Sang-Kyung Choi

Gyeongsang National University, Chinju, South Gyeongsang, South Korea

Are you Sang-Kyung Choi?

Claim your profile

Publications (32)46.2 Total impact

  • Article: Prognostic value of CAPZA1 overexpression in gastric cancer.
    [show abstract] [hide abstract]
    ABSTRACT: F-actin capping protein α1 subunit (CAPZA1) was previously identified in a proteomic analysis of human gastric cancer clinical specimens and selected for further study. The association between CAPZA1 overexpression, detected by immunohistochemistry, and clinicopathological features including survival were evaluated. In vitro gain-of-function and loss-of-function approaches were utilized to assess the function of CPAZA1 in malignancy. Univariate analysis revealed that poorly differentiated disease, according to the World Health Organization (WHO) classification, advanced T stage, positive lymph nodes, high TNM stage, D2 lymph node dissection, adjuvant chemotherapy and CAPZA1 underexpression were significantly associated with cancer-related death (p<0.05); however, only high TNM stage remained significantly associated by multivariate analysis (p<0.01). CAPZA1 overexpression was associated with well differentiated histology, smaller tumor size, lower T stage, absence of lymph node metastasis, lower TNM stage, lower recurrence rate and longer survival time, compared to CAPZA1 underexpression. In vitro, forced expression of CAPZA1 caused a significant decrease in gastric cancer cell migration and invasion, whereas CAPZA1 depletion had the opposite effect. The present study suggests that CAPZA1 could be a marker of good prognosis in gastric cancer and shows that CAPZA1 is associated with decreased cancer cell migration and invasion.
    International Journal of Oncology 03/2013; · 2.40 Impact Factor
  • Article: Current status of the use of antiadhesive agents for gastric cancer surgery: a questionnaire survey in South Korea.
    [show abstract] [hide abstract]
    ABSTRACT: The aim of this study was to investigate the current status of the use of antiadhesive agents (AAdAs) via a questionnaire and to discuss the availability of AAdAs. The survey was sent to a list of members that was approved by the Korean Gastric Association. The survey included questions on AAdA use by surgeons, the type of AAdAs used, and the reasons for not using AAdAs. Surgeons were also asked to describe complications related to AAdAs, and the reliability of its use. The response rate was 21%. The rates of frequent use stratified by procedure were 26.9% (14/52) for open gastrectomy, 5.9% (3/51) for laparoscopic gastrectomy, and 31.5% (17/54) for surgery for postoperative bowel obstruction (P < 0.01). After including data from the occasional use group, the corresponding values were 51.9% (27/52), 19.6% (10/51), and 70.4% (38/54), respectively (P < 0.01). Sefrafilm and Guardix were most commonly used for open procedures. Guardix and Interceed were most commonly used for laparoscopic surgery. The primary reasons for nonuse of AAdAs were ineffectiveness and high cost. Ten percent (4/40) of surgeons observed complications associated with AAdAs. A minority (17.3%, 9/52) had positive attitudes toward AAdAs. The majority of respondents expressed neutral (73.1%, 38/52) or negative (9.6%, 5/52) attitudes toward AAdAs. The low use rates of AAdAs in gastric cancer surgery may be attributable to perceptions that AAdAs are ineffective, unreliable, and costly. We anticipate the emergence of promising antiadhesive strategies that reach far beyond the limitations of current products.
    Journal of the Korean Surgical Society 03/2013; 84(3):160-7. · 0.12 Impact Factor
  • Article: Totally laparoscopic distal gastrectomy after learning curve completion: comparison with laparoscopy-assisted distal gastrectomy.
