The risk of lymph node metastases in 3951 surgically resected mucosal gastric cancers: implications for endoscopic resection.

BACKGROUND AND AIMS: Endoscopic resection for mucosal gastric cancer (MGC) is highly recommended in the absence of lymph node metastasis (LNM). We aimed to clarify the risk factors for LNM in MGC and to investigate the association of LNM with the indication criteria for endoscopic submucosal dissection (ESD). METHODS: A retrospective cohort study was performed on 3951 patients with MGC who underwent radical gastrectomy at the Samsung Medical Center in Seoul, Republic of Korea, between September 1994 and September 2010. RESULTS: Of the patients with MGC, 101 (2.60%) were positive for LNM. Multivariate analysis, followed by univariate analysis, revealed the following risk factors for LNM in MGC: large tumor size, undifferentiated tumor type, lymphatic invasion, perineural invasion, and associated ulceration in the tumor (hazard ratio 1.25, 7.49, 20.65, 23.45, and 4.07, respectively). Patients without LNM had significantly increased survival and/or recurrence-free survival rates than patients with LNM (188.4/209.8 months vs 169.5/188.0 months; P = .029/.004, respectively). Only 3 of 1065 patients (0.3%) who met the absolute indication criteria for ESD had LNM. Of those who met the expanded indication criteria for ESD, 11 of 2678 patients (0.4%) had LNM. LNM also was found in 2 patients who had a differentiated tumor <0.5 cm without ulceration. CONCLUSION: The risk for LNM was very low when patients with MGC met the absolute and/or expanded criteria for endoscopic resection, which meant the indication criteria for ESD was safe and acceptable. However, although the risk for LNM is very low, it should not be considered negligible in endoscopic resection.

Lymphoepithelioma-like carcinoma: a distinct type of gastric cancer.

BACKGROUND: Lymphoepithelioma-like carcinoma (LELC) is a rare type of gastric carcinoma and has histologic features of intense lymphocytic infiltration. In this study, we attempted to analyze the clinicopathologic characteristics and survival outcome of patients with LELC compared with those with non-lymphoepithelioma-like carcinoma (NLELC). METHODS: We studied 4282 patients who underwent gastrectomies to treat gastric cancer at the Department of Surgery of the Samsung Medical Center in Seoul, between January 2008 and December 2010. The clinicopathologic features and clinical outcomes of patients with LELC (n = 46) were compared with those with NLELC (n = 4236). In situ hybridization for Epstein-Barr virus (EBV) positivity was performed on the tissue of patients with LELC (n = 46) and NLELC (n = 1247). RESULTS: The patients with LELC are male predominant and had more upper locations, more indeterminate Lauren classifications, lower T stages, less lymphatic invasion, and more positive EBV in situ hybridization compared with those of the NLELC group (80.4% versus 6.5%). Age, histologic type, Lauren type, the location of the tumor, the depth of the invasion, lymph node metastasis, and venous invasion were independent prognostic factors; however, the LELC type itself was not predictive of outcome. The 5-y survival rate of the LELC group (97.7%) was better than that of the NLELC group (89.4%); however, this difference was not statistically significant (P = 0.127). CONCLUSIONS: The results of our study suggest that LELC is a less advanced disease than NLELC in terms of depth of invasion and lymphatic invasion at diagnosis. However, our study does not examine LELC as an independent prognostic factor of gastric cancer. Further studies are needed to explore its associations with EBV and a distinct pathway of carcinogenesis from NLELC.

Preoperative smoking cessation can reduce postoperative complications in gastric cancer surgery.

