Treatment results for gastric cancer surgery: 12 years' experience at a single institute in Korea

Doxifluridine versus Tegafur/Gimeracil/Oteracil (S-1) as adjuvant chemotherapy for patients with gastric cancer after gastrectomy: A propensity score-matched analysis

INTRODUCTION

Doxifluridine (DF), an oral 5-FU prodrug, has been used for various solid cancers due to its efficacy and low toxicity. We aim to evaluate the effect of DF as adjuvant monotherapy in advanced gastric cancer.

METHODS

We retrospectively reviewed the clinical data of 263 patients with advanced gastric cancer who underwent curative gastrectomy between January 2010 and December 2013 at our institute. Since previous randomized control trials have confirmed the efficacy of S-1 as adjuvant chemotherapy in advanced gastric cancer, we analyzed the oncologic effect and patient compliance of the DF group compared to the S-1 group. After propensity score matching, 48 patients were included in each group.

RESULTS

There was no significant difference in 5-year overall survival (OS) and 5-year disease-free survival (DFS) between DF and S-1 groups (5-year OS; 77.1% vs 75.0%; p = 0.729, 5-year DFS; 76.6% vs 73.9%; p = 0.748). The completion rates of the DF and S-1 groups were 60.4% and 72.9%, respectively (p = 0.194). The mean relative dose intensity of the DF and S-1 groups were 76.2% and 84.2%, respectively (p = 0.195). After multivariate analysis, the chemotherapy regimen was not a risk factor for OS and DFS, whereas relative dose intensity and pathologic stage were independent prognostic factors.

CONCLUSION

There was no significant difference in the oncologic effect and patient compliance between DF and S-1 groups. DF could be an alternative option for adjuvant chemotherapy in advanced gastric cancer. In addition, we confirmed that relative dose intensity is an important independent prognostic factor for survival.

Prediction of lymph node metastasis in early gastric signet-ring cell carcinoma: A real-world retrospective cohort study

BACKGROUND

Signet-ring cell carcinoma (SRCC) was previously thought to have a worse prognosis than other differentiated gastric cancer (GC), however, recent studies have shown that the prognosis of SRCC is related to pathological type. We hypothesize that patients with SRCC and with different SRCC pathological components have different probability of lymph node metastasis (LNM).

AIM

To establish models to predict LNM in early GC (EGC), including early gastric SRCC.

METHODS

Clinical data from EGC patients who had undergone gastrectomy at the First Affiliated Hospital of Nanjing Medical University from January 2012 to March 2022 were reviewed. The patients were divided into three groups based on type: Pure SRCC, mixed SRCC, and non-signet ring cell carcinoma (NSRC). The risk factors were identified through statistical tests using SPSS 23.0, R, and Em-powerStats software.

RESULTS

A total of 1922 subjects with EGC were enrolled in this study, and included 249 SRCC patients and 1673 NSRC patients, while 278 of the patients (14.46%) presented with LNM. Multivariable analysis showed that gender, tumor size, depth of invasion, lymphovascular invasion, ulceration, and histological subtype were independent risk factors for LNM in EGC. Establishment and analysis using prediction models of EGC showed that the artificial neural network model was better than the logistic regression model in terms of sensitivity and accuracy (98.0% vs 58.1%, P = 0.034; 88.4% vs 86.8%, P < 0.001, respectively). Among the 249 SRCC patients, LNM was more common in mixed (35.06%) rather than in pure SRCC (8.42%, P < 0.001). The area under the ROC curve of the logistic regression model for LNM in SRCC was 0.760 (95%CI: 0.682-0.843), while the area under the operating characteristic curve of the internal validation set was 0.734 (95%CI: 0.643-0.826). The subgroups analysis of pure types showed that LNM was more common in patients with a tumor size > 2 cm (OR = 5.422, P = 0.038).

CONCLUSION

A validated prediction model was developed to recognize the risk of LNM in EGC and early gastric SRCC, which can aid in pre-surgical decision making of the best method of treatment for patients.

Actual 3-Year Survival After Reduced-Port Laparoscopic Distal Gastrectomy for Gastric Cancer (RpLDG): a Propensity Score Matching Analysis

BACKGROUND

Total laparoscopic distal gastrectomy for early gastric cancer has been widely accepted; however, reduced-port laparoscopic distal gastrectomy has not gained the same popularity because of technical difficulties and oncologic safety issues. This study aimed to analyze the oncologic safety and short-term surgical outcomes of patients who underwent reduced-port laparoscopic distal gastrectomy (RpLDG) for gastric cancer.

METHODS

Consecutive patients who underwent surgical treatment between January 2016 and May 2018 were included in this study. Of the 833 patients enrolled, 158 underwent RpLDG and were propensity-matched with 158 patients who underwent conventional port laparoscopic distal gastrectomy (CpLDG). The groups were compared in terms of short-term outcomes and disease-free and overall survival rates.

RESULTS

The RpLDG group had shorter operation times (161.8 min vs. 189.0 min, p < 0.00) and shorter postoperative hospital stays (7.6 days vs. 9.1 days, p = 0.04) compared to the CpLDG group. Estimated blood loss was lower in the RpLDG group than in the CpLDG group (52.6 mL vs. 73.7 mL, p < 0.00), while hospital costs incurred by the RpLDG group were lower than those of the CpLDG group (10,033.7 vs. 11,016.8 USD, p < 0.00). No statistical differences were found regarding overall morbidity and occurrence of surgical complications of grade III or higher, as defined by the Clavien-Dindo classification. Furthermore, no significant differences between RpLDG and CpLDG were found in 3-year disease-free (99.4% vs. 98.1%; p = 0.42) and 3-year overall survival rates (98.7% vs. 96.8%; p = 0.25).

CONCLUSION

Patients who underwent RpLDG had better short-term surgical outcomes than those who underwent CpLDG in terms of operation time, estimated blood loss, duration of hospital stay, and hospital costs. The oncologic safety of RpLDG was satisfactory.

Different clinicopathologic features and prognostic significance of signet ring cell histology in early and locally advanced gastric cancer patients

BACKGROUND

Although many studies have evaluated the prognostic significance of signet ring cell (SRC) histology for gastric cancer (GC) patients, the results were conflicting. The objective of this study was to compare clinicopathologic characteristics between SRC type and other types, and evaluate its impact on survival outcome.

METHODS

We retrospectively reviewed clinicopathologic and survival data of 1891 patients who underwent curative resection for GC. All patients were divided into differentiated, undifferentiated and SRC type according to the histological classification. The prognostic differences between different types were compared and clinicopathologic factors were analyzed.

RESULTS

SRC histology type had a poorer disease-free survival (DFS) than differentiated type (5-year DFS, 37.7% vs 52.2%, P<0.001), but there was no prognostic difference between SRC type and undifferentiated type (37.7% vs 41.9%, P>0.05). For early GC patients, SRC type was more frequent in younger, female patients and T1a stage tumors; the 5-year DFS of SRC type was similar to that of any other histology type (P>0.05). SRC type showed more aggressive biological features, including extensive stomach involvement, large tumor size, advanced pTstage and pN stage, than other types for locally advanced GC patients; poorer DFS was observed in SRC type compared with differentiated type. Multivariate analysis indicated that SRC type (HR:1.71, 95%CI:1.10-1.68, P<0.01) and undifferentiated type (HR:1.21, 95%CI:1.04-1.40, P<0.05) were independently associated with poor DFS in locally advanced GC patients.

CONCLUSION

There was a significant difference between early and locally advanced GC patients with regard to clinicopathologic features and prognostic significance of SRC histology. SRC type was an independent prognostic factor for locally advanced GC patients, but not for early GC patients.

