CD151 overexpression is associated with poor prognosis in patients with pT3 gastric cancer

INTRODUCTION

CD151, a transmembrane protein of the tetraspanin family, is implicated in the regulation of cell-substrate adhesion and cell migration. Overexpression of CD151 has been reported in several cancers and controls MET-dependent neoplastic growth by enhancing receptor signaling. However, association of CD151 overexpression with MET or tumor progression has not been reported in gastric cancer.

MATERIALS AND METHODS

We conducted immunohistochemical analysis of CD151 overexpression in 491 pT3 gastric carcinomas and analyzed the relationship with MET overexpression and prognostic significance.

RESULTS

CD151 was highly expressed in 119 gastric carcinomas (24.2 %) and was significantly associated with higher pN stages. Patients with CD151-positive gastric cancer showed shorter overall (p = 0.003) and disease-free survival (p = 0.001) compared with patients with CD151-negative gastric carcinoma. CD151 overexpression was an independent prognostic factor for overall survival [hazard ration (HR) 1.335; 95 % CI 1.005-1.775; p = 0.046] and disease-free survival (HR 1.903; 95 % CI 1.348-2.685; p < 0.001). Co-overexpression of CD151 and MET was observed in 30 (6.1 %) gastric cancers and was more frequent in advanced pN stages than in other groups. Moreover, co-overexpression of CD151 and MET was a strong independent prognostic factor for overall survival (HR 3.163; 95 % CI 1.958-5.108; p < 0.001) and disease-free survival (HR 3.834; 95 % CI 2.145-6.852; p < 0.001).

CONCLUSION

CD151 overexpression is an independent prognostic factor and could be a potential molecular therapeutic target in patients with advanced gastric cancers. Further studies are needed to establish the biological significance of CD151/MET co-overexpression and the potential of targeting both molecules as a therapeutic strategy.

Prognostic implication of the CpG island methylator phenotype in colorectal cancers depends on tumour location

BACKGROUND

Colorectal cancer (CRC) is usually categorised as proximal or distal CRC. Recently, many researchers have tried to determine the molecular heterogeneity of CRCs along bowel subsites. However, the differential effects of the CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) on the clinical outcome according to tumour location are not well-known.

METHODS

We analysed clinicopathologic and molecular characteristics, including CIMP, MSI, KRAS and BRAF mutations, in 734 CRCs according to bowel subsites. And the prognostic value of CIMP and MSI was analysed according to tumour location.

RESULTS

We found a linear increase of female predominance, T, N category, stage, differentiation, absence of luminal necrosis, tumour -infiltrating lymphocytes, Crohn's-like lymphoid reaction, serration and mucin production from the rectum to caecum. CpG island methylator phenotype -high and MSI-high gradually increased from the rectum to caecum. CpG island methylator phenotype is a poor prognostic factor of overall survival (hazard ratio (HR): 4.13, 95% confidence interval (CI): 1.27-13.46) and disease-free survival (HR: 2.90, 95% CI: 1.04-8.08) in rectal cancers.

CONCLUSION

Clinicopathologic and molecular profiles of CRCs gradually change along bowel subsites, and the prognostic implication of CIMP is different according to tumour location.

Changes in postoperative recurrence and prognostic risk factors for patients with gastric cancer who underwent curative gastric resection during different time periods

BACKGROUND

Current rates of survival for gastric cancer patients are much improved compared with those of the past. The purpose of our study was to analyze the survival of gastric cancer patients according to time period and to examine how different prognostic factors are related to changing survival rates.

METHODS

We analyzed data from 7,757 patients who underwent curative gastrectomy after diagnoses of gastric cancer at Samsung Medical Center from 1994 to 2006. Clinicopathologic characteristics and prognostic factors were analyzed retrospectively, with patients divided into period I, from 1994 to 2001, and period II, from 2002 to 2006.

