Picture of Emily Merfeld

Emily Merfeld, MD

Radiation Oncology Resident

Department of Human Oncology


Intern, University of Wisconsin–Madison, (2019)

MD, Washington University School of Medicine, (2018)

BS, University of Iowa, Biology (2014)

Selected Honors and Awards

American Medical Women’s Association Glasgow-Rubin Citation for Academic Achievement Award (2018)

Dr. John Esben Kirk Scholastic Award, Washington University School of Medicine (2018)

Alpha Omega Alpha, Washington University School of Medicine (2017)

Robert Carter Medical School Prize, Washington University School of Medicine (2017)

T35 NIH NHLBI Training Grant (2015)

Presidential Scholarship, University of Iowa (2010-2014)

National Merit Semifinalist (2009)

  • Artificially Enhancing and Suppressing Hippocampus-Mediated Memories. Curr Biol
    Chen BK, Murawski NJ, Cincotta C, McKissick O, Finkelstein A, Hamidi AB, Merfeld E, Doucette E, Grella SL, Shpokayte M, Zaki Y, Fortin A, Ramirez S
    2019 Jun 03; 29 (11): 1885-1894.e4
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      Emerging evidence indicates that distinct hippocampal domains differentially drive cognition and emotion [1, 2]; dorsal regions encode spatial, temporal, and contextual information [3-5], whereas ventral regions regulate stress responses [6], anxiety-related behaviors [7, 8], and emotional states [8-10]. Although previous studies demonstrate that optically manipulating cells in the dorsal hippocampus can drive the behavioral expression of positive and negative memories, it is unknown whether changes in cellular activity in the ventral hippocampus can drive such behaviors [11-14]. Investigating the extent to which distinct hippocampal memories across the longitudinal axis modulate behavior could aid in the understanding of stress-related psychiatric disorders known to affect emotion, memory, and cognition [15]. Here, we asked whether tagging and stimulating cells along the dorsoventral axis of the hippocampus could acutely, chronically, and differentially promote context-specific behaviors. Acute reactivation of both dorsal and ventral hippocampus cells that were previously active during memory formation drove freezing behavior, place avoidance, and place preference. Moreover, chronic stimulation of dorsal or ventral hippocampal fear memories produced a context-specific reduction or enhancement of fear responses, respectively, thus demonstrating bi-directional and context-specific modulation of memories along the longitudinal axis of the hippocampus. Fear memory suppression was associated with a reduction in hippocampal cells active during retrieval, while fear memory enhancement was associated with an increase in basolateral amygdala activity. Together, our data demonstrate that discrete sets of cells throughout the hippocampus provide key nodes sufficient to bi-directionally reprogram both the neural and behavioral expression of memory.

      View details for PubMedID 31130452
  • Predictors of Locoregional Recurrence After Failure to Achieve Pathologic Complete Response to Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer. J Natl Compr Canc Netw
    Gabani P, Merfeld E, Srivastava AJ, Weiner AA, Ochoa LL, Mullen D, Thomas MA, Margenthaler JA, Cyr AE, Peterson LL, Naughton MJ, Ma C, Zoberi I
    2019 04 01; 17 (4): 348-356
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      BACKGROUND: This study evaluated factors predictive of locoregional recurrence (LRR) in women with triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy who do not experience pathologic complete response (pCR).

      METHODS: This is a single-institution retrospective review of women with TNBC treated with neoadjuvant chemotherapy, surgery, and radiation therapy in 2000 through 2013. LRR was estimated between patients with and without pCR using the Kaplan-Meier method. Patient-, tumor-, and treatment-specific factors in patients without pCR were analyzed using the Cox proportional hazards method to evaluate factors predictive of LRR. Log-rank statistics were then used to compare LRR among these risk factors.

      RESULTS: A total of 153 patients with a median follow-up of 48.6 months were included. The 4-year overall survival and LRR were 70% and 15%, respectively, and the 4-year LRR in patients with pCR was 0% versus 22.0% in those without (P<.001). In patients without pCR, lymphovascular space invasion (LVSI; hazard ratio, 3.92; 95% CI, 1.64-9.38; P=.002) and extranodal extension (ENE; hazard ratio, 3.32; 95% CI, 1.35-8.15; P=.009) were significant predictors of LRR in multivariable analysis. In these patients, the 4-year LRR with LVSI was 39.8% versus 15.0% without (P<.001). Similarly, the 4-year LRR was 48.1% with ENE versus 16.1% without (P=.002). In patients without pCR, the presence of both LVSI and ENE were associated with an even further increased risk of LRR compared with patients with either LVSI or ENE alone and those with neither LVSI nor ENE in the residual tumor (P<.001).

      CONCLUSIONS: In patients without pCR, the presence of LVSI and ENE increases the risk of LRR in TNBC. The risk of LRR is compounded when both LVSI and ENE are present in the same patient. Future clinical trials are warranted to lower the risk of LRR in these high-risk patients.