Early Surgical and Long-term Oncological Outcomes of Totally Laparoscopic Near-total Gastrectomy in >150 Cases

BACKGROUND

This study aimed to examine the early surgical outcomes and long-term oncological safety of totally laparoscopic near-total gastrectomy for the treatment of upper-third early gastric cancer.

MATERIALS AND METHODS

We retrospectively collected and analyzed the data of 167 consecutive patients who underwent totally laparoscopic near-total gastrectomy for upper-third early gastric cancer between January 2008 and May 2018. Data on clinical characteristics and surgical outcomes, including operation time, length of postoperative hospital stay, pathologic findings, and postoperative complications, were obtained. We also analyzed recurrence-free and overall survival rates to evaluate the oncological outcomes.

RESULTS

The mean operation time was 149.44±37.59 minutes; none of the patients required conversion to laparotomy during surgery. The average postoperative hospital stay was 7.57±5.69 days. On final pathologic analysis, the mean proximal resection margin was 1.97±1.68 cm. No patients had an involved proximal resection margin. Twenty-seven patients (16.17%) had postoperative complications; of them, 6 patients (3.59%) had Clavien-Dindo classification grade 3 or higher complications, all within 1 month. The median follow-up duration was 54.35 months. The 3- and 5-year recurrence-free survival rates were 98.3% and 97.1%, respectively. The overall survival rate was 97.1% at both 3 and 5 years.

CONCLUSIONS

Our study shows that totally laparoscopic near-total gastrectomy is a safe and feasible procedure for treating the upper-third early gastric cancer. Further, in the current study, the procedure demonstrated a favorable oncological outcome for a relatively long follow-up period and large sample size.

The value of spleen-preserving lymphadenectomy in total gastrectomy for gastric and esophagogastric junctional adenocarcinomas: A long-term retrospective propensity score match study from a high-volume institution in China

BACKGROUND

The benefit of removing the splenic lymph nodes in patients with proximal gastric cancer has been controversial. The purpose of our study was to investigate the importance of performing a splenic hilar lymph node dissection without splenectomy in patients undergoing total gastrectomy for gastric cancer.

METHODS

From January 2006 to December 2015, we retrospectively reviewed patients who underwent a curative total gastrectomy for gastric cancer. Propensity score matching was used to balance any potential discrepancy of the other covariates between patients with and without splenic hilar lymph node dissection. Survival analysis, Cox univariate and multivariate analysis, and subgroups analysis were conducted to determine the value of splenic hilar lymph node dissection. After matching, 2 nomograms among patients with and without splenic hilar lymph node dissection were established respectively, the C-index, calibration curve and decision curve analysis were used to further evaluate the value of splenic hilar lymph node dissection.

RESULTS

The rate of metastatic splenic hilar lymph nodes in the 274 patients undergoing splenic hilar lymph node dissection was 16.4% (45/274). Patients undergoing splenic hilar lymph node dissection had better survival outcomes than those not undergoing splenic hilar lymph node dissection before (P = .003) and after (P = .003) propensity score matching. Cox multivariate analysis also confirmed that splenic hilar lymph node dissection was an independent prognostic factor both before (hazard ratio 1.284, 95% confidence interval 1.042-1.583, P = .019) and after (hazard ratio 1.480, 95% confidence interval 1.156-1.894, P = .002) propensity score matching. Subgroup analysis indicted that splenic hilar lymph node dissection offered better survival outcomes for esophagogastric junctional adenocarcinoma (P < .001, P for interaction = .018). After propensity score matching, the nomogram of patients with splenic hilar lymph node dissection (C-index 0.735, 95% confidence interval 0.695-0.774) also indicated a statistically significant advantage compared with that without splenic hilar lymph node dissection (C-index 0.708, 95% confidence interval 0.668-0.748, P < .001).

CONCLUSION

Our study suggests that spleen-preserving splenic hilar lymph node dissection should be an essential procedure among patients undergoing total gastrectomy.

Is there a role for treatment-oriented surgery in liver metastases from gastric cancer?

BACKGROUND

Distant metastases are found in approximately 35% of patients with gastric cancer at their first clinical observation, and of these, 4%-14% involves the liver. Unfortunately, only 0.4%-2.3% of patients with metastatic gastric cancer are eligible for radical surgery. Although surgical resection for gastric cancer metastases is still debated, there have been changes in recent years, although several clinical issues remain to be defined and that must be taken into account before surgery is proposed.

AIM

To analyze the clinicopathological factors related to primary gastric tumor and metastases that impact the survival of patients with liver metastatic gastric cancer.

METHODS

We performed a systematic review of the literature from 2000 to 2018 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The study protocol was based on identifying studies with clearly defined purpose, eligibility criteria, methodological analysis, and patient outcome.

RESULTS

We selected 47 studies pertaining to the purpose of the review, which involved a total of 2304 patients. Median survival was 7-52.3 mo, median disease-free survival was 4.7-18 mo. The 1-, 2-, 3-, and 5-year overall survival (OS) was 33%-90.1%, 10%-60%, 6%-70.4%, and 0%-40.1%, respectively. Only five papers reported the 10-year OS, which was 5.5%–31.5%. The general recurrence rate was between 55.5% and 96%, and that for hepatic recurrence was between 15% and 94%.

CONCLUSION

Serous infiltration and lymph node involvement of the primary cancer indicate an unfavorable prognosis, while the presence of single metastasis or ≤ 3 metastases associated with a size of < 5 cm may be considered data that do not contraindicate liver resection.

Impact of Lymphovascular Invasion on Survival Outcome in Patients With Gastric Cancer

OBJECTIVES

To evaluate the prognostic significance of lymphovascular invasion (LVI) for patients with gastric cancer (GC).

METHODS

A total of 1,720 consecutive patients who underwent curative gastrectomy were retrospectively identified. The association between LVI and clinicopathologic characteristics was determined and its impact on survival outcome was evaluated.

RESULTS

LVI was detected in 21.3% of GC patients, 5.9% of patients with early GC, 24.0% of patients with advanced GC, and 6.7% of node-negative patients using H&E staining. Tumor size (odds ratio [OR], 1.509; 95% confidence interval [CI], 1.159-1.965; P < .01), differentiated type (OR, 1.817; 95% CI, 1.377-2.398; P < .001), and the depth of tumor invasion (OR, 3.011; 95% CI, 2.174-4.171; P < .001) were independent predictive factors for LVI. LVI-positive patients have a poorer prognosis than LVI-negative patients, irrespective of tumor stage or lymph node metastasis. LVI was an independent prognostic factor for patients with GC (hazard ratio, 1.299; 95% CI, 1.112-1.518; P < .001).

CONCLUSIONS

LVI provided additional prognostic information for GC patients, and LVI-positive patients should be considered candidates for adjuvant chemotherapy.

Poorly differentiated is more significant than signet ring cell component for lymph node metastasis in mixed-type early gastric cancer: a retrospective study from a large-volume hospital

Objective

The purpose of this study was to explore the role of different undifferentiated components in the lymph node metastasis (LNM) of early mixed gastric cancer.

Methods

A total of 1596 patients with EGC who underwent gastrectomy were divided into four types: pure differentiated (PD), pure poorly differentiated (Poorly D), pure signet ring cell carcinoma (SRC), and mixed. Mixed type was classified into four subtypes: differentiated-predominant type mixed with poorly differentiated component (MD-P), poorly differentiated-predominant type mixed with differentiated component (MP-D), differentiated-predominant type mixed with SRC component (MD-S), and poorly differentiated-predominant type mixed with SRC component (MP-S). We analyzed the clinicopathological differences between all types and the rates of LNM of patients fulfilling endoscopic submucosal dissection (ESD) criteria.