RESULTS

The 5-year, disease-free survival rate of patients with gastric cancer increased significantly from 76.7 % during period I to 85.9 % during period II (p < 0.001). The prognosis of the patient who underwent surgery during period I was worse than that of the patient in period II. When multivariate analyses were performed for each time period, independent prognostic factors for period I included patient age >60 years, tumor located in the whole stomach, tumor size, stage, vascular invasion, perineural invasion, and adjuvant chemotherapy. For period II, tumor size, vascular, and adjuvant chemotherapy were no longer independent prognostic risk factors.

CONCLUSIONS

The disease-free survival of gastric cancer improved and prognostic factors changed over time. Active, concurrent chemoradiotherapy together with radical gastric resection performed by an expert surgeon seemed to contribute to the improvement in the survival rates of gastric cancer.

Effects of surface chemical structure on the mechanical properties of Si(1-x)Ge(x) nanowires

The Young's modulus and fracture strength of Si(1-x)Ge(x) nanowires (NWs) as a function of Ge concentration were measured from tensile stress measurements. The Young's modulus of the NWs decreased linearly with increasing Ge content. No evidence was found for a linear relationship between the fracture strength of the NWs and Ge content, which is closely related to the quantity of interstitial Ge atoms contained in the wire. However, by removing some of the interstitial Ge atoms through rapid thermal annealing, a linear relationship could be produced. The discrepancy in the reported strength of Si and Ge NWs between calculated and experimented results could be related to SiO(2-x)/Si interfacial defects that are found in Si(1-x)Ge(x) NWs. It was also possible to significantly decrease the number of interfacial defects in the NWs by incorporating a surface passivated Al2O3 layer, which resulted in a substantial increase in fracture strength.

Heterogeneous target protein expression in synchronous multiple gastric carcinomas

OBJECTIVE

To explore the target protein expression in separate tumors in a patient with synchronous multiple gastric carcinomas (SMGCs).

STUDY DESIGN

Immunohistochemistry for HER2, EGFR, and MET were performed in 282 carcinomas from 141 patients.

RESULTS

Of 141 patients with SMGCs, 11.3%, 23.4%, and 14.9% of cases showed HER2, EGFR, and MET protein overexpression, respectively. In SMGC cases with overexpression of target proteins in > 1 tumor, intertumoral heterogeneity was 81.3% (13/16) for HER2, 78.8% (26/33) for EGFR, and 90.5% (19/21) for MET protein. The concordance rate of HER2, EGFR, and MET expression between 2 carcinomas from the same patient was 90.8%, 81.6%, and 86.5%, respectively, with a kappa value below 0.3, indicating slight to fair agreement.

CONCLUSION

We found a considerable intertumoral heterogeneity of target protein overexpression in SMGCs. Our findings support a multicentric origin for SMGC and emphasize the need to perform immunohistochemistry for all synchronous lesions.

A novel proteomics-based clinical diagnostics technology identifies heterogeneity in activated signaling pathways in gastric cancers

Purpose

The aim of this study was to utilize the proteomics-based Collaborative Enzyme Enhanced Reactive (CEER) immunoassay to investigate protein tyrosine phosphorylations as diagnostic markers in gastric cancers (GCs).

Experimental Design

Protein lysates from fresh-frozen 434 advanced stage GCs were analyzed for phosphorylation of HER1, HER2, p95HER2, HER3, cMET, IGF1R and PI3K. The pathway activation patterns were segregated based on the tumor HER2 status. Hierarchical clustering was utilized to determine pathway coactivations in GCs. Prognostic value of pathway activation patterns was determined by correlating disease-free survival times of the various GC subgroups using Kaplan-Meier survival analysis. CEER was also used to determine the presence of tyrosine phosphorylated signaling cascades in circulating tumor cells (CTCs) and ascites tumor cells (ATCs).

Results

Utilizing a novel diagnostics immunoassay, CEER, we demonstrate the presence of p95HER2 and concomitantly activated signaling pathways in GC tumor tissues, CTCs and ATCs isolated from GC patients for the first time. p95HER2 is expressed in ∼77% of HER2(+) GCs. Approximately 54% of GCs have an activated HER1, HER2, HER3, cMET or IGF1R and demonstrate a poorer prognosis than those where these receptor tyrosine kinases (RTKs) are not activated. Hierarchical clustering of RTKs reveals co-clustering of phosphorylated HER1:cMET, HER2:HER3 and IGF1R-PI3K. Coactivation of HER1 with cMET renders GCs with a shorter disease-free survival as compared to only cMET activated GCs.