BACKGROUND: Despite the close link between cigarette smoking and the development of gastric cancer, little is known about the effects of cigarette smoking on surgical outcomes after gastric cancer surgery. The aim of this study was to investigate whether preoperative smoking status and the duration of smoking cessation were associated with short-term surgical consequences in gastric cancer surgery. METHODS: Among 1,489 consecutive patients, 1,335 patients who underwent curative radical gastrectomy at the Samsung Medical Center between January and December 2009 were included in the present study. The smoking status was determined using questionnaires before surgery. Smokers were divided into four groups according to the duration of smoking cessation preoperatively (<2, 2-4, 4-8, and >8 weeks). The primary endpoint was postoperative complications (wound, lung, leakage, and bleeding); secondary endpoints were 3-year recurrence-free survival (RFS) and overall survival (OS). RESULTS: Five hundred twenty-two patients (39.1 %) were smokers. Smokers had a significantly higher overall incidence of postoperative complications than nonsmokers (12.3 vs. 5.2 %, P < 0.001, respectively), especially in impaired wound healing, pulmonary problems, and leakage. Smokers also had more severe complications than nonsmokers. After adjusting for other risk factors, the odds ratio (95 % CI) for the development of postoperative complications in the subgroups who stopped smoking <2 weeks, 2-4, 4-8, and >8 weeks preoperatively were 3.35 (1.92-5.83), 0.99 (0.22-4.38), 2.18 (1.00-4.76), and 1.32 (0.70-2.48), respectively, compared with the nonsmokers. There were no significant differences in 3-year RFS (P = 0.884) and OS (P = 0.258) between smokers and nonsmokers. CONCLUSIONS: Preoperative smoking cessation for at least 2 weeks will help to reduce the incidence of postoperative complications in gastric cancer surgery.

Ultrasonically activated shears versus electrocautery in open gastrectomy for gastric cancer: a randomized controlled trial.

BACKGROUND: Use of ultrasonically activated shears (UAS) is gaining popularity in open surgery but without concrete evidence. We conducted a prospectively randomized study to assess the efficacy of ultrasonic dissection in open gastrectomy for gastric cancer. METHODS: Patients with gastric cancer who were to undergo gastrectomy with D2 lymph node dissection were enrolled and assigned to either the conventional surgery group (n = 125) or the UAS group (n = 128). RESULTS: The mean operating time was significantly reduced in the UAS group (89.3 ± 15.6 min) when compared to the conventional group (97.8 ± 17.2 min; p < 0.001). However, we did not find any significant difference in operative blood loss, the amount of postoperative abdominal drainage, or the rate of postoperative complications between the groups. A multivariate analysis for operating time revealed that the use of UAS, female gender and BMI less than 25 were significantly associated with reduced operating time. The operating time was significantly longer in the conventional group than in the UAS group (B 7.786; 95 % CI 4.103-11.468; p < 0.001). In the subgroup analysis, the use of UAS significantly reduced the operating time, especially in male patients, regardless of the BMI status. CONCLUSIONS: The use of UAS in gastrectomy for gastric cancer was a safe and efficient method, especially in terms of reducing operating time for male patients.

Factors related to clinically relevant fatigue in disease-free stomach cancer survivors and expectation-outcome consistency.

BACKGROUND: Although early detection and improved treatment have increased the number of long-term survivors, little is known about the prevalence and associations of clinically relevant fatigue (CRF) in disease-free stomach cancer survivors. Because no effective CRF management strategy yet exists, understanding CRF risk factors is important for developing treatment approaches. METHODS: Stomach cancer survivors (N = 374) completed a mailed survey that included the Brief Fatigue Inventory, Beck Depression Inventory, and the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaire and its gastric module QLQ-STO22. We assessed sociodemographic, clinical, and symptom characteristics using multivariate logistic regression models to identify CRF-associated factors. RESULTS: Approximately half of disease-free stomach cancer survivors reported CRF, which was associated with female gender, low economic status, rural residence, current smoker, early tumor progress, current depression, and poor performance. Significant relationships of CRF with current depression and poor performance status remained robust after adjusting for potential confounders. Most functional and symptom scores of fatigued survivors deteriorated more than in non-fatigued survivors. Additionally, congruence between tumor progress and surgery type might influence CRF severity. CONCLUSION: In disease-free stomach cancer survivors, CRF is a common problem that is strongly associated with quality of life and other symptoms. Current depression, poor performance, and perceived understanding regarding postoperative condition are important CRF risk factors. Thus, CRF management in this population should focus on identifying these factors.