    [show abstract] [hide abstract]
    ABSTRACT: THE AIMS ARE TO: (i) display the multidimensional learning curve of totally laparoscopic distal gastrectomy, and (ii) verify the feasibility of totally laparoscopic distal gastrectomy after learning curve completion by comparing it with laparoscopy-assisted distal gastrectomy. From January 2005 to June 2012, 247 patients who underwent laparoscopy-assisted distal gastrectomy (n=136) and totally laparoscopic distal gastrectomy (n=111) for early gastric cancer were enrolled. Their clinicopathological characteristics and early surgical outcomes were analyzed. Analysis of the totally laparoscopic distal gastrectomy learning curve was conducted using the moving average method and the cumulative sum method on 180 patients who underwent totally laparoscopic distal gastrectomy. Our study indicated that experience with 40 and 20 totally laparoscopic distal gastrectomy cases, is required in order to achieve optimum proficiency by two surgeons. There were no remarkable differences in the clinicopathological characteristics between laparoscopy-assisted distal gastrectomy and totally laparoscopic distal gastrectomy groups. The two groups were comparable in terms of open conversion, combined resection, morbidities, reoperation rate, hospital stay and time to first flatus (P>0.05). However, totally laparoscopic distal gastrectomy had a significantly shorter mean operation time than laparoscopy-assisted distal gastrectomy (P<0.01). We also found that intra-abdominal abscess and overall complication rates were significantly higher before the learning curve than after the learning curve (P<0.05). Experience with 20~40 cases of totally laparoscopic distal gastrectomy is required to complete the learning curve. The use of totally laparoscopic distal gastrectomy after learning curve completion is a feasible and timesaving method compared to laparoscopy-assisted distal gastrectomy.
    Journal of gastric cancer. 03/2013; 13(1):26-33.
  • Article: Effectiveness of endoscopic clipping and computed tomography gastroscopy for the preoperative localization of gastric cancer.
    [show abstract] [hide abstract]
    ABSTRACT: Before laparoscopic gastrectomy for gastric cancer can be planned, it is very important to know the precise location of the tumor. The aim of this study was to evaluate 3 methods of predicting the exact location of the tumor: preoperative gastrofibroscopy (GFS), preoperative computed tomography gastroscopy (CT), and intraoperative gastroscopy-guided laparoscopy (Lap). In this study, 15 patients were prospectively identified, and endoscopic clips were preoperatively placed on the proximal 1 cm of the tumor, at the angle on the greater curvature and opposite the angle on the greater curvature. The distances between the pylorus and the proximal tumor clip (PT), the angle clip (PA), the greater curvature clip (PG), and the gastroesophageal junction were measured by preoperative GFS, preoperative CT, intraoperative Lap, and visual inspection (Vis). PT, PA, and PG values measured by preoperative GFS differed significantly from the Vis values (P < 0.01). However, preoperative CT measurements of PT, PA, and PG did not differ from the Vis values (P = 0.78, P = 0.48, and P = 0.53, respectively). Intraoperative Lap and Vis PT values differed by only 1.1 cm on an average (P = 0.10), but PA and PG values varied by 1.9 and 3.4 cm, respectively (P = 0.01 for both). Endoscopic clipping combined with preoperative CT gastroscopy is more useful than preoperative GFS for preoperatively predicting the location of early gastric cancers and will be helpful for planning laparoscopic gastrectomy.
    Journal of the Korean Surgical Society 02/2013; 84(2):80-7. · 0.12 Impact Factor
  • Article: Laparoscopic left hemihepatectomy for left intrahepatic duct stones.
    [show abstract] [hide abstract]
    ABSTRACT: The feasibility of laparoscopic left hemihepatectomy for the management of intrahepatic duct (IHD) stones was evaluated. The clinical data of 26 consecutive patients who underwent total laparoscopic left hemihepatectomy for IHD stones at Gyeongsang National University Hospital between January 2009 and June 2011 were reviewed retrospectively. The mean operation time was 312.1 ± 63.4 minutes and the mean postoperative hospital stay was 11.8 ± 5.0 days. There were 2 cases of postoperative bile leakage and 3 cases of intra-abdominal fluid collection, which were successfully managed conservatively. Remnant stones were detected in 2 patients. The initial success rate of stone clearance was 92.3% (24 of 26). The remnant stones were located in the common bile duct in both cases and were removed by endoscopic retrograde cholangiopancreatography and endoscopic sphincterotomy. Therefore, the final success rate of stone clearance was 100% (26 of 26). During a mean follow-up of 22 months (range, 7 to 36 months), there was no patient with recurrent stone. Laparoscopic surgery could be an effective treatment modality for the management of IHD stones in select patients.