Conclusions

Our study highlights the utility of a novel companion diagnostics technology, CEER that has strong implications for drug development and therapeutic monitoring. CEER is used to provide an increased understanding of activated signaling pathways in advanced GCs that can significantly improve their clinical management through accurate patient selection for targeted therapeutics.

A large cohort of consecutive patients confirmed frequent HER2 positivity in gastric carcinomas with advanced stages

BACKGROUND

Trastuzumab in association with systemic cytotoxic chemotherapy is the standard of care for patients with advanced HER2-positive gastric carcinoma (GC). However, HER2 as a prognostic factor in GC remains controversial.

METHODS

HER2 overexpression and amplification was evaluated by immunohistochemistry (IHC) and silver in situ hybridization (SISH) in 2,798 GCs obtained from 2,727 gastrectomy and 71 open/laparoscopic biopsy specimens from patients with peritoneal seeding. Regional heterogeneity was defined as the proportion of tumor cells showing membranous staining in 10-70 % of tumor cells. Genetic heterogeneity was determined by the existence of HER2/CEP17 ratio higher than 2.0 in >5 to <50 % of tumor cells.

RESULTS

In IHC, 184 cases (6.6 %) were 3+ and 44 cases (1.6 %) were 2+. Of 44 HER2 2+ cases, SISH showed HER2 gene amplification in 21 cases (47.7 %), chromosome 17 polysomy in six cases (13.6 %), and genetic heterogeneity in five cases (11.4 %). HER2 positivity found in 7.3 % of GCs was significantly associated with older age, male gender, intestinal histology, upper third in location, higher lymph node stage (p < .002), and advanced AJCC stage (p = .033). Regional heterogeneity of HER2 was closely associated with 2+ (70.5 vs 42.9 % in 3+, p = .001) and diffuse or mixed histologic type (p = .005).

CONCLUSIONS

Regional heterogeneity of HER2 expression was closely associated with weak HER2 overexpression (2+) and with diffuse or mixed histology. Polysomy of chromosome 17 would be an important cause of HER2 2+ in IHC. Frequent HER2 positivity observed in GCs with advanced stages suggests that HER2 may be involved in tumor progression and poor prognosis.

Predictive factors for lymph node metastasis in patients with poorly differentiated early gastric cancer

BACKGROUND

Endoscopic submucosal dissection is gaining popularity in the treatment of early gastric cancer. This study aimed to identify clinicopathological factors predictive of lymph node metastasis in patients with the poorly differentiated early gastric cancer to assess the feasibility of using endoscopic submucosal dissection for these cancers.

METHODS

The records of patients with poorly differentiated early gastric cancer who had undergone gastric cancer surgery between January 2002 and December 2009 were reviewed. Associations between clinicopathological factors and the presence of lymph node metastasis were analysed by univariable and multivariable logistic regression analysis.

RESULTS

Some 1005 patients were included in the analysis. Univariable analysis indicated that lymph node metastasis was associated with sex, ulceration, tumour size, depth of invasion, macroscopic type, lymphatic invasion and venous invasion. Logistic regression revealed that lymph node metastasis was significantly associated with sex, tumour size, depth of tumour invasion and lymphatic involvement. In the group with none of these risk factors (men with mucosal tumour no larger than 2 cm in size, with no lymphatic involvement), lymph node metastasis was present in four (3·2 per cent) of 124 patients.

CONCLUSION

In the present study 3·2 per cent of patients who were negative for all identified risk factors had lymph node metastasis. The use of endoscopic submucosal dissection should be considered carefully in the treatment of poorly differentiated early gastric cancer.

Impact of body mass index on surgical outcomes in radical total gastrectomy

BACKGROUND/AIMS

In this study, the authors evaluated the impact of body mass index (BMI) on surgical outcomes in patients undergoing total gastrectomy for upper third early gastric cancer.

