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Dive into the research topics where John R. Bergquist is active.

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Featured researches published by John R. Bergquist.


Journal of Surgical Oncology | 2016

Implications of CA19-9 elevation for survival, staging, and treatment sequencing in intrahepatic cholangiocarcinoma: A national cohort analysis

John R. Bergquist; Tommy Ivanics; Curtis B. Storlie; Ryan T. Groeschl; May C. Tee; Elizabeth B. Habermann; Rory L. Smoot; Michael L. Kendrick; Michael B. Farnell; Lewis R. Roberts; Gregory J. Gores; David M. Nagorney; Mark J. Truty

Optimal management of patients with intrahepatic cholangiocarcinoma (ICCA) and elevated CA19‐9 remains undefined. We hypothesized CA19‐9 elevation above normal indicates aggressive biology and that inclusion of CA19‐9 would improve staging discrimination.


British Journal of Surgery | 2016

Outcomes with multimodal therapy for elderly patients with rectal cancer.

Cornelius A. Thiels; John R. Bergquist; A. J. Meyers; C. L. Johnson; K. T. Behm; A. V. Hayman; Elizabeth B. Habermann; David W. Larson; Kellie L. Mathis

Treatment guidelines for stage II and III rectal cancer include neoadjuvant chemoradiotherapy, surgery and postoperative adjuvant chemotherapy. Although data support this recommendation in younger patients, it is unclear whether this benefit can be extrapolated to elderly patients (aged 75 years or older).


JAMA Surgery | 2017

Medical Malpractice Lawsuits Involving Surgical Residents

Cornelius A. Thiels; Asad J. Choudhry; Mohamed D. Ray-Zack; Rachel A. Lindor; John R. Bergquist; Elizabeth B. Habermann; Martin D. Zielinski

Importance Medical malpractice litigation against surgical residents is rarely discussed owing to assumed legal doctrine of respondeat superior, or “let the master answer.” Objective To better understand lawsuits targeting surgical trainees to prevent future litigation. Design, Setting, and Participants Westlaw, an online legal research database containing legal records from across the United States, was retrospectively reviewed for malpractice cases involving surgical interns, residents, or fellows from January 1, 2005, to January 1, 2015. Infant-related obstetric and ophthalmologic procedures were excluded. Exposures Involvement in a medical malpractice case. Main Outcomes and Measures Data were collected on patient demographics, case characteristics, and outcomes and were analyzed using descriptive statistics. Results During a 10-year period, 87 malpractice cases involving surgical trainees were identified. A total of 50 patients were female (57%), and 79 were 18 years of age or older (91%), with a median patient age of 44.5 years (interquartile range, 45-56 years). A total of 67 cases (77%) resulted in death or permanent disability. Most cases involved elective surgery (61 [70%]) and named a junior resident as a defendant (24 of 35 [69%]). Cases more often questioned the perioperative medical knowledge, decision making errors, and injuries (53 [61%]: preoperative, 19 of 53 [36%]) and postoperative, 34 of 53 [64%]) than intraoperative errors and injuries (43 [49%]). Junior residents were involved primarily with lawsuits related to medical decision making (21 of 24 [87%]). Residents’ failure to evaluate the patient was cited in 10 cases (12%) and lack of direct supervision by attending physicians was cited in 48 cases (55%). A total of 42 cases (48%) resulted in a jury verdict or settlement in favor of the plaintiff, with a median payout of


Diseases of The Colon & Rectum | 2016

Benefit of Postresection Adjuvant Chemotherapy for Stage III Colon Cancer in Octogenarians: Analysis of the National Cancer Database

John R. Bergquist; Cornelius A. Thiels; Blake A. Spindler; Christopher R. Shubert; Amanda V. Hayman; Scott R. Kelley; David W. Larson; Elizabeth B. Habermann; John H. Pemberton; Kellie L. Mathis

900 000 (range,


Modern Pathology | 2017

Environmental exposures as a risk factor for fibrolamellar carcinoma

Rondell P. Graham; John R Craig; Long Jin; Andre M. Oliveira; John R. Bergquist; Mark J. Truty; Taofic Mounajjed; Patricia T. Greipp; Michael Torbenson

1852 to


Journal of Gastrointestinal Surgery | 2017

Incorporation of CEA Improves Risk Stratification in Stage II Colon Cancer.

