Won Kon Han
Sungkyunkwan University
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Featured researches published by Won Kon Han.
Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 2003
Yong Lai Park; Won Kon Han; Won Gil Bae
Neck surgery is one of the newest fields of endoscopic surgical application. One hundred patients underwent endoscopic thyroidectomy. We used 3 incisions: 1 on both upper circumareolar areas and 1 approximately 3 cm below the clavicle on the tumor side. Subplatysmal and subcutaneous operative space was created with CO2 insufflation at 6 mm Hg of pressure. The thyroidal vessels and the parenchyma of the gland were dissected and divided with ultrasonic scalpel and commonly used laparoscopic instruments. The mean (±SD) operation time was 136 ± 10 minutes before the year 2000 and 67 ± 9 in the year 2000 (P < 0.05). There were six cases of conversion to conventional thyroidectomy. Postoperative complications occurred in five cases. There was no subcutaneous emphysema. The patients were satisfied with the cosmetic result. On the basis of our experience with these 100 patients, we believe that endoscopic thyroidectomy is feasible and safe for resection of thyroid tumors. Thus, this procedure will provide another surgical technique for treatment of thyroid tumors, with maximized cosmetic effect.
International Journal of Colorectal Disease | 2007
Dong Il Park; Mun Su Kang; Suk Joong Oh; Hong Joo Kim; Yong Kyun Cho; Chong Il Sohn; Woo Kyu Jeon; Byung Ik Kim; Won Kon Han; Hungdai Kim; Seung Ho Ryu; Antonia R. Sepulveda
Background and aimsThe HER-2/neu protein is intimately involved with normal cell proliferation and tissue growth, as it is extensively homologous and is related to the epidermal growth factor receptor. This phenomenon has been most intensively studied in the context of breast carcinoma, in which its amplification and overexpression correlate with the overall course of disease and poor prognoses, and also constitute a predictive factor of poor response to chemotherapy and endocrine therapy. In this study, we investigated the relationships between the expression of HER-2/neu and the clinicopathological characteristics of colorectal cancer, including survival. This study was performed with a view toward the future introduction of Herceptin therapy for colorectal cancer patients.Patients and methodsHER-2/neu overexpression and gene amplification were examined via semiquantitative standardized immunohistochemical staining and fluorescence in situ hybridization (FISH) in 137 colorectal cancer patients who underwent curative surgery at the Kangbuk Samsung Hospital.ResultsSixty-five (47.4%) out of 137 patients were determined by immunohistochemistry to have overexpressed HER-2/neu protein. HER-2/neu gene amplification was detected in two patients by FISH. Tumors with HER-2/neu overexpression showed higher postoperative recurrence rate (39.3% vs 14.6%, p=0.013). Tumors with HER-2/neu overexpression were associated with poor 3-year (70.8% vs 83.7%) and 5-year survival rates (55.1% vs 78.3%, p<0.05). Advanced TNM stage, postoperative recurrence, and overexpression of HER-2/neu were found to be independently related to survival by multivariate analysis.ConclusionHER-2/neu overexpression may constitute an independent prognostic factor in colorectal cancer patients, and patients exhibiting HER-2/neu overexpression might constitute potential candidates for a new adjuvant therapy which involves the use of humanized monoclonal antibodies.
European Journal of Surgery | 2002
Chang Hak Yoo; Byung Ho Son; Won Kon Han; Won Kil Pae
OBJECTIVE To assess the need for routine nasogastric decompression after extensive resections in patients with gastric cancer. DESIGN Prospective randomised study. SETTING University hospital, Korea. SUBJECTS Over a 1-year period (July 1999-July 200), 136 patients with gastric cancer who underwent radical gastrectomy with D2 or more lymph node dissection. INTERVENTIONS Randomised to have nasogastric decompression (n = 69) or not (n = 67). MAIN OUTCOME MEASURES Postoperative course, morbidity, and mortality. RESULTS Time to passage of first flatus, time to taking liquid diet, length of operation, and postoperative hospital stay were all significantly shorter in the no decompression group. Two patients in each group required subsequent nasogastric decompression. There were no significant differences between the two groups concerning the presence of postoperative fever, nausea, vomiting, anastomotic leaks, or pulmonary or wound complications. No patients died. CONCLUSIONS Routine nasogastric decompression is not necessary in elective operations for gastric cancer.
