Should lymph node micrometastasis be considered in node staging for gastric cancer?: the significance of lymph node micrometastasis in gastric cancer.

BACKGROUND: In TNM staging system, lymph node staging is based on the number of metastatic lymph nodes in gastric cancer and micrometastasis is not considered. Several reports proposed the importance of lymph node micrometastasis as the causative factor for recurrence and poor survival, but it remains controversial among researchers. METHODS: A total of 482 gastric cancer patients who underwent curative resection from 2004 to 2010 at Korea University Medical Center Ansan Hospital, South Korea were prospectively enrolled. For detecting lymph node micrometastasis, immunohistochemical staining with anti-cytokeratin antibody (CAM 5.2) was performed on negative lymph nodes by hematoxylin-eosin (H-E) staining. Survival differences were compared between conventional node staging and new node staging that took micrometastasis into consideration. Also, the prognostic value of lymph node micrometastasis was investigated in multivariate analysis. RESULTS: A total of 156 patients (32.4%) showed lymph node micrometastasis. Overall, the micrometastatic group had more advanced tumor and lymph node stage, lymphovascular cancer cell invasion, a higher rate of recurrence, and poor survival. Furthermore, when the cumulative numbers of macro- and micrometastatic lymph nodes were calculated together, the discriminative power of survival difference between each node stage became more stratified. Also, multivariate analysis using Cox's proportional hazards model demonstrated perineural invasion, pathologic T stage, dissected lymph nodes, macro- and micrometastatic lymph nodes are independent prognostic factors. CONCLUSIONS: Lymph node micrometastasis was clinically significant as a risk factor for recurrent gastric cancer. Lymph node micrometastasis should be considered when estimating TNM stage for determining prognosis and the best treatment strategy.

High occupational stress and low career satisfaction of Korean surgeons.

Surgery is a demanding and stressful field in Korea. Occupational stress can adversely affect the quality of care, decrease job satisfaction, and potentially increase medical errors. The aim of this study was to investigate the occupational stress and career satisfaction of Korean surgeons. We have conducted an electronic survey of 621 Korean surgeons for the occupational stress. Sixty-five questions were used to assess practical and personal characteristics and occupational stress using the Korean occupational stress scale (KOSS). The mean KOSS score was 49.31, which was higher than the average of Korean occupational stress (45.86) or that of other specialized professions (46.03). Young age, female gender, long working hours, and frequent night duties were significantly related to the higher KOSS score. Having spouse, having hobby and regular exercise decreased the KOSS score. Multiple linear regression analysis showed that long working hours and regular exercise were the independent factors associated with the KOSS score. Less than 50% of surgeons answered that they would become a surgeon again. Most surgeons (82.5%) did not want to recommend their child follow their career. Korean Surgeons have high occupational stress and low level of career satisfaction.

Expression of estrogen receptors in gastric cancer and their clinical significance.

BACKGROUNDS AND OBJECTIVES: The male predominance of gastric cancer suggests that female sex hormones may have a protective effect against gastric cancer. We evaluated the expression of estrogen receptors in gastric cancer tissue and cells and the clinical significance of ER-ß expression in gastric cancer. METHOD: ER-α, ER-ß proteins extracted from normal stomach, gastric cancer tissues, and cultured gastric cancer cells (KATO-III, mkn28, mkn45, and mkn74) were assessed by Western blot analysis. The clinical significance of ER-ß was explored using tissue microarray methods and immunohistochemical staining of specimens from 148 gastric cancers. RESULTS: Both ER-α and ß protein expression were noted in normal and gastric cancer tissues. However, in cultured gastric cells, only ER-ß was noted in mkn28 and mkn74. Of 148 gastric cancers, 67 (45.3%) were ER-ß positive. The ER-ß positive group was associated with lower tumor stage, Lauren's intestinal type, negative perineural invasion, and free of recurrence. The ER-ß positive group had a better 3-year survival compared with the negative group in survival analysis. CONCLUSION: Our results suggest that the presence of ER-ß in gastric cancer could have a protective effect against invasiveness of gastric cancer. Further studies are needed to clarify the role of ER-ß in gastric cancers.

Metastatic lymph node targeted chemosensitivity test for gastric cancer.

