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Dive into the research topics where William A. Stokes is active.

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Featured researches published by William A. Stokes.


Journal of Clinical Oncology | 2018

Post-Treatment Mortality After Surgery and Stereotactic Body Radiotherapy for Early-Stage Non–Small-Cell Lung Cancer

William A. Stokes; Michael R. Bronsert; Robert A. Meguid; Matthew G. Blum; Bernard L. Jones; Matthew Koshy; David J. Sher; Alexander V. Louie; David A. Palma; Suresh Senan; Laurie E. Gaspar; Brian D. Kavanagh; Chad G. Rusthoven

Purpose In early-stage non-small cell lung cancer (NSCLC), post-treatment mortality may influence the comparative effectiveness of surgery and stereotactic body radiotherapy (SBRT), with implications for shared decision making among high-risk surgical candidates. We analyzed early mortality after these interventions using the National Cancer Database. Patients and Methods We abstracted patients with cT1-T2a, N0, M0 NSCLC diagnosed between 2004 and 2013 undergoing either surgery or SBRT. Thirty-day and 90-day post-treatment mortality rates were calculated and compared using Cox regression and propensity score-matched analyses. Results We identified 76,623 patients who underwent surgery (78% lobectomy, 20% sublobar resection, 2% pneumonectomy) and 8,216 patients who received SBRT. In the unmatched cohort, mortality rates were moderately increased with surgery versus SBRT (30 days, 2.07% v 0.73% [absolute difference (Δ), 1.34%]; P < .001; 90 days, 3.59% v 2.93% [Δ, 0.66%]; P < .001). Among the 27,200 propensity score-matched patients, these differences increased (30 days, 2.41% v 0.79% [Δ, 1.62%]; P < .001; 90 days, 4.23% v 2.82% [Δ, 1.41%]; P < .001). Differences in mortality between surgery and SBRT increased with age, with interaction P < .001 at both 30 days and 90 days (71 to 75 years old: 30-day Δ, 1.87%; 90-day Δ, 2.02%; 76 to 80 years old: 30-day Δ, 2.80%; 90-day Δ, 2.59%; > 80 years old: 30-day Δ, 3.03%; 90-day Δ, 3.67%; all P ≤ .001). Compared with SBRT, surgical mortality rates were higher with increased extent of resection (30-day and 90-day multivariate hazard ratio for mortality: sublobar resection, 2.85 and 1.37; lobectomy, 3.65 and 1.60; pneumonectomy, 14.5 and 5.66; all P < 0.001). Conclusion Differences in 30- and 90-day post-treatment mortality between surgery and SBRT increased as a function of age, with the largest differences in favor of SBRT observed among patients older than 70 years. These representative mortality data may inform shared decision making among patients with early-stage NSCLC who are eligible for both interventions.


Cancer | 2017

A comparison of overall survival for patients with T4 larynx cancer treated with surgical versus organ-preservation approaches: A National Cancer Data Base analysis.

William A. Stokes; Bernard L. Jones; Shilpa Bhatia; Ayman Oweida; Daniel W. Bowles; David Raben; Julie A. Goddard; Jessica D. McDermott; Sana D. Karam

Although laryngectomy is the treatment of choice for patients with T4 larynx cancer, many patients are unable or unwilling to undergo laryngectomy and instead pursue larynx‐preservation strategies combining radiotherapy (RT) and chemotherapy. Herein, the authors analyzed the National Cancer Data Base to evaluate overall survival (OS) between patients treated with surgical and organ‐preserving modalities.


Practical radiation oncology | 2017

Implementation of hypofractionated prostate radiation therapy in the United States: A National Cancer Database analysis

William A. Stokes; Brian D. Kavanagh; David Raben; Thomas J. Pugh

PURPOSE Preclinical and clinical research over the past several decades suggests that hypofractionated (HFxn) radiation therapy schedules produce similar treatment outcomes compared with conventionally fractionated (CFxn) radiation therapy for definitive treatment of localized prostate cancer (PCa). We sought to evaluate national trends and identify factors associated with HFxn utilization using the US National Cancer Database. METHODS AND MATERIALS We queried the National Cancer Database for men diagnosed with localized (N0,M0) PCa from 2004 through 2013 treated with external beam radiation therapy. Patients were grouped by dose per fraction (DpF) in Gray: CFxn was defined as DpF ≤2.0, moderate HFxn as DpF >2.0 but <5.0, and extreme HFxn as DpF ≥5.0. Men receiving DpF <1.5 or >15.0 were excluded, as were those receiving <25 or >90 Gy total dose. Multiple logistic regression was performed to identify demographic, clinical, and treatment factor associations. RESULTS A total of 132,403 men were identified, with 120,055 receiving CFxn, 7264 moderate HFxn, and 5084 extreme HFxn. Although CFxn was by far the most common approach over the analysis period, HFxn use increased from 6.2% in 2004 to 14.2% in 2013 (P < .01). Extreme HFxn use increased the most (from 0.3% to 8.5%), whereas moderate HFxn utilization was unchanged (from 5.9% to 5.7%). HFxn use was independently associated with younger age, later year of diagnosis, non-black race, non-Medicaid insurance, non-Western residence, higher income, academic treatment facility, greater distance from treatment facility, low-risk disease group (by National Comprehensive Cancer Network criteria), and nonreceipt of hormone therapy. CONCLUSIONS Although CFxn remains the most common radiation therapy schedule for localized PCa, use of HFxn appears to be increasing in the United States as a result of increased extreme HFxn use. Financial and logistical factors may accelerate adoption of shorter schedules. Considering the multiple demographic and prognostic differences identified between these groups, randomized outcome data comparing extreme HFxn to alternatives are desirable.


