black and White patients with HPV- status and prolonged RT times was no longer significant (hazard ratio, 1.55; 95% CI, 0.90-2.69; P = .116).

CONCLUSIONS

There is a significant disparity in overall survival between Black and White patients with HPV- OPSCC when RT duration is prolonged. Clinicians should be aware of the negative impact of prolonged RT, especially in Black patients, so that they can attempt to decrease treatment-related time intervals. Facility type was also found to affect the outcomes of patients with OPSCC, and efforts should be made to improve patient access to well-equipped, high-volume facilities.

Socio-economic factors do not affect overall survival in soft tissue sarcoma when patients treated at a single high-volume center

BACKGROUND

Treatments for soft tissue sarcoma (STS) include extensive surgical resection, radiation and chemotherapy, and can necessitate specialized care and excellent social support. Studies have demonstrated that socioeconomic factors, such as income, marital status, urban/rural residence, and educational attainment as well as treatment at high-volume institution may be associated with overall survival (OS) in STS.

METHODS

In order to explore the effect of socio-economic factors on OS in patients treated at a high-volume center, we performed a retrospective analysis of STS patients treated at a single institution.

RESULTS

Overall, 435 patients were included. Thirty-seven percent had grade 3 tumors and 44% had disease larger than 5 cm. Patients were most commonly privately insured (38%), married (67%) and retired or unemployed (43%). Median distance from the treatment center was 42 miles and median area deprivation index (ADI) was 5 (10 representing most deprived communities). The majority of patients (52%) were treated with neoadjuvant therapy followed by resection. As expected, higher tumor grade (HR 3.1), tumor size > 5 cm (HR 1.3), and involved lymph nodes (HR 3.2) were significantly associated with OS on multivariate analysis. Demographic and socioeconomic factors, including sex, age at diagnosis, marital status, employment status, urban vs. rural location, income, education, distance to the treatment center, and ADI were not associated with OS.

CONCLUSIONS

In contrast to prior studies, we did not identify a significant association between socioeconomic factors and OS of patients with STS when patients were treated at a single high-volume center. Treatment at a high volume institution may mitigate the importance of socio-economic factors in the OS of STS.

Contracture Severity at Hospital Discharge in Children: A Burn Model System Database Study

Contractures can complicate burn recovery. There are limited studies examining the prevalence of contractures following burns in pediatrics. This study investigates contracture outcomes by location, injury, severity, length of stay, and developmental stage. Data were obtained from the Burn Model System between 1994 and 2003. All patients younger than the age of 18 with at least one joint contracture at hospital discharge were included. Sixteen areas of impaired movement from the shoulder, elbow, wrist, hand, hip, knee, and ankle joints were examined. Analysis of variance was used to assess the association between contracture severity, burn size, and length of stay. Age groupings were evaluated for developmental patterns. A P value of less than .05 was considered statistically significant. Data from 225 patients yielded 1597 contractures (758 in the hand) with a mean of 7.1 contractures (median 4) per patient. Mean contracture severity ranged from 17% (elbow extension) to 41% (ankle plantarflexion) loss of movement. Statistically significant associations were found between active range of motion loss and burn size, length of stay, and age groupings. The data illustrate quantitative assessment of burn contractures in pediatric patients at discharge in a multicenter database. Size of injury correlates with range of motion loss for many joint motions, reflecting the anticipated morbidity of contracture for pediatric burn survivors. These results serve as a potential reference for range of motion outcomes in the pediatric burn population, which could serve as a comparison for local practices, quality improvement measures, and future research.

Safety of image-guided radiotherapy in definitive radiotherapy for localized prostate cancer: a population-based analysis

Objectives:

Image-guided radiotherapy (IGRT) is a recommended advanced radiation technique that is associated with fewer acute and chronic toxicities. However, one Phase III trial showed worse overall survival in the IGRT arm. The purpose of this observational study is to evaluate the impact of IGRT on overall survival.

Methods:

We used the Taiwan Cancer Registry Database to enroll cT1-4N0M0 prostate cancer patients who received definitive radiotherapy between 2011 and 2015. We used inverse probability treatment weighting (IPW) to construct balanced IGRT and non-IGRT groups. We compared the overall survival of those in the IGRT and non-IGRT groups. Supplementary analyses (SA) were performed with alternative covariates in propensity score (PS) models and PS approaches. The incidence rates of prostate cancer mortality (IPCM), other cancer mortality (IOCM), and cardiovascular mortality (ICVM) were also evaluated.

Results:

There were 360 patients in the IGRT arm and 476 patients in the non-IGRT arm. The median follow-up time was 50 months. The 5-year overall survival was 88% in the IGRT arm and 86% in the non-IGRT arm (adjusted hazard ratio [HR] of death = 0.93; 95% CI, 0.61–1.45; p = 0.77). The SA also showed no significant differences in the overall survival between those in the IGRT and non-IGRT arms. Both groups did not significantly differ in terms of IPCM, IOCM, and ICVM.

Conclusions:

The overall survival of localized prostate cancer patients who underwent IGRT was not inferior to those who did not.

Advances in knowledge:

We demonstrated that the overall survival for prostate cancer patients with IGRT was not worse than those who did not undergo IGRT; this important outcome comparison has not been previously examined in the general population.

Prevalence of Missing Data in the National Cancer Database and Association With Overall Survival

IMPORTANCE

Cancer registries are important real-world data sources consisting of data abstraction from the medical record; however, patients with unknown or missing data are underrepresented in studies that use such data sources.

OBJECTIVE

To assess the prevalence of missing data and its association with overall survival among patients with cancer.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cohort study, all variables within the National Cancer Database were reviewed for missing or unknown values for patients with the 3 most common cancers in the US who received diagnoses from January 1, 2006, to December 31, 2015. The prevalence of patient records with missing data and the association with overall survival were assessed. Data analysis was performed from February to August 2020.

EXPOSURES

Any missing data field within a patient record among 63 variables of interest from more than 130 total variables in the National Cancer Database.

MAIN OUTCOMES AND MEASURES

Prevalence of missing data in the medical records of patients with cancer and associated 2-year overall survival.