BACKGROUND: The objective of this study was to compare the chemosensitivity of primary tumor and metastasized lymph node from patient with gastric adenocarcinoma. MATERIALS AND METHODS: We studied 26 gastric cancer patients with lymph node metastasis who underwent gastric resection at the Korea University Guro Hospital from Feb 2007 to July 2008. The chemosensitivity of primary tumor and metastatic lymph node were studied using an adenosine triphosphate-based chemotherapy response assay (ATP-CRA). RESULTS: The concordance rate of the ATP-CRA test was 30.8% (8/26). The concordance rate between primary tumor and metastatic N2 group lymph node was only 9.1% (1/11). The metastatic tumor inhibition rates with 5-fluorouracil, cisplatin, doxorubicin, and oxaliplatin were higher than the inhibition rates for primary tumor. Tumor inhibition rates was significantly different between primary tumor and metastatic tumor after doxorubicin treatment (27.734±20.95 versus 38.403±26.87, P=0.021). We detected simple correlations of tumor inhibition rates between primary and metastatic tumors with cisplatin (r=0.661, P<0.001) and doxorubicin (r=0.475, P=0.031). CONCLUSIONS: We observed differences between first choice chemotherapeutic agents based on ATPCRA tests of primary tumor and metastatic tumor in lymph node. Therefore, chemotherapeutic agents should be carefully selected for adjuvant chemotherapy using a chemosensitivity test.

Laparoscopic resection of small gastric submucosal tumors.

BACKGROUND: No consensus exists regarding the necessity of operative resection for patients with small, asymptomatic gastric submucosal tumors (SMTs). The purpose of this study is to evaluate clinical outcomes of resection by minimally invasive surgery. METHODS: The medical records of 20 consecutive patients who had undergone laparoscopic or robotic wedge resection for small (<5 cm) gastric SMTs between March 2008 and February 2009 were reviewed. Operative indications included all SMTs unquestionably visible by endoscopy, irrespective of symptoms. The operative procedures, clinicopathologic features, and operative results were assessed. RESULTS: Out of a total of 20 patients, 17 were asymptomatic, and 3 presented with vague abdominal discomfort. One patient had two tumors, therefore 21 total lesions were resected and evaluated (19 by laparoscopy and 2 by robotic procedures). There were 12 exogastric and 9 transgastric wedge resections. Mean operative time was 84 ± 28 min, and mean length of hospitalization was 4.7 ± 1.6 days. There were no major peri- or postoperative complications or mortalities. Mean tumor size was 2.4 ± 1.2 cm (range 0.6-4.8 cm). All lesions had microscopically negative resection margins. There were 16 gastrointestinal tumors (GISTs) and 5 other benign lesions. Fifteen of the GISTs had mitotic count (MC) <5 per 50 high-power fields (HPFs), and one lesion measuring 2.5 cm in size had MC of 38 per 50 HPFs. CONCLUSIONS: Small size cannot guarantee a specific malignant risk for gastric SMTs. Laparoscopic/robotic wedge resection is safe and effective in treating small, asymptomatic lesions. Therefore, an active surgical approach should be considered for management of patients with small gastric SMTs.

Clinical significance of immunohistochemically-identified lymphatic and/or blood vessel tumor invasion in gastric cancer.

BACKGROUND: Tumor invasion and lymph node metastasis are significant prognostic factors for gastric cancer, and lymphatic and vascular tumor invasion are also significant risk factors for gastric cancer recurrence. Recently, the immunohistochemical detection of lymphatic and blood vessel tumor invasion (LBVI) has been shown to have a higher sensitivity and specificity than hematoxylin-eosin staining methods. MATERIALS AND METHODS: One hundred forty-nine gastric cancer patients who underwent curative resection at Korea University Hospital between November 2003 and December 2006 served as the study subjects. Lymphatic vessel invasion was evaluated by immunostaining with the new selective marker, D2-40, and blood vessel invasion was assessed with anti-CD31 antibody. Patients were divided according to the presence of LBVI, clinicopathologic factors were compared, and postoperative surgical outcomes were analyzed. RESULTS: LBVI was present in 66 patients (44.3%). LBVI was significantly correlated with depth of tumor invasion (P < 0.001), lymph node stage (P < 0.001), and lymph node micrometastasis (P = 0.013). Cancer recurrence was more common in the LBVI group (P = 0.007), and peritoneal seeding was the most prevalent type of recurrence (P = 0.028). Univariate analysis showed tumor size, depth of tumor invasion, lymph node stage, and LBVI to have a significant impact on survival. Based on multivariate analysis, however, depth of tumor invasion and lymph node stage were correlated with survival. CONCLUSION: Immunohistochemical demonstration of LBVI is an additional prognostic marker, and provides useful information for planning treatment strategies in gastric cancer patients.