Suicide ideation in stomach cancer survivors and possible risk factors.

PURPOSE: Although the suicide rate of cancer survivors is higher than that of the general population, few studies have examined the potential risk factors. We assessed suicide ideation (SI) and investigated its correlates among survivors of stomach cancer, which is one of the most prevalent cancers in Korea. METHODS: We surveyed 378 stage I-III stomach cancer survivors who had been disease free for at least 1 year. The survey contained demographic questions and quality of life assessments from the European Organization for Research and Treatment of Cancer QLQ-C30 and its stomach cancer-specific module, the McGill Quality of Life Questionnaire, the Brief Fatigue Inventory, and one question from the Beck Depression Inventory. RESULTS: We found that 131/378 stomach cancer survivors (34.7 %) experienced SI. Univariate analyses showed that SI was significantly associated with income, comorbidity, smoking, and the following quality of life factors: general health status, emotional functioning, fatigue, nausea/vomiting, dyspnea, appetite loss, constipation, diarrhea, financial problems, eating restriction, anxiety, dry mouth, trouble belching, hair loss, body image, existential well-being, and social support. Multivariate logistic regression confirmed that SI was independently associated with diarrhea (adjusted odds ratio (aOR) 2.84; 95 % confidence interval (CI) 1.44-5.62), hair loss (aOR 2.77; 95 % CI 1.04-7.36), existential well-being (aOR 6.18; 95 % CI 2.91-13.1), and usual fatigue (aOR 2.29; 95 % CI 1.30-4.06). CONCLUSION: Our findings reveal a high prevalence of SI among stomach cancer survivors and identify health-related quality of life issues such as diarrhea, hair loss, existential well-being, and fatigue as important risk factors of SI.

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.

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.

Changes of quality of life in gastric cancer patients after curative resection: a longitudinal cohort study in Korea.

OBJECTIVE: Little is known about how quality of life (QOL) changes over time after gastrectomy. We prospectively examined changes of QOL in Korean patients with gastric cancer after curative resection. BACKGROUND: As early detection and improved treatment have led to higher survival rates and an increasing number of long-term survivors, the importance of QOL has increased. METHODS: Patients newly diagnosed with gastric cancer, who were expected to undergo curative resection, were studied. QOL was assessed, using the European Organization for Research and Treatment of Cancer QLQ-C30 and its gastric module QLQ-STO22, before and after 3 and 12 months of gastrectomy. RESULTS: In total, 465 patients were included in the study, and 377 and 88 patients underwent subtotal gastrectomy and total gastrectomy, respectively. For most of the functional or symptom scales, the mean score deteriorated at 3 months and generally improved during follow-up period. Patients with total gastrectomy had more functional and symptomatic problems related to QOL than those with subtotal gastrectomy during the follow-up. For both groups, there were temporal, unrecovered, improved, and unchanged problems in QOL. Fatigue; digestive symptoms such as diarrhea, dysphagia, and eating restrictions; body image disturbance; and cognitive functioning were the representative unrecovered problems, which persisted at 12 months after surgery. CONCLUSIONS: Our findings show that there are various functional and symptomatic problems, which health care providers need to manage during the postsurgical period. We need to continuously address fatigue, diarrhea, dysphagia, eating restrictions, body image disturbance, and cognitive functioning. In addition, it would be necessary to inform patients about possible QOL outcomes while they are receiving information about surgery and signing informed consent for surgery.

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.

EBV infection and mismatch repair deficiency mediated by loss of hMLH1 expression contribute independently to the development of multiple synchronous gastric carcinomas.