RESULTS

A total of 1 198 749 patients with non-small cell lung cancer (mean [SD] age, 68.5 [10.9] years; 628 811 men [52.5%]), 2 120 775 patients with breast cancer (mean [SD] age, 61.0 [13.3] years; 2 101 758 women [99.1%]), and 1 158 635 patients with prostate cancer (mean [SD] age, 65.2 [9.0] years; 100% men) were included in the analysis. Among those with non-small cell lung cancer, 851 295 patients (71.0%) were missing data for variables of interest; 2-year overall survival was 33.2% for patients with missing data and 51.6% for patients with complete data (P < .001). Among those with breast cancer, 1 161 096 patients (54.7%) were missing data for variables of interest; 2-year overall survival was 93.2% for patients with missing data and 93.9% for patients with complete data (P < .001). Among those with prostate cancer, 460 167 patients (39.7%) were missing data for variables of interest; 2-year overall survival was 91.0% for patients with missing data and 95.6% for patients with complete data (P < .001).

CONCLUSIONS AND RELEVANCE

This study found that within a large cancer registry-based real-world data source, there was a high prevalence of missing data that were unable to be ascertained from the medical record. The prevalence of missing data among patients with cancer was associated with heterogeneous differences in overall survival. Improvements in documentation and data quality are necessary to make optimal use of real-world data for clinical advancements.

Effectiveness of image-guided radiotherapy for locally advanced lung cancer patients treated with definitive concurrent chemoradiotherapy

Background

Image‐guided radiotherapy (IGRT) is an advanced radiotherapy technique to improve the precision and accuracy of treatment delivery. A recent randomized controlled trial (RCT) for prostate cancer patients treated with radiotherapy via either IGRT or routine care reported statistically significantly worse overall survival (OS) for those patients treated with IGRT. This raised the concern regarding the effectiveness of IGRT in definitive concurrent chemoradiotherapy (dCCRT) for locally advanced lung cancer (LALC).

Methods

Eligible LALC patients diagnosed between 2011 and 2016 were identified via the Taiwan Cancer Registry. We used propensity score (PS) weighting to balance observable potential confounders between groups. The hazard ratio (HR) of death and other outcomes were compared between IGRT and non‐IGRT. We also evaluated OS in various subgroups.

Results

Our primary analysis consisted of 797 patients in whom covariates were well balanced after PS weighing. The HR for death when IGRT was compared with non‐IGRT was 0.96 (95% confidence interval 0.79–1.15, P = 0.65). There were also no significant differences for most of the other outcomes or subgroup analyses.

Conclusions

In this updated nonrandomized study, we found that OS of LALC patients treated with dCCRT was not statistically different between those treated with IGRT versus non‐IGRT. The results should be interpreted with caution given the nonrandomized design. Studies regarding toxicity, local control, or designed as RCT are needed to clarify the role of IGRT.

Key points

Significant findings of the study

The OS of LALC patients treated with dCCRT was not statistically different between those treated with IGRT versus those without IGRT, although the observed HR for death was less than unity (ie, in favor of IGRT).

What this study adds

In this updated nonrandomized study using real world data with additional potential confounders, our study provided a reasonable tentative evidence in the lack of RCT as suggested in the literature.

Evaluation of the Use of Cancer Registry Data for Comparative Effectiveness Research

Importance

Researchers often analyze cancer registry data to assess for differences in survival among cancer treatments. However, the retrospective, nonrandomized design of these analyses raises questions about study validity.

Objective

To examine the extent to which comparative effectiveness analyses using observational cancer registry data produce results concordant with those of randomized clinical trials.

Design, Setting, and Participants

In this comparative effectiveness study, a total of 141 randomized clinical trials referenced in the National Comprehensive Cancer Network Clinical Practice Guidelines for 8 common solid tumor types were identified. Data on participants within the National Cancer Database (NCDB) diagnosed between 2004 and 2014, matching the eligibility criteria of the randomized clinical trial, were obtained. The present study was conducted from August 1, 2017, to September 10, 2019. The trials included 85 118 patients, and the corresponding NCDB analyses included 1 344 536 patients. Three Cox proportional hazards regression models were used to determine hazard ratios (HRs) for overall survival, including univariable, multivariable, and propensity score-adjusted models. Multivariable and propensity score analyses controlled for potential confounders, including demographic, comorbidity, clinical, treatment, and tumor-related variables.

Main Outcomes and Measures

The main outcome was concordance between the results of randomized clinical trials and observational cancer registry data. Hazard ratios with an NCDB analysis were considered concordant if the NDCB HR fell within the 95% CI of the randomized clinical trial HR. An NCDB analysis was considered concordant if both the NCDB and clinical trial P values for survival were nonsignificant (P ≥ .05) or if they were both significant (P < .05) with survival favoring the same treatment arm in the NCDB and in the randomized clinical trial.

Results

Analyses using the NCDB-produced HRs for survival were concordant with those of 141 randomized clinical trials in 79 univariable analyses (56%), 98 multivariable analyses (70%), and 90 propensity score models (64%). The NCDB analyses produced P values concordant with randomized clinical trials in 58 univariable analyses (41%), 65 multivariable analyses (46%), and 63 propensity score models (45%). No clinical trial characteristics were associated with concordance between NCDB analyses and randomized clinical trials, including disease site, type of clinical intervention, or severity of cancer.

Conclusions and Relevance

The findings of this study suggest that comparative effectiveness research using cancer registry data often produces survival outcomes discordant with those of randomized clinical trial data. These findings may help provide context for clinicians and policy makers interpreting observational comparative effectiveness research in oncology.

Big Data in Cancer Research: Real-World Resources for Precision Oncology to Improve Cancer Care Delivery

In oncology, the term "big data" broadly describes the rapid acquisition and generation of massive amounts of information, typically from population cancer registries, electronic health records, or large-scale genetic sequencing studies. The challenge of using big data in cancer research lies in interdisciplinary collaboration and information processing to unify diverse data sources and provide valid analytics to harness meaningful information. This article provides an overview of how big data approaches can be applied in cancer research, and how they can be used to translate information into new ways to ultimately make informed decisions that improve cancer care and delivery.

Effectiveness of image-guided radiotherapy for locally advanced esophageal squamous cell carcinoma patients treated with definitive concurrent chemoradiotherapy

BACKGROUND

Image-guided radiotherapy (IGRT) is an advanced radiotherapy technique to improve the accuracy of treatment delivery. However, a recent randomized controlled trial (RCT) for prostate cancer patients treated with radiotherapy either via IGRT or routine care (no daily IGRT) reported a statistically significant worse overall survival for those treated with IGRT. This raised the concern regarding the effectiveness of IGRT for definitive concurrent chemoradiotherapy (dCCRT) for locally advanced esophageal squamous cell carcinoma (LA-ESqCC).

