• The Korean Journal of Applied Statistics
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• v.34 no.2
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• pp.255-266
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• 2021

The purpose of this study is to compare the effects of treatment on stage III stomach cancer data obtained from the SEER program of the National Cancer Institute and to identify the significant risk factors for the survival rates of stage III stomach cancer. Since the proportional hazards assumption was violated for treatment, we used the restricted mean survival time as an alternative to the proportional hazards model. The restricted mean survival time was estimated using pseudo-observations, and the effects of treatment were compared using a test statistic based on the estimated restricted mean survival times. We conducted the regression analysis using a generalized linear model to investigate the significant predictors for the restricted mean survival time of patients with stage III stomach cancer. We found that there was a significant difference between the restricted mean survival times of treatment groups. Age at diagnosis, race, substage, grade, tumor size, surgery, and treatment were significant predictors for the restricted mean survival time of patients with stage III stomach cancer. Surgery was the most significant predictor for increasing the restricted mean survival time of patients with stage III stomach cancer.

• Journal of Gastric Cancer
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• v.8 no.2
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• pp.91-96
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• 2008

Purpose: The early detection of gastric cancer and accuracy of preoperative staging has currently been on the increase due to the development of endoscopy and imaging techniques, but there are still many cases of advanced gastric cancer detected at the first diagnosis and there are also many cases of stage IV gastric cancer diagnosed after a postoperative pathological examination. Although the prognosis of stage IV gastric cancer is very poor, this study was performed to determine the value of the use of aggressive treatment determined after a clinical analysis. Materials and Methods: We retrospectively analyzed 150 patients that were diagnosed with stage IV gastric cancer among 1376 patients who underwent a laparotomy for gastric cancer from January 1994 to December 2006. Results: Of the 150 patients with stage IV gastric cancer who underwent a laparotomy, there were 104 men and 46 women. The mean patient age was 57.8 years (age range, 28~93 years). A subtotal gastrectomy or total gastrectomy was performed in 119 patients and 31 patients underwent an explorative laparotomy. The mean survival time of patients that underwent a gastrectomy and patients that did not undergo a gastrectomy was 722 days (range, 14~4,559 days) and 173 days (range, 16~374 days), respectively this result was statistically significant. When patients that underwent a gastrectomy were classified according to the TNM stage, the mean survival time of 33 patients with stage T4 disease was 534 days (range, 17~3,378 days) and the mean survival time of 63 patients with stage N3 disease was 521 days (range, 14~4,190 days), but there was no statistical significance. Chemotherapy was administered to 98 patients and 52 patients did not receive chemotherapy. The mean survival time of patients that received chemotherapy was 792 days (range, 36~4,559 days) and the mean survival time of patients that did not receive chemotherapy was 243 days (range, 14~2,413 days), with statistical significance. Conclusion: If there is no evidence of distant metastasis in stage IV gastric cancer, one can expect improvement of the survival rate by the use of aggressive treatment, including curative gastric resection with radical lymph node dissection and chemotherapy.

• Journal of Gastric Cancer
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• v.6 no.1
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• pp.18-24
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• 2006

Purpose: The prognosis of stage IV gastric cancer is poor with the 5-year survival rate still being about 10%. We investigated the prognostic factors of stage IV gastric cancer patients who underwent resection. Materials and Methods: A retrospective study of 383 patients with stage IV gastric cancer who underwent surgery in our department between September 1983 to December 2000 was conducted. We classified the 383 patients into two groups: patients surviving 2 years or more (n=77) and those surviving less than 2 years (n=306). Clinicopathologic differences were analyzed between the two groups. We also performed univariate and multivariate analyses of various clinicopathologic factors concerning survival. Results: Statistically significant clinicopathologic differences between the two groups were observed in regard to macroscopic type, distant metastasis, lymph node dissection, curability, and histology. Curability and histology were significant survival factors in 2-year survival. The 5-year survival rate was 5.4% in stage IV gastric cancer. Significant differences in survival among macroscopic type, distant metastasis, lymph node dissection, curability and histology were observed in the univariate analysis. In the Multivariate analysis, Curability, lymph node dissection, and histology were significantly beneficial factors for survival. Conclusion: Lymph node dissection, curability, and histology were independent prognostic factors in stage IV gastric cancer, and radical treatment is recommended to improve survival.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.251-258
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• 2010