METHODOLOGY

Sixty-one consecutive patients with upper third early gastric cancer that underwent radical total gastrectomy from May 2009 to December 2009 were included in this prospective cohort study. Patients were stratified by BMI (in accordance with the WHO guidelines) into a normal group (18.5-24.9kg/m2), and an overweight group (≥25.0kg/m2). These two groups were compared with respect to stomach specimen weight (g), operative time (min), number of lymph nodes harvested, length of postoperative hospital stay (day), and postoperative complication rate (%).

RESULTS

Thirty-seven (61%) patients had a normal weight and 24 (39%) were overweight. According to multivariate analysis, the only factor correlated with BMI was the weight of stomach extirpated en bloc with omentum, and the weight of stomach extirpated en bloc with omentum was also significantly correlated with operative time. However, BMI was not found to be significantly correlated with postoperative complications.

CONCLUSIONS

This study suggested that an elevated BMI was significantly associated with increased weight of stomach extirpated en bloc with omentum, which was found to elongate operative times.

The predictors and clinical impact of positive resection margins on frozen section in gastric cancer surgery

Purpose

The aim of this study is to compare the characteristics of tumor and prognosis, depending on the status of resection margin involvement, on the frozen section diagnosis in gastric cancer.

Materials and Methods

This study was conducted retrospectively, in 83 margin-positive patients on the frozen section diagnosis, who underwent gastrectomy from July 1995 to September 2006. The control group was selected by matching the age, gender, TNM stage and status of adjuvant chemoradiotherapy, among those who had shown clear resection margins. The characteristics of tumor and patient survival are investigated, and they were analyzed between the two groups.

Results

The tumor size was significantly larger in the study group than that of the control group (P=0.037). There was significant difference between the two groups in location of the tumors (P=0.003). Multivariate analysis indicated that only the location and Lauren's classification are independent factors, which affected the resection margin involvement. Median survival was 41.0±11.5 months in the study group and 93.0±30.3 months in the control group (P=0.049). In the survival analysis, it was investigated that TNM stage and the resection margin involvement of the frozen section diagnosis were the critical variables.

Conclusions

When the tumor is located at the middle or the upper third, or the Lauren's indeterminate type, they are highly likely to show the resection margin involvement on the frozen section diagnosis, and it can, therefore, have negative effects on the prognosis. It is considered as good to perform more extensive resection as possible, during the initial resection.

Tumor size predicts survival in mucinous gastric carcinoma

BACKGROUND

Mucinous gastric carcinoma (MGC) is a distinct histologic subtype of gastric cancer. However, the prognostic significances of the current TNM staging system and histology in MGC have not been studied.

METHODS

206 patients who underwent R0 resection for MGC were classified by tumor size (<3 cm as T1; ≥ 3-5 cm as T2; ≥ 5-9 cm as T3; and ≥ 9 cm as T4). Immunohistochemistry for EGFR and HER2 was also performed.

RESULTS

Tumor sizes ranged from 1.2 to 21.0 cm (median 6.2 cm). Large tumor size (≥ 5 cm) was significantly associated with older patient age, deeper invasion depth, and more frequent lymph node metastasis (P < 0.05). Tumor size was a significant prognostic factor in both univariate (P < 0.001) and multivariate (P < 0.04) analyses. However, depth of invasion was not significant in multivariate analyses. A modified staging system based on tumor size predicted survival more accurately than did the conventional TNM staging system. We verified our results in an independent validation cohort of 123 MGC patients. Overexpression of either EGFR or HER2 was rare.

CONCLUSIONS

In MGCs, tumor size is an independent prognostic factor and a modified TNM system based on tumor size predicted survival accurately.

Circular stapler size and risk of anastomotic complications in gastroduodenostomy for gastric cancer

BACKGROUND

A Billroth I reconstruction with a mechanically sutured anastomosis is commonly performed in gastric cancer patients. Some surgeons prefer to use large circular staplers during suturing to minimize risks for anastomotic stricture and gastric stasis after surgery. The effect of stapler size on anastomotic complications has not been validated.