International Journal of Radiation Oncology Biology Physics | 2017

Patterns of Care for Patients With Early-Stage Glottic Cancer Undergoing Definitive Radiation Therapy: A National Cancer Database Analysis

William A. Stokes; Diana Abbott; Andy Phan; David Raben; R.M. Lanning; Sana D. Karam

PURPOSE To characterize practice patterns, including temporal trends, in fractionation schedules among patients in the United States undergoing definitive radiation therapy for early-stage glottic cancer and to compare overall survival outcomes between fractionation schedules. METHODS AND MATERIALS We queried the National Cancer Database for patients with TisN0M0, T1N0M0, or T2N0M0 squamous cell carcinoma of the glottic larynx diagnosed between 2004 and 2012 and undergoing definitive radiation therapy. Dose per fraction was calculated to define cohorts undergoing conventional fractionation (CFxn) and hypofractionation (HFxn). Logistic regression was performed to identify predictors of receiving HFxn, and Cox regression was used to determine predictors of death. One-to-one propensity score matching was then used to compare survival between fractionation schedules. RESULTS The study included 10,539 patients, with 6576 undergoing CFxn and 3963 undergoing HFxn. Patients with T1 disease comprised a majority of each cohort. Use of HFxn increased significantly over the period studied (P<.001), but even in the final year, nearly one-half of patients continued to receive CFxn. Receipt of HFxn was also independently associated with higher income and facility types other than community cancer programs on logistic regression. On multivariate Cox regression, HFxn was associated with improved survival (hazard ratio [HR] for death, 0.90; 95% confidence interval [CI], 0.83-0.97; P=.008), a finding redemonstrated on univariate Cox regression among a well-matched cohort after propensity score matching (HR, 0.88; 95% CI, 0.80-0.96; P=.003). Subgroup Cox multivariate analysis demonstrated a significant survival advantage with HFxn among patients with T1 disease (HR, 0.90; 95% CI, 0.81-0.99; P=.042) but a nonsignificant benefit among those with Tis (HR, 0.86; 95% CI, 0.57-1.30; P=.472) or T2 (HR, 0.88; 95% CI, 0.76-1.02; P=.099) disease. CONCLUSIONS Use of HFxn is increasing and is associated with improved survival over CFxn. Our findings support the broadened use of HFxn for patients with early-stage glottic cancer undergoing definitive radiation therapy.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2017

Survival impact of induction chemotherapy in advanced head and neck cancer: A National Cancer Database analysis

William A. Stokes; Arya Amini; Bernard L. Jones; Jessica D. McDermott; David Raben; Debashis Ghosh; Julie A. Goddard; Daniel W. Bowles; Sana D. Karam

Adding induction chemotherapy to concurrent chemotherapy and radiotherapy (RT) has generally not improved the overall survival (OS) in randomized trials of patients with head and neck cancer. This failure may stem from inadequate power or inappropriate patient selection, prompting this National Cancer Data Base analysis.


Journal of Neuroimmunology | 2017

Impact of immunotherapy among patients with melanoma brain metastases managed with radiotherapy

William A. Stokes; David C. Binder; Bernard L. Jones; Ayman Oweida; Arthur K. Liu; Chad G. Rusthoven; Sana D. Karam

BACKGROUND Patients with melanoma brain metastases (MBM) have been excluded from trials evaluating immunotherapy in melanoma. As such, immunotherapys role in MBM is poorly understood, particularly in combination with radiotherapy. METHODS The National Cancer Database was queried for patients with MBM receiving brain radiotherapy. They were classified according to immunotherapy receipt. Multivariate Cox regression was performed to identify factors associated with survival. RESULTS Among 1287 patients, 185 received immunotherapy. Factors associated with improved survival included younger age, academic facility, lower extracranial disease burden, stereotactic radiotherapy, chemotherapy, and immunotherapy. CONCLUSIONS Adding immunotherapy to radiotherapy for MBM is associated with improved survival.