Despite significant advance in laparoscopy, upper gastrointestinal (UGI) series is still generally carried out for preoperative localization of gastrectomy. The aim of the study was to compare the accuracy of UGI series and postoperative pathological findings in the diagnosis and localization of gastric cancer. A retrospective review was carried out for 102 patients who underwent gastrectomy between October 2007 and April 2009. Preoperative reports of UGI series were compared with postoperative pathology reports and the accuracy of the preoperative reports was calculated. Two radiographer retrospectively reviewed the analysis of UGI series. postoperative pathology reports of the surgical specimens, were compared with the preoperative reports of the location and extent of the tumor were correct in 81 case("sure", 79.4%) and incorrect in 21 case("failed, 20.6%). In 92 case UGI series revealed intestinal metaplasia (90.2%) at consensus review and these results demonstrate the limitation of the UGI series in the diagnosis of type IIb gastric cancer with size less than 1.0cm and the poor detection of gastric cancer is that the overlying mucous membrane often appears to be normal in these patients. In conclusion, UGI series is accurate the detection of the tumor localization and diagnosis of intestinal metaplasia. However, for the overcome with the limitation of UGI series should be used accurate technique for the region of the stomach. To achieve this goal, it is necessary to determine the changes of the mucus membrane of the stomach and UGI series is gaining acceptance as a standard method for preoperative gastric cancer screening.

• Journal of Gastric Cancer
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• v.6 no.2
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• pp.109-113
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• 2006

Purpose: Various minimally invasive surgical techniques, such as an endoscopic mucosal resection and a laparoscopic gastrectomy, are becoming common practice for some cases of early gastric cancer (EGC) defined in terms of the depth of invasion being limited to the mucosa or submucosa. However, there are rare cases of early gastric cancer with massive lymph-node metastasis. Materials and Methods: From 6 university hospitals of Korea, 2,772 EGC cases were resected during the various period of analysis (1,432 cases of mucosal cancer and 1,340 of submucosal cancer). Results: As control data, we used the data from a single institute, CHA University Hospital. There were nine cases of early gastric cancer (9/2,772, 0.32%) with N3 lymph node metastasis defined by more than 15 lymph nodes being metastasized according to the UICC-TNM classification (pT1N3, stage IV). Two cases were mucosal cancer (2/1,432, 0.1 4%), and seven cases were submucosal cancer (7/1,340, 0.52%). Metastasized lymph nodes varied in number from 18 to 52. There were three male and six female patients with a mean age of 57. This is a totally reversed sex ratio compared to the usual gastric cancer or EGC. Among the total of 9 EGC patients, there were 5 who had superficial spreading carcinomas with surface areas larger than $25\;cm^2$. This is a significantly higher proportion compared to the general EGC population. When we compared the tumor size according to the LN status, the N3 group was definitely larger than the other groups. 78% of the pT1N3 cases showed lymphatic invasion, which is very high compared to the 4.7% in general EGC cases. Among the 9 cases, 6 patients had too short a follow-up period to evaluate the correct prognosis, but there was one patient with a non-curative resection and two patients with early recurrence. Although the sample size is small and the follow-up period is short, we can expect a very poor prognosis when we consider the common prognosis of EGC that is widely known and accepted. Conclusion: From these results, we can a conclude that the risk factors for pT1N3 gastric cancer are female patients, submucosal invasion, larger tumor size, and lymphatic invasion. However rare, the existence of pT1N3 gastric cancer needs to be taken into consideration, especially during the diagnosis. Furthermore, minimally invasive treatment for EGC needs to be chosen with great precaution. Since the prognosis of pT1N3 gastric cancer is expected to be poor, aggressive adjuvant chemotherapy may be necessary. (J Korean Gastric Cancer Assoc 2006;6:109-113)