BACKGROUND: To explore the possible association between EBV, microsatellite instability (MSI), and alterations of hMLH1 protein, 282 tumors from 141 patients with multiple synchronous gastric carcinomas (MSGC) were studied. METHODS: In situ hybridization for EBV-encoded small RNA and hMLH1 immunohistochemistry were performed in tissue microarrays. In 19 MSGC cases with altered hMLH1 expression, methylation analyses by MethyLight and MSI tests were performed. RESULTS: Loss of hMLH1 was found in 19 of 141 MSGC patients (13.5%) and 26 of 282 MSGC tumors (9.2%). hMLH1 loss was associated with differentiated histology (P = 0.03). Out of the 38 tumors from 19 hMLH1-negative MSGCs, 12 tumors from six cases (31.6%) showed concurrent methylation of hMLH1 and MSI-high in both multiple tumors. EBV was found in 31 of 141 MSGC patients (21.9%) and 49 of 282 MSGC tumors (17.4%) and was significantly associated with undifferentiated histology and a location within the upper third of the stomach (P < 0.002). EBV was not observed in any of the tumors that had a loss of hMLH1 expression. CONCLUSIONS: Considering that EBV-associated GCs show global CpG island methylation, our findings suggest that EBV infection allows the gastric mucosa to escape from aberrant methylation of hMLH1 and induces a malignant pathway independent of MSI.

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.

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 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.

Prognostic role of p-mTOR expression in cancer tissues and metastatic lymph nodes in pT2b gastric cancer.

Despite the great interest in mammalian target of rapamycin (mTOR) as a potential anticancer therapy target, the prognostic role of mTOR in gastric cancer has not been elucidated. In this study, we investigated mTOR expression in gastric cancer tissues and in metastatic lymph nodes and examined its association with clinical outcome. A total of 290 patients with pT2b gastric cancer were enrolled in this study. Patients were divided into 3 groups according to metastatic lymph node status: Group 1 contained 96 patients without lymph node metastasis, Group 2 contained 102 patients with a few (1-2) metastatic lymph nodes and Group 3 contained 92 patients with extensive (>16) lymph node metastasis. Phosphorylated mTOR expression was determined immunohistochemically using tissue microarrays. p-mTOR expression was observed in 36.5% of the gastric cancer tissues in Group 1, 39.2% in Group 2 and 60.9% in Group 3. A significant correlation was found between p-mTOR expression in gastric cancer tissues and in metastatic lymph nodes. The Borrmann type in Group 1, perineural invasion and p-mTOR expression in metastatic lymph nodes in Group 2 and p-mTOR expression in metastatic lymph nodes in Group 3 were found to be independent prognostic factors of disease-free survival. The 5-year disease free survival rate of Group 2 patients was 84.4% in negative p-mTOR and 66.1% in positive p-mTOR expression in metastatic lymph nodes (p = 0.015). The 5-year disease free survival rate of Group 3 patients was 37.3% in negative p-mTOR and 14.9% in positive p-mTOR expression in metastatic lymph nodes (p = 0.037). There was a linear correlation between the rate of tumor recurrence and mTOR expression scores in metastatic lymph nodes. In pT2b gastric cancer, p-mTOR expression in gastric cancer is associated with the extent of lymph node metastasis, and p-mTOR expression in metastatic lymph nodes is correlated with poor disease-free survival. mTOR may harbor significant potential for a prognostic biomarker and therapeutic target for gastric cancer treatment.

Mucinous gastric cancer presents with more advanced tumor stage and weaker ß-catenin expression than nonmucinous cancer.