Blake A. Spindler; John R. Bergquist; Cornelius A. Thiels; Elizabeth B. Habermann; Scott R. Kelley; David W. Larson; Kellie L. Mathis

32 million). Conclusions and Relevance This review of malpractice cases involving surgical residents highlights the importance of perioperative management, particularly among junior residents, and the importance of appropriate supervision by attending physicians as targets for education on litigation prevention.


International Journal of Surgery | 2018

Adjuvant systemic therapy after resection of node positive gallbladder cancer: Time for a well-designed trial? (Results of a US-national retrospective cohort study)

John R. Bergquist; Harsh N. Shah; Elizabeth B. Habermann; Matthew C. Hernandez; Tommy Ivanics; Michael L. Kendrick; Rory L. Smoot; David M. Nagorney; Mitesh J. Borad; Robert R. McWilliams; Mark J. Truty

BACKGROUND: Clinical trials demonstrate that postresection chemotherapy conveys survival benefit to patients with stage III colon cancer. It is unclear whether this benefit can be extrapolated to the elderly, who are underenrolled in clinical trials. OBJECTIVE: The purpose of this study was to determine outcomes of selected octogenarians with stage III colon cancer with/without postresection adjuvant therapy. DESIGN: This was a retrospective cohort study (2006–2011) using unadjusted Kaplan–Meier and adjusted Cox proportional hazards analyses of overall survival. SETTING: The study was conducted with the National Cancer Database. PATIENTS: We included patients 80 to 89 years of age who were undergoing curative-intent surgery for stage III colon cancer and excluded patients who received neoadjuvant therapy, died within 6 weeks of surgery, or had high comorbidity. MAIN OUTCOME MEASURES: Overall survival was the main measure. RESULTS: A total of 8141 octogenarians were included; 3483 (42.8%) received postresection chemotherapy, and 4658 (57.2%) underwent surgery alone. Patients receiving chemotherapy were younger (82.0 vs 84.0 years; p < 0.001), healthier (73.1% vs 70.4% with no comorbidities; p = 0.009), and more likely to have N2 disease (40.4% vs 32.8%; p < 0.001). Overall survival was improved in patients receiving adjuvant chemotherapy (median = 61.7 vs 35.0 months; p < 0.001). Subgroup analysis of patients offered chemotherapy but refusing (n = 1315) demonstrated overall survival worse than those receiving adjuvant chemotherapy (median = 42.7 vs 61.7 months; p < 0.001). Multivariable analysis adjusting for potential confounders showed therapy with surgery alone to be independently associated with increased mortality hazard (HR = 1.83; p < 0.001), and the mortality hazard remained elevated in patients who voluntarily refused adjuvant therapy (HR = 1.45; p < 0.001). LIMITATIONS: The study was limited by its retrospective, nonrandomized design. CONCLUSIONS: In selected octogenarians with stage III colon cancer, postresection adjuvant chemotherapy was associated with superior overall survival. However, less than half of the octogenarians with stage III colon cancer in the National Cancer Database received it. The remaining majority, who were all fit and survived ≥6 weeks postsurgery, could have derived benefit from adjuvant chemotherapy. This represents a substantial opportunity for quality improvement in treating octogenarians with stage III colon cancer.