• Journal of Gastric Cancer
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• v.6 no.3
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• pp.173-180
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• 2006

Purpose: The TNM staging system showed limitation in stratifying patients into different prognostic groups with gastric cancer Since the treatment for stage IV gastric cancer with distant metastasis (M1) is defined as non-curative one, we hypothesized that the survival rate of stage IV gastric cancer with M1 is different to that of stage IV gastric cancer with no distant metastasis (M0), which will provide a rationale to subdivide stage IV into IVa and IVb. Materials and Methods: From June 1992 to December 2005, of 1,630 gastric cancer patients who underwent surgery, 308 patients with stage IV gastric cancer were selected and analyzed. The clinicopathologic characteristics and survival of the patients, according to distant metastasis, were determined retrospectively. Median follow-up period was 13 months (range: $1{\sim}154$ month). Results: 5 year survival rate of M0 and M1 group was 35% and 16% respectively with statistic significance (P=0.0000). When the survival rate of M0 group was analyzed according to the difference of T and M factor, T1-3N3M0 and T4N1-2M0 group showed no significant statistical difference (P=0.1898). Conclusion: Given the result in this study, we suggest that the stage IV gastric cancer be subclassified into stage IVa and IVb according to M factor.

• Journal of Gastric Cancer
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• v.7 no.1
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• pp.23-30
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• 2007

Purpose: Evaluating the clinicopathologic characteristics of recurred gastric cancer is essential for early detection of the recurrence and for better clinical outcome. The aim of this study was to establish the patterns of the recurrence, the timing of the recurrence, and the clinical result after recurrence according to the clinicopathologic characteristics of gastric cancer. Materials and Methods: From June 1992 to December 2005, of the 1338 gastric cancer patients who underwent a curative gastric resection, 241 patients who recurred during the follow-up period were selected and their cases were analyzed. The clinicopathologic characteristics of the patients, the time to recurrence after operation and survival were determined retrospectively according to the type of recurrence. Results: For the recurrent group, the numbers of total gastrectomies, advanced stages, lymphatic and/or venous infiltrations, whole stomach cancer cases, large tumors, undifferentiated tumors, and Borrmann type 4 tumors were higher than they were for the non-recurrent group, and the differences were statistically significant. When the recurrence types were classified as peritoneal seeding, hematogenous recurrence, and locoregional recurrence, independent risk factors were female gender, stage III, upper third, and whlole stomach cancer, and undifferentiated- type, diffuse-type, and Borrmann type 4 tumors for peritoneal seeding; early gastric cancer, stage I for hematogenous recurrence; and Borrmann type 1, 2, and 3 tumors for locoregional recurrence. Survival duration after detection of the recurrence was shorter for peritoneal seeding than for hematogenous or locoregional recurrence (7.0 months vs. 9.5 months and 12.5 months). Conclusion: For early detection of the recurrence after curative surgery for gastric cancer, it is important to recognize that the high risk factors for recurrence vary with the clinicopathologic data for the patients.

• Journal of Gastric Cancer
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• v.1 no.2
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• pp.100-105
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• 2001

Purpose: In the UICC staging system, stage IV contains not only those patients with distant metastasis but also patients with far advanced T and N status but without distant metastasis. We investigated the prognostic factors of stage IV gastric carcinoma patients without distant metastasis after curative resection. Materials and Methods: 190 stage IV gastric carcinoma patients without distant metastasis were reviewed after curative resection. Results: Male sex, distal third location, Borrmann type III, IV and histologically undifferentiated type were common. 5 year survival rate of the 190 patients was $22.2\%$. Depth of invasion and lymph node metastasis did not influence survival. The lymph node ratio (positive lymph node / retrieved lymph node) and combined resection affected survival by univariate and multivariate analysis. Conclusion: Combined resection and positive lymph node ratio were the independent prognostic factors in the patients with stage IV gastric carcinoma who underwent curative resection.