Advanced gastric cancer in the middle one-third of the stomach: Should surgeons perform total gastrectomy?

BACKGROUND AND OBJECTIVES: To determine which optimal surgical procedure for middle-third advanced gastric cancer (AGC) based on comparative study of the long-term prognosis between total gastrectomy (TG) and distal gastrectomy (DG). METHODS: Between March 1993 and December 2005, 402 patients with middle-third AGC who underwent gastric resection were enrolled in this study. We analyzed the long-term prognosis according to the length of the proximal resection margin (PRM) and the extent of gastric resection, and determined independent prognostic factors. RESULTS: TG was performed in 244 patients (60.7%) and DG was performed in 158 patients (39.3%). There were no significant differences in the 5-year survival rates according to the length of PRM. The 5-year survival rates of patients who underwent DG were significantly higher than the rates of the patients who underwent TG in curative cases (67.8% vs. 58.4%, P = 0.037). Nevertheless, there was no significant difference in the stage-stratified survival rates according to the extent of gastric resection. Multivariate analysis revealed that surgical curability, extent of lymphadenectomy, and stage were independent prognostic factors. CONCLUSION: If curative resection can be performed, the long-term prognosis of patients with middle-third AGC was not affected by the length of PRM or the extent of gastric resection.

Clinical significance of gastric outlet obstruction on the oncologic and surgical outcomes of radical surgery for carcinoma of the distal stomach.

BACKGROUND AND OBJECTIVES: To determine the significance of gastric outlet obstruction (GOO) on the outcomes of radical surgery for distal gastric cancer. METHODS: Three hundred seventy-one patients who underwent radical surgery for advanced gastric cancer arising at the distal stomach were categorized into two groups according to the presence of GOO, that is, 59 patients with GOO and 312 patients without. Clinicopathologic variables, postoperative morbidity and mortality, recurrence pattern, and survival outcomes of the two groups were compared. RESULTS: Distal gastric carcinoma with GOO was usually diagnosed at a more advanced stage with aggressive pathologic features. GOO adversely affected overall survival after radical surgery with an odds ratio of 2.068 (P < 0.001). In patients with recurrent diseases, patients with GOO had higher rate of locoregional recurrence after radical surgery (P = 0.021). High-grade postoperative complications occurred at similar rates in both groups (P = 0.539). CONCLUSIONS: The presence of GOO is an independent prognostic factor after radical surgery for advanced distal gastric cancer and provide additional information for identifying patients at higher risk of recurrence and pattern of recurrence during follow-up. Radical surgery in patients with GOO can be performed with acceptable morbidity and mortality.

Gastric cancer histology: clinicopathologic characteristics and prognostic value.

BACKGROUND AND OBJECTIVES: Gastric cancer can be divided into two major histologic categories, that is, differentiated and undifferentiated types. In the present study, we sought to clarify the prognoses and clinicopathologic characteristics of signet ring cell carcinoma and mucinous carcinoma, both of which are mucin-producing tumors of the undifferentiated type. METHODS: We retrospectively reviewed medical records of 2,275 patients who underwent gastric resection. Cases were divided into four histologic groups: differentiated carcinoma (well differentiated and moderately differentiated, WMD), poorly differentiated (PD), signet ring cell carcinoma (SRC), and mucinous carcinoma (MC). RESULTS: The overall cumulative 5-year survival rates for patients were 67% for WMD, 54% for PD, 65% for SRC, and 48% for MC. The outcome of SRC was similar to that of WMD, whereas that of MC was similar to that of PD. Stage-stratified analysis revealed that histologic type was not statistically related to survival in patients with stage I, II, or III. On the other hand, histologic type in patients with stage IV disease was found to be significantly associated with survival. CONCLUSIONS: Histologic classifications of mucin-producing gastric cancers should separately be considered from other histologic types.