Annals of Surgical Oncology | 2017

Incorporation of Treatment Response, Tumor Grade and Receptor Status Improves Staging Quality in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy

John R. Bergquist; Brittany L. Murphy; Curtis B. Storlie; Elizabeth B. Habermann; Judy C. Boughey

Fibrolamellar carcinoma was first described in 1956. Subsequent large studies failed to identify cases before 1939 (the start of the World War II). This finding, combined with the presence of aryl hydrocarbon receptors on the tumor cells, have suggested that fibrolamellar carcinomas may be caused by environmental exposures that are new since World War II. To investigate this possibility, the surgical pathology files before 1939 were reviewed for hepatocellular carcinomas resected in young individuals. Two cases of fibrolamellar carcinoma were identified, from 1915 to 1924. The diagnosis of fibrolamellar carcinoma was confirmed at the histologic, ultrastructural and proteomic levels. These two fibrolamellar carcinoma cases clarify a key aspect of fibrolamellar carcinoma biology, reducing the likelihood that these tumors result exclusively from post World War II environmental exposures.


Pancreas | 2016

Small Cell Carcinoma of the Pancreas: A Surgical Disease

Tommy Ivanics; John R. Bergquist; Christopher R. Shubert; Rory L. Smoot; Elizabeth B. Habermann; Mark J. Truty

High-risk features are used to direct adjuvant therapy for stage II colon cancer. Currently, high-risk features are identified postoperatively, limiting preoperative risk stratification. We hypothesized carcinoembryonic antigen (CEA) can improve preoperative risk stratification for stage II colon cancer. The National Cancer Database (NCDB 2004–2009) was reviewed for stage II colon adenocarcinoma patients undergoing curative intent resection. A novel risk stratification including both traditional high-risk features (T4 lesion, <12 lymph nodes sampled, and poor differentiation) and elevated CEA was developed. Unadjusted Kaplan-Meier and adjusted Cox proportional hazards analyzed overall survival. Concordance Probability Estimates (CPE) assessed discrimination. Seventy-four thousand nine hundred forty-five patients were identified; 40,844 (54.5%) had CEA levels reported and were included. Chemotherapy administration was similar between normal and elevated CEA groups (23.8 vs. 25.1%, p = 0.003). Compared to patients with CEA elevation, 5-year overall survival in patients with normal CEA was improved (74.5 vs. 63.4%, p < 0.001). Restratification incorporating CEA resulted in reclassification of 6912 patients (16.9%) from average to high risk. CPE increased for novel risk stratification (0.634 vs. 0.612, SE = 0.005). The routinely available CEA test improved risk stratification for stage II colon cancer. CEA not only may improve staging of colon cancer but may also help guide additional therapy.


Journal of Surgical Oncology | 2016

Survival following synchronous colon cancer resection.

Cornelius A. Thiels; Nimesh D. Naik; John R. Bergquist; Blake A. Spindler; Elizabeth B. Habermann; Scott R. Kelley; Bruce G. Wolff; Kellie L. Mathis

BACKGROUND Ideal oncologic management of gallbladder carcinoma (GBCA) after complete surgical resection is unclear. We sought to define benefit of post-resection adjuvant systemic chemotherapy alone in T2 or greater gallbladder carcinoma utilising a large national dataset. STUDY DESIGN The National Cancer Data Base (NCDB) 2004-2012 cohort was retrospectively reviewed for patients with GBCA (T2+) undergoing curative-intent resection and surviving at least 6 weeks. Univariate group comparisons, unadjusted Kaplan-Meier and adjusted Cox proportional hazards analyzed overall survival. RESULTS 4373 patients were included (N = 2479 T2, N = 1894 T3/4). Overall, 22.1% of patients received adjuvant chemotherapy. Use of multi-agent chemotherapy increased during the study period. Patients receiving adjuvant therapy were younger, had fewer comorbidities, more often node-positive and more likely R1-margins than those receiving surgery alone. Unadjusted overall survival was improved in all patients with node-positive disease as well as for those with inadequate nodal staging. The benefit of chemotherapy persisted after adjustment for patient and tumor factors. CONCLUSION Adjuvant systemic chemotherapy is associated with survival benefit in patients with T2 or greater GBCA with node positive disease. We recommend a multidisciplinary approach in these patients as less than 1-in-4 of them currently receive adjuvant chemotherapy. Future clinical trials should address adjuvant chemotherapy in node positive GBCA.

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