    Journal of the Korean Surgical Society. 09/2012; 83(3):149-54.
  • Article: Prognostic value of sonic hedgehog protein expression in gastric cancer.
    [show abstract] [hide abstract]
    ABSTRACT: Sonic hedgehog is produced in gastric epithelial cells and plays a crucial role in parietal cell function and the regulation of gastric epithelial cell differentiation. Emerging evidence suggests that the sonic hedgehog pathway is not only involved in the development of cancers but also in their progression and aggressiveness. To assess its prognostic value in gastric cancer, sonic hedgehog protein expression was measured by immunohistochemistry in a clinically annotated tissue microarray comprising 319 human gastric cancer specimens. Cytoplasmic sonic hedgehog expression was scored from 0 to 4, reflecting the percentage of sonic hedgehog-positive cells. Specimens were classified into two groups according to their sonic hedgehog score: those with a score ranging from 0 to 3 were considered low expressers and those with a score of 4 were considered overexpressers. The sonic hedgehog overexpression group included more patients with early gastric cancer than the low sonic hedgehog expression group (25.9 vs. 74.1%, P = 0.000). Sonic hedgehog expression was lower in patients with lymph node metastasis than in patients without lymph node metastasis (31.4 vs. 68.4%, P = 0.02). Similarly, patients with a lower TNM stage showed significantly higher sonic hedgehog expression. In addition, the survival time of patients with sonic hedgehog overexpression was significantly prolonged (69.27 ± 1.39 months) compared with that of patients with low sonic hedgehog expression (61.23 ± 2.04 months, log-rank test, P = 0.03). These results indicate that sonic hedgehog overexpression may be a marker of good prognosis in gastric cancer.
    Japanese Journal of Clinical Oncology 08/2012; 42(11):1054-9. · 1.78 Impact Factor
  • Article: Fatty acid-binding protein 5 promotes cell proliferation and invasion in human intrahepatic cholangiocarcinoma.
    [show abstract] [hide abstract]
    ABSTRACT: Intrahepatic cholangiocarcinoma (ICC) is a rare primary malignant liver tumor with an extremely poor prognosis. Recently its incidence has increased, however, little attention has been directed to factors related to its molecular carcinogenesis, including oncogenes, tumor suppressor genes and cell cycle-related proteins. ICC is generally characterized by strong proliferation, invasion and early metastasis. These biological behaviors of ICC, with respect to the genetic and molecular aspects, remain to be clarified. In this study, we performed a proteomic analysis to identify the proteomic alterations associated with carcinogenesis of ICC. Protein expression profiles of sixteen cases of ICC were compared with those of adjacent non-involved bile duct tissue. Among the 151 protein spots that showed a statistically significant expression difference (P<0.05), there were 50 spots with significantly increased intensity (3-fold increase) and 17 spots with decreased intensity (3-fold decrease) in cancerous tissues. Of these, increased expression of fatty acid-binding protein 5 (FABP5) was further confirmed by western blot analysis and immunohistochemical analysis. Immunohistochemical analysis of FABP5 expression in tumor specimens obtained from 43 patients with mass-forming (MF) type ICC showed a positive correlation of FABP5 immunoreactivity with tumor size (P=0.047), lymph node metastasis (P=0.013), angioinvasion (P=0.032) and staging (P=0.007). In addition, silencing FABP5 with short hairpin RNA (shRNA) suppressed cell proliferation and invasiveness in HuCCT1 cells, and conversely, overexpression of FABP5 in FABP5-negative Hep3B cells increased cell proliferation and invasiveness. Our study shows that FABP5 is significantly overexpressed in ICC combined lymph node metastasis and is involved in cell proliferation and invasion in vitro. Our data suggest that FABP5 may be associated with tumor progression in ICC.
