Gwang-Un Kim

Clinical outcomes of rectal neuroendocrine tumors ≤ 10 mm following endoscopic resection

BACKGROUND AND STUDY AIMS This study was conducted to determine the clinical outcome of rectal neuroendocrine tumors (NETs)≤ 10 mm following conventional endoscopic resection. PATIENTS AND METHODS A total of 107 patients who underwent conventional endoscopic treatment for rectal NETs (median size 5.0 mm [range 1.0-10.0]) were followed up for a median of 31 months (range 13-121). The following data were analyzed: lesion characteristics, clinical outcomes, and histological features determined using tissue microarray analysis (TMA), including the mitotic count and the Ki-67 index. RESULTS En bloc removal was achieved for all tumors, and the complete resection rate was 49.5% (53/107). Resection margin status was indeterminate in 37 patients (34.6%) and positive in 17 (15.9%). Rectal NETs in 71 patients demonstrated a score of ≤2 % on the Ki-67 index and<2 for mitotic count on TMA. In another 28 tumors that did not undergo TMA, the mitotic count was 0-1 per 10 high-power fields. Neither recurrence nor metastasis was noted during the follow-up period following resection. CONCLUSIONS Rectal NETs (≤10 mm in size) appear to demonstrate benign behavior based on the mitotic count and the Ki-67 index. These results suggest that the outcome of rectal NETs (≤10 mm in size) following conventional endoscopic resection might be comparatively excellent, regardless of the resection margin status. However, long term follow-up data are required to confirm this.

Underestimation of Smoking Rates in an East Asian Population with Crohn’s Disease

Background/Aims The reported rates of current smoking at the time of Crohn’s disease (CD) diagnosis tend to be low in East Asian studies. However, we hypothesized that East Asian patients may be reluctant to disclose their smoking history, likely because of the influence of the Confucian culture. Methods We prospectively re-evaluated the smoking status at diagnosis in 1,437 Korean CD patients whose smoking status had been reported in our previous study. Results After re-evaluation, the current smokers at diagnosis increased from 388 patients (27.0%) to 445 patients (31.0%), indicating that 12.8% (57 of 445 patients) of the current smokers at diagnosis did not disclose their smoking status at their initial evaluation. The proportion of current smokers at diagnosis who had initially concealed their smoking status was significantly higher among the female patients (29.7%, 11/37) compared with the male patients (11.3%, 46/408) (p<0.005) and among the patients who were ≤18 years old at diagnosis (56.4%, 22/39) compared with the patients >18 years old at diagnosis (8.6%, 35/406) (p<0.001). Conclusions Subgroups of Korean CD patients, particularly young patients and female patients, are reluctant to disclose their smoking history. Therefore, the suggestion that smoking is not a risk factor for the development of CD in East Asians should be made with caution.

Elevated C-reactive protein level during clinical remission can predict poor outcomes in patients with Crohn’s disease

Intestinal inflammation and mucosal damage in Crohn’s disease (CD) are believed to progress even during clinical remission. We investigated the long-term prognosis of CD patients in clinical remission according to serum C-reactive protein (CRP) levels. This study included 339 CD patients in clinical remission (Crohn’s disease activity index < 150) for more than 6 months between January 2008 and December 2010. Clinical outcomes were compared between patients with normal and elevated CRP levels during clinical remission. During clinical remission, 150 patients had normal CRP consistently and 189 had elevated CRP at least once. During follow-up (median, 7.9 years [interquartile range, 6.8–8.0]), the Kaplan–Meier analysis with the log-rank test showed that normal CRP group had a longer CD-related hospitalization-free survival (P = 0.007) and a longer CD-related intestinal resection-free survival (P = 0.046) than elevated CRP group. In multivariate analysis, elevated CRP was significantly and independently associated with an increased risk of subsequent CD-related hospitalization (adjusted hazard ratio [aHR] 1.787, 95% confidence interval [CI]: 1.245–2.565, P = 0.002) and of subsequent CD-related intestinal resection (aHR 1.726, 95% CI: 1.003–2.969, P = 0.049). The most common reason for CD-related hospitalization was penetrating complications (35.6%). Even when CD patients are in clinical remission, elevated CRP is significantly associated with subsequent CD-related hospitalization and CD-related intestinal resection during follow-up. CD patients in clinical remission but elevated CRP should receive more careful attention and timely interventions to improve long-term outcomes.

Clinical correlations of infliximab trough levels and antibodies to infliximab in South Korean patients with Crohn’s disease

AIM To investigate the clinical implications of infliximab trough levels (IFX-TLs) and antibodies to infliximab (ATI) levels in Crohn’s disease (CD) patients in Asian countries. METHODS IFX-TL and ATI level were measured using prospectively collected samples obtained with informed consent from CD patients being treated at Asan Medical Center, South Korea. We analyzed the correlations between IFX-TLs/ATI levels and the clinical activity of CD (quiescent vs active disease) based on the CD activity index, C-reactive protein level, and physician’s judgment of patients’ clinical status at enrollment. The impact of concomitant immunomodulators was also investigated. RESULTS This study enrolled 138 patients with CD (84 with quiescent and 54 with active disease). In patients with quiescent and active diseases, the median IFX-TLs were 1.423 μg/mL and 0.163 μg/mL, respectively (P < 0.001) and the median ATI levels were 8.064 AU/mL and 11.209 AU/mL, respectively (P < 0.001). In the ATI-negative and -positive groups, the median IFX-TLs were 1.415 μg/mL and 0.141 μg/mL, respectively (P < 0.001). In patients with and without concomitant immunomodulator use, there were no differences in IFX-TLs (0.632 μg/mL and 1.150 μg/mL, respectively; P = 0.274) or ATI levels (8.655 AU/mL and 9.017 AU/mL, respectively; P = 0.083). CONCLUSION IFX-TL/ATI levels were well correlated with the clinical activity in South Korean CD patients. Our findings support the usefulness of IFX-TLs/ATI levels in treating CD patients receiving IFX in clinical practice.