METHODS

This study was conducted with 1,031 patients who underwent gastrectomy and Billroth I reconstruction at Samsung Medical Center in Seoul, Korea, between January 2007 and October 2008. Patients were assigned to group A (384 patients) or group B (647 patients) depending on the size of the circular stapler that the surgeon selected for mechanical anastomosis. A 25 mm circular stapler was used for patients in group A, and a 28 or 29 mm circular stapler was used for patients in group B. Postoperative complications were analyzed retrospectively.

RESULTS

The incidence of complications (e.g., gastric stasis, anastomotic stricture, and bleeding) did not differ significantly between groups. Age greater than 60 years was the only significant risk factor for anastomotic complications identified in univariate and multivariate analyses.

CONCLUSIONS

Stapler size was unrelated to complications, such as stricture and gastric stasis. Age was the only significant risk factor for anastomotic complications after gastroduodenostomy.

Clinical significance of gastritis cystica profunda and its association with Epstein-Barr virus in gastric cancer

BACKGROUND

Gastritis cystica profunda (GCP) is a relatively rare disorder characterized by hyperplastic and cystic down growth of gastric glands into the submucosa. In the current study, the authors attempted to clarify the clinical and pathologic features of GCP in patients with gastric cancer.

METHODS

The records of 10,728 patients with gastric cancer who underwent gastric cancer surgery were reviewed. The clinicopathologic features of patients who had GCP (n = 161) were compared with the features of patients without GCP (n = 10,567). In situ hybridization to determine Epstein-Barr virus (EBV) positivity was performed in cancer tissues from patients with (n = 119) and without (n = 503) GCP.

RESULTS

GCP was associated significantly with older age, male gender, proximal tumor location, differentiated histology and Lauren intestinal type compared with non-GCP. GCP also was present more frequently in remnant and multiple gastric cancers. Patients who had GCP presented with earlier tumor stages in terms of depth of invasion and lymph node metastasis, and they had less lymphatic and perineural invasion than patients without GCP; however, the presence of GCP was not an independent prognostic factor. The EBV-positive rate was significantly higher in the GCP group (31.1%) than in the non-GCP group (5.8%).

CONCLUSIONS

Patients with gastric cancer who had GCP had clinicopathologic features that differed from the features observed in patients without GCP. GCP was associated significantly with EBV-positive gastric cancers, and its possible role as a premalignant lesion needs to be clarified.

Nutritional risk index as a predictor of postoperative wound complications after gastrectomy

AIM: To investigate the correlation between the nutritional risk index (NRI) and postoperative wound complications.

METHODS: From January 2008 through June 2008, 669 patients who underwent curative gastrectomy for gastric cancer were included in a retrospective study. Medical records of consecutive patients were collected and analyzed to determine postoperative wound complication rates. The NRI was assessed on the fifth postoperative day and other possible risk factors for the incidence of wound complications were analyzed to identify the factors affecting postoperative wound complications. Patients with other postoperative complications were excluded from the study.

RESULTS: On the 5th postoperative day, the NRI sh-owed a malnutrition rate of 84.6% among postoperative patients. However, postoperative wound complications occurred in only 66/669 (9.86%) patients. Of the patients with wound complications, 62/66 (94%) belonged to the malnourished group (NRI < 97.5), and 4/66 (6%) patients to the non-malnourished group (NRI ≥ 97.5). The only factor correlated with wound complications was the NRI on the 5th postoperative day (odds ratio of NRI ≥ 97.5 vs NRI < 97.5: 0.653; 95% confidence interval: 0.326-0.974; P = 0.014) according to univariate analysis as well as multivariate analysis.

CONCLUSION: This study suggests that malnutrition immediately after surgery may play a significant role in the development of wound complications.

Phase III trial comparing capecitabine plus cisplatin versus capecitabine plus cisplatin with concurrent capecitabine radiotherapy in completely resected gastric cancer with D2 lymph node dissection: the ARTIST trial

PURPOSE

The ARTIST (Adjuvant Chemoradiation Therapy in Stomach Cancer) trial was the first study to our knowledge to investigate the role of postoperative chemoradiotherapy therapy in patients with curatively resected gastric cancer with D2 lymph node dissection. This trial was designed to compare postoperative treatment with capecitabine plus cisplatin (XP) versus XP plus radiotherapy with capecitabine (XP/XRT/XP).