Results

LNM was more common in mixed (21.9%) than in PD (7.5%, P < 0.001) or SRC (11.3%, P < 0.001). When analyzed the subgroups of mixed type, LNM was more frequent in MD-P (15.4%) than in PD (7.5%, P = 0.003). LNM in MD-S (7.4%, P = 1.000) was not higher than in PD. MP-S (24.5%) showed a higher rate of LNM than SRC (11.3%, P < 0.001) rather than Poorly-D (22.7%, P = 0.681). For lesions satisfying ESD criteria, MD-S (0%, P = 1.000), and MD-P (5.9%, P = 0.12) did not have higher rates of LNM than PD (1.4%).

Conclusion

The presence of poorly differentiated component but not SRC increases the LNM rate of mixed type. ESD is recommended for the treatment of MD-S and MD-P consistent with ESD criteria.

Clinicopathologic factors associated with recurrence and long-term survival in node-negative advanced gastric cancer patients

BACKGROUND

despite a better prognosis in node-negative advanced gastric cancer (GC), a proportion of patients have a tumor recurrence within five years and eventually die due to cancer-related causes. The present study aimed to evaluate the predictive factors of tumor recurrence and long-term survival in node-negative advanced GC.

METHODS

a total of 646 node-negative advanced GC patients who underwent a curative gastrectomy in our institution were included in the study. The impact of different clinicopathologic factors on tumor recurrence and overall survival were analyzed.

RESULTS

tumor recurrences were observed in 181 patients and the cumulative recurrence rate at two-years and five-years were 50.8% and 86.2%, respectively. Lymphovascular invasion, advanced T stage (T3-T4) and an inadequate number of retrieved lymph nodes (LNs) were independent predictive factors of tumor recurrence in node-negative advanced GC. Older age, an upper 1/3 tumor, lymphovascular invasion, infiltration growth pattern (INFγ) and the depth of tumor invasion (T4 stage) were independently associated with long-term survival. With regard to node-negative patients with ≥ 15 retrieved LNs, infiltration growth pattern (INFγ) and advanced T stage (T3-T4) were independent risk factors for both tumor recurrence and long-term survival.

CONCLUSION

in addition to lymphovascular invasion, inadequate RLNs and advanced T stage, the prognostic significance of infiltration growth pattern in node-negative advanced GC was especially emphasized. These risk factors should be considered when selecting candidates for adjuvant chemotherapy and postoperative surveillance.

Risk Factors for Gallbladder Stone Formation after Gastric Cancer Surgery

Purpose

Although an increased incidence of gallbladder (GB) stone formation after gastrectomy has been reported, its etiology remains uncertain. The goal of this study was to explore the incidence of gallstone formation after gastrectomy in gastric cancer patients and investigate the risk factors therein.

Materials and Methods

Medical records of patients who underwent curative gastrectomy, performed by a single surgeon between August 2012 and December 2015 at the Asan Medical Center, were retrospectively reviewed. Baseline characteristics and surgical outcomes, including GB stone gallstone formation after gastrectomy, were analyzed.

Results

Of 561 patients included in the study, 36 presented with GB stone formation after gastrectomy for gastric cancer. The incidence of gallstone formation was 6.4%. The mean interval between gallstone formation and gastrectomy was 21.9 months. In multivariate analyses, the incidence of gallstone formation increased in patients 63 years or older, with greater than 6.2 kg weight loss in the first 6 months after the procedure, a preoperative serum total bilirubin level greater than 0.5 mg/dL, and in patients who did not receive adjuvant chemotherapy.

Conclusions

This study presented risk factors for GB stone formation after gastric cancer surgery, and special attention should be afforded to patients with such risk factors.

Expression patterns of programmed death-1 and programmed death-1 ligand-1 on T cells in gastric cancer

The aim of the present study was to evaluate programmed death-1 (PD-1) and programmed death-1 ligand-1 (PD-L1) expression in gastric carcinoma and to assess their effect on survival rate. A total of 170 surgically resected specimens were obtained from patients diagnosed with gastric carcinoma at St. Vincents Hospital, The Catholic University of Korea. Paraffin tissue sections from tissue microarray blocks were subjected to immunohistochemical analysis of PD-1 and PD-L1. In addition, PD-1 expression on CD4⁺ and CD8⁺ T cells isolated from peripheral blood mononuclear cells and gastric cancer tissues was evaluated by multicolor flow cytometry. PD-1 and PD-L1 were expressed in 30.0 and 60.5% of the gastric cancer tissues, respectively. The expression of PD-L1 was higher in patients with advanced T (P=0.035) and Tumor, Node and Metastasis stage (P=0.05). The patients with positive PD-L1 expression had shorter disease-free survival time than those without PD-L1 expression (P=0.005). Additionally, PD-L1 expression was significantly associated with poor prognosis (P=0.015). PD-1 and PD-L1 expression levels were significantly higher on CD8⁺ T cells than on CD4⁺ T cells (P<0.001). The data of the present study suggested that PD-L1 expression may be an independent indicator of poor prognosis in patients with gastric cancer. Furthermore, PD-L1 expression may play a role in immune evasion of gastric cancer.

Nature versus nurture: the impact of nativity and site of treatment on survival for gastric cancer

BACKGROUND

The prognosis of gastric cancer patients is better in Asia than in the West. Genetic, environmental, and treatment factors have all been implicated. We sought to explore the extent to which the place of birth and the place of treatment influences survival outcomes in Korean and US patients with localized gastric cancer.

METHODS

Patients with localized gastric adenocarcinoma undergoing potentially curative gastrectomy from 1989 to 2010 were identified from the SEER registry and two single institution databases from the US and Korea. Patients were categorized into three groups: Koreans born/treated in Korea (KK), Koreans born in Korea/treated in the US (KUS), and White Americans born/treated in the US (W), and disease-specific survival rates compared.

RESULTS

We identified 16,622 patients: 3,984 (24.0%) KK, 1,046 (6.3%) KUS, and 11,592 (69.7%) W patients. KK patients had longer unadjusted median (not reached) and 5-year disease-specific survival (81.6%) rates than KUS (87 months, 55.9%) and W (35 months, 39.2%; p < 0.001 for all comparisons) patients. This finding persisted on subset analyses of patients with stage IA tumors, without cardia/GEJ tumors, with > 15 examined lymph nodes, and treated at a US center of excellence. On multivariable analysis, KUS (HR 2.80, p < 0.001) and W (HR 5.79, p < 0.001) patients had an increased risk of mortality compared to KK patients.

CONCLUSIONS

Both the place of birth and the place of treatment significantly contribute to the improved prognosis of patients with gastric cancer in Korea relative to those in the US, implicating both nature and nurture in this phenomenon.

Mixed Histology Is a Risk Factor for Lymph Node Metastasis in Early Gastric Cancer

BACKGROUND

The risk factors of lymph node (LN) metastasis are important factors to consider in endoscopic submucosal dissection in early gastric cancer (EGC). The aim of the study was to identify the correlation between mixed histology and LN metastasis in EGC.

METHODS

A total of 1645 patients who underwent curative radical gastrectomy for EGC were divided into three groups (pure differentiated [pure D], mixed, and pure undifferentiated [pure UD]) according to histologic type. They were subsequently analyzed retrospectively for LN metastasis. The patients who had mixed histology between differentiated and undifferentiated tubular adenocarcinoma were defined as mixed group.