Oral Oncology | 2017

Patterns of fractionation for patients with T2N0M0 glottic larynx cancer undergoing definitive radiotherapy in the United States

William A. Stokes; Priscilla K. Stumpf; Bernard L. Jones; Patrick J. Blatchford; Sana D. Karam; R.M. Lanning; David Raben

OBJECTIVES Among patients with T2N0M0 glottic larynx cancer undergoing definitive radiotherapy, recent retrospective and prospective data have suggested improved outcomes with altered fractionation over conventional fractionation (CFxn). We sought to characterize national fractionation patterns and to compare outcomes among them. MATERIALS AND METHODS We queried the National Cancer Database for T2N0M0 squamous cell carcinomas of the glottis diagnosed from 2004-2014 and managed with definitive radiotherapy. Dose-per-fraction and duration of radiotherapy were used to define cohorts undergoing CFxn, hypofractionation (HypoFxn), and hyperfractionation (HyperFxn). Logistic regression was performed to identify predictors of receiving altered fractionation. Cox regression and propensity-score matching (PSM) analyses were used to compare survival between schedules. RESULTS We abstracted 2 006 CFxn patients, 1 166 HypoFxn patients, and 161 HyperFxn patients. Fractionation patterns changed significantly from 2004 to 2014, with use of HyperFxn decreasing from 6.3% to 1.8% and use of HypoFxn increasing from 23.9% to 54.1% (p<0.001). Receipt of altered fractionation was independently associated with later year of diagnosis and higher facility volume. On Cox regression, both HypoFxn (hazard ratio [HR] for mortality 0.84, 95% confidence interval [95%CI] 0.73-0.97) and HyperFxn (HR 0.74, 95%CI 0.56-0.99) were associated with improved survival over CFxn. The survival advantage of each altered fractionation schedule over CFxn was redemonstrated on comparison of PSM groups. CONCLUSION Increasing utilization of HypoFxn for T2N0M0 glottic cancer is driving national practice patterns away from CFxn. Our findings support the use of altered fractionation, particularly HypoFxn, for patients undergoing definitive radiotherapy, although HyperFxn remains understudied in a prospective fashion.


Clinical Breast Cancer | 2017

Patterns of Fractionation and Boost Usage in Adjuvant External Beam Radiotherapy for Ductal Carcinoma in Situ in the United States

William A. Stokes; Arya Amini; Matthew W. Jackson; S. Reed Plimpton; Nicole Kounalakis; Peter Kabos; Rachel Rabinovitch; Chad G. Rusthoven; Christine M. Fisher

Micro‐Abstract Among 101,615 American women with ductal carcinoma in situ diagnosed from 2004 through 2014, the use of hypofractionated radiotherapy after surgery increased, while that of boost decreased. However, conventional fractionation with a boost remained the most common strategy used. Both clinical factors, including age and pathologic features, and nonclinical factors, including income, facility type, and facility volume, were associated with these patterns. Background: While the roles of hypofractionated (HFxn) radiotherapy and lumpectomy boost in the adjuvant management of invasive breast cancer are supported by the results of clinical trials, randomized data supporting their use for ductal carcinoma in situ (DCIS) are forthcoming. We sought to evaluate current national trends and identify factors associated with HFxn and boost usage using the National Cancer Database. Patients and Methods: We queried the National Cancer Database for women diagnosed with DCIS from 2004 to 2014 undergoing external beam radiotherapy after breast conservation surgery. Patients were categorized as receiving either conventional fractionation (CFxn) or HFxn and as either receiving or not receiving a boost. Multiple logistic regression was performed to identify demographic, clinical, and treatment factor associations. Results: A total of 101,615 women were identified, with 87,641 (86.2%) receiving CFxn, 13,974 (13.8%) receiving HFxn, and most patients in each group (84.9% and 57.7%, respectively) receiving a boost. Implementation of HFxn increased from 4.3% in 2004 to 33.0% in 2014, and the use of a boost declined from 83.3% to 74.6%. HFxn receipt was independently associated with later year of diagnosis, older age, higher income, greater distance from treatment facility, greater facility volume, academic facility type, Western residence, smaller lesions, and nonreceipt of a boost. Factors associated with boost receipt included earlier year of diagnosis, younger age, higher income, community facility type, adverse pathologic features, and nonreceipt of HFxn. Conclusion: Although CFxn with a boost remains the most common external beam radiotherapy strategy for DCIS, implementation of HFxn without a boost appears to be increasing. Practice patterns at present seem to be driven by guidelines for invasive breast cancer and nonclinical factors.