      View details for PubMedID 30959467
  • Wound Complication Rates After Vulvar Excisions for Premalignant Lesions. Obstet Gynecol
    Mullen MM, Merfeld EC, Palisoul ML, Massad LS, Woolfolk C, Powell MA, Mutch DG, Thaker PH, Hagemann AR, Kuroki LM
    2019 04; 133 (4): 658-665
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      OBJECTIVE: To assess the rate of wound complications and evaluate the effectiveness of antibiotic prophylaxis in vulvar wide local excision procedures.

      METHODS: We performed a single-institution, retrospective cohort study of women undergoing vulvar surgery for premalignant lesions between January 2007 and January 2017. The primary outcome was a composite wound complication rate that included breakdown or infection within 8 weeks postoperatively. Data were analyzed using Fisher exact or χ test, Student t-test, and Poisson regression.

      RESULTS: Wound complications occurred in 154 (28.7%) of the 537 patients. Mean age was 52 years; most patients were white (83.1%), cigarette smokers (65.2%), had no prior vulvar treatment (54.4%), and had a preoperative diagnosis of high-grade squamous intraepithelial lesion (vulvar HSIL) (70.0%). The presence of other predisposing factors was similar between groups. In multivariate analysis, smoking (odds ratio [OR] 1.64, 95% CI 1.14-2.38) and primary rather than repeat vulvar surgery (OR 1.99, 95% CI 1.31-3.01) were associated with increased risk for wound complications. There was no significant difference in wound complications between women who received preoperative antibiotics and those who did not (30.4% vs 27.4%, P=.45), although the mean length of wound separation in the antibiotic group was shorter (1 vs 2 cm, P=.03).

      CONCLUSION: Wound complications are common among women undergoing surgery for vulvar HSIL, and interventional trials are warranted to evaluate the role of smoking cessation and prophylactic antibiotics to reduce postoperative morbidity.

      View details for PubMedID 30870300
  • Clinical Outcomes and Prognostic Features of Angiosarcoma: Significance of Prior Radiation Therapy. Clin Oncol (R Coll Radiol)
    Merfeld E, Gabani P, Spraker MB, Zoberi I, Kim H, Van Tine B, Chrisinger J, Michalski JM
    2019 04; 31 (4): 232-241
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      AIMS: Angiosarcoma is a rare and aggressive malignancy with a poor prognosis. There is limited literature describing prognostic factors and guidelines for treatment. We aim to describe outcomes in angiosarcoma, including the impact of patient-, tumour- and treatment-related factors on prognosis.

      MATERIALS AND METHODS: Patients with non-metastatic angiosarcoma diagnosed between 2008 and 2017 were retrospectively reviewed. Univariable and multivariable Cox proportional hazards methods were used to evaluate factors associated with locoregional recurrence, distant failure and overall survival. The Kaplan-Meier method and log-rank statistics were used to compare outcomes among patients with and without a history of prior radiation therapy.

      RESULTS: The cohort included 65 patients. The median age at diagnosis was 68 years (35-93). Nineteen patients had a history of receiving prior radiation therapy at the anatomic location of their angiosarcoma. Treatment modalities included surgery (n = 19), surgery + radiation therapy (n = 12), surgery + chemotherapy (n = 8), chemotherapy + radiation therapy (n = 7) and all three modalities (n = 14). The median follow-up was 18 (2-192) months. The 2-year locoregional control, distant control and overall survival were 61.8, 63.6 and 58.9%, respectively. On multivariable analysis, a history of previous radiation therapy was associated with inferior outcomes with respect to locoregional recurrence (hazard ratio 89.67, 95% confidence interval 8.45-951.07, P < 0.001), distant failure (hazard failure 3.74, 95% confidence interval 1.57-8.91, P = 0.003) and overall survival (hazard ratio 3.89, 95% confidence interval 1.56-9.60, P = 0.003). In patients with primary angiosarcoma, the rates of locoregional control, distant control and overall survival were 72.4, 73.4 and 65.1%, respectively, compared with 31.9, 41.1 and 45.1% in patients with radiation therapy-induced angiosarcoma (P = 0.001).

      CONCLUSION: Angiosarcomas that arise as a result of previous radiation therapy have worse outcomes compared with primary angiosarcomas. Although selection bias and compromise of clinical care in radiation therapy-induced angiosarcoma are partially to blame, differences in genomic profiles of the tumours need to be characterised to evaluate the underlying biological differences, as this may guide future treatment management. This study adds to the existing body of literature on angiosarcoma. Results from the current study are presented alongside previously published data to further characterise outcomes and prognostic factors on this rare and aggressive malignancy.

      View details for PubMedID 30718086
  • Patterns of care and treatment outcomes of patients with astroblastoma: a National Cancer Database analysis. CNS Oncol
    Merfeld EC, Dahiya S, Perkins SM
    2018 04; 7 (2): CNS13
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      AIM: To evaluate the use of chemotherapy and radiation, and their outcomes for patients with astroblastoma.

      PATIENTS & METHODS: This is a retrospective review of patients extracted from the National Cancer Database. We investigated overall survival (OS) using Kaplan-Meier curves. Cox proportional hazards models were used to correlate OS with risk variables and treatments.