    Oncology Reports 07/2012; 28(4):1283-92. · 1.84 Impact Factor
  • Article: Pyrophosphatase overexpression is associated with cell migration, invasion, and poor prognosis in gastric cancer.
    [show abstract] [hide abstract]
    ABSTRACT: Inorganic pyrophosphatase (PPase) catalyzes the hydrolysis of pyrophosphate to form orthophosphate. Pyrophosphate can substitute for ATP under certain circumstances. We previously conducted a proteomic analysis to investigate tumor-specific protein expression in gastric cancer, and PPase was identified as a potential gastric tumor-specific marker; it was therefore selected for further study. Clinicopathological analysis, using proteomic analysis and immunohistochemistry, was used to validate PPase as a prognostic marker in gastric cancers. Proteomic analysis showed that PPase was overexpressed in patients with lymph node (LN) metastases and high tumor node metastasis (TNM) stages (p < 0.05). Based on immunohistochemistry, patients whose tumors overexpressed PPase had higher T stages, LN metastasis, a higher TNM stage, a higher cancer recurrence rate, and shorter survival times than patients whose tumors exhibited PPase underexpression (p < 0.05). Gain-of-function and loss-of-function approaches were employed to examine the malignant phenotypes of PPase-overexpressing or PPase-depleted cells. A decrease in PPase expression caused a significant decrease in gastric cancer cell migration and invasion in vitro, whereas forced overexpression of PPase enhanced migration but not invasion. Our findings indicate that PPase is involved in gastric tumor progression and that PPase may be a useful marker for poor prognosis of human gastric cancers.
    Tumor Biology 07/2012; · 1.94 Impact Factor
  • Source
    Article: Clinical features and prognostic factors in papillary thyroid microcarcinoma depends on age.
    [show abstract] [hide abstract]
    ABSTRACT: Clinical outcomes of papillary thyroid microcarcinoma (PTMC) vary. In general, age at diagnosis is an independent prognostic factor in conventional papillary thyroid carcinoma. However, it is unclear in patients of PTMC. The purpose of this study was to identify clinicopathologic features and prognostic factors of PTMC according to patients' age. Five hundred twenty-seven patients who received thyroid surgery and diagnosed as having PTC between January 2001 and December 2009 were included. The clinical data were retrospectively analyzed. We divided the patients into two groups; group I who were younger than 45 years, and group II who were 45 years old or older. The mean tumor size and incidences of neck lymph nodes involvement of group I was larger than group II. In group II, however, there were more patients who had multiple cancer foci and were body mass index ≥ 25 kg/m(2). The overall incidence of recurrent disease was 3.2%. The incidence of recurrence was higher in group II (2.0% vs. 4.0%), without a statistical difference. In multivariate analysis, the significant risk factors of recurrence were male gender and multifocality in group I, and lymph node metastasis and multifocality in group II. In particular, the male gender and multifocality showed the highest odds ratio (OR) on each group (OR, 4.721 and 6.177). The patients with PTMCs had different clinical features and prognostic factors according to age. Hence, clinicians should consider a different strategy for therapy and plan for follow-up according to age.
    Journal of the Korean Surgical Society. 05/2012; 82(5):281-7.
  • Article: Comparison of hybrid natural orifice transluminal endoscopic surgery and single-port laparoscopic surgery for sentinel node basin dissection in a porcine model.