METHODS

Eligible LA-ESqCC patients diagnosed between 2011 and 2015 were identified via the Taiwan Cancer Registry. We estimated propensity scores to construct a 1:1 propensity-score-matched groups and balance observable potential confounders. The hazard ratio (HR) of death as well as other outcomes was compared between IGRT and non-IGRT matched groups during the entire follow-up period. The impact of additional covariables was considered in the sensitivity analysis.

RESULTS

Our study population included 590 patients in the primary analysis. The HR for death when IGRT was compared with non-IGRT was 0.92 (95% confidence interval 0.77-1.10, P = 0.35). There were also no significant differences for other outcomes or sensitivity analyses.

CONCLUSIONS

In this updated nonrandomized study using real world data, we found that the overall survival of LA-ESqCC patients treated with dCCRT was not statistically different between those treated with IGRT versus those without IGRT, although the hazard ratio was less than unity, ie, in favor of IGRT. The results should be interpreted with caution given the nonrandomized design and RCTs are needed to clarify our findings.

KEY POINTS

Significant findings of the study: The OS of LA-ESqCC patients treated with dCCRT was not statistically different between those treated with IGRT versus those without IGRT, although the hazard ratio was less than unity, ie, in favor of IGRT.

WHAT THIS STUDY ADDS

In this updated nonrandomized study using real world data with additional potential confounders, our study provided a reasonable tentative evidence of lack of RCT as suggested in the literature.

Impact of the interval between neoadjuvant concurrent chemoradiotherapy and esophagectomy in the modern era: a population-based propensity-score-matched retrospective cohort study in Asia

Background

Neoadjuvant concurrent chemoradiotherapy (nCCRT) is one of the standard-of-care options for locally advanced esophageal squamous cell carcinoma (LA-ESqCC). The optimal interval between nCCRT and esophagectomy is unknown.

Methods

We constructed a propensity-score-matched [1:1 for long (8–12 weeks) vs short (4–7 weeks) intervals] cohort of LA-ESqCC patients who were diagnosed from 2011 to 2015 and treated with nCCRT via the Taiwan Cancer Registry and related databases. We compared the hazard ratios (HRs) of death using a robust variance estimator. We also evaluated alternative covariables, outcomes, and interval definitions.

Results

Our study population included 80 patients for each group; groups were balanced with respect to the observed covariables. There was no significant difference for the HR of death [1.22; 95% confidence interval 0.78–1.91, P = 0.39] when the long interval group was compared to the short interval group. There were also no significant differences when alternative covariables, outcomes, or interval definitions were evaluated.

Conclusions

In this population-based study in modern Asia, we found that for LA-ESqCC patients treated with nCCRT and esophagectomy, overall survival was similar for either long or short intervals between nCCRT and esophagectomy. Randomized controlled trials are needed to verify this finding.

Survival advantage of chemoradiotherapy in anaplastic thyroid carcinoma: Propensity score matched analysis with multiple subgroups

BACKGROUND

We compared overall survival (OS) between radiation therapy (RT) and chemoradiotherapy (CRT) in patients with anaplastic thyroid carcinoma (ATC) using a large database.

METHODS

The National Cancer Data Base was queried for ATC patients diagnosed between 2004 and 2013 who received RT or CRT. Groups were balanced by propensity score matching (PSM) on nine relevant variables. OS was also examined in five paired subgroups given known patient heterogeneity.

RESULTS

Of 858 total patients, 575 received CRT and 283 received RT. CRT was associated with decreased risk of death (hazard ratio [HR] 0.66, P < .001), 1-year OS 25.5% vs 14.3%. A survival advantage to CRT was seen using PSM cohorts (HR 0.75, P = .006). Those receiving definitive surgery saw the greatest benefit to CRT over RT (HR 0.65, P = .009), 1-year OS 39.6% vs 20.4%.

CONCLUSIONS

CRT is associated with decreased risk of death in ATC; the magnitude of CRT vs RT benefit varied by subgroup.

Comparative effectiveness of simultaneous integrated boost vs sequential intensity-modulated radiotherapy for oropharyngeal or hypopharyngeal cancer patients: A population-based propensity score-matched analysis

There were 2 common radiotherapy dose fractionation strategies in head-and-neck cancer patients (such as oropharyngeal cancer [OPC] or hypopharyngeal cancer [HPC]) treated with radiotherapy: intensity-modulated radiotherapy using simultaneous integrated boost (IMRT-SIB) and sequential IMRT (IMRT-SEQ). There is a lack of high-level clinical evidence to compare IMRT-SIB vs IMRT-SEQ specifically for OPC or HPC patients. The present study investigated the survival outcomes of OPC or HPC patients receiving definite concurrent chemoradiotherapy (CCRT) with either IMRT-SIB or IMRT-SEQ via a population-based propensity score (PS)-based analysis.The localized stage OPC or HPC patients diagnosed between 2011 and 2015 were identified based on the Health and Welfare Data Science Center database in Taiwan. These patients received definitive CCRT with either IMRT-SIB or IMRT-SEQ. We constructed a PS-matched cohort (1:1 for IMRT-SIB vs IMRT-SEQ) to balance observable potential confounders. We compared the hazard ratio (HR) of death between IMRT-SIB and IMRT-SEQ during the entire follow-up period. We also evaluated other disease outcome or subgroups.Our study population constituted 200 patients with well balance in observed covariables. The HR of death when IMRT-SIB was compared to IMRT-SEQ was 1.23 (95% confidence interval 0.84-1.80, P = .29). The results were similar for other disease outcome or subgroups.We found the survival outcome might be comparable for those treated with IMRT-SIB vs those treated with IMRT-SEQ.

Development of a Radiation Oncology-Specific Prospective Data Registry for Research and Quality Improvement: A Clinical Workflow-Based Solution

PURPOSE

The computerized paperless medical recording system has transformed the modern health information system and serves as an idea platform for registry development, particularly in a specialty such as radiation oncology, where technologic advances continue to generate unprecedented amounts of complex data. We present our single-institution experience with the development of a real-time observational registry fully integrated into the process of routine clinical workflow and show how this has the potential to transform research and quality assurance.