BACKGROUND: Mucinous gastric carcinoma (MGC) is a rare type of gastric cancer; its biological behavior is controversial. In this study, we attempted to clarify the clinical and pathological features as well as the prognostic significance of MGC. We also compared the expression patterns of CDX-2 and ß-catenin between MGC and nonmucinous gastric carcinoma (NMGC). METHODS: We reviewed the records of 9218 patients with gastric cancer who underwent gastric cancer surgery between January 1997 and December 2006. The clinicopathological features and clinical outcome of MGC (n = 197) were compared to NMGC (n = 9021). Immunohistochemical staining using the tissue array method was performed on MGC (n = 194) and NMGC (n = 89) tissues. RESULTS: MGC had a larger size and a higher frequency of Borrmann type I findings in advanced cases than NMGC. In addition, MGC had deeper invasion, more lymph node and lymphatic involvement, a more advanced tumor stage, and lower 5-year survival rates than NMGC. Age, depth of invasion, lymph node metastasis, lymphatic invasion, and curability were independent prognostic factors; but the mucinous histological type itself was not predictive of outcome. ß-Catenin immunoreactivity was statistically significantly weaker in MGC than NMGC; however, there was no difference in CDX-2 expression between the two groups. CONCLUSIONS: MGC presents at a more advanced stage and was larger than NMGC. The poor prognosis of MGC was related to the more advanced tumor stage at diagnosis; the histological type was not an independent prognostic factor. The result of immunohistochemical staining suggests that MGC has a distinct pathway of carcinogenesis from NMGC.

Recurrence after curative resection of early gastric cancer.

BACKGROUND: Few studies have evaluated the recurrence of EGC after curative gastrectomy, due to its relatively low incidence. This study evaluated recurrence patterns and independent predictive factors for recurrence in order to determine appropriate follow-up and early detection of recurrence. METHODS: We reviewed the medical records of 3,883 consecutive patients who underwent curative gastrectomy for EGC at Samsung Medical Center between February 1995 and January 2006 and were followed up until January 2008. The clinical and pathological characteristics and the predictive factors for recurrence were evaluated retrospectively. RESULTS: Eighty-five (2.2%) patients had recurrence, and liver was the most common site of recurrence (45.9%). The recurrence rates within 2, 3, and 5 years were 43.5%, 67.1%, and 85.6%, respectively. There were 106 overall recurrences, with 86 (81.1%) being detected by computed tomography (CT). Second primary cancer was the primary cause of death after gastrectomy, followed by recurrence. Old age (>60 years), tumor size (>3 cm), multiple tumor, N category, and N2 station metastasis were significant factors for recurrence by multivariate analysis, but depth of invasion was not a significant factor. CONCLUSIONS: Age, tumor size, number of tumors, N category, and N2 station metastasis were predictive factors for recurrence, with lymph node metastasis being the most significant factor. After curative gastrectomy, follow-up programs should be applied for more than 5 years for EGC patients, and computed tomography could be an essential diagnostic tool.

Clinical significance of the discrepancy between preoperative and postoperative diagnoses in gastric cancer patients.

BACKGROUND: Discrepancies between pre- and postoperative diagnoses can lead to dilemma for operative management adequacy. PATIENTS AND METHODS: A total of 2,910 patients with gastric adenocarcinoma underwent curative surgery at the Samsung Medical Center between 2001 and 2003. Patients were divided into four groups: early gastric cancer (EGC)-EGC group that consisted of subjects who were diagnosed as having EGC pre- and postoperatively, advanced gastric cancer (AGC)-EGC group, EGC-AGC group, and AGC-AGC group. Clinicopathologic features and survival rates of groups were analyzed retrospectively. RESULTS: Of the 2,910 patients, 1,491 (51.2%) patients were included in the EGC-EGC group, 132 (4.5%) in the AGC-EGC group, 120 (4.1%) in the EGC-AGC group, and 1,167 (40.1%) in the AGC-AGC group. The EGC-AGC group showed higher proportions of the followings than the EGC-EGC group: upper-third and middle-third tumor localizations, a tumor size from 2 to 5 cm, undifferentiated adenocarcinoma, Lauren's diffuse type, endolymphatic invasion, vascular invasion, and perineural invasion. Five-year survival rates were dependent on the final pathologic stages, not on the preoperative stages. Multivariate analysis revealed that age and American Joint Committee of Cancer stage were independent prognostic factors of patient survival. CONCLUSION: A decision regarding minimally invasive treatment for EGC must be made having considered tumor location, size, and cellular differentiation, because of the possibility of an incorrect preoperative diagnosis.