PATIENTS AND METHODS

The XP arm received six cycles of XP (capecitabine 2,000 mg/m2 per day on days 1 to 14 and cisplatin 60 mg/m2 on day 1, repeated every 3 weeks) chemotherapy. The XP/XRT/XP arm received two cycles of XP followed by 45-Gy XRT (capecitabine 1,650 mg/m2 per day for 5 weeks) and two cycles of XP.

RESULTS

Of 458 patients, 228 were randomly assigned to the XP arm and 230 to the XP/XRT/XP arm. Treatment was completed as planned by 75.4% of patients (172 of 228) in the XP arm and 81.7% (188 of 230) in the XP/XRT/XP arm. Overall, the addition of XRT to XP chemotherapy did not significantly prolong disease-free survival (DFS; P = .0862). However, in the subgroup of patients with pathologic lymph node metastasis at the time of surgery (n = 396), patients randomly assigned to the XP/XRT/XP arm experienced superior DFS when compared with those who received XP alone (P = .0365), and the statistical significance was retained at multivariate analysis (estimated hazard ratio, 0.6865; 95% CI, 0.4735 to 0.9952; P = .0471). CONCLUSION The addition of XRT to XP chemotherapy did not significantly reduce recurrence after curative resection and D2 lymph node dissection in gastric cancer. A subsequent trial (ARTIST-II) in patients with lymph node-positive gastric cancer is planned.

Adenocarcinoma derived from gastric hamartomatous polyps

Most hamartomatous polyps in the stomach occur in patients with adenomatous polyposis coli and dysplasia. The authors report a case of a 57-year-old man without prior history of polyposis coli who presented with adenocarcinomas derived from hamartomatous polyps in the stomach. The patient underwent a radical subtotal gastrectomy with Billroth I anastomosis. Pathology revealed adenocarcinomas with moderate differentiation without evidence of lymph node metastasis in 60 nodes. We report a case of gastric cancers arising from de novo gastric hamartomatous polyps.

Long-term results and prognostic factors of gastric cancer patients with only positive peritoneal lavage cytology

BACKGROUND AND OBJECTIVES

The purpose of the present study was to investigate clinicopathologic features of gastric cancer patients with only positive peritoneal cytology in the absence of overt peritoneal metastases, and which might distinguish patients with poorer prognosis.

METHODS

Between September 1994 and August 2006, clinicopathological features were retrospectively evaluated in 37 consecutive patients with gastric cancer who underwent a curative resection and had positive peritoneal cytology in the absence of overt peritoneal metastases. Survival including disease-free survival (DFS) and overall survival (OS), and recurrence patterns were analyzed according to clinicopathologic characteristics.

RESULTS

The median follow-up period was 16.1 months (range, 3-45 months). The median DFS and OS of patients after curative resection were 10 months (range, 1-33 months) and 15 months (range, 2-45 months), respectively. All patients had recurred, in 34 (92%) with peritoneal dissemination. The overall 1-, 2-, 3-, and 5-year survival rates for the 37 consecutive patients were 43.2%, 45.9%, 5.4%, and 0%, respectively. Multiple linear regression analysis revealed that Borrmann type IV was an independent predictor for poorer prognosis.

CONCLUSIONS

A Borrmann type IV carcinoma may be the candidates for intraperitoneal chemotherapy among advanced gastric cancer patients.

Validation of seventh edition AJCC gastric cancer staging modifications

BACKGROUND AND OBJECTIVES

The seventh edition of the AJCC has more detailed staging categories for gastric cancer than does the sixth edition. The aim of our study was to compare the prognostic accuracies of the sixth and seventh AJCC editions for gastric cancer patients.

METHODS

We analyzed survival rates by category using the sixth and seventh editions of the AJCC in 10,060 patients with gastric cancer who had undergone gastrectomy between 1994 and 2007 at Samsung Medical Center.