RESULTS

The pure UD group was significantly younger than the other groups. Tumor size was larger in the mixed group. LN metastasis occurred more frequently in the mixed group and the pure UD group than in the pure D group (pure D, mixed, and pure UD, 7.7%, 23.2%, and 10.8%, respectively; P < 0.001). A logistic regression analysis revealed that the independent risk factors for LN metastasis were large tumor size (odd ratio [OR], 1.308), submucosal invasion (OR, 3.565), lymphovascular invasion (OR, 9.755), and histologic types of mixed (OR, 2.360) and pure UD (OR, 1.657).

CONCLUSIONS

Mixed histology is an important risk factor for LN metastasis in EGC. Thus, radical gastrectomy should be considered in the cases of mixed-type histology after endoscopic resection.

A comparison of the operative outcomes of D1 and D2 gastrectomy performed at a single Western center with multiple surgeons: a retrospective analysis with propensity score matching

BACKGROUND

There has been worldwide debate on lymphadenectomy for gastric cancer, with increasing consensus on performing an extended (D2) resection. There is a paucity of data in Australia. Our aim is to compare overall outcomes between a D1 and D2 lymphadenectomy for gastric cancer in a single specialist unit.

METHODS

We performed a retrospective analysis on patients who underwent a curative primary gastric resection for gastric adenocarcinoma between January 1996 and April 2016, primary outcomes included overall survival (OS) and disease-free survival (DFS). Propensity score matching (PSM) analysis was used to balance covariates between D1/D1+ and D2 groups. Kaplan-Meier survival curves of D1/D1+ versus D2 were constructed and evaluated using the log-rank test with subgroup analyses for pathological node (pN) status. Multiple Cox proportional hazards model was used to determine predictors of overall survival.

RESULTS

Two hundred four patients underwent a gastrectomy, 54 had D1/D1+, and 150 had a D2 lymphadenectomy. After PSM, there were 39 patients in each group, the 10-year OS for D1/D1+ was 52.1 and 76.2% for D2 (p = 0.008), and 10-year DFS was 35% for D1 and 58.1% for D2 (p = 0.058). Subgroup analysis showed that node-negative (N0) patients had improved 5-year OS for D2 (90.9%), compared to D1/D1+ (76.4%) (p = 0.028). There was no difference in operative mortality between the groups (D1 vs D2: 2 vs 0%, p = 0.314), nor in post-operative complications (p = 0.227). Multiple Cox analysis showed advanced tumor stage (stages III and IV), and lymphadenectomy type (D1) and the presence of postoperative complications were independent predictors of poor overall survival.

CONCLUSIONS

D2 lymphadenectomy with spleen and pancreas preservation can be performed safely on patients with gastric adenocarcinoma. Significant improvement in overall survival is observed in patients with N0 disease who underwent D2 lymphadenectomy without increasing operative morbidity or mortality. This paper supports the notion of a global consensus for a D2 lymphadenectomy, particularly in the Western context.

Anatomical location of metastatic lymph nodes: an indispensable prognostic factor for gastric cancer patients who underwent curative resection

BACKGROUND

Although the numeric-based lymph node (LN) staging was widely used in the worldwide, it did not represent the anatomical location of metastatic lymph nodes (MLNs) and not reflect extent of LN dissection. Therefore, in the present study, we investigated whether the anatomical location of MLNs was still necessary to evaluate the prognosis of node-positive gastric cancer (GC) patients.

METHODS

We reviewed 1451 GC patients who underwent radical gastrectomy in our institution between January 1986 and January 2008. All patients were reclassified into several groups according to the anatomical location of MLNs and the number of MLNs. The prognostic differences between different patient groups were compared and clinicopathologic features were analyzed.

RESULTS

In the present study, both anatomical location of MLNs and the number of MLNs were identified as the independent prognostic factors (p < .01). The patients with extraperigastric LN involvement showed a poorer prognosis compared with the perigastric-only group (p < .001). For the N1-N2 stage patients, the prognostic discrepancy was still observed among them when the anatomical location of MLNs was considered (p < .05). For the N3-stage patients, although the anatomical location of MLNs had no significant effect on the prognosis of these patients, the higher number of MLNs in the extraperigastric area was correlated with the unfavorable prognosis (p < .05).

CONCLUSION

The anatomical location of MLNs was an important factor influencing the prognostic outcome of GC patients. To provide more accurate prognostic information for GC patients, the anatomical location of MLNs should not be ignored.

The retrieval of at least 25 lymph nodes should be essential for advanced gastric cancer patients with lymph node metastasis: A retrospective analysis of single-institution database study design: Cohort study

BACKGROUND

Recently, increased evidence have shown that the better prognosis of gastric cancer (GC) patients was associated with the larger number of retrieved lymph nodes (RLNs), but the optimal number of RLNs remains controversial. In the present study, we investigated whether adequate LN retrieval (≥15) was necessary to evaluate the prognosis of patients and attempted to propose an appropriate cutoff-point for the number of RLNs.

METHODS

We reviewed 2246 GC patients who underwent radical gastrectomy in our research institution between January 1986 and January 2008. All patients were divided into several groups based on the number of RLNs. The prognostic outcomes of different patient groups were compared and clinicopathologic features were analyzed.

RESULTS

In the present study, our results indicated that ≥15 RLNs showed a better survival outcome than inadequate LN retrieval (<15), regardless of the node-negative or node-positive GC patients (P < 0.001). For the more advanced GC patients (T2-T4 stage, N1-N3 stage, and stage II-stage III), the retrieval of 25-29 LNs could provide a better survival benefit compared with <25 or ≥30 RLNs (P < 0.05). In addition, for the patients who underwent proximal or total gastrectomy, the superior prognosis was still observed in the patient group with 25-29 RLNs.

CONCLUSION

The minimal goal of 15 RLNs may not be enough to accurately evaluate prognosis of all patients and at least 25 RLNs should be necessary for advanced GC patients with lymph node metastasis.

Frequency and risk factors of colorectal adenoma in patients with early gastric cancer

BACKGROUND/AIM

The authors aimed to determine the clinical value of colonoscopy by evaluating the frequency of colorectal neoplasm (CRN) detection in patients with early gastric cancer (EGC) as compared with healthy controls and analysed the risk factors of advanced CRN in patients with EGC.

METHODS

The medical records of 201 patients diagnosed as EGC and age- and gender-matched healthy controls were retrospectively reviewed. Frequencies and clinical features of colorectal polyps of patients and controls were compared. Risk factors of advanced CRN in patients with EGC were also analysed.

RESULTS

Frequencies of CRN in patients and controls were 49.8 and 49.3% respectively (P = 0.90). They were more common in the right colon in patients (P < 0.05). Advanced CRN were found in 10.3% of patients and in 3% of controls (P < 0.05). Multivariate analysis revealed that old age and smoking history were risk factors of an advanced CRN in patients with EGC.

CONCLUSION

The prevalence of a coexisting advanced CRN was higher in EGC patients. The study shows colonoscopy plays an important role with respect to the detection of synchronous advanced CRN in patients with EGC.

Harvest of at Least 23 Lymph Nodes is Indispensable for Stage N3 Gastric Cancer Patients

BACKGROUND

The National Comprehensive Cancer Network (NCCN) recommends that at least 15 lymph nodes (LNs) be removed during radical gastrectomy. This study aims to investigate the optimal number of LNs resected for radical gastrectomy.

PATIENTS AND METHODS

From September 2008 to March 2015, a total of 1990 gastric cancer patients were enrolled in this study. Clinicopathological features and survivals were recorded, and the association between the number of LNs resected and the prognosis of gastric cancer were analyzed.