Overall and Cause-specific Mortality in Korean Patients with Inflammatory Bowel Disease: A Hospital-based Cohort Study.

Limited data are available regarding mortality from inflammatory bowel disease in non‐Caucasian populations. Herein, we evaluated overall and cause‐specific mortality in a hospital‐based cohort of Korean inflammatory bowel disease patients.

Association between the ulcer status and the risk of delayed bleeding after the endoscopic mucosal resection of colon

Bleeding is the most common adverse event following colonoscopic endoscopic mucosal resection (EMR). We aimed to assess the clinical outcomes of a colon EMR according to the post‐EMR ulcer status and determine the risk factors of delayed postpolypectomy bleeding (DPPB) based on the post‐EMR ulcer status.

Assessment of factors associated with smoking cessation at diagnosis or during follow‐up of Crohn's disease

Smoking cessation is known to improve the course of Crohns disease (CD). However, the factors associated with smoking cessation after CD diagnosis have not been well established.

Early anti-TNF/immunomodulator therapy is associated with better long-term clinical outcomes in Asian patients with Crohn’s disease with poor prognostic factors

Although early treatment of Crohn’s disease (CD) patients with anti-tumor necrosis factor (TNF) agents or immunomodulators (IMs) may improve long-term outcomes, especially those with poor prognostic factors, their effectiveness in Asians remains unclear. In this study, Korean patients with CD naïve to both intestinal surgery and intestinal complications, and with at least two risk factors for progression (diagnosis at age <40 years, systemic corticosteroid treatment <3 months after diagnosis, and perianal fistula at diagnosis) were retrospectively analyzed. Patients were classified into those who started anti-TNFs, or IMs but not anti-TNFs, within 2 years of diagnosis, and those who started anti-TNFs and/or IMs later. Their probabilities of intestinal surgery and intestinal complications were compared. A total of 670 patients were enrolled, 79 in the early anti-TNF, 286 in the early IM, and 305 in the late treatment group. Kaplan-Meier analysis with the log-rank test showed that from starting anti-TNFs/IMs, times to intestinal surgery (P < 0.001), stricturing complications (P = 0.002), and penetrating complications (P < 0.001) were significantly longer in the early anti-TNF/IM groups than in the late treatment group. Multivariate Cox regression analysis showed that, from starting anti-TNFs/IMs, late anti-TNF/IM treatment was independently associated with higher risks of intestinal surgery (adjusted hazard ratio [aHR] 2.321, 95% confidence interval [CI] 1.503–3.584, P < 0.001), behavioral progression (aHR 2.001, 95% CI 1.449–2.763, P < 0.001), stricturing complications (aHR 1.736, 95% CI 1.209–2.493, P = 0.003), and penetrating complications (aHR 3.315, 95% CI 2.094–5.249, P < 0.001) than early treatment. In conclusion, treatment of Asian CD patients having poor prognostic factors with anti-TNFs/IMs within 2 years of diagnosis is associated with better clinical outcomes than later treatment.

Long-term outcomes of infliximab treatment and predictors of response in 195 patients with ulcerative colitis: a hospital-based cohort study from Korea

Abstract Background: Large-scale studies regarding the long-term efficacy of infliximab (IFX) treatment in non-Caucasian patients with ulcerative colitis (UC) are lacking. Study: We analyzed the long-term outcomes of IFX in 195 Korean UC patients who received scheduled IFX treatments at Asan Medical Center. IFX failure was defined as IFX discontinuation due to colectomy or non-response to IFX, and additionally UC-related hospitalization or a need for rescue corticosteroids during the course of IFX. Results: Between December 2006 and October 2016, a total of 3101 infusions of IFX were administered to 195 patients over a median period of 21 months. At the end of the follow-up, 86 patients (44.1%) were still receiving IFX without failure. IFX was stopped in 73 (37.4%) patients due to colectomy (23 patients, 11.8%), non-response to IFX (35 patients, 17.9%) or other reasons such as adverse events or patients’ preferences (15 patients, 7.7%). An additional 36 (18.5%) patients experienced IFX failure during follow-up due to a need for rescue corticosteroids (13 patients, 6.7%), UC-related hospitalization (8 patients, 4.1%), or both (15 patients, 7.7%). The survival free of IFX failure was 58.1% at 1 year, 50.7% at 3 years and 44.8% at 5 years. In a multivariate regression analysis, cytomegalovirus colitis within 3 months before IFX initiation was a predictor of IFX failure (hazard ratio 1.57; 95% confidence interval 1.04–2.37; p = .032). Conclusions: The long-term efficacy of IFX in a large, real-life cohort of Korean UC patients appears to be comparable to that in previously published Western studies.