RESULTS

Significant differences in prognosis were seen when comparing the new stages of the seventh edition of the AJCC that are subgroups of stages IB, II, IIIA, and IV in the sixth edition. In particular, stage IV of the AJCC sixth edition is divided into stages IIB, IIIA, IIIB, IIIC and IV in the seventh edition, and the 5-year survival rates of these respective stages were 80.2%, 45.3%, 23.5%, 17.2%, and 10.1% (P < 0.001).

CONCLUSIONS

Each category of the AJCC sixth edition has been divided into multiple stages in the AJCC seventh edition, each with a different prognosis. The newly divided subgroups from AJCC sixth edition stage IV showed more accurate outcome classification based on AJCC seventh edition staging stratification.

Stapling technique for performing Billroth II anastomosis after distal gastrectomy

The circular stapling technique has been widely applied for gastrointestinal anastomosis in gastrectomies (open or laparoscopic) for distal gastric cancers. We describe this method for use in performing Billroth II anastomosis in distal gastrectomies. From 2002-2009, we report the results following the use of the circular stapling technique performed in 520 patients at a single institution. The median time of completing the anastomosis was shorter using the stapling technique compared to the hand-sewn technique. The use of the stapler resulted in two cases of minor intraluminal bleeding at the anastomotic site. The circular stapling method can be applied safely and more efficiently in performing Billroth II reconstruction after distal gastrectomy compared to the hand-sewn method in patients with gastric cancer.

The relationships between perioperative CEA, CA 19-9, and CA 72-4 and recurrence in gastric cancer patients after curative radical gastrectomy

BACKGROUND AND OBJECTIVES

The correlation between perioperative CEA, CA 19-9, and CA 72-4 and recurrence of gastric cancer has not been clarified. The aim of this study was to investigate the relationships between perioperative CEA, CA 19-9, and CA 72-4 and recurrence of gastric cancer.

METHODS

We retrospectively analyzed the relationships between the tumor markers CEA, CA 19-9, and CA 72-4 and recurrence of gastric cancer.

RESULTS

In patients with early gastric cancer, the recurrence sensitivity of postoperative CEA, CA 19-9, and CA 72-4 was 40.0, 5.6, and 2.8%, respectively. And in patients with advanced gastric cancer, the recurrence sensitivity of postoperative CEA, CA 19-9, and CA 72-4 was 100.0, 68.2, and 51.3%, respectively. Multivariate analyses showed that an increase in postoperative CEA in early gastric cancer was an independent prognostic factor of recurrence. In patients with advanced gastric cancer, age >60 years, stage III, and postoperative CEA increase and CA 72-4 increase were independent prognostic factors of recurrence.

CONCLUSIONS

For patients with advanced gastric cancer, CEA, CA 19-9, and CA 72-4 are considered useful for follow-up tests. Although, CEA is considered useful for follow-up test for patients with early gastric cancer, but CA19-9 and CA72-4 are less useful due to their low sensitivity.

Early gastric cancer arising from heterotopic gastric mucosa in the gastric submucosa

The incidence of heterotopic gastric mucosa located in the submucosa in resected stomach specimens has been reported to be 3.0 to 20.1%. Heterotopic gastric mucosa is thought to be a benign disease, which rarely becomes malignant. Heterotopic gastric mucosa exists in the gastric submucosa, and gastric cancer rarely occurs in heterotopic gastric mucosa. Since tumors are located in the normal submucosa, they appear as submucosal tumors during endoscopy, and are diagnosed through endoscopic biopsies with some difficulty. For such reasons, heterotopic gastric mucosa is mistaken as gastric submucosal tumor. Recently, two cases of early gastric cancer arising from heterotopic gastric mucosa in the gastric submucosa were treated. Both cases were diagnosed as submucosal tumors based on upper gastrointestinal endoscopy, endoscopic ultrasound, and computed tomography findings, and in both cases, laparoscopic wedge resections were performed, the surgical findings of which also suggested submucosal tumors. However, pathologic assessment of the surgical specimens led to the diagnosis of well-differentiated intramucosal adenocarcinoma arising from heterotopic gastric mucosa in the gastric submucosa.

