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Eugene F. Yen, M.D.

Eugene F. Yen, M.D.

Eugene F. Yen, M.D.

Crohn's Disease, Ulcerative Colitis, Microscopic Colitis
  • Locations

    NorthShore Medical Group

    1000 Central St.
    Suite 615
    Evanston, IL 60201
    847.657.1900 847.733.5041 fax Get Directions This location is wheelchair accessible.

    NorthShore Medical Group

    2150 Pfingsten Rd.
    Suite 3000
    Glenview, IL 60026
    847.657.1900 847.570.5041 fax Get Directions This location is wheelchair accessible.
  • Publications
    • Screening Colonoscopy Withdrawal Time Threshold for Adequate Proximal Serrated Polyp Detection Rate.

      Digestive diseases and sciences 2018 11

      Authors: Patel VD, Thompson WK, Lapin BR, Goldstein JL, Yen EF
      For adequate adenoma detection rate (ADR), guidelines recommend a mean withdrawal time (MWT) of ≥ 6 min. ADR has been shown to correlate strongly with proximal serrated polyp detection rate (PSP-DR), which is another suggested quality measure for screening colonoscopy. However, the impact of directly measured withdrawal time on PSP-DR has not been rigorously studied. We examined the relationship between MWT to ADR and PSP-DR, with the aim of identifying a functional threshold withdrawal time associated with both increased ADR and PSP-DR.
      This was a retrospective study of endoscopy and pathology data from average-risk screening colonoscopy examinations performed at a large system with six endoscopy laboratories. A natural language processing tool was used to determine polyp location and histology. ADR and PSP-DR were calculated for each endoscopist. MWT was calculated from colonoscopy examinations in which no polyps were resected.
      In total, 31,558 colonoscopy examinations were performed, of which 10,196 were average-risk screening colonoscopy examinations with cecal intubation and adequate prep by 24 gastroenterologists. When assessing the statistical significance of increasing MWT by minute, the first significant time mark for PSP-DR was at 11 min at a rate of 14.2% (p = 0.01). There was a significant difference comparing aggregated MWT < 11 min compared to ≥ 11 min looking at the rates of adenomas [OR 1.65 (1.09-2.51)] and proximal serrated polyps [OR 1.81 (1.06-3.08)]. While ADR linearly correlated well with MWT (R = 0.76, p < 0.001), the linear relationship with PSP-DR was less robust (R = 0.42, p = 0.043).
      In this large cohort of average-risk screening colonoscopy, a MWT of 11 min resulted in a statistically significant increase in both ADR and PSP-DR. Our data suggest that a longer withdrawal time may be required to meet both quality metrics.
      PMID: 29974376 [PubMed - as supplied by publisher]
    • Prevalence, Pathogenesis, Diagnosis, and Management of Microscopic Colitis.

      Gut and liver 2018 May 15

      Authors: Gentile N, Yen EF
      Microscopic colitis (MC), which is comprised of lymphocytic colitis and collagenous colitis, is a clinicopathological diagnosis that is commonly encountered in clinical practice during the evaluation and management of chronic diarrhea. With an incidence approaching the incidence of inflammatory bowel disease, physician awareness is necessary, as diagnostic delays result in a poor quality of life and increased health care costs. The physician faces multiple challenges in the diagnosis and management of MC, as these patients frequently relapse after successful treatment. This review article outlines the risk factors associated with MC, the clinical presentation, diagnosis and histologic findings, as well as a proposed treatment algorithm. Prospective studies are required to better understand the natural history and to develop validated histologic endpoints that may be used as end points in future clinical trials and serve to guide patient management.
      PMID: 28669150 [PubMed - as supplied by publisher]
    • The Incidence of Microscopic Colitis: Microscopic No More.

      Digestive diseases and sciences 2017 06

      Authors: Radosevich AJ, Mutyal NN, Eshein A, Nguyen TQ, Gould B, Rogers JD, Goldberg MJ, Bianchi LK, Yen EF, Konda V, Rex DK, Van Dam J, Backman V, Roy HK
      Colorectal cancer remains the second leading cause of cancer deaths in the United States despite being eminently preventable by colonoscopy via removal of premalignant adenomas. In order to more effectively reduce colorectal cancer mortality, improved screening paradigms are needed. Our group pioneered the use of low-coherence enhanced backscattering (LEBS) spectroscopy to detect the presence of adenomas throughout the colon via optical interrogation of the rectal mucosa. In a previous ex vivo biopsy study of 219 patients, LEBS demonstrated excellent diagnostic potential with 89.5% accuracy for advanced adenomas. The objective of the current cross-sectional study is to assess the viability of rectal LEBS in vivo.
      Measurements from 619 patients were taken using a minimally invasive 3.4-mm diameter LEBS probe introduced into the rectum via anoscope or direct insertion, requiring approximately 1 minute from probe insertion to withdrawal. The diagnostic LEBS marker was formed as a logistic regression of the optical reduced scattering coefficient [Formula: see text] and mass density distribution factor D.
      The rectal LEBS marker was significantly altered in patients harboring advanced adenomas and multiple non-advanced adenomas throughout the colon. Blinded and cross-validated test performance characteristics showed 88% sensitivity to advanced adenomas, 71% sensitivity to multiple non-advanced adenomas, and 72% specificity in the validation set.
      We demonstrate the viability of in vivo LEBS measurement of histologically normal rectal mucosa to predict the presence of clinically relevant adenomas throughout the colon. The current work represents the next step in the development of rectal LEBS as a tool for colorectal cancer risk stratification.
      PMID: 28168580 [PubMed - as supplied by publisher]
    • Non-IBD colitides (eosinophilic, microscopic).