Hepatic cyst misdiagnosed as a gastric submucosal tumor: a case report.

We describe here a case of 51-year-old woman with a symptomatic hepatic cyst that was misdiagnosed as a gastric submucosal tumor (SMT) with endoscopic ultrasound (EUS) and CT scan. The patient presented with an epigastric pain for two months. On endoscopy, a submucosal tumor was found on the cardia of the stomach. Based on EUS and abdominal CT scan, the lesion was diagnosed as a gastric duplication cyst or a gastrointestinal stromal tumor (GIST). The operative plan was laparoscopic wedge resection for the GIST of the gastric cardia. A cystic mass arising from the left lateral segment of the liver was found at the laparoscopic examination. There was no abnormal finding at the gastric cardia. She was treated by laparoscopic hepatic wedge resection including the hepatic cyst using an endoscopic linear stapler.

Laparoscopic treatment of a huge cystic lymphangioma: partial aspiration technique with a spinal needle.

A cystic lymphangioma is a rare intra-abdominal lesion. Treatment is a complete excision of the cyst because of complications and a rare chance of malignancy. In this paper we report on 2 patients with a huge cystic lymphangioma who were treated by laparoscopic surgery successfully. Each of the cysts were 13 and 11 cm in diameter, were diagnosed by ultrasonography and computed tomography scan. After partial aspiration of the cysts, using a spinal needle, we were prone to grasp the cysts without spillage. Traction and dissection were easy without spillage or injury of the mesenteric vessels. The laparoscopic approach can be successfully and safely performed by an experienced surgeon in keeping with oncologic principles.

Multiple malignant extragastrointestinal stromal tumors of the greater omentum and results of immunohistochemistry and mutation analysis: a case report.

To report an extragastrointestinal stromal tumor (EGIST) that occurs outside the gastrointestinal tract and shows unique clinicopathologic and immunohistochemical features. In our case, we experienced multiple soft tissue tumors that originate primarily in the greater omentum, and in immunohistochemical analysis, the tumors showed features that correspond to malignant EGIST. Two large omental masses measured 15 cm multiply 10 cm and 5 cm multiply 4 cm sized and several small ovoid fragments were attached to small intestine, mesentery and peritoneum. On histologic findings, the masses were separated from small bowel serosa and had high mitotic count (115/50 HPFs). In the results of immunohistochemical stains, the tumor showed CD117 (c-kit) positive reactivity and high Ki-67 labeling index. On mutation analysis, the c-kit gene mutation was found in the juxtamembrane domain (exon 11) and it was heterozygote. Platelet-derived growth factor receptor (PDGFR) gene mutation was also found in the juxtamemembrane (exon 12) and it was polymorphism. From above findings, we proposed that there may be several mutational pathways to malignant EGIST, so further investigations could be needed to approach this unfavorable disease entity.

Surgical outcomes and immunohistochemical features for gastrointestinal stromal tumors (GISTS) of the stomach: with special reference to prognostic factors.

BACKGROUND/AIMS: Stomach is the most common site of gastrointestinal stromal tumors (GISTs). But the preoperative pathologic diagnosis is often difficult to make and it is hard to decide an appropriate surgical extent and also adjuvant therapy due to obscure malignant potential. Our purpose was to observe the outcomes for the patients with GIST of the stomach and reveal the significant prognostic factors. METHODOLOGY: Forty patients operated for primary GIST of the stomach expressing CD 117 were studied. We evaluated immunohistochemical and clinicopathologic features, and analyzed them to reveal the significant prognostic factors. The surgical outcomes of the patients were also investigated. RESULTS: Multivariate analysis for disease-free survival disclosed mitotic activity was the only independent factor, but the immunohistochemical features did not have any prognostic value. Among the patients with recurrence, all of the patients treated with imatinib mesylate (formerly STI-571) have survived until now, but half of the untreated patients died. CONCLUSIONS: In gastric GISTs, most important prognostic factor is mitotic count, not tumor size. We suggest that the wider application of imatinib mesylate to clinically malignant gastric GIST as adjuvant therapy may contribute to the improvement of outcomes.

Lymph Node Dissection Using Bipolar Vessel-Sealing Device During Reduced Port Laparoscopic Distal Gastrectomy for Gastric Cancer: Result of a Pilot Study from a Single Institute.