• Journal of Gastric Cancer
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• v.8 no.4
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• pp.256-261
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• 2008

Purpose: Intra-abdominal fluid collection is one of the risk factors associated with postoperative morbidity or mortality for patients who undergo gastric cancer surgery. The aim of this study was to analyze the clinicopathological characteristics of the patients with postoperative intra-abdominal fluid collection and to identify the indications for inserting a percutaneous drain (PCD) in patients with intra-abdominal fluid collection. Materials and Methods: Among the 1,277 patients who underwent operations for gastric cancer at Seoul National University Hospital between April 2005 and July 2006, the data of 117 patients with an intra-abdominal fluid collection were reviewed. Results: The number of patients' with pathologic stage I, II, III and IV disease was 42 (36.8%), 23 (20.2%), 16 (14%) and 33 (28.9%), respectively. Forty-three patients (36.3%) underwent PCD insertion and the other 43 patients received conservative management. A univariate analysis of multiple clinical variables revealed that age, gender, diabetes, liver disease, lymph node dissection, the pathologic stage and the body mass index (BMI, $kg/m^2$) were not significantly associated with PCD insertion (P>0.05). However, the univariate analysis showed that two characteristics were associated with a significantly high incidence of PCD insertion: a diameter of an intra-abdominal fluid collection greater than 4 cm and infectious signs such as leukocytosis, fever and bacteremia. Conclusion: About two thirds of the intra-abdominal fluid collections after surgery for gastric cancer were managed with only conservative method without other morbidities of mortality. Surgeons should consider performing PCD insertion if the largest diameter of an intra-abdominal fluid collection is over 4 cm or if infectious signs are seen.

• Journal of Gastric Cancer
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• v.6 no.3
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• pp.154-160
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• 2006

Purpose: According to the 2nd English Edition of the Japanese Gastric Cancer Association (JGCA) in 1998, in case of distal gastric cancer, the 14v (superior mesenteric vein) lymph node (LN) is included in the N2 group. However, in Korea, a modified radical gastrectomy is performed, and a 14v LN dissection is not done as a routine procedure. Thus, we investigated the rate of metastatic 14v LNs, evaluated the necessity of dissection of the 14v LN, and searched for indications of 14v LN dissection. Materials and Methods: From April 2004 to August 2005, we enrolled the patients who were diagnosed as having advanced gastric cancer in the distal third portion of the stomach. We peformed a distal gastrectomy with D2 lymph node dissection as defined in the 2nd English edition of the JGCA classification. We calculated the positive rate of metastatic LNs of each station and analyzed the relationship between the positive rates of No.6 LNs and 14v LNs. We also compared the positive 14v LN group with the negative 14v LN group. Results: The total number of patients was 50, the mean age was 56 (range $30{\sim}80$) years, and sex ratio (Male/Female) was 1.63 : 1. In 47 (94%) cases, distal a gastrectomy with gastroduodenostomy was done, and in the remaining 3 (6%) cases, a distal gastrectomy with gastrojejunostomy was done. The most frequently metastatic LNs were nos. 3 and 6 (54%). The metastatic rate of the f4v LN was 10%, which was similar to that of LN no. 9. In the comparison of the 14v positive group with the 14v negative group, there were significant differences in the numbers of metastatic LNs (mean 25.4 vs 4.91, P<0.001) and the numbers of metastatic no. 6 LNs, (mean 6.8 vs 1.42, P<0.001), and if no. 6 LNs were metastatic, the possibility of metastasis to the 14v LN was 19.2%. In the 14v positive group, all cases were more than stage 3 by the UICC 6th edition. Conclusion: In cases of advanced cancer with metastasis to the no. 6 IN, there was a good chance of metastasis to the 14v LN. Thus, in the operative field, if the tumor is advanced to more than stage 3 by the UICC classification and the no. 6 LN is metastatic, a 14v LN dissection is necessary. However, the usefulness of a 14v LN dissection should be evaluated prospectively through an analysis of tumor recurrence and long-term survival.