MATERIALS AND METHODS

From May 2011 to May 2016, physicians prospectively inputted data during the process of routine charting on patients seen in clinic. Using a customized interface established between an in-house registry and a commercially available, hospital-based electronic medical record system (Epic Systems, Verona, WI), a departmentally based parser was created for automatic data deposition, which was also linked to the Aria Treatment Planning Station (Varian Medical Systems, Palo Alto, CA). The total number of data fields embedded per disease site ranged from nine to 73 (median, 21 fields).

RESULTS

A total of 12,341 patients were logged into the registry, of whom 6,911 completed a course of radiation therapy. Primary disease sites were prostate (n = 2,340), breast (n = 2,159), head or neck (n = 1,426), primary CNS (n = 1,338), lung (n = 749), brain metastasis (n = 739), GI (n = 638), gynecologic (n = 534), and other or benign (n = 3,618). A total of 54 independent, investigator-initiated research studies have been initiated using queries supported by the registry from multiple access points, of which 23 were published in peer-reviewed journals.

CONCLUSION

The development of a radiation oncology-specific registry enhanced research efficiency and facilitated quality assurance by producing clear and quality information to guide clinical practice.

Use of Claims Data for Cost and Cost-Effectiveness Research

Administrative claims data are big data generated from healthcare encounters. Claims data contain information on insurance payment as well as clinical diagnoses and procedure codes to ascertain medical conditions and treatments, making them valuable sources for economic evaluation research. This paper offers an introductory overview of the use of claims data for oncology-related cost-of-illness, cost comparison, and cost-effectiveness analyses. We reviewed analytical methods commonly employed in these analyses, such as the phase of care approach and net costing method for cost-of-illness studies, propensity score matching methods for cost comparison studies, and net benefit regression models for cost-effectiveness studies. We used published studies to explain each method and to discuss methodological challenges of conducting economic studies using claims data.

Survival outcomes in patients with gastric and gastroesophageal junction adenocarcinomas treated with perioperative chemotherapy with or without preoperative radiotherapy

BACKGROUND

Perioperative chemotherapy (POC) is one standard approach for the treatment of resectable cancers of the stomach and gastroesophageal junction (GEJ), whereas there has been growing interest in preoperative therapies. The objective of the current study was to compare survival between patients treated with preoperative chemoradiotherapy and adjuvant chemotherapy (PCRT) with those receiving POC using a large database.

METHODS

The National Cancer Data Base was queried for patients diagnosed between 2004 and 2013 with American Joint Committee on Cancer clinical group stage IB to stage IIIC (excluding T2N0 disease) adenocarcinoma of the stomach or GEJ. Patients treated with definitive surgery and POC with or without preoperative radiotherapy of 41 to 54 Gy were included. Overall survival (OS) was defined from the date of definitive surgery and estimated using the Kaplan-Meier method. A total of 14 patient and treatment variables were used for propensity score matching (PSM).

RESULTS

A total of 1048 patients were analyzed: 53.2% received POC and 46.8% received PCRT. The primary tumor site was the GEJ in 69.1% of patients and stomach in 30.9% of patients. The median age of the patients was 60 years, and the median follow-up was 25.8 months. The use of PCRT was associated with a greater pathologic complete response rate of 13.1% versus 8.2% (P = .01). POC was associated with a decreased risk of death in unmatched groups (hazard ratio [HR], 0.83; P = .043). Using PSM cohorts, POC decreased the risk of death with a median OS of 45.1 months versus 31.4 months (HR, 0.70; P = .016). The 2-year OS rate was 72.9% versus 62.5% and the 5-year OS rate was 40.7% versus 33.1% for POC versus PCRT, respectively. Survival favored POC in PSM gastric (HR, 0.41; P = .07) and GEJ (HR, 0.77; P = .08) patient subgroups.

CONCLUSIONS

The addition of preoperative radiotherapy to POC appears to be associated with an increased risk of death in patients with resectable gastric and GEJ cancers.

Strengths and limitations of large databases in lung cancer radiation oncology research

There has been a substantial rise in the utilization of large databases in radiation oncology research. The advantages of these datasets include a large sample size and inclusion of a diverse population of patients in a real-world setting. Such observational studies hold promise in enhancing our understanding of questions for which evidence is conflicting or absent in lung cancer radiotherapy. However, it is critical that investigators understand the strengths and limitations of large databases in order to avoid the common pitfalls that beset observational analyses. This review begins by outlining the data variables available in major registries that are used most often in observational analyses. This is followed by a discussion of the type of radiotherapy-related questions that can be addressed using such datasets, accompanied by examples from the lung cancer literature. Finally, we describe some limitations of observational research and techniques to mitigate bias and confounding. We hope that clinicians and researchers find this review helpful for designing new research studies and interpreting published analyses in the literature.

Use of metrics to quantify IMRT and VMAT treatment plan complexity: A systematic review and perspectives

PURPOSE

Fixed-field intensity modulated radiation therapy (FF-IMRT) or volumetric modulated arc therapy (VMAT) beams complexity is due to fluence fluctuation. Pre-treatment Quality Assurance (PTQA) failure could be linked to it. Several plan complexity metrics (PCM) have been published to quantify this complexity but in a heterogeneous formalism. This review proposes to gather different PCM and to discuss their eventual PTQA failure identifier abilities.

METHODS AND MATERIALS

A systematic literature search and outcome extraction from MEDLINE/PubMed (National Center for Biotechnology Information, NCBI) was performed. First, a list and a synthesis of available PCM is made in a homogeneous formalism. Second, main results relying on the link between PCM and PTQA results but also on other uses are listed.

RESULTS

A total of 163 studies were identified and n = 19 were selected after inclusion and exclusion criteria application. Difference is made between fluence and degree of freedom (DOF)-based PCM. Results about the PCM potential as PTQA failure identifier are described and synthesized. Others uses are also found in quality, big data, machine learning and audit procedure.

CONCLUSIONS

A state of the art is made thanks to this homogeneous PCM classification. For now, PCM should be seen as a planning procedure quality indicator although PTQA failure identifier results are mitigated. However limited clinical use seems possible for some cases. Yet, addressing the general PTQA failure prediction case could be possible with the big data or machine learning help.