      Best practice & research. Clinical gastroenterology 2012 Oct

      Authors: Yen EF, Pardi DS
      Microscopic colitis includes the terms lymphocytic colitis and collagenous colitis, and is a common cause of chronic diarrhoea in older adults. The incidence of microscopic colitis has increased over time and has reached levels comparable to other forms of inflammatory bowel disease. In this chapter, an updated review on the epidemiology, diagnosis and treatment of microscopic colitis has been provided. There is limited data available about eosinophilic colitis, which is the least common of the eosinophilic GI disorders. It is important to rule out the secondary causes of colonic eosinophilia in patients with suspected eosinophilic colitis.
      PMID: 23384806 [PubMed - as supplied by publisher]
    • Current and past cigarette smoking significantly increase risk for microscopic colitis.

      Inflammatory bowel diseases 2012 Oct

      Authors: Yen EF, Pokhrel B, Du H, Nwe S, Bianchi L, Witt B, Hall C
      Cigarette smoking is an important environmental factor affecting inflammatory bowel disease. The role of smoking has not been rigorously studied in microscopic colitis (MC). The aim of this study was to compare the association of cigarette smoking in individuals with MC compared to a control population without MC.
      We reviewed the records of patients with a clinical and histologic diagnosis of collagenous colitis (CC) or lymphocytic colitis (LC). Clinical history, including alcohol and smoking status at the time of diagnosis of MC, were reviewed. In this case-control study, age- and gender-matched patients without diarrhea presenting for outpatient colonoscopy served as the control population.
      We analyzed a total of 340 patients with MC: 124 with CC and 216 with LC. Overall, any smoking status (former or current) was associated with MC (odds ratio [OR] 2.12, 95% confidence interval [CI]: 1.56-2.88). This risk was more prominent in current smokers (adjusted OR 5.36, 3.81, and 4.37 for CC, LC, and all MC, respectively, 95% CI all greater than 1). The association of smoking was not significantly affected by gender or average alcohol consumption.
      In our study population, cigarette smoking is a risk factor for the development of both forms of microscopic colitis. There were no significant differences between LC and CC, and current smoking and the development of microscopic colitis affected men and women similarly. We feel that these data are sufficient to discuss the potential risks of tobacco use in patients with microscopic colitis.
      PMID: 22147506 [PubMed - as supplied by publisher]
    • Decreased colorectal cancer and adenoma risk in patients with microscopic colitis.

      Digestive diseases and sciences 2012 Jan

      Authors: Yen EF, Pokhrel B, Bianchi LK, Roy HK, Du H, Patel A, Hall CR, Witt BL
      Microscopic colitis is currently considered to harbor no increased risk for colorectal cancer, based on a few small studies with limited long-term follow-up. Our aim was to identify patients with microscopic colitis, and to compare long-term rates of colorectal cancer or adenoma to a control group of patients without microscopic colitis.
      We reviewed the records of patients diagnosed with microscopic colitis, as identified by a hospital-based pathology database from January 2000 to August 2008. Clinical factors, including history of adenoma or adenocarcinoma, and all colonoscopy findings, were recorded. Age and gender-matched patients without microscopic colitis served as the control in a 1:1 fashion.
      A total of 647 patients (153 male: 494 female) were identified with microscopic colitis (MC). Any history of colorectal cancer was detected in 1.92, 1.81, and 4.17% of patients with collagenous colitis (CC), lymphocytic colitis (LC), and controls, respectively (P = 0.095, P = 0.040, P = 0.015 for CC, LC, and all MC, respectively, comparing to controls). Overall, covariate-adjusted risk (odds ratio) of any history of colorectal cancer and colorectal adenoma in MC patients was 0.34 (95% confidence interval [CI] 0.16-0.73, P = 0.006) and 0.52 (95% CI 0.50-0.76, P < 0.0001), respectively. The mean duration of follow-up was 4.63 years, with 147/647 (22.7%) of patients with clinical follow-up >7 years.
      In this case-control study involving a large retrospective cohort, microscopic colitis is negatively associated with the risk for colorectal cancer and adenoma. Further studies are required to determine a temporal relationship between microscopic colitis and the future development of colorectal neoplasia.
      PMID: 21847567 [PubMed - as supplied by publisher]
    • Review of the microscopic colitides.