Oral Oncology | 2018

Survival impact and toxicity of metformin in head and neck cancer: An analysis of the SEER-Medicare dataset

William A. Stokes; Megan Eguchi; Arya Amini; Mohammad Hararah; Ding Ding; Jessica D. McDermott; Cathy J. Bradley; Sana D. Karam

OBJECTIVES Recent preclinical research has renewed interest in the interplay between glucose dysregulation and cancer. Metformin holds promise as an adjunctive antineoplastic agent in head and neck cancer (HNC). We aimed to explore the impact of metformin in HNC patients from a population-based dataset. PATIENTS & METHODS Patients diagnosed with HNC from 2008 to 2011 were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked dataset and categorized into three groups: non-diabetics (nD), diabetics not taking metformin (DnM), and diabetics taking metformin (D + M). Overall survival (OS) and cancer-specific survival (CSS) were compared between groups using Kaplan-Meier and Cox regression controlling for sociodemographic, clinical, and treatment covariates. The incidence of toxicities associated with HNC therapy was compared among groups using χ2 analysis. RESULTS Among 1646 patients, there were 1144 nD, 378 DnM, and 124 D + M. 2-year OS rates was 65.6% for nD, 57.7% for DnM, and 73.4% for D + M by Kaplan-Meier (p < 0.01), and corresponding rates of 2-year CSS were 73.7%, 66.1%, and 88.8% (p < 0.01), respectively. On Cox multivariable analysis, OS among the three groups did not significantly differ; however, CSS was significantly worse among both nD versus DnM as compared to D + M. Toxicity rates were not significantly increased among D + M. CONCLUSION HNC patients with diabetes taking metformin experience improved CSS. Prospective investigation of the addition of metformin to standard-of-care HNC therapy is warranted.


Oral Oncology | 2018

Nomogram for preoperative prediction of nodal extracapsular extension or positive surgical margins in oropharyngeal squamous cell carcinoma

Mohammad Hararah; William A. Stokes; Bernard L. Jones; Ayman Oweida; Ding Ding; Jessica D. McDermott; Julie A. Goddard; Sana D. Karam

INTRODUCTION Extracapsular extension (ECE) in regional lymph nodes and positive surgical margins (PSM) are considered high-risk adverse pathologic features in patients with oropharyngeal squamous cell carcinoma (OPSCC) that each constitute an indication for postoperative adjuvant chemoradiation. We identify pre-operative clinical factors that can predict post-operative ECE and/or PSM and create a nomogram to help clinical decision making. METHODS Adult patients with non-metastatic OPSCC with initial surgical treatment and confirmed HPV status diagnosed between 2010 and 2014 were selected from the National Cancer Database. Clinical staging was modified to American Joint Committee on Cancer 8th edition parameters. Logistic regression was used for multivariate analysis to identify predictors of pathologic ECE and/or PSM. RESULTS 5065 patients were included. 47.5% of the 3336 HPV-positive (HPV+) patients had ECE/PSM. 40.4% of the 1729 HPV-negative (HPV-) patients with had ECE/PSM. A model was built that included age, clinical ECE, tumor grade, and clinical T and N staging for HPV+ patients. Increasing N-classification was highly predictive of pathologic ECE and/or PSM (N1 OR = 3.6, N2 OR = 7.0, N3 OR = 11.2, p < 0.01). Clinical ECE (OR = 4.1, p < 0.01), tumor grade (ORs 2.2-4.4 with p < 0.05), and increasing clinical T-classification (ORs 1.2-1.8, p < 0.05) were also associated with ECE and/or PSM. A similar model was built for HPV- with similar predictive capability. Two internally validated nomograms were designed that demonstrated good discrimination (HPV+ AUC = 0.66, 95% CI: 0.64-0.68, and HPV- AUC = 0.70, 95% CI: 0.67-0.72) and good calibration (goodness-of-fit statistic of HPV+ 6.32, p = 0.61 and HPV- 11.66, p = 0.17). CONCLUSIONS These are the first nomograms designed to help predict ECE or PSM for both HPV+ and HPV- OPSCC. The nomograms can facilitate shared decision-making between clinicians and patients as they consider upfront treatment selection for OPSCC.

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David Raben

University of Colorado Denver

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Arya Amini

University of Colorado Denver

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Jessica D. McDermott

University of Colorado Denver

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Sana D. Karam

University of Colorado Denver

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Bernard L. Jones

University of Colorado Denver

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Chad G. Rusthoven

University of Colorado Denver

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R.M. Lanning

University of Colorado Denver

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Christine M. Fisher

University of Colorado Denver

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S.D. Karam

University of Colorado Boulder

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Brian D. Kavanagh

University of Colorado Denver

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