INTRODUCTION: The electrothermal bipolar vessel-sealing device (BVSD) is known to supply a strong vessel-sealing power. However, only few studies have reported lymph node dissection (LND) using only BVSD during laparoscopic surgery for gastric cancer. The purpose of this study was to investigate the feasibility of LND using BVSD during reduced port laparoscopic distal gastrectomy for gastric cancer. METHODS: From May 2015, patients in whom three- or single-port laparoscopic distal gastrectomy had been engaged for gastric cancer were enrolled in this study. We performed D1+ or D2 LND using only LigaSure™ Maryland (Medtronics, Minneapolis, MN), a recently developed BVSD. Clinical outcomes of these patients were investigated. RESULTS: From May 2015 to November 2016, 20 patients were enrolled in this study. The mean operation time was 262.6 ± 36.6 (200-340) minutes. The mean time for LND was 124.7 ± 19.2 (93-171) minutes. Only one patient had a morbidity of Clavien-Dindo grade more than II. No mortality was observed in all patients. The mean number of retrieved lymph nodes was 46.8 ± 22.8 (15-105). CONCLUSIONS: LND using the Maryland jaw type BVSD was feasible during reduced port (single- or three-port) laparoscopic distal gastrectomy for gastric cancer. Objectively evaluating the potential advantages of BVSD in reduced port laparoscopic surgery is necessary.

A comparison between two methods for tumor localization during totally laparoscopic distal gastrectomy in patients with gastric cancer.

PURPOSE: The aim of this study was to compare two methods of tumor localization during totally laparoscopic distal gastrectomy (TLDG) in patients with gastric cancer. METHODS: From March 2014 to November 2014, patients in whom TLDG had been engaged for middle third gastric cancer enrolled in this study. The patients were allocated to either the radiography or endoscopy group based on the type of tumor localization technique. Clinicopathologic outcomes were compared between the 2 groups. RESULTS: The accrual was suspended in November 2014 when 39 patients had been enrolled because a failed localization happened in the radiography group. The radiography and endoscopy groups included 17 (43.6 %) and 22 patients (56.4 %), respectively. Mean length of the proximal resection margin did not differ between the radiography and endoscopy groups (4.0 ± 2.6 and 2.8 ± 1.2 cm, respectively; P = 0.077). Mean localization time was longer in the radiography group than in the endoscopy group (22.7 ± 11.4 and 6.9 ± 1.8 minutes, respectively, P < 0.001). There were no statistically significant differences in the incidence of severe complications between the 2 groups (5.9% and 4.5%, respectively, P = 0.851). CONCLUSION: As an intraoperative tumor localization for TLDG, radiologic method was unsafe even though other comparable parameters were not different from that of endoscopy group. Moreover, intraoperative endoscopic localization may be advantageous because it is highly accurate and contributes to reducing operation time.

Impact of skip metastasis in gastric cancer.

BACKGROUND: Several studies have shown the features of skip metastasis in other cancers besides gastric cancer. Since minimally invasive surgery has been applied to gastric cancer, the concerns and awareness of skip metastasis have grown in the medical community. We conducted the present retrospective study to reveal the clinicopathological characteristics of patients with skip metastasis. We also wished to clarify the clinical impact of skip metastasis for gastric cancer. METHODS: Five hundred and eighty-nine patients having lymphatic metastases were enrolled in the present study. Among them, 266 patients had positive nodes extending into the N2 group. We divided these patients into the skip positive (+) and the skip negative (-) group, and we comparatively analysed clinicopathological factors and calculated the survival probabilities for the two groups. RESULTS: The skip (+) and skip (-) groups involved 14 (5.3%) and 252 (94.7%) patients, respectively. Of all the investigated factors, a significant difference between two groups was observed only in the total number of retrieved nodes. Stations of skip nodes were along left gastric (7), anterior common hepatic (8a), celiac (9), splenic (11) artery and right paracardial nodes (1). The survival curves calculated in the present study did not show any statistical differences between the groups. CONCLUSIONS: Due to problems of skip metastasis in gastric cancer, D2 lymph node dissection should be performed until sentinel node detection is feasible and reliable. The potential risk from skip metastasis is not great and skip metastasis itself should not be a major consideration in therapeutic decisions.