World Journal of Surgery | 2005
Chang Hak Yoo; Byung Ho Sohn; Won Kon Han; Won Kil Pae
Proximal gastrectomy with jejunal pouch interposition (PGJP) has been advocated as an alternative operation for upper third gastric cancer. However, there has been no prospective randomized trial comparing PGJP with total gastrectomy with Roux-en-Y esophagojejunostomy (TGRY). The aim of this study was to compare the short- and medium-term results of PGJP and TGRY in a randomized clinical trial. Fifty-one patients with upper third gastric cancer were randomized to either PGJP (n = 25) or TGRY (n = 26). Outcome measures were postoperative complications, nutritional status assessed by serum nutritional parameters, and postgastrectomy symptoms. There were no significant differences in operating time, hospital stay, and postoperative complications. Blood loss was significantly less in the PGJP group (P = 0.036). Nineteen patients (73%) in the TGRY group had one or more postgastrectomy symptoms, which was significantly more frequent than in the PGJP group (32%; P = 0.012). There were also significant differences between the two groups with regard to food intake, weight recovery, hemoglobin, and serum vitamin B12 levels in favor of PGJP. In conclusion, proximal gastrectomy with jejunal pouch interposition for upper third gastric cancer is safe, and is associated with a greater reduction in postgastrectomy symptoms and better nutritional status compared with conventional total gastrectomy.
Cancer Research and Treatment | 2004
Chang Hak Yoo; Byung Ho Sohn; Won Kon Han; Won Kil Pae
PURPOSE The choice of surgical strategy for patients with adenocarcinoma of the upper one third of the stomach is controversial. This study was performed to analyze the surgical results of a 11-year experience with these lesions. MATERIALS AND METHODS From January 1990 to December 2000, 259 patients with upper third gastric cancer underwent proximal gastrectomy (n=74) or total gastrectomy (n=185) through an abdominal approach. Morbidity, mortality, recurrence patterns, and survival were compared between these two groups retrospectively. RESULTS There were no significant differences in general complication and mortality rates between the two groups. However, the incidences of reflux esophagitis (16.2%) and anastomotic stricture (35.1%) were more common in the proximal gastrectomy group compared with the total gastrectomy group (0.5 and 8.1%). Regarding the main patterns of recurrence, local recurrence was dominant in the proximal gastrectomy group, whereas distant recurrence was dominant in the total gastrectomy group. Five-year overall survival (54.8 versus 47.8%) and survival according to tumor stage were no different between the groups. Multivariate analysis showed that the extent of resection was not an independent prognostic factor. CONCLUSION The extent of resection for upper third gastric cancer did not appear to affect long-term outcome. However, proximal gastrectomy is associated with an increased risk of reflux esophagitis, anastomotic stricture, and local recurrence.
The Journal of Clinical Endocrinology and Metabolism | 2014
Yiyi Zhang; Yoosoo Chang; Seungho Ryu; Juhee Cho; Won Young Lee; Eun-Jung Rhee; Min Jung Kwon; Roberto Pastor-Barriuso; Sanjay Rampal; Won Kon Han; Hocheol Shin; Eliseo Guallar
CONTEXT Hyperthyroidism and hypothyroidism, both overt and subclinical, are associated with all-cause and cardiovascular mortality. The association between thyroid hormones and mortality in euthyroid individuals, however, is unclear. OBJECTIVE To examine the prospective association between thyroid hormones levels within normal ranges and mortality endpoints. SETTING AND DESIGN A prospective cohort study of 212 456 middle-aged South Korean men and women who had normal thyroid hormone levels and no history of thyroid disease at baseline from January 1, 2002 to December 31, 2009. Free T4 (FT4), free T3 (FT3), and TSH levels were measured by RIA. Vital status and cause of death ascertainment were based on linkage to the National Death Index death certificate records. RESULTS After a median follow-up of 4.3 years, 730 participants died (335 deaths from cancer and 112 cardiovascular-related deaths). FT4 was inversely associated with all-cause mortality (HR = 0.77, 95% confidence interval 0.63-0.95, comparing the highest vs lowest quartile of FT4; P for linear trend = .01), and FT3 was inversely associated cancer mortality (HR = 0.62, 95% confidence interval 0.45-0.85; P for linear trend = .001). TSH was not associated with mortality endpoints. CONCLUSIONS In a large cohort of euthyroid men and women, FT4 and FT3 levels within the normal range were inversely associated with the risk of all-cause mortality and cancer mortality, particularly liver cancer mortality.