Impact of MET amplification on gastric cancer: possible roles as a novel prognostic marker and a potential therapeutic target

Identification of critical genes which play pivotal roles in controlling tumor growth and survival will establish the basis for developing therapeutic targets. With the aim of establishing personalized medicine for treatment of solid tumors, we focused on MET amplification in gastric cancer patients, given the extreme sensitivity to c-Met inhibitor in MET amplified gastric cancer cell lines. We tested MET amplification and activation of c-Met in various gastric cancer cell lines and tissue samples from 482 gastric cancer patients who underwent curative surgery. Gastric cancer cell lines with MET amplification by quantitative real-time PCR (qPCR) and FISH predicted sensitivity to PHA-665,752, a selective c-Met kinase inhibitor. Of the 472 patients who had DNA sample available for qPCR analysis, 100 patients (21.2%) had a MET copy number greater than 4.0 copies and demonstrated poorer survival following curative surgery with statistical significance (5-year OS; 50.0 vs. 59.1%; MET amplification (+) vs. MET amplification (-); P = 0.0134). These results suggest that the increased MET copy number measured by qPCR plays an important role in determining prognosis in gastric cancer patients. However, the predictive role of MET amplification for treatment response should be further explored in upcoming clinical trials.

Frequency and predictive factors of lymph node metastasis in mucosal cancer

Purpose

The incidence of lymph node metastasis has been reported to range from 2.6 to 4.8% in early stage gastric cancer with mucosal invasion (T1a cancer). Lymph node metastasis in early stage gastric cancer is known as an important predictive factor. We analyzed the prediction factors of lymph node metastasis in T1a cancer.

Materials and Methods

A total of 9,912 patients underwent radical gastrectomy due to gastric cancer from October 1994 to July 2006 in the Department Of Surgery at Samsung Medical Center. We did a retrospective analysis of 2,524 patients of these patients, ones for whom the cancer was confined within the mucosa.

Results

Among the 2,524 patients, 57 (2.2%) were diagnosed with lymph node metastasis, and of these, cancer staging was as follows: 41 were N1, 8 were N2, and 8 were N3a. Univariate analysis of clinicopathological factors showed that the following factors were significant predictors of metastasis: tumor size larger than 4 cm, the presence of middle and lower stomach cancer, poorly differentiated adenocarcinoma and signet-ring cell carcinoma, diffuse type cancer (by the Lauren classification), and lymphatic invasion. Multivariate analysis showed that lymphatic invasion and tumor larger than 4 cm were significant factors with P<0.001 and P=0.024, respectively.

Conclusions

The frequency of lymph node metastasis is extremely low in early gastric cancer with mucosal invasion. However, when lymphatic invasion is present or the tumor is larger than 4 cm, there is a greater likelihood of lymph node metastasis. In such cases, surgical treatments should be done to prevent disease recurrence.

Surgical outcome after incomplete endoscopic submucosal dissection of gastric cancer

BACKGROUND

Endoscopic resection of early gastric cancer is a relatively new and attractive treatment, but occasionally fails to remove all cancer lesions completely. This study aimed to elucidate clinicopathological factors that could be helpful in predicting residual tumour in the surgical specimen after incomplete endoscopic submucosal dissection (ESD).

METHODS

Patients who underwent gastrectomy because of incomplete ESD between August 2004 and August 2008 were analysed. Clinicopathological characteristics were reviewed retrospectively from prospectively collected medical records. Patients were classified into groups with and without residual tumour. Pathology results following gastrectomy were compared with those of incomplete ESD.

RESULTS

A total of 118 patients were included. The incidence of residual tumour in the surgical specimen was 24·6 per cent after incomplete ESD. Elevated/flat-type cancers, large tumours (at least 2 cm) and those limited to the mucosa had significantly higher incomplete ESD rates. Cancer limited to the mucosa and the presence of tumour in the lateral margin were associated with residual tumour in the surgical specimen (both P = 0·001).

CONCLUSION

Radical gastrectomy should be performed if pathological examination reveals a positive lateral resection margin after ESD.