RESULTS

Overall, 1520 males (76.4%) and 470 females (23.6%) were included in the study, with a median age of 57 years (range 20-90). The median number of LNs resected was 24 (range 15-83) for stage N1, 25 (range 15-62) for stage N2, 25 (range 15-88) for stage N3a, and 28 (range 16-73) for stage N3b. The optimal cut-off value for the number of LNs resected was 22 for stage N3a (p = 0.000) and N3b (p = 0.003) patients, while no other cut-off value was significantly superior to 15 for stage N1-2 patients (both p > 0.05). Age, tumor size, tumor depth, and number of LNs resected were independent prognostic predictors for stage N3a patients, while resection type and number of LNs resected were independent prognostic predictors for stage N3b patients. Removing more than 22 LNs exhibited a significant survival benefit compared with removing 15-22 LNs for stage N3a and N3b patients (29.7 vs. 21.6%, p = 0.000; 12.9% vs. 0%, p = 0.003, respectively).

CONCLUSION

Removing at least 23 LNs could yield better survival outcomes in stage N3 gastric cancer patients.

Changes of Esophagogastric Junctional Adenocarcinoma and Gastroesophageal Reflux Disease Among Surgical Patients During 1988-2012: A Single-institution, High-volume Experience in China

OBJECTIVE

To evaluate the changes of esophagogastric junctional adenocarcinoma (EGJA) and gastroesophageal reflux disease (GERD) among surgical patients from 1988 to 2012 in a Chinese high-volume hospital.

BACKGROUND

The incidence of EGJA in Western countries has rapidly increased in recent decades. However, recent data from China remain sparse.

METHODS

A retrospective analysis was performed on the basis of 5053 patients who underwent surgery for gastric and distal esophageal adenocarcinoma. Total of 1723 patients with EGJA who underwent surgery were included. Changes of the prevalence of GERD and the clinicopathological features and surgical treatment of EGJA were longitudinally analyzed by a 5-year interval.

RESULTS

The proportion of EGJA was increased from 22.3% in period 1 (1988-1992) to 35.7% in period 5 (2008-2012) (P < 0.001). The proportion of Siewert type III (35.9% vs 47.0%) (P < 0.001) and type I (8.7% vs 15.8%) (P = 0.002) tumors of EGJA was also increased during the past 25 years. The prevalence of GERD had increased gradually from 6.5% in period 1 to 10.9% in period 5 for the 3 subgroups without significant difference (P = 0.459). There was an upward tendency with significant difference between the proportion of EGJA and the prevalence of GERD (r = 0.946, P = 0.000). Instead of type II and type III tumors, there was a positive correlation with change in GERD for type I tumors (r = 0.438, P = 0.029). Total gastrectomy was more preferred among patients with EGJA in period 5 than in period 1 (42.0% vs 19.6%) (P < 0.001).

CONCLUSIONS

An increasing trend of EGJA is observed during the past 25 years in West China Hospital. The prevalence of GERD among EGJA had showed a gradually increased trend. However, the causality between GERD and EGJA still needs to be researched further. Total gastrectomy is becoming more preferred procedure in patients with EGJA.

Overall Survival Is Impacted by Birthplace and Not Extent of Surgery in Asian Americans with Resectable Gastric Cancer

Survival from gastric cancer in the USA still lags behind Asia. Genetic, environmental, and tumor biology differences, along with extent of surgery have been implicated. Our aim was to evaluate survival outcomes in Asian-American gastric cancer patients undergoing surgical resection by comparing place of birth and clinicopathologic characteristics (including evaluation of 15 lymph nodes).The Surveillance, Epidemiology, and End Results database was queried to identify patients treated surgically for gastric cancer with curative intent in the USA (2000-2010). US-born versus foreign-born Asian-American patients were analyzed for survival. Secondary comparison was made to non-Asian patients. Stage IV and non-surgical patients were excluded. Of 10,089 patients identified, 1467 patients were Asian: 271 were born in the USA, and 1196 were born outside the USA. Median survival was 32 months for non-Asians and 29 months for US-born Asians versus 61 months for Asian immigrants (p < 0.001). On multivariable analysis of overall survival in Asian patients, only US birthplace, older age, and higher stage yielded a significantly poorer outcome. Asian-American patients have a worse prognosis if born in the USA. Anatomic and surgical differences do not explain this disparity; environmental factors may be responsible.

HMGA1/HMGA2 protein expression and prognostic implications in gastric cancer

BACKGROUND

The high mobility group A1 (HMGA1) and high mobility group A2 (HMGA2) proteins are architectural transcription factors that have been implicated in the pathogenesis and progression of multiple malignant tumors, including gastric cancer. The aim of this study was to explore the roles of HMGA1 and HMGA2 in gastric carcinogenesis.

METHODS

The expression of HMGA1 and HMGA2 was examined in 110 gastric adenocarcinomas, 29 gastric adenomas, and 30 normal controls. The results were correlated with the clinicopathological parameters of the tumors and patient outcome.

RESULTS

The levels of HMGA1 and HMGA2 proteins were significantly increased in gastric cancer samples compared with adenoma and normal gastric tissues. High HMGA1 nuclear immunoreactivity was not correlated with clinicopathological features; however, high levels of HMGA2 protein were significantly associated with T stage, N stage, lymphatic invasion, perineural invasion, and TNM stage. Moreover, HMGA2 expression was significantly associated with shorter recurrence free survival. Multivariate analysis showed that HMGA2 expression was an independent prognostic factor for tumor recurrence.

CONCLUSIONS

Our results suggest that HMGA1 and HMGA2 are implicated in gastric carcinogenesis and may play a role in tumor progression towards a more malignant phenotype. The HMGA2 protein may be a useful prognostic marker for predicting tumor recurrence.

Predicting recurrence after curative resection for gastric cancer: External validation of the Italian Research Group for Gastric Cancer (GIRCG) prognostic scoring system

BACKGROUND

Most nomograms for Gastric Cancer (GC) were developed to predict overall survival (OS) after curative resection. The Italian Research Group for Gastric Cancer (GIRCG) prognostic scoring system (PSS) was designed to predict the recurrence risk after curative treatment based on pathologic tumor stage and treatment performed (D1-D2/D3 lymphadenectomy). This study was carried out to externally validate the GIRCG's PSS.

PATIENTS AND METHODS

Adopting the same criteria used by GIRCG to build the PSS, 185 patients with GC operated with curative intention were selected. The median follow-up period was 77.8 months (1.93-150.8) for all patients and 102.5 months (60.9-150.8) for patients free of disease. The NRI (net reclassification improvement) was calculated to estimate the overall improvement in the reclassification of patients using the PSS in place of the TNM stage system.

RESULTS

GC recurrence occurred in 70 (37.8%) patients. The mean time to recurrence was 22.2 (range 1.9-98.1) months. For patients with recurrence, the gain in the proportion of reclassification was 0.257 (p < 0.001), indicating an improvement of 26%. For patients without recurrence, the gain in the proportion of reclassification was -0.122 (p < 0.001), indicating a worsening of 12%. The NRI calculated was 0.135 (p = 0.0527).

CONCLUSION

The GIRCG's PSS, which predicts the likelihood of recurrence after radical surgical treatment for GC, is more accurate than TNM system to predict recurrence mainly for high-risk patients. Yet, the PSS does not have the same effectiveness for low-risk patients, overestimating the chance of recurrence occurs even for disease-free patients.

