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Elizabeth Handorf, PhD

Elizabeth Handorf, PhD
About

Assistant Professor

Research Program

Education and Training

Educational Background

  • PhD, Biostatistics, University of Pennsylvania, Philadelphia, PA, 2012
  • BSE, Systems Engineering, University of Pennsylvania, Philadelphia, PA, 2005

Memberships

  • International Biometrics Society
  • American Statistical Association

Honors & Awards

  • Student Travel Award, International Conference in Health Policy Statistics, 2011
  • Jonathan Raz Award, 2010
  • GlaxoSmithKline Scholar Award, 2010
Research Profile

Research Program

Research Interests

  • Statistical methods for observational data
  • Cost-effectiveness and comparative effectiveness studies
  • Assessing sensitivity to unmeasured confounding variables
  • Application of methods for analysis of large databases
  • Interventional studies
  • Tissue microarray analysis

Lab Overview

  • Collaborative work with clinicians and scientists

I provide statistical expertise for a wide variety of studies led by Fox Chase Cancer Center investigators, including efficacy analysis of interventions, biomarker analysis and non-therapeutic randomized trials. Often, these studies require advanced statistical analyses or novel applications of existing methods. For example, I have used Classification and Regression Trees (CART) to test biomarker data from tumor microarrays (Beck et al, 2015).  For another study, I used hierarchical clustering and latent class analysis to evaluate quality of survey responses from an anonymous web panel.

  • Development of sensitivity analysis methods for cost and cost-effectiveness data

One major drawback of non-randomized data is that groups of patients with different exposures of interest are often systematically different. Although most secondary data allows us to adjust for basic risk factors, such as gender, age and disease characteristics, it is unlikely that all important variables will be available in an observational dataset. These omitted variables, also called unmeasured confounders, may bias conclusions of study results. I developed a comprehensive framework for evaluating the effect of unmeasured confounders on cost outcomes. (Handorf et al, 2014) The method is flexible, and allows the underlying distribution of the unmeasured confounder to take on many forms, such as skewed continuous (gamma), binary or count distributions. This method allows a researcher to hypothesize a potential confounding variable, based on prior research and clinical expertise, and determine precisely the strength of its effect and the imbalance between arms that would be required to change the inferential meaning of the conclusions. If the required effects are implausible given subject matter knowledge, then the investigator can conclude that the results are robust to unmeasured confounding.

  • Application of methods for observational data to clinically relevant questions

I have conducted many analyses of large datasets based on questions from clinical collaborators, using methods appropriate for the observational nature of the data and the outcome of interest. For example, I analyzed the comparative effectiveness of radiotherapy plus androgen deprivation therapy versus androgen deprivation alone in patients with locally advanced prostate cancer based on SEER-Medicare data. (Bekelman et al, JCO, 2015) Of particular interest was the effect of radiotherapy in older men, as prior randomized studies demonstrated a benefit for younger patients, but these studies excluded older patients. I used propensity scores to balance measured confounders, and also instrumental variable methods and sensitivity analyses to explore the effects of unmeasured confounding. Our results showed that older men receive a benefit from radiation therapy similar to what was found for younger men.

Publications

Selected Publications

Patel D, Handorf E, von Mehren M, Martin L, Movva S. Adjuvant Chemotherapy in Uterine Leiomyosarcoma: Trends and Factors Impacting Usage. Sarcoma, 2019:3561501, 2019. PMC6387708

Esposito AC, Crawford J, Sigurdson ER, Handorf EA, Hayes SB, Boraas M, Bleicher RJ. Omission of radiotherapy after breast conservation surgery in the postneoadjuvant setting. Journal of Surgical Research, 221:49-57, 2018. PMC5729922

Correa AF, Handorf E, Joshi SS, Geynisman DM, Kutikov A, Chen DY, Uzzo RG, Viterbo R, Greenberg RE, Smaldone MC. Differences in Survival Associated with Performance of Lymph Node Dissection in Patients with Invasive Penile Cancer: Results from the National Cancer Database. J Urol, 199(5):1238-44, 2018. PubMed

Esposito AC, Crawford J, Sigurdson ER, Handorf EA, Hayes SB, Boraas M, Bleicher RJ. Omission of radiotherapy after breast conservation surgery in the postneoadjuvant setting. Journal of Surgical Research, 221:49-57, 2018. PMC5729922

Joshi SS, Handorf E, Strauss D, Correa AF, Kutikov A, Chen DYT, Viterbo R, Greenberg RE, Uzzo RG, Smaldone MC, Geynisman DM. Treatment Trends and Outcomes for Patients With Lymph Node-Positive Cancer of the Penis. JAMA Oncol, 2018.

Semenova G, Stepanova DS, Dubyk C, Handorf E, Deyev SM, Lazar AJ, Chernoff J. Targeting group I p21-activated kinases to control malignant peripheral nerve sheath tumor growth and metastasis. Oncogene, 36(38):5421-31, 2017. PMC5608634

Beck TN, Kaczmar J, Handorf E, Nikonova A, Dubyk C, Peri S, Lango M,Ridge JA, Serebriiskii1 IG, Burtness B, Golemis EA, and Mehra R. Phospho-T356RB1 predicts survival in HPV-Negative Squamous Cell Carcinoma of the Head and Neck. Oncotarget. In press. PubMed

Corcoran AT, Handorf E, Canter D, Tomaszewski JJ, Bekelman JE, et al. Variation in performance of candidate surgical quality measures for muscle-invasive bladder cancer by hospital type. BJU Int. 2015 Feb;115(2):230-7. PubMed

Murphy CT, Galloway TJ, Handorf EA, Wang L, Mehra R, et al. Increasing time to treatment initiation for head and neck cancer: An analysis of the National Cancer Database. Cancer. In press. PubMed

Bekelman JE, Mitra N, Handorf EA, Uzzo RG, Hahn SA, et al. Effectiveness of androgen-deprivation therapy and radiotherapy for older men with locally advanced prostate cancer. J Clin Oncol. 2015 Mar 1;33(7):716-22. PubMed

Tomaszewski JJ, Handorf E, Corcoran AT, Wong YN, Mehrazin R, et al. Care transitions between hospitals are associated with treatment delay for patients with muscle invasive bladder cancer. J Urol. 2014 Nov;192(5):1349-54. PubMed

Johnson ME, Handorf EA, Martin JM, Hayes SB. Postmastectomy radiation therapy for T3N0: a SEER analysis. Cancer. 2014 Nov 15;120(22):3569-74. PubMed

Martin JM, Handorf EA, Kutikov A, Uzzo RG, Bekelman JE, et al. The rise and fall of prostate brachytherapy: use of brachytherapy for the treatment of localized prostate cancer in the National Cancer Data Base. Cancer. 2014 Jul 15;120(14):2114-21. PubMed

Handorf EA, Bekelman JE, Heitjan DF, Mitra N. Evaluating costs with unmeasured confounding: A sensitivity analysis for the treatment effect. Ann Appl Stat. 2013;7(4):2062-2080. PubMed

Bekelman JE, Handorf EA, Guzzo T, Evan Pollack C, Christodouleas J, et al. Radical cystectomy versus bladder-preserving therapy for muscle-invasive urothelial carcinoma: examining confounding and misclassification biasin cancer observational comparative effectiveness research. Value Health. 2013 Jun;16(4):610-8. PubMed

Additional Publications

PubMed

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