    [show abstract] [hide abstract]
    ABSTRACT: The aim of the present study was to use a porcine model to compare one- and two-port transvaginal natural orifice transluminal endoscopic surgery (NOTES) with single-port laparoscopic surgery (SPLS) for sentinel node basin dissection. Three groups (n=3 per group) of healthy female pigs were subjected to lymph node dissection. For hybrid NOTES, an endoscope was inserted via the transvaginal route. For SPLS, a 5-mm 30° telescope with two-port laparoscopic instrument was inserted via the transumbilical port. The three methods were used to dissect the regions of the pig stomach that corresponded to four lymph node areas on the lesser curvature of the anterior wall and greater curvatures in humans. For two-port NOTES, SPLS, and one-port NOTES, the overall rates of complete dissection of the lymph node stations were 91.6 %, 83%, and 50%, respectively (P>.05). The mean resected tissue weights were 49.3, 37.9, and 22.5 g, respectively (P=.03). The mean operation times for two-port NOTES (69.9 minutes) and SPLS (68 minutes) were shorter than that for one-port NOTES (99 min) (P>.05). Two-port NOTES and SPLS are more feasible than one-port NOTES for sentinel node basin dissection in a porcine model. One-port NOTES is difficult to perform and requires long operation times; however, we foresee this operation as becoming more common in the future.
    Journal of Laparoendoscopic & Advanced Surgical Techniques 03/2012; 22(2):132-8. · 1.40 Impact Factor
  • Source
    Article: Analysis of risk factors for postoperative morbidity in perforated peptic ulcer.
    [show abstract] [hide abstract]
    ABSTRACT: Emergency operations for perforated peptic ulcer are associated with a high incidence of postoperative complications. While several studies have investigated the impact of perioperative risk factors and underlying diseases on the postoperative morbidity after abdominal surgery, only a few have analyzed their role in perforated peptic ulcer disease. The purpose of this study was to determine any possible associations between postoperative morbidity and comorbid disease or perioperative risk factors in perforated peptic ulcer. In total, 142 consecutive patients, who underwent surgery for perforated peptic ulcer, at a single institution, between January 2005 and October 2010 were included in this study. The clinical data concerning the patient characteristics, operative methods, and complications were collected retrospectively. The postoperative morbidity rate associated with perforated peptic ulcer operations was 36.6% (52/142). Univariate analysis revealed that a long operating time, the open surgical method, age (≥60), sex (female), high American Society of Anesthesiologists (ASA) score and presence of preoperative shock were significant perioperative risk factors for postoperative morbidity. Significant comorbid risk factors included hypertension, diabetes mellitus and pulmonary disease. Multivariate analysis revealed a long operating time, the open surgical method, high ASA score and the presence of preoperative shock were all independent risk factors for the postoperative morbidity in perforated peptic ulcer. A high ASA score, preoperative shock, open surgery and long operating time of more than 150 minutes are high risk factors for morbidity. However, there is no association between postoperative morbidity and comorbid disease in patients with a perforated peptic ulcer.
    Journal of gastric cancer. 03/2012; 12(1):26-35.
  • Source
    Article: Diagnosis of a trocar site mass as omental herniation after laparoscopic gastrectomy.
    [show abstract] [hide abstract]
    ABSTRACT: A trocar site hernia is a rare complication. We report a patient who had an abdominal wall mass at a previous trocar site after laparoscopic distal gastrectomy. It was diagnosed as omental herniation and fat necrosis. We conclude that patients with trocar site masses exhibiting fat density on a computed tomography scan could be followed up without surgery, and that fascial defects located at 10-mm or larger trocar sites should be closed whenever possible to prevent hernia formation.
    Journal of gastric cancer. 03/2012; 12(1):46-8.
  • Source
    Article: Laparoscopic resection of a appendiceal mucocele.