Cancer Research and Treatment | 2004
Gun Ick Hwang; Chang Hak Yoo; Byung Ho Sohn; Jun Ho Shin; Yong Lai Park; Heung Dai Kim; Yong Shin Kim; Won Kon Han; Won Kil Pae
PURPOSE Peritoneal metastasis is a crucial factor for the prognosis in gastric cancer, but its diagnosis is difficult before laparotomy. This study analyzed the usefulness of diagnostic imaging and various tumor markers in the detection of peritoneal metastasis in gastric cancer. MATERIALS AND METHODS The sera from 768 patients with gastric cancer were measured for CEA, CA19-9 and CA125 levels using a commercial immunoradiometric assay. All the patients underwent diagnostic imaging with computed tomography (CT) and ultrasound (US) before laparotomy. RESULTS Preoperative levels of CEA, CA19-9 and CA125 were above the cut-off levels in 15.4%, 8.7% and 5.7% of all cases, respectively. Eighty-eight patients were diagnosed with peritoneal metastasis by laparotomy. CT and US revealed peritoneal dissemination in 15 of 88 patients (17%). Among the three tumor markers, CA19-9 and CA125 showed similar detection rates of peritoneal metastasis (37.5% and 38.6%, respectively). In particular, the serum CA125 levels showed the best sensitivity (38.6%), specificity (98.4%), and diagnostic accuracy (91.5%), and the highest odd ratio (24.46, 95% CI: 11.17 approximately 53.57) for predicting peritoneal metastasis among the markers tested. CEA did not add significant predictive information (p=0.471). CONCLUSION Preoperative serum CA19-9 and CA125 levels may provide a predictable value in determining peritoneal metastasis in patients with gastric cancer.
Journal of The Korean Society of Coloproctology | 2015
Taekhyun Kang; Hyung Ook Kim; Hungdai Kim; Ho-Kyung Chun; Won Kon Han; Kyung Uk Jung
Purpose With extended life expectancy, the mean age of patients at the time of diagnosis of colorectal cancer and its treatment, including radical resection, is increasing gradually. We aimed to evaluate the impact of age on postoperative clinical outcomes after a laparoscopic resection of colorectal cancers. Methods This is a retrospective review of prospectively collected data. Patients with primary colorectal malignancies or premalignant lesions who underwent laparoscopic colectomies between January 2009 and April 2013 were identified. Patients were divided into 6 groups by age using 70, 75, and 80 years as cutoffs: younger than 70, 70 or older, younger than 75, 75 or older, younger than 80, and 80 or older. Demographics, pathological parameters, and postoperative clinical outcomes, including postoperative morbidity, were compared between the younger and the older age groups. Results All 578 patients underwent a laparoscopic colorectal resection. The overall postoperative complication rate was 21.1% (n = 122). There were 4 cases of operative mortality (0.7%). Postoperative complication rates were consistently higher in the older groups at all three cutoffs; however, only the comparison with a cutoff at 80 years showed a statistically significant difference between the younger and the older groups. Conclusion Age over 80 is a possible risk factor for postoperative morbidity after a laparoscopic resection of colorectal cancer.
Cancer Research and Treatment | 2002
Chang Hak Yoo; Byung Ho Sohn; Won Kon Han; Won Kil Pae
PURPOSE Little is known about local recurrence following proximal gastrectomy in patients with upper third gastric cancer. We performed this study to evaluate the long-term results of a proximal gastrectomy, and to analyze the risk factors of local recurrence affecting survival in these patients. MATERIALS AND METHODS We undertook a retrospective study of 63 patients who underwent potentially curative proximal gastrectomy between 1990 and 1999, with special reference to local recurrence. RESULTS During a median follow-up period of 37 months, 25 of the 63 patients (39.7%) developed a recurrence of cancer, with local recurrence in 15 patients (23.8%), the majority of these occurring at the remnant stomach or anastomosis. The median time to local recurrence was 38 months (8~78 months). Univariate analysis of risk factors for local recurrence revealed an infiltrative or diffuse gross type, with a tumor sizes>5 cm, a distal resection margin <or=3 cm and serosal invasion. Reoperation for cure was possible in only 4 patients and most died within the first year following diagnosis of recurrence. CONCLUSION When performing a proximal gastrectomy for upper third gastric cancer, even after curative resection, all risk factors should be considered to reduce rates of local recurrence.
International Journal of Epidemiology | 2014
Yiyi Zhang; Yoosoo Chang; Seungho Ryu; Juhee Cho; Won Young Lee; Eun-Jung Rhee; Min Jung Kwon; Roberto Pastor-Barriuso; Sanjay Rampal; Won Kon Han; Hocheol Shin; Eliseo Guallar