Occupational stress and related factors among surgical residents in Korea.

PURPOSE: The application rate for surgical residents in Korea has continuously decreased over the past few years. The demanding workload and the occupational stress of surgical training are likely causes of this problem. The aim of this study was to investigate occupational stress and its related factors in Korean surgical residents. METHODS: With the support of the Korean Surgical Society, we conducted an electronic survey of Korean surgical residents related to occupational stress. We used the Korean Occupational Stress Scale (KOSS) to measure occupational stress. We analyzed the data focused on the stress level and the factors associated with occupational stress. RESULTS: The mean KOSS score of the surgical residents was 55.39, which was significantly higher than that of practicing surgeons (48.16, P < 0.001) and the average score of specialized professionals (46.03, P < 0.001). Exercise was the only factor found to be significantly associated with KOSS score (P = 0.001) in univariate analysis. However, in multiple linear regression analysis, the mean number of assigned patients, resident occupation rate and exercise were all significantly associated with KOSS score. CONCLUSION: Surgical residents have high occupational stress compared to practicing surgeons and other professionals. Their mean number of assigned patients, resident recruitment rate and exercise were all significantly associated with occupational stress for surgical residents.

Lessons learned from a comparative analysis of surgical outcomes of and learning curves for laparoscopy-assisted distal gastrectomy.

PURPOSE: Before expanding our indications for laparoscopic gastrectomy to advanced gastric cancer and adopting reduced port laparoscopic gastrectomy, we analyzed and audited the outcomes of laparoscopy-assisted distal gastrectomy (LADG) for adenocarcinoma; this was done during the adoptive period at our institution through the comparative analysis of short-term surgical outcomes and learning curves (LCs) of two surgeons with different careers. MATERIALS AND METHODS: A detailed comparative analysis of the LCs and surgical outcomes was done for the respective first 95 and 111 LADGs performed by two surgeons between July, 2006 and June, 2011. The LCs were fitted by using the non-linear ordinary least squares estimation method. RESULTS: The postoperative morbidity and mortality rates were 14.6% and 0.0%, respectively, and there was no significant difference in the morbidity rates (12.6% vs. 16.2%, P=0.467). More than 25 lymph nodes were retrieved by each surgeon during LADG procedures. The LCs of both surgeons were distinct. In this study, a stable plateau of the LC was not achieved by both surgeons even after performing 90 LADGs. CONCLUSIONS: Regardless of the experience with gastrectomy or laparoscopic surgery for other organs, or the age of surgeon, the outcome was quite acceptable; the learning process differ according to the surgeon's experience and individual characteristics.

Gastrectomy for the treatment of refractory gastric ulceration after radioembolization with 90Y microspheres.

Transcatheter arterial radioembolization (TARE) with Yttrium-90 ((90)Y)-labeled microspheres has an emerging role in treatment of patients with unresectable hepatocellular carcinoma. Although complication of TARE can be minimized by aggressive pre-evaluation angiography and preventive coiling of aberrant vessels, radioembolization-induced gastroduodenal ulcer can be irreversible and can be life-threatening. Treatment of radioembolization-induced gastric ulcer is challenging because there is a few reported cases and no consensus for management. We report a case of severe gastric ulceration with bleeding that eventually required surgery due to aberrant deposition of microspheres after TARE.

Primary gastric malignant melanoma mimicking adenocarcinoma.

We report a case of primary gastric malignant melanoma that was diagnosed after curative resection but initially misdiagnosed as adenocarcinoma. A 68-year-old woman was referred to our department for surgery for gastric adenocarcinoma presenting as a polypoid lesion with central ulceration located in the upper body of the stomach. The preoperative diagnosis was confirmed by endoscopic biopsy. We performed laparoscopic total gastrectomy, and the final pathologic evaluation led to the diagnosis of primary gastric malignant melanoma without a primary lesion detected in the body. To the best of our knowledge, primary gastric malignant melanoma is extremely rare, and this is the first case reported in our country. According to the literature, it has aggressive biologic activity compared with adenocarcinoma, and curative resection is the only promising treatment strategy. In our case, the patient received an early diagnosis and underwent curative gastrectomy with radical lymphadenectomy, and no recurrence was noted for about two years.