    [show abstract] [hide abstract]
    ABSTRACT: Laparoscopic resection of appendiceal mucoceles has recently been described, but the safety and efficacy are controversial. We present two cases of laparoscopic mucocelectomies involving 14 and 15 cm cystic masses originating from the appendix. The laparoscopic mucocelectomies were performed using four ports. From the beginning of the procedure, a laparoscopic bag was used to safely contain the mucocele, prevent rupture of the mucocele, and retract the mucocele. An endoscopic stapling device was used to transect the base of the cecum. Minimal handling was achieved by gravity and with the use of laparoscopic instruments. Laparoscopic appendectomies are widely performed for acute appendicitis, but laparoscopic resection is not routinely performed for an appendiceal mucocele because of the risk of perforation and subsequent pseudomyxoma peritonei. We report two cases of laparoscopic appendiceal mucocelectomies, which were performed safely with laparoscopic instruments and minimal manipulation.
    Journal of the Korean Surgical Society. 06/2011; 80 Suppl 1:S21-5.
  • Source
    Article: Synchronous Adenocarcinoma and Gastrointestinal Stromal Tumor of the Stomach Treated by a Combination of Laparoscopy-assisted Distal Gastrectomy and Wedge Resection.
    [show abstract] [hide abstract]
    ABSTRACT: The simultaneous occurrence of a gastrointestinal stromal tumor (GIST) and a gastric adenocarcinoma is uncommon, and has rarely been reported in the literature. The present report describes the case of a 74-year-old male patient who initially presented with an adenocarcinoma that had invaded the antral mucosa. Computed tomography then revealed the presence of a suspected GIST, in the form of a 2×2 cm mass at the hilum of the spleen. In view of the advanced age of the patient, a surgical approach that would minimize risk and maximize quality of life was preferred. The patient therefore underwent simultaneous laparoscopy-assisted distal gastrectomy for the adenocarcinoma and wedge resection for the GIST. This approach was only chosen after confirming that it would be possible to preserve three or more of the short gastric arteries that supply the area below the wedge resection site. This may be considered a feasible approach to the management of the simultaneous occurrence of a mid-to-low gastric body adenocarcinoma and a high gastric body GIST.
    Journal of gastric cancer. 03/2011; 11(1):55-8.
  • Article: Trans-vaginal specimen extraction following totally laparoscopic subtotal gastrectomy in early gastric cancer.
    [show abstract] [hide abstract]
    ABSTRACT: Although natural orifice extraction is now widely performed, there have been no reports of this procedure following subtotal gastrectomy for gastric cancer. This report describes trans-vaginal specimen extraction in four patients with early gastric cancer. The clinical data of four patients with early gastric cancer were reviewed. Totally laparoscopic subtotal gastrectomy and D1 + β lymph node dissection was performed using five trocars and a conventional procedure. Posterior colpotomy was performed by an experienced gynecologist, who retrieved the specimens in a retrieval bag via the trans-vaginal route. The colpotomy site was repaired immediately following specimen removal. Reconstruction was performed using the intracorporeal Billroth II method and an endo-GIA 60. Totally laparoscopic subtotal gastrectomy and trans-vaginal specimen extraction was successfully accomplished in all patients without intraoperative complications. The present technique may be a safe and feasible operative procedure for some limited groups of elderly female patients with early gastric cancer.
    Gastric Cancer 01/2011; 14(1):91-6. · 2.42 Impact Factor
  • Article: Risk of recurrence after laparoscopy-assisted radical gastrectomy for gastric cancer performed by a single surgeon.