Clinicopathological significance of N-cadherin and VEGF in advanced gastric cancer brain metastasis and the effects of metformin in preclinical models

Gastric cancer is the second most common cause of cancer-related death worldwide. Although brain metastasis is a rare complication of gastric cancer, no standard therapy for gastric cancer brain metastasis has been established. We attempted to identify biological markers that predict brain metastasis, and investigated how to modulate such markers. A case-control study of patients newly diagnosed with gastric cancer who had developed brain metastasis during follow-up, was conducted. These patients were compared with patients who had advanced gastric cancer but no evidence of brain metastasis. Immunohistochemistry was used to analyze the expression of E-cadherin, N-cadherin, MSS1, claudin-3, claudin-4, Glut1, clusterin, ITGB4, vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR) and p53. The expression of VEGF tended to be higher in the case group (33.3 vs. 0%, p=0.055). Median survival was significantly correlated with vascular invasion (12 vs. 33 months, p=0.008) and N-cadherin expression (36 vs. 12 months, p=0.027). We also investigated the effects of metformin in tumor-bearing mouse models. VEGF expression was decreased and E-cadherin increased in the metformin‑treated group when compared with the control group. The expression of the mesenchymal marker MMP9 was decreased in the metformin-treated group. Brain metastasis of advanced gastric cancer was associated with the expression of VEGF. Metformin treatment may be useful for modulating the metastatic capacity by reducing VEGF expression and blocking epithelial-to-mesenchymal transition.

Time trends of clinicopathologic features and surgical treatment for gastric cancer: Results from 2 high-volume institutions in southern China

BACKGROUND

The objective of this study was to evaluate the time-related trends of tumor characteristics and postoperative survival of patients with gastric cancer (GC) in 2 high-volume centers in high incidence areas of southern China.

METHODS

Based on the meticulously collected data from 5,327 patients with GC treated with operative intervention at Sun Yat-sen University Cancer Center and Fujian Medical University Union Hospital, we analyzed the differences in clinicopathologic features and postoperative survival over the following 4 consecutive periods: 1991-1995 (period 1), 1996-2000 (period 2), 2001-2005 (period 3), and 2006-2010 (period 4).

RESULTS

Tumor size decreased (P = .001), but the proportion of poorly differentiated tumors increased (P < .001) over the study periods. Early GC was diagnosed more often in later periods, gradually increasing from 7 to 15% (P < .001). A surprising improvement was observed in the mean number of retrieved lymph nodes, ranging from 10.36 to 26.22 (P < .001). The radical resection rate increased from 88 to 93%. The overall 5-year survival rate improved steadily over the 4 periods, from 39 to 53% (P < .001). Multivariate analysis revealed that age, tumor location, histologic type, tumor size, depth of invasion, lymphatic invasion, number of retrieved lymph nodes, radical resection, and time periods were independent prognostic factors.

CONCLUSION

The clinicopathologic features of tumors changed during the observation period in our region. The increasingly early detection of patients with GC and more standardized regimens for operative management, including routinely performed D2 lymphadenectomy, most likely resulted in the increase in overall survival.

Risk factors of early proximal gastric carcinoma in Chinese diagnosed using WHO criteria

OBJECTIVE

The incidence of proximal gastric carcinoma (PGC) is rising worldwide for unknown reasons. Herein we compare the risk factors of early PGC with distal gastric carcinoma (DGC) in patients treated at a single tertiary hospital in China.

METHODS

Risk factors of 379 consecutive surgically resected early gastric carcinoma (EGC) diagnosed according to the 2010 World Health Organization criteria were studied by reviewing their medical records and esophagogastroduodenoscopy/biopsy findings and interviewing patients and family members for the patients' history of environmental toxin exposure (ETE), dietary habits, family (FCH) and personal cancer history (PCH) and survival. Differences between PGC (n = 115), DGC (n = 264) and age-matched and gender-matched controls (n = 225) were compared.

RESULTS

Proportion of early PGC in all EGC patients was increased significantly (P < 0.05). The independent risk factors for both PGC and DGC identified by multivariate analysis were intake of preserved food and little fruit, and gastric mucosal intestinal metaplasia and atrophy (all P < 0.05). Advanced age (odds ratio [OR] 9.83, P < 0.01), PCH (OR 5.09, P < 0.05), a high body mass index (>24 kg/m(2) ) (OR 2.79, P < 0.01) and ETE (OR 2.31, P < 0.05) were independent risk factors for PGC, but not male gender, tobacco or alcohol abuse, hiatus hernia, gastroesophageal reflux disease or columnar-lined esophagus. In contrast, FCH (OR 2.34, P < 0.01) and Helicobacter pylori infection (OR 2.81, P < 0.001) were independent risk factors for DGC.

CONCLUSION

Independent risk factors for PGC in Chinese patients differ from those of DGC or esophageal adenocarcinoma, supporting the classification of PGC as a separate gastric carcinoma entity in the Chinese populations.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients' desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Significant differences in the clinicopathological characteristics and survival of gastric cancer patients from two cancer centers in china and Korea

PURPOSE

To compare the clinicopathological data and long-term survival of gastric cancer patients in China and Korea.

MATERIALS AND METHODS

Patients who had undergone gastrectomy for gastric cancer between 1998 and 2009 in 2 high-volume institutions in both China (n=1,637) and Korea (n=2,231) were retrospectively evaluated. Clinicopathological variables, overall survival (OS), progression-free survival (PFS), and surgery-related complications were assessed for all patients and compared between the 2 institutions.

RESULTS

Chinese patients included in the study were significantly older and had a significantly lower body mass index (BMI) than the Korean patients. Esophagogastric junction tumors were more frequent in Chinese patients. However, the number of patients with stage I gastric cancer, the number of harvested lymph nodes, and the number of total gastrectomies were significantly higher in the Korean population. Korean patients also presented with fewer undifferentiated tumors than Chinese patients. Furthermore, Korean patients had prolonged OS and PFS for stage III cancers only. BMI, tumor-node-metastasis (TNM) stage, tumor invasion, number of positive lymph nodes, and distant metastases were all independent factors affecting OS and PFS.

CONCLUSIONS

Although China and Korea are neighboring Asian countries, the clinicopathological characteristics of Chinese patients are significantly different from those of Korean patients. Korean gastric cancer patients had longer OS and PFS than Chinese patients. Influencing factors included TNM stage, tumor invasion, and lymph node metastasis.

Subtotal gastrectomy for gastric cancer

Although a steady decline in the incidence and mortality rates of gastric carcinoma has been observed in the last century worldwide, the absolute number of new cases/year is increasing because of the aging of the population. So far, surgical resection with curative intent has been the only treatment providing hope for cure; therefore, gastric cancer surgery has become a specialized field in digestive surgery. Gastrectomy with lymph node (LN) dissection for cancer patients remains a challenging procedure which requires skilled, well-trained surgeons who are very familiar with the fast-evolving oncological principles of gastric cancer surgery. As a matter of fact, the extent of gastric resection and LN dissection depends on the size of the disease and gastric cancer surgery has become a patient and “disease-tailored” surgery, ranging from endoscopic resection to laparoscopic assisted gastrectomy and conventional extended multivisceral resections. LN metastases are the most important prognostic factor in patients that undergo curative resection. LN dissection remains the most challenging part of the operation due to the location of LN stations around major retroperitoneal vessels and adjacent organs, which are not routinely included in the resected specimen and need to be preserved in order to avoid dangerous intra- and postoperative complications. Hence, the surgeon is the most important non-TMN prognostic factor in gastric cancer. Subtotal gastrectomy is the treatment of choice for middle and distal-third gastric cancer as it provides similar survival rates and better functional outcome compared to total gastrectomy, especially in early-stage disease with favorable prognosis. Nonetheless, the resection range for middle-third gastric cancer cases and the extent of LN dissection at early stages remains controversial. Due to the necessity of a more extended procedure at advanced stages and the trend for more conservative treatments in early gastric cancer, the indication for conventional subtotal gastrectomy depends on multiple variables. This review aims to clarify and define the actual landmarks of this procedure and the role it plays compared to the whole range of new and old treatment methods.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: Do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients’ desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

A nomogram for predicting individual survival of patients with gastric cancer who underwent radical surgery with extended lymph node dissection

BACKGROUND

We developed and validated a nomogram for use at a high-volume center where radical surgery with extended lymph node dissection is the standard treatment for gastric cancer.