      Current gastroenterology reports 2011 Oct

      Authors: Yen EF, Pardi DS
      Microscopic colitis is a common cause of chronic diarrhea in predominantly older adults. Incidence rates of microscopic colitis (including lymphocytic and collagenous colitis) have increased over time to levels comparable to other forms of inflammatory bowel disease. The possibility of drug-induced microscopic colitis is an important consideration when evaluating these patients, although this concept requires further investigation. There are few controlled treatment trials in microscopic colitis, with much of the data on treatment coming from retrospective studies. In patients with microscopic colitis, a systematic approach to therapy often leads to satisfactory control of symptoms. In this review, we will provide an updated assessment of the epidemiology, diagnosis, and treatment of microscopic colitis.
      PMID: 21773709 [PubMed - as supplied by publisher]
    • Review article: Microscopic colitis--lymphocytic, collagenous and 'mast cell' colitis.

      Alimentary pharmacology & therapeutics 2011 Jul

      Authors: Yen EF, Pardi DS
      Microscopic colitis is a relatively common cause of chronic diarrhoea in predominantly older adults, traditionally termed lymphocytic colitis and collagenous colitis. Increased mast cells found in the colonic biopsies of some patients with chronic diarrhoea may represent a distinct type of microscopic colitis.
      To provide an updated review of the epidemiology, diagnosis and treatment of microscopic colitis, and to discuss the role of mast cells in the gastrointestinal tract and their potential role in cases of functional diarrhoea.
      A MEDLINE literature search was performed to identify pertinent articles. Relevant clinical abstracts were also reviewed.
      Incidence rates of microscopic colitis (lymphocytic and collagenous colitis) have increased over time, to levels comparable with other forms of inflammatory bowel disease. The possibility of drug-induced microscopic colitis and concomitant coeliac sprue are important considerations when evaluating these patients. There are few controlled treatment trials in microscopic colitis, with much of the data on treatment coming from retrospective studies. Mast cells have been implicated in functional bowel disorders, with increased mast cells possibly contributing to cases of otherwise unexplained chronic diarrhoea, although this concept requires further investigation.
      In patients with microscopic colitis, a systematic approach to therapy often leads to satisfactory control of symptoms. The role of mast cells in chronic diarrhoea represents an evolving field, with the potential to offer alternative treatment pathways in patients with otherwise unexplained functional diarrhoea.
      PMID: 21545473 [PubMed - as supplied by publisher]
    • Cost-effectiveness of 5-aminosalicylic acid therapy for maintenance of remission in ulcerative colitis.

      The American journal of gastroenterology 2008 Dec

      Authors: Yen EF, Kane SV, Ladabaum U
      Oral 5-aminosalicylic acid (5-ASA, mesalamine) is effective in inducing and maintaining remission in ulcerative colitis (UC). The relative benefits and costs of maintenance 5-ASA therapy are uncertain. Our aims were to evaluate this strategy's potential cost-effectiveness.
      We constructed a Markov model to compare two strategies over 2 yr: (a) no maintenance 5-ASA, with 5-ASA 4.8 g/day given for flares, (b) maintenance 5-ASA 2.4 g/day, escalated and maintained at 4.8 g/day after the first flare. In both arms, the failure to induce remission led to other treatments, as needed: prednisone, parenteral corticosteroids, cyclosporine, 6-mercaptopurine, infliximab, and colectomy.
      Without maintenance 5-ASA, the mean flares per person were 1.92, and the mean cost per person was $3,402. With maintenance 5-ASA providing a relative risk of flare of 0.7 at 5-ASA cost of $198/month, flares per person decreased to 1.38 at a cost of $8,810/flare prevented. Maintenance 5-ASA increased discounted quality-adjusted life-years per person (QALYs per person) from 1.75 to 1.77 at a discounted cost of $224,000/QALY gained. The results were most sensitive to the flare risk reduction and cost of 5-ASA, the utilities of being in remission without or with 5-ASA, and the colectomy rates. At $15/month (the cost of sulfasalazine), maintenance 5-ASA cost $640/flare prevented and $16,300/QALY gained.
      Maintenance 5-ASA therapy decreases UC flares, but its cost may be substantial, depending on society's willingness to pay. If sulfasalazine can be tolerated and yields comparable benefits, sulfasalazine maintenance therapy is likely to be cost-effective. The cost per QALY gained by 5-ASA maintenance is highly dependent on the quality of life while taking versus not taking maintenance 5-ASA, highlighting the importance of patients' preferences.
      PMID: 18775007 [PubMed - as supplied by publisher]
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