    [show abstract] [hide abstract]
    ABSTRACT: The risk of recurrence after laparoscopy-assisted radical gastrectomy (LAG) was investigated. Clinical data of 398 consecutive patients who underwent radical gastrectomy with R0 resection for gastric cancer at Gyeongsang National University Hospital between January 2005 and December 2007 were reviewed retrospectively. Of the patients, 65.4% (n = 261) and 34.6% (n = 138) underwent LAG and open radical gastrectomy (OG), respectively. Of the LAG cases, 73.2% (n = 192), 10.7% (n = 28), 12.6% (n = 33), and 3.1% (n = 8) had stage I, II, III, and IV gastric cancer, respectively. All patients were followed up for a mean of 36.8 ± 13.7 months, and 14.6% (n = 58) had recurrence during the follow-up period. Univariate analysis revealed that tumor size, tumor-node-metastasis (TNM) stage, method of approach (LAG versus OG), and operation type were associated significantly with recurrence. Multivariate analysis revealed that only high TNM stage was significantly associated with recurrence (P = 0.00). While patients who underwent OG had higher incidence of recurrence than patients who underwent LAG, OG was not significantly associated with recurrence on multivariate analysis (P = 0.06). LAG and OG did not differ significantly in terms of recurrence, even when used in advanced gastric cancer cases. Multivariate analysis revealed that high TNM stage was significantly associated with recurrence. Thus, LAG appears to be a safe and feasible procedure that has the potential to be an alternative to open surgery, even for advanced gastric cancer.
    Surgical Endoscopy 11/2010; 25(3):872-8. · 4.01 Impact Factor
  • Article: Gastric lymphatic basin dissection for sentinel node biopsy using hybrid natural orifice transluminal endoscopic surgery (NOTES).
    [show abstract] [hide abstract]
    ABSTRACT: The aim of the present study was to describe a method of gastric lymphatic basin dissection for sentinel node biopsy using natural orifice transluminal endoscopic surgery with laparoscopic assistance (hybrid NOTES) in a porcine model. Lymph node dissection was performed in three healthy female domestic farm pigs (each around 40 kg) between October, 2007, and December, 2007. The pigs were administered a general anesthetic and laparoscopy-guided transvaginal colpotomy was performed. A two-channel endoscope was then inserted through the incision into the peritoneal cavity via the transvaginal route. An endoscope was inserted simultaneously into the mouth and indocyanine green solution was injected into the submucosal layer of the gastric wall at four sites. Dyed omentum and lymphatics were dissected using a laparoscopic dissector and the grasping forceps of a transvaginal endoscope. Lymphatics and omentum (mean 13.3 cm, range 8-20 cm) were removed transvaginally. The mean number of detected and resected sentinel nodes was 2.6 (range 1-4, diameter 2~12 mm). Sentinel lymphatic basin dissection was performed successfully and without intraoperative complications in all three cases. Hybrid NOTES is technically feasible, and this procedure may represent an alternative to laparoscopic sentinel lymph node dissection of the stomach.
    Minimally invasive therapy & allied technologies: MITAT: official journal of the Society for Minimally Invasive Therapy 10/2010; 19(5):299-303. · 1.33 Impact Factor
  • Article: Up-regulation of RhoGDI2 in human breast cancer and its prognostic implications.
    [show abstract] [hide abstract]
    ABSTRACT: Recent research has identified many genes and proteins that play specific roles in the process of systemic metastasis in various types of cancer. Rho GDP dissociation inhibitor 2 (RhoGDI2) has been shown to inhibit metastasis in human bladder cancer, but its role in breast cancer is controversial. We examined the regulation and clinical significance of RhoGDI2 in Korean breast cancer patients by using proteomic approaches. By using a proteomic approach, we observed an increased expression of RhoGDI2 in human breast cancer tissues when compared to that of the normal breast tissues, and we validated its up-regulation in an independent cohort of 8 breast cancer patients. The clinical implication of a RhoGDI2 expression was investigated in 57 breast cancer patients by performing immunohistochemistry. RhoGDI2 did not show a significant association with the tumor size, lymph node metastasis, the histologic grade or the hormone receptor status. However, the patients with RhoGDI2-expressing tumors had significantly shorter disease-free survival (p=0.043; hazard ratio, 3.87) and distant metastasis-free survival (p=0.039; hazard ratio, 5.15). Our results demonstrated a potential role of RhoGDI2 as a poor prognostic marker as well as a potential therapeutic target. The pro-metastatic nature of RhoGDI2 shown in our study may indicate its organ-specific role in cancer metastasis.