Effectiveness of image-guided radiotherapy for rectal cancer patients treated with neoadjuvant concurrent chemoradiotherapy: A population-based propensity score-matched analysis

AIM

The effects of image-guided radiotherapy (IGRT, an advanced RT technology) have been debated in the literature. We compared the outcomes of locally advanced rectal cancer (LARC) patients treated with neoadjuvant concurrent chemoradiotherapy (NCCRT; with vs without IGRT) in a large population-based propensity score (PS)-matched analysis.

METHODS

We identified LARC patients diagnosed between 2007 and 2015 via the Taiwan cancer registry (TCR) and constructed a PS-matched cohort to balance observable potential confounders. Outcomes (R0 resection, overall survival, incidence of local regional recurrence [ILRR], rectal cancer mortality [IRCM], other cancer mortality [IOCM] and cardiovascular mortality [ICVM]) were obtained from TCR and the national death registry. We compared the hazard ratio (HR) of death and other endpoints between IGRT and non-IGRT groups. We performed supplementary analysis (SA) to evaluate the robustness of these results in a subgroup, taking an additional potential confounder into account.

RESULTS

Our study population comprised of 586 patients that were balanced with regard to observed covariables. There was no significant difference in HR for death (0.99; 95% confidence interval 0.70-1.39; P = 0.94) between IGRT and non-IGRT groups. There were also no significant differences in R0 resection, ILRR, IRCM, IOCM or ICVM. The results of our SA were consistent with these findings.

CONCLUSION

For LARC patients treated with NCCRT, the treatment outcome was not significantly different among patients treated with and without IGRT. Further study is needed to clarify these results with consideration to additional potential confounding factors and toxicity profiles at endpoints.

The opportunities and shortcomings of using big data and national databases for sarcoma research

The rarity and heterogeneity of sarcomas make performing appropriately powered studies challenging and magnify the significance of large databases in sarcoma research. Established large tumor registries and population-based databases have become increasingly relevant for answering clinical questions regarding sarcoma incidence, treatment patterns, and outcomes. However, the validity of large databases has been questioned and scrutinized because of the inaccuracy and wide variability of coding practices and the absence of clinically relevant variables. In addition, the utilization of large databases for the study of rare cancers such as sarcoma may be particularly challenging because of the known limitations of administrative data and poor overall data quality. Currently, there are several large national cancer databases, including the Surveillance, Epidemiology, and End Results database, the National Cancer Data Base of the American College of Surgeons and the American Cancer Society, and the National Program of Cancer Registries of the Centers for Disease Control and Prevention. These databases are often used for sarcoma research, but they are limited by their dependence on administrative or billing data, the lack of agreement between chart abstractors on diagnosis codes, and the use of preexisting documented hospital diagnosis codes for tumor registries, which lead to a significant underestimation of sarcomas in large data sets. Current and future initiatives to improve databases and big data applications for sarcoma research include increasing the utilization of sarcoma-specific registries and encouraging national initiatives to expand on real-world, evidence-based data sets.

Survival outcomes by high-risk human papillomavirus status in nonoropharyngeal head and neck squamous cell carcinomas: A propensity-scored analysis of the National Cancer Data Base

BACKGROUND

The prognostic relevance of human papillomavirus (HPV) status in patients with nonoropharyngeal (OPX) squamous cell cancer (SCC) of the head and neck is controversial. In the current study, the authors evaluated the impact of high-risk HPV status on overall survival (OS) in patients with non-OPX SCC using a large database approach.

METHODS

The National Cancer Data Base was queried to identify patients diagnosed from 2004 through 2014 with SCC of the OPX, hypopharynx (HPX), larynx, and oral cavity (OC) with known HPV status. Survival was estimated using Kaplan-Meier methods; distributions were compared using log-rank tests. Propensity score-matching and inverse probability of treatment weighing (IPTW) methods were used; cohorts were matched based on age, sex, Charlson-Deyo score, clinical American Joint Committee on Cancer (AJCC) group stage, treatments received, and anatomic subsite. Propensity analyses were stratified by group stage of disease.

RESULTS

A total of 24,740 patients diagnosed from 2010 through 2013 were analyzed: 1085 patients with HPX, 4804 with laryngeal, 4,018 with OC, and 14,833 with OPX SCC. The percentages of HPV-positive cases by disease site were 17.7% for HPX, 11% for larynx, 10.6% for OC, and 62.9% for OPX. HPV status was found to be prognostic in multiple unadjusted and propensity-adjusted non-OPX populations. HPV positivity was associated with superior OS in patients with HPX SCC with a hazard ratio (HR) of 0.61 (P < .001 by IPTW), in patients with AJCC stage III to IVB laryngeal SCC (HR, 0.79; P = .019 by IPTW), and in patients with AJCC stage III to IVB OC SCC (HR, 0.78; P = .03 by IPTW).

CONCLUSIONS

Positive high-risk HPV status appears to be associated with longer OS in multiple populations of patients with non-OPX head and neck disease (HPX, locally advanced larynx, and OC). If prospectively validated, these findings have implications for risk stratification.

Comparison of Population-Based Observational Studies With Randomized Trials in Oncology

PURPOSE

Comparative efficacy research performed using population registries can be subject to significant bias. There is an absence of objective data demonstrating factors that can sufficiently reduce bias and provide accurate results.

METHODS

MEDLINE was searched from January 2000 to October 2016 for observational studies comparing two treatment regimens for any diagnosis of cancer, using SEER, SEER-Medicare, or the National Cancer Database. Reporting quality and statistical methods were assessed using components of the STROBE criteria. Randomized trials comparing the same treatment regimens were identified. Primary outcome was correlation between survival hazard ratio (HR) estimates provided by the observational studies and randomized trials. Secondary outcomes included agreement between matched pairs and predictors of agreement.

RESULTS

Of 3,657 studies reviewed, 350 treatment comparisons met eligibility criteria and were matched to 121 randomized trials. There was no significant correlation between the HR estimates reported by observational studies and randomized trials (concordance correlation coefficient, 0.083; 95% CI, -0.068 to 0.230). Forty percent of matched studies were in agreement regarding treatment effects (κ, 0.037; 95% CI, -0.027 to 0.1), and 62% of the observational study HRs fell within the 95% CIs of the randomized trials. Cancer type, data source, reporting quality, adjustment for age, stage, or comorbidities, use of propensity weighting, instrumental variable or sensitivity analysis, and well-matched study population did not predict agreement.