METHODS

Overall, 1,614 patients were randomly divided into the test set (n = 805) and validation set (n = 809). The scoring system was calculated using a Cox proportional hazard regression model with the survival of gastric cancer as the predicted endpoint. The concordance index (c-index) was used as an accuracy measure, with bootstrapping to correct for optimistic bias. Calibration plots were constructed.

RESULTS

Based on a Cox model, we developed a nomogram that predicts the probability of 3- and 5-year survival from the time of surgery. The bootstrap-corrected c-indices were 0.87 and 0.84 in the test and validation sets, respectively. Survival was well predicted in both sets. The predictions of our nomogram discriminated better than the AJCC staging system (test set: c-index, 0.87 vs. 0.77; P < 0.0001; validation set: c-index, 0.84 vs. 0.79; P < 0.001).

CONCLUSION

We developed and validated a nomogram that provided a significantly accurate prediction of postoperative survival in Korean patients with gastric cancer who underwent radical gastrectomy with extended lymph node dissection.

Is gastric cancer different in Korea and the United States? Impact of tumor location on prognosis

PURPOSE

To compare the characteristics and prognoses of gastric cancers by tumor location in Korean and U.S. subjects after curative-intent (R0) resection for gastric cancer (GC).

METHODS

Data were collected for all patients who had undergone R0 resection at one U.S. institution (n = 567) and one South Korean institution (n = 1,620). Patients with gastroesophageal junction tumors or neoadjuvant therapy were excluded. Patient, surgical, and pathologic variables were compared by tumor location. Factors associated with disease-specific survival (DSS) were determined via multivariate analysis.

RESULTS

In the Korean cohort, significantly more upper third GC (UTG) patients had undifferentiated, diffuse type, and advanced stage cancers compared to lower third GC (LTG) and middle third GC (MTG) patients. In the U.S. cohort, however, T stage was relatively evenly distributed among UTG, MTG, and LTG patients. The independent predictors of DSS in the Korean cohort were T stage, tumor size, retrieved and positive lymph node counts, and age, but in the U.S. cohort, the only independent predictors were T stage and positive lymph node count. Tumor size significantly affected DSS of Korean UTG patients but not U.S. UTG patients.

CONCLUSIONS

There were significant differences in tumor characteristics by tumor location within and between both national cohorts. On the basis of these findings, further study to investigate the biological difference between the two countries is needed.

A novel oncolytic viral therapy and imaging technique for gastric cancer using a genetically engineered vaccinia virus carrying the human sodium iodide symporter

Background

Gastric cancers have poor overall survival despite recent advancements in early detection methods, endoscopic resection techniques, and chemotherapy treatments. Vaccinia viral therapy has had promising therapeutic potential for various cancers and has a great safety profile. We investigated the therapeutic efficacy of a novel genetically-engineered vaccinia virus carrying the human sodium iodide symporter (hNIS) gene, GLV-1 h153, on gastric cancers and its potential utility for imaging with ^99mTc pertechnetate scintigraphy and ¹²⁴I positron emission tomography (PET).

Methods

GLV-1 h153 was tested against five human gastric cancer cell lines using cytotoxicity and standard viral plaque assays. In vivo, subcutaneous flank tumors were generated in nude mice with human gastric cancer cells, MKN-74. Tumors were subsequently injected with either GLV-1 h153 or PBS and followed for tumor growth. ^99mTc pertechnetate scintigraphy and ¹²⁴I microPET imaging were performed.

Results

GFP expression, a surrogate for viral infectivity, confirmed viral infection by 24 hours. At a multiplicity of infection (MOI) of 1, GLV-1 h153 achieved > 90% cytotoxicity in MNK-74, OCUM-2MD3, and AGS over 9 days, and >70% cytotoxicity in MNK- 45 and TMK-1. In vivo, GLV-1 h153 was effective in treating xenografts (p < 0.001) after 2 weeks of treatment. GLV-1 h153-infected tumors were readily imaged by ^99mTc pertechnetate scintigraphy and ¹²⁴I microPET imaging 2 days after treatment.

Conclusions

GLV-1 h153 is an effective oncolytic virus expressing the hNIS protein that can efficiently regress gastric tumors and allow deep-tissue imaging. These data encourages its continued investigation in clinical settings.

Treatment results of curative gastric resection from a specialist Australian unit: low volume with satisfactory outcomes

BACKGROUND

The incidence of gastric cancer is decreasing in Australia, yet it remains a common cause of cancer-related mortality. Surgical resection remains the cornerstone of curative treatment. High-volume specialized units have reported superior perioperative and oncological outcomes. The role of D2 lymphadenectomy has been controversial as a result of concerns over increased morbidity. Our aim is to report the perioperative and oncological outcomes of curative gastric resection from a specialist Australian upper GI unit.

METHODS

Data from a prospectively maintained database were reviewed for all patients undergoing curative resection for gastric adenocarcinoma from a single unit during a 12-year period. Perioperative and long-term outcomes were compiled.

RESULTS

There were 255 curative gastric resections during 12 years. An R0 resection was performed in 96 % with a perioperative mortality rate of 1.6 %. A D2 dissection was performed in 85 % of cases in the past 6 years, with no increase in perioperative morbidity or mortality detected. The 5-year overall survival was 53 %.

CONCLUSION

Our results demonstrate that both short- and long-term outcomes of surgical resection in gastric cancer patients, comparable to international high-volume centers, can be achieved in an Australian upper GI unit. A D2 lymph node dissection can be performed safely without any increase in perioperative risk in a specialist unit that has the necessary training but also the perioperative support structures to manage these complex patients.

Systematic review and meta-analysis of laparoscopic and open gastrectomy for advanced gastric cancer

Background

The use of laparoscopic gastrectomy (LG) in advanced gastric cancer (AGC) remains a controversial topic, mainly because of doubts about its oncologic validity. This study is a systematic review and meta-analysis of the available evidence.

Methods

A comprehensive search was performed until June 2013 to identify comparative studies evaluating survival rates, recurrence rates, surgical outcomes and complications. Pooled risk ratios (RR) and weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated using the random effects model. Data synthesis and statistical analysis were carried out using RevMan 5.1 software.

Results

Fifteen trials were involved in this analysis. Compared to open gastrectomy (OG), LG involved a longer operating time (WMD = 48.67 min, 95% CI 34.09 to 63.26, P < 0.001); less blood loss (WMD = −139.01 ml, 95% CI −174.57 to −103.44, P < 0.001); earlier time to flatus (WMD = −0.79 days, 95% CI −1.14 to −0.44, P < 0.001); shorter hospital stay (WMD = −3.11 days, 95% CI −4.13 to −2.09, P < 0.001); and a decrease in complications (RR = 0.74, 95% CI 0.61 to 0.90, P = 0.003). There was no significant difference in the number of harvested lymph nodes, margin distance, mortality, cancer recurrence rate and long-term survival rate between the AGC patients treated with LG or OG (P > 0.05).