      RESULTS: OS at 5 years was 79.5%. Patients with high-grade tumors were more likely to receive chemotherapy and radiation. Patients with high-grade astroblastoma who did not receive adjuvant radiation had poor survival.

      CONCLUSION: Patients with astroblastoma should be treated with curative intent. Radiation is likely beneficial in high-grade astroblastoma. The exact role of radiation and chemotherapy following surgical resection warrant further investigation.

      View details for PubMedID 29708401
  • Neonatal Outcomes Differ after Spontaneous and Indicated Preterm Birth. Am J Perinatol
    Stout MJ, Demaree D, Merfeld E, Tuuli MG, Wambach JA, Cole FS, Cahill AG
    2018 Apr; 35 (5): 494-502
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      OBJECTIVE:  Preterm birth (PTB) at <37 weeks of gestation complicates 10% of pregnancies and requires accurate counseling regarding anticipated neonatal outcomes. PTB classification as spontaneous or indicated is commonly used to cluster PTB into subtypes, but whether neonatal outcomes differ by PTB subtype is unknown. We tested the hypothesis that neonatal morbidity differs based on subtype of PTB.

      METHODS:  We performed a retrospective cohort study of live-born, non-anomalous preterm infants from 2004 to 2008. Spontaneous PTB was defined as PTB from spontaneous preterm labor or preterm rupture of membranes. Indicated PTB was defined as PTB from any maternal or fetal medical complication necessitating delivery. The primary outcome was a composite of early respiratory morbidity. Secondary outcomes included late composite respiratory morbidity and other neonatal morbidities.

      RESULTS:  Of 1,223 preterm neonates, 60.9% were born after spontaneous PTB and 30.1% after indicated PTB. Composite early respiratory morbidity was significantly higher after indicated PTB versus spontaneous PTB (1.3, 95% confidence interval [CI] 1.2-1.4). Composite late respiratory morbidity (1.8, 95% CI 1.3-2.3) and neonatal death (2.8, 95% CI 1.5-5.1) were also significantly higher after indicated PTB versus spontaneous PTB.

      CONCLUSION:  Neonatal respiratory outcomes and death differ according to PTB subtype. PTB subtype should be considered while counseling families and anticipating neonatal outcomes after PTB.

      View details for PubMedID 29183099
  • Potential mechanisms of Zika-linked microcephaly. Wiley Interdiscip Rev Dev Biol
    Merfeld E, Ben-Avi L, Kennon M, Cerveny KL
    2017 07; 6 (4):
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      A recent outbreak of Zika virus (ZIKV) in Brazil is associated with microcephaly in infants born of infected mothers. As this pandemic spreads, rapid scientific investigation is shedding new light on how prenatal infection with ZIKV causes microcephaly. In this analysis we provide an overview of both microcephaly and ZIKV, explore the connection between prenatal ZIKV infection and microcephaly, and highlight recent insights into how prenatal ZIKV infection depletes the pool of neural progenitors in the developing brain. WIREs Dev Biol 2017, 6:e273. doi: 10.1002/wdev.273 For further resources related to this article, please visit the WIREs website.

      View details for PubMedID 28383800
  • Ghrelin alters the stimulatory effect of cocaine on ethanol intake following mesolimbic or systemic administration. Neuropharmacology
    Cepko LC, Selva JA, Merfeld EB, Fimmel AI, Goldberg SA, Currie PJ
    2014 Oct; 85: 224-31
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      Emerging evidence suggests that ghrelinergic and dopaminergic signaling interact in the neural control of motivation and ethanol reward. To further investigate a possible interaction between these two neurochemical systems, we examined the impact of ghrelin, cocaine and combined injections of ghrelin with cocaine, on voluntary ethanol intake. Male Sprague-Dawley rats were habituated to an 8% ethanol solution until intakes stabilized. Rats were then injected with ghrelin (2.5-10 nmol IP), cocaine (0.625-10 mg/kg IP) or ghrelin paired with cocaine. We also examined the impact of direct ghrelin (30-300 pmol) injections into the ventral tegmental area (VTA) co-administered with systemic cocaine. Ethanol consumption was measured at 2 and 6 h postinjection. While ghrelin and cocaine reliably increased ethanol intake, peripheral administration of the peptide elicited a dose-dependent differential effect on cocaine-induced intake. Pretreatment with ghrelin potentiated the effect of cocaine on ethanol intake at a low dose of 2.5 nmol, whereas 10 nmol suppressed cocaine-induced ethanol intake. This same 10 nmol dose was found to induce anxiogenic behavior as measured using an elevated plus maze paradigm. Finally, when injected directly into the VTA, ghrelin (300 pmol) potentiated the effect of systemic cocaine on ethanol intake. Combined subthreshold dosing of VTA ghrelin with a subthreshold dose of cocaine also evoked reliable increases in intake compared to vehicle. Overall, our data suggest that low doses of ghrelin elicit a stimulatory effect on cocaine-induced ethanol consummatory behavior and provide further support for an interactive role of dopaminergic and ghrelinergic transmission in ethanol reward.

      View details for PubMedID 24880084



Contact Information

Emily Merfeld, MD

600 Highland Avenue,
Madison, WI 53792