CONCLUSION

We were unable to identify any modifiable factor present in population-based observational studies that improved agreement with randomized trials. There was no agreement beyond what is expected by chance, regardless of reporting quality or statistical rigor of the observational study. Future work is needed to identify reliable methods for conducting population-based comparative efficacy research.

Protect us from poor-quality medical research

Much of the published medical research is apparently flawed, cannot be replicated and/or has limited or no utility. This article presents an overview of the current landscape of biomedical research, identifies problems associated with common study designs and considers potential solutions. Randomized clinical trials, observational studies, systematic reviews and meta-analyses are discussed in terms of their inherent limitations and potential ways of improving their conduct, analysis and reporting. The current emphasis on statistical significance needs to be replaced by sound design, transparency and willingness to share data with a clear commitment towards improving the quality and utility of clinical research.

Definitive radiotherapy dose escalation with chemotherapy for treating non-metastatic oesophageal cancer

The locoregional failure rate remains high after concurrent chemoradiotherapy with standard-dose radiotherapy (RT, 50–50.4 Gy) for oesophageal cancer (EC). This retrospective study evaluated whether RT dose escalation was effective among 115 consecutive patients with non-metastatic EC (July 2003 to November 2016). Forty-four patients received an RT dose of <66 Gy and 71 patients received ≥66 Gy, with most patients receiving concurrent cisplatin plus fluorouracil. The median follow-up was 12 months for all patients (52 months for 18 surviving patients). The ≥66 Gy group had significantly higher 3-year rates of overall survival (17.9% vs. 32.1%, p = 0.026) and local progression-free survival (46.1% vs. 72.1%, p = 0.005), but not disease progression-free survival (11.4% vs. 21.9%, p = 0.059) and distant metastasis-free survival (49% vs. 52.6%, p = 0.852). The ≥66 Gy group also had significantly better 5-year overall survival compared with 41.4–65.9 Gy. The only significant difference in treatment-related toxicities involved acute dermatitis (7% vs. 28%, p = 0.009). Inferior overall survival was associated with poor performance status, clinical N2–3 stage and not receiving maintenance chemotherapy. In conclusion, patients with inoperable EC experienced better survival outcomes and acceptable toxicities if they received higher dose RT (≥66 Gy) rather than lower dose RT (<66 Gy).

Comparative effectiveness of concurrent chemoradiotherapy versus EGFR-tyrosine kinase inhibitors for the treatment of clinical stage IIIb lung adenocarcinoma patients with mutant EGFR

BACKGROUND

The standard of care for fit locally advanced non-small cell lung cancer (NSCLC) patients is concurrent chemoradiotherapy (CCRT). However, in a subset of patients with lung adenocarcinoma with mutant EGFR (LA-mEGFR), the role of EGFR-tyrosine kinase inhibitors (TKIs) is not clear. We compared CCRT versus TKIs for the treatment of stage IIIb LA-mEGFR in a Taiwanese population.

METHODS

We identified patients from the Taiwan Cancer Registry with good performance status at clinical stage IIIb LA-mEGFR, diagnosed from June 2011 to December 2015 and treated with either TKIs or CCRT. Clinical covariables and survival status were also collected. The Cox regression method was used in the primary analyses and several propensity score methods and alternative study cohort definitions were used in additional analyses.

RESULTS

We compared the data of 177 TKI and 22 CCRT patients and found no statistically significant difference in overall (adjusted hazard ratio of death 0.71, 95% confidence interval 0.34-1.47) or lung cancer-specific survival (hazard ratio 0.65, 95% confidence interval 0.31-1.35). The results of most additional analyses were insignificant.

CONCLUSION

In this population-based study from Taiwan with limited case numbers, no statistical difference in the survival outcomes of patients with clinical stage IIIb LA-mEGFR treated with either EGFR-TKIs or CCRT was determined. Further prospective studies are needed to clarify our findings.

Neoadjuvant vs definitive concurrent chemoradiotherapy in locally advanced esophageal squamous cell carcinoma patients

Background

The optimal treatment for locally advanced esophageal squamous cell carcinoma remains unclear. We compared the clinical outcomes of neoadjuvant concurrent chemoradiotherapy (CCRT) followed by esophagectomy [the surgery group] and CCRT without surgery [the CCRT group] in patients with squamous cell carcinoma from an Asian population.

Methods

Eligible patients diagnosed from 2008 to 2015 were identified through the Taiwan Cancer Registry. To balance observable potential confounders, we constructed a 1:1 propensity score-matched cohort [surgery vs CCRT]. We compared the hazard ratios between the surgery and CCRT groups for death using a robust variance estimator. We also evaluated the outcomes of patients for freedom from local regional recurrence (FFLRR) and esophageal cancer-specific survival (ECSS). Extensive supplementary analyses were performed to examine the robustness of our findings.

Results

Our study population included 298 patients balanced with respect to the observed covariables. The hazard ratio of death was 0.56 [95% confidence interval 0.42~0.75] when surgery was compared to CCRT. The results remained significant in the FFLRR and ECSS outcomes. In the supplementary analyses, our results also remained significant when additional covariables were taken into consideration or when the definition of the index date was changed.

Conclusions

When compared to definitive CCRT, neoadjuvant CCRT followed by esophagectomy was associated with improved overall survival for locally advanced esophageal squamous cell carcinoma. However, given the nonrandomized nature of the study and the sensitivity to potentially unmeasured confounders, our results should be interpreted cautiously.

Evaluation of classification and regression tree (CART) model in weight loss prediction following head and neck cancer radiation therapy

OBJECTIVE

We explore whether a knowledge-discovery approach building a Classification and Regression Tree (CART) prediction model for weight loss (WL) in head and neck cancer (HNC) patients treated with radiation therapy (RT) is feasible.

METHODS AND MATERIALS

HNC patients from 2007 to 2015 were identified from a prospectively collected database Oncospace. Two prediction models at different time points were developed to predict weight loss ≥5 kg at 3 months post-RT by CART algorithm: (1) during RT planning using patient demographic, delineated dose data, planning target volume-organs at risk shape relationships data and (2) at the end of treatment (EOT) using additional on-treatment toxicities and quality of life data.