    Cancer Research and Treatment 09/2010; 42(3):151-6.
  • Article: Decreased annexin A3 expression correlates with tumor progression in papillary thyroid cancer.
    [show abstract] [hide abstract]
    ABSTRACT: The aim of this study is to identify the potential tumor markers that function in carcinogenesis and tumor progression, thus providing important diagnostic and prognostic information. We performed 2-D gel electrophoresis and MALDI-TOF MS to investigate the differentially expressed proteins in 25 papillary thyroid carcinoma tissues. For validation of candidate proteins and investigation of clinical significance, we performed Western, Northern blot analysis and immunohistochemical staining. Our proteomic analyses revealed significantly decreased annexin A3 expression in papillary thyroid carcinoma at both the protein and mRNA levels, compared with normal thyroid tissue. ANXA3 immunoreactivity was not significantly correlated with lymph node metastasis, multifocality, capsular invasion or perithyroidal extension in thyroid cancer. However, the tumor subgroup with a lymph node metastasis score of >3 displayed significantly lower ANXA3 expression than did subgroups with negative and ≤3 scores (p=0.001). Moreover, ANXA3 expression was markedly lower in large tumors (>1  cm in diameter) than in microcarcinomas (p=0.001). Decreased expression of ANXA3 in papillary thyroid cancer supports the idea that ANXA3 may be an effective marker of microcarcinoma, and a negative predictor of papillary thyroid cancer progression.
    PROTEOMICS - CLINICAL APPLICATIONS 05/2010; 4(5):528-37. · 1.81 Impact Factor
  • Article: Phase II study of irinotecan/S-1 combination chemotherapy for patients with oxaliplatin-refractory colorectal cancer.
    [show abstract] [hide abstract]
    ABSTRACT: To determine the efficacy and tolerance of irinotecan in combination with S-1 (IRIS) for patients whose disease progressed after treatment with an oxaliplatin-based therapy for colorectal cancer (CRC). Each patient's disease had progressed after the administration of a regimen containing oxaliplatin and 5-FU. S-1 was administered orally at a fixed dose of 40 mg/m(2) twice daily on days 1-14 and 21-35. Irinotecan (150 mg/m(2)) was administered via intravenous infusion on days 1, 15, and 29. Courses were repeated every 6 weeks. 20 patients were enrolled in this study between April 2006 and March 2008. The median age was 63 years (range: 34-74), and the dominant metastasis sites were the liver, lung, and lymph nodes. The objective response rate was 20%; 1 patient registered complete response and 3 patients registered partial responses; 7 patients were stabilized (35%); and 9 evidenced progression of disease (45%). Median progression-free survival was 3.0 months (95% CI, 2.1-3.9 months) and median overall survival was 9.8 months (95% CI, 6.3-13.3 months). For the 41 cycles analyzed, the most commonly detected hematologic toxicity was grade I-II anemia (63.4%). Leukopenia occurred in 18 cycles (41.5%), including eight cycles (19.5%) of grade 3-4 leukopenia. Frequently observed non-hematologic toxicities included the following: grade I vomiting was reported in 4 patients (20%), grade 2 neuropathy occurred in 3 patients (15%), and grade 2 mucositis was noted in 2 patients (10%). Two patients died from sepsis and hematemesis during treatment. Although the response rate in stage I reached the target (≥ 3/18, p0 = 10%) established for movement to stage II, this study had to be discontinued because two patients died during treatment. Additionally, the follow-up loss rate was higher (16.6%) than we had anticipated (<10%). Even though a regime consisting of irinotecan combined with S-1 (IRIS) has proven effective in oxaliplatin-pretreated patients with advanced CRC, treatment-related mortalities and the high follow-up loss rate suggested that this IRIS protocol should result in early closure and modification.
    Investigational New Drugs 03/2010; 29(5):1050-6. · 3.36 Impact Factor