RESULTS

Among 391 patients identified, WL predictors during RT planning were International Classification of Diseases diagnosis; dose to masticatory and superior constrictor muscles, larynx, and parotid; and age. At EOT, patient-reported oral intake, diagnosis, N stage, nausea, pain, dose to larynx, parotid, and low-dose planning target volume-larynx distance were significant predictive factors. The area under the curve during RT and EOT was 0.773 and 0.821, respectively.

CONCLUSIONS

We demonstrate the feasibility and potential value of an informatics infrastructure that has facilitated insight into the prediction of WL using the CART algorithm. The prediction accuracy significantly improved with the inclusion of additional treatment-related data and has the potential to be leveraged as a strategy to develop a learning health system.

Factors Predictive of Receiving Adjuvant Radiotherapy in High-Intermediate-Risk Stage I Endometrial Cancer

OBJECTIVES

Randomized trials have shown a local control benefit with adjuvant radiotherapy (RT) in high-intermediate-risk endometrial cancer patients, although not all such patients receive RT. We reviewed the National Cancer Data Base to investigate which patient/tumor-related factors are associated with delivery of adjuvant RT.

METHODS

The National Cancer Data Base was queried for patients diagnosed with International Federation of Gynecology and Obstetrics 2009 stage I endometrioid adenocarcinoma from 1998 to 2012 who underwent surgery +/- adjuvant RT. Exclusion criteria were unknown stage/grade, nonsurgical primary therapy, less than 30 days' follow-up, RT of more than 6 months after surgery, or palliative treatment. High-intermediate risk was defined based on Post Operative Radiation Therapy in Endometrial Carcinoma 2 criteria: older than 60 years with stage IA grade 3 or stage IB grade 1-2.

RESULTS

Seventeen thousand five hundred twenty-four met inclusion criteria, and the 13,651 patients with complete data were subjected to a multiple logistic regression analysis; 7814 (57.2%) received surgery alone, and 5837 (42.8%) received surgery + RT. Receipt of adjuvant RT was more likely among black women and women with higher income, Northeastern residence, diagnosis after 2010, greater than 50% myometrial invasion, and receipt of adjuvant chemotherapy (P < 0.05). Patients older than 80 years or those undergoing lymph node dissection were less likely to receive adjuvant RT (P < 0.05). Of those treated with RT, 44.0% received external beam therapy, 54.8% received vaginal cuff brachytherapy, and 0.6% received both. Among irradiated women, patients older than 80 years and those with Northeastern residence, treatment at academic facilities, diagnosis after 2004, and lymph node dissection were more likely to undergo brachytherapy over external beam radiation therapy (P < 0.05). Overall use of adjuvant RT was 28.8% between 1998 and 2004, 42.0% between 2005 and 2010, and 43.4% between 2011 and 2012; the difference between 1998-2004 and 2005-2010 was not statistically significant.

CONCLUSIONS

Fewer than half of patients with high-intermediate-risk endometrial cancer by Post Operative Radiation Therapy in Endometrial Carcinoma 2 criteria received adjuvant RT despite evidence demonstrating improved local control. Both patient- and tumor-related factors are associated with delivery of adjuvant RT and the modality selected.

Comparative effectiveness of image-guided radiotherapy for non-operated localized esophageal squamous cell carcinoma patients receiving concurrent chemoradiotherapy: A population-based propensity score matched analysis

Background

Although concurrent chemoradiotherapy (CCRT) coupled with image-guided radiotherapy (IGRT) is associated with a theoretical benefit in non-operated localized esophageal squamous cell carcinoma (NOL-ESCC) patients, there is currently no clinical evidence to support this.

Results

The study population in the primary analysis comprised 866 patients who were well balanced in terms of their co-variables. The HR for mortality when group A was compared with group B was 0.82 (95% confidence interval, 0.7–0.95). SA revealed that the result was moderately sensitive.

Materials and Methods

Eligible patients diagnosed between 2008 and 2013 were identified in the Taiwan Cancer Registry. A propensity score-matched cohort was constructed [1:1 in groups A (with IGRT) and B (without IGRT)] to balance any observable potential confounders. The hazard ratio (HR) for mortality was compared between groups A and B during the follow-up period. Sensitivity analyses (SA) were performed to evaluate the robustness of the findings regarding the selection of confounders and a potential unobserved confounder.

Conclusions

The current results provide the first clinical evidence that CCRT coupled with IGRT is associated with better overall survival when compared with CCRT without IGRT in NOL-ESCC patients. However, this study should be interpreted with caution given its non-randomized nature and the moderate sensitivity of the data. Further studies are needed to clarify this finding.

Adjuvant breast radiotherapy: How to trade-off cost and effectiveness?

INTRODUCTION

A series of health economic evaluations (HEE) has analysed the efficiency of new fractionation schedules and techniques for adjuvant breast radiotherapy. This overview assembles the available evidence and evaluates to what extent HEE-results can be compared.

METHODS

Based on a systematic literature review of HEEs from 1/1/2000 to 30/10/2016, all cost comparison (CC) and cost-effectiveness analyses (CEA) comparing different adjuvant breast radiotherapy approaches were analysed. Costs were extracted and converted to Euro 2016 and costs per QALY were summarized in cost-effectiveness planes.

RESULTS

Twenty-four publications are withheld, comparing different fractionation schedules and/or irradiation techniques or evaluating the value of adding radiotherapy. Normofractionation and intensity-modulated, interstitial or intraluminal techniques are important cost-drivers. Highest reimbursements are observed in the US, but may overestimate the real cost. Hypofractionation is cost-effective compared to normofractionation, the results of partial breast irradiation are less unequivocal. Intra-operative and external beam approaches seem the most cost-effective for favourable risk groups, but whole breast irradiation is superior in terms of health effect and omission of radiotherapy in terms of costs.

CONCLUSION

Hypofractionation may be considered the most relevant comparator for new strategies in adjuvant breast radiotherapy, with omission of radiotherapy as an interesting alternative in the very favourable subcategories, especially for partial breast techniques. Although comparison of CC and CEA is hampered by the variability in clinical and economic settings, HEE-based evidence can guide decision-making to tailor-made strategies, allocating the optimal treatment in terms of effectiveness as well as efficiency to the right indication.

A systematic review of health economic evaluation in adjuvant breast radiotherapy: Quality counted by numbers

BACKGROUND

Evolving practice in adjuvant breast radiotherapy inevitably impacts healthcare budgets. This is reflected in a rise of health economic evaluations (HEE) in this domain. The available HEE literature was analysed qualitatively and quantitatively, using available instruments.

METHODS

HEEs published between 1/1/2000 and 31/10/2016 were retrieved through a systematic search in Medline, Cochrane and Embase. A quality-assessment using CHEERS (Consolidated Health Economic Evaluation Reporting Standards) was translated into a quantitative score and compared with Tufts Medical Centre CEA registry and Quality of Health Economic Studies (QHES) results.

RESULTS

Twenty cost-effectiveness analyses (CEA) and thirteen cost comparisons (CC) were analysed. In qualitative evaluation, valuation or justification of data sources, population heterogeneity and discussion on generalizability, in addition to declaration on funding, were often absent or incomplete. After quantification, the average CHEERS-scores were 74% (CI 66.9-81.1%) and 75.6% (CI 70.7-80.5%) for CEAs and CCs respectively. CEA-scores did not differ significantly from Tufts and QHES-scores.

CONCLUSION

Quantitative CHEERS evaluation is feasible and yields comparable results to validated instruments. HEE in adjuvant breast radiotherapy is of acceptable quality, however, further efforts are needed to improve comprehensive reporting of all data, indispensable for assessing relevance, reliability and generalizability of results.

A conceptual framework for evaluating data suitability for observational studies

Objective

To contribute a conceptual framework for evaluating data suitability to satisfy the research needs of observational studies.

Materials and Methods

Suitability considerations were derived from a systematic literature review on researchers’ common data needs in observational studies and a scoping review on frequent clinical database design considerations, and were harmonized to construct a suitability conceptual framework using a bottom-up approach. The relationships among the suitability categories are explored from the perspective of 4 facets of data: intrinsic, contextual, representational, and accessible. A web-based national survey of domain experts was conducted to validate the framework.

Results

Data suitability for observational studies hinges on the following key categories: Explicitness of Policy and Data Governance, Relevance, Availability of Descriptive Metadata and Provenance Documentation, Usability, and Quality. We describe 16 measures and 33 sub-measures. The survey uncovered the relevance of all categories, with a 5-point Likert importance score of 3.9 ± 1.0 for Explicitness of Policy and Data Governance, 4.1 ± 1.0 for Relevance, 3.9 ± 0.9 for Availability of Descriptive Metadata and Provenance Documentation, 4.2 ± 1.0 for Usability, and 4.0 ± 0.9 for Quality.

Conclusions

The suitability framework evaluates a clinical data source’s fitness for research use. Its construction reflects both researchers’ points of view and data custodians’ design features. The feedback from domain experts rated Usability, Relevance, and Quality categories as the most important considerations.

Propensity Score Matched Comparison of Intensity Modulated Radiation Therapy vs Stereotactic Body Radiation Therapy for Localized Prostate Cancer: A Survival Analysis from the National Cancer Database

PURPOSE

No direct comparisons between extreme hypofractionation and conventional fractionation have been reported in randomized trials for the treatment of localized prostate cancer. The goal of this study is to use a propensity score matched (PSM) analysis with the National Cancer Database (NCDB) for the comparison of stereotactic body radiation therapy (SBRT) and intensity modulated radiation therapy (IMRT) for organ confined prostate cancer.

METHODS

Men with localized prostate cancer treated with radiation dose ≥72 Gy for IMRT and ≥35 Gy for SBRT to the prostate only were abstracted from the NCDB. Men treated with previous surgery, brachytherapy, or proton therapy were excluded. Matching was performed to eliminate confounding variables via PSM. Simple 1-1 nearest neighbor matching resulted in a matched sample of 5,430 (2,715 in each group). Subset analyses of men with prostate-specific antigen (PSA) > 10, GS = 7, and GS > 7 yielded matched samples of 1,020, 2,194, and 247, respectively.

RESULTS

No difference in survival was noted between IMRT and SBRT at 8 years (p = 0.65). Subset analyses of higher risk men with PSA > 10 or GS = 7 histology or GS > 7 histology revealed no difference in survival between IMRT and SBRT (p = 0.58, p = 0.68, and p = 0.62, respectively). Variables significant for survival for the matched group included: age (p < 0.0001), primary payor (p = 0.0001), Charlson/Deyo Score (p = 0.0002), PSA (p = 0.0013), Gleason score (p < 0.0001), and use of hormone therapy (p = 0.02).

CONCLUSION

Utilizing the NCDB, there is no difference in survival at 8 years comparing IMRT to SBRT in the treatment of localized prostate cancer. Subset analysis confirmed no difference in survival even for intermediate- and high-risk patients based on Gleason Score and PSA.

Regional Nodal Irradiation After Breast Conserving Surgery for Early HER2-Positive Breast Cancer: Results of a Subanalysis From the ALTTO Trial

Background

Two randomized trials recently demonstrated that regional nodal irradiation (RNI) could reduce the risk of recurrence in early breast cancer; however, these trials were conducted in the pretrastuzumab era. Whether these results are applicable to human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients treated with anti-HER2-targeted therapy is unknown.

Methods

This retrospective analysis was performed on patients with node-positive breast cancer who were enrolled in the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization phase III adjuvant trial and subjected to BCS. The primary objective of the present study was to examine the effect of RNI on disease-free survival (DFS). A multivariable cox regression analysis adjusted for number of positive lymph nodes, tumor size, grade, age, hormone receptors status, presence of macrometastatis, treatment arm, and chemotherapy timing was carried out to investigate the relationship between RNI and DFS.

Results

One thousand six hundred sixty-four HER2-positive breast cancer patients were included, of whom 878 (52.8%) had received RNI to the axillary, supraclavicular, and/or internal mammary lymph nodes. Patients in the RNI group had higher nodal burden and more frequently had tumors larger than 2 cm. At a median follow-up of 4.5 years, DFS was 84.3% in the RNI group and 88.3% in the non-RNI group. No differences in regional recurrence (0.9 % vs 0.6 %) or in overall survival (93.6% vs 95.3%) were observed between the two groups. After adjustment in multivariable analysis, there was no statistically significant association between RNI and DFS (hazard ratio = 0.96, 95% confidence interval = 0.71 to 1.29).

Conclusions

Our analysis did not demonstrate a DFS benefit of RNI in HER2-positive, node-positive patients treated with adjuvant HER2-targeted therapy. The benefit of RNI in HER2-positive breast cancer needs further testing within randomized clinical trials.