Conclusions

Despite a longer operation, LG is a safe technical alternative to OG for AGC with a lower complication rate and enhanced postoperative recovery. Moreover, there were similar outcomes between both approaches in terms of cancer recurrence and the long-term survival rate. Because of the limitation of this study, methodologically high-quality studies are needed for further evaluation.

Lower esophageal sphincter-preserving laparoscopy-assisted proximal gastrectomy in patients with early gastric cancer: a method for the prevention of reflux esophagitis

Although laparoscopy-assisted proximal gastrectomy (LAPG) with esophagogastrostomy for early gastric cancer (EGC) is technically feasible and oncologically safe, it has not been popularized because of the frequent occurrence of reflux esophagitis associated with loss of the lower esophageal sphincter (LES). Herein, we present surgical outcomes in patients with LES-preserving LAPG (LES-p LAPG), which may contribute to protecting against postoperative gastroesophageal reflux or stricture in the treatment of proximal EGC. From November 2009 to May 2010, LES-p LAPG was performed in nine patients with clinical EGC, located at the proximal one-third of the stomach with the upper margin of the tumor 3-4 cm from the esophagogastric junction. After the resection of the proximal stomach with D1 + β lymph node dissection, gastrogastrostomy was performed using a 25-mm circular stapler through a mini-laparotomy wound at the epigastrium. The median operating time was 137.5 min (range 120-180). The median number of retrieved lymph nodes and length of the proximal resection margin were 27 (range 7-49) and 2.4 cm (range 0.7-5), respectively. The postoperative complications included one gastrogastrostomy stricture and one case of leakage, which were managed by endoscopic balloon dilation and conservative treatment, respectively. None of the patients suffered from symptoms of reflux esophagitis during the follow-up period (median 15 months; range 8-28 months). This technique of LES-p LAPG for the treatment of proximal EGC could be a simple, safe, and useful technique to prevent esophageal reflux or stricture. This technique requires prospective validation.

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.

Surgical treatment results of intestinal and diffuse type gastric cancer. Implications for a differentiated therapeutic approach?

AIM

To study the outcome of patients who were surgically treated for primary gastric cancer with specific attention to differences in treatment results for intestinal and diffuse type tumours.

METHODS

All patients who underwent a potentially curative gastric resection between 1995 and 2011 in our institute were included. Patient, tumour and treatment characteristics were obtained retrospectively. Binary logistic and Cox regression models were used for multivariate analysis.

RESULTS

A consecutive series of 132 patients was included. Median follow-up was 53 months. There were no significant differences between patients with intestinal (N = 62) versus diffuse type (N = 70) gastric cancer with regard to the proportion of patients who underwent (neo)adjuvant treatment. Postoperative mortality was 2%. Pathological T- and N-stage were significantly more advanced for patients with diffuse type tumours. There was a significant difference in the percentage of microscopically irradical resections (2% versus 24%, p < 0.001) and median overall survival (129 versus 17 months, p < 0.001) between patients with intestinal type tumours and those with diffuse type tumours. On multivariate analysis, diffuse type histology was the only factor significantly associated with an R1 resection. In a multivariate Cox regression model, diffuse type histology was a significant adverse prognostic factor for overall survival.

CONCLUSIONS

Striking differences were found between patients with diffuse type tumours and those with intestinal type tumours. These differences call for a differentiated approach in the potentially curative treatment of these two tumour types.

Race and correlations between lymph node number and survival for patients with gastric cancer

BACKGROUND

There is ongoing debate whether extended lymphadenectomy improves survival in gastric cancer patients who undergo surgical resection. We previously observed that Korean-American patients had the highest overall survival in Los Angeles County. Our objective was to assess lymph node (LN) number and its impact on survival for Korean-American gastric cancer patients.

METHODS

We utilized the National Cancer Institute's Surveillance, Epidemiology, and End Results registry to identify Korean-Americans with gastric adenocarcinoma treated with curative-intent gastrectomy between 1988 and 2008. We grouped patients according to examined LN number (1-15 and 16+) and compared characteristics. We performed similar analysis for white patients.

RESULTS

Out of 982 Korean-American patients with gastric adenocarcinoma, most patients had 1-15 examined LNs (60 %). When we compared LN groups, we observed higher overall survival in the 1-15 group than the 16+ group (5-year survival, 59 % vs 52 %, respectively; p = 0.04). However, LN number was not prognostic of overall survival on stepwise Cox proportional hazards analysis. In contrast, LN number was prognostic for white patients.

CONCLUSIONS

Although examined LN number may impact survival for white patients, outcomes of Korean-American gastric cancer patients were independent of LN number. Our data suggest that survival of Korean-American gastric cancer patients are comparable with outcomes from East Asian hospitals and may be independent of surgical technique.

Role of preoperative colonoscopy in patients with gastric cancer: a case control study of the prevalence of coexisting colorectal neoplasms

BACKGROUND

We evaluated the prevalence of coexisting asymptomatic colorectal neoplasm (CRN) in patients with gastric cancer (GC).

METHODS

Preoperative colonoscopic examinations were performed in 495 patients with GC who underwent gastrectomy between January 2009 and December 2010. To compare the prevalence of CRN in these patients with that in a normal population, we selected 495 sex- and age-matched persons who underwent colonoscopies for health screening. Risk factors for CRN were evaluated by univariate and multivariate analyses.

RESULTS

The overall incidence of CRN was 41.8 % (414/990). The prevalence of overall CRN, high-risk CRN, and colorectal carcinoma (CRC) were significantly higher in the GC group than in the control group (overall CRN: 48.9 % vs. 34.7 %; high-risk CRN: 28.3 % vs. 13.5 %; CRC: 2.6 % vs. 0.2 %; all P < 0.001). The presence of GC [odds ratio (OR), 1.82; 95 % confidence interval (CI), 1.4-2.38; P < 0.001], age ≥50 years (OR, 2.58; 95 % CI, 1.75-3.81; P < 0.001), and male sex (OR, 2.28; 95 % CI, 1.72-3.02; P < 0.001) were risk factors for overall CRN. In patients with GC, age ≥40 years (OR, 3.22; 95 % CI, 1.24-8.37; P = 0.016) and male sex (OR, 3.21; 95 % CI, 2.17-4.76; P < 0.001) were risk factors for overall CRN.

CONCLUSIONS

The prevalence of coexisting CRN, including CRC, was higher in patients with GC than in the normal population. Preoperative colonoscopy is strongly indicated in patients with GC who are male and/or ≥40 years of age.

The clinical value of non-curative resection followed by chemotherapy for incurable gastric cancer

BACKGROUND

The clinical value of a non-curative resection for gastric cancer is still controversial. We analyzed the clinical outcomes of patients who underwent non-curative gastric resection.

METHODS

Data from a total of 178 patients who underwent non-curative resection for advanced gastric cancer at Seoul St. Mary's hospital were reviewed. Factors related to the incurability were classified as peritoneal metastasis (P), liver metastasis (H), extra-abdominal metastasis (X), direct adjacent organ invasion that was unresectable (T). The clinicopathologic data, survival, and quality of life of patients were evaluated.

RESULTS

The overall median survival time was 12.1 months, and that for the patients with gastrectomy with chemotherapy was 14.3 months. Operation-related complications occurred in 20 patients (11.2 %). Five patients (2.8 %) died of postoperative complications within 30 days, and 43 patients (24.2 %) had symptoms and signs of gastric outlet obstruction or uncontrolled bleeding. The mean duration of postoperative hospital stay was 15.9 days for those symptomatic patients, and the symptom-relieved period was 8.6 months.

CONCLUSIONS

There might be a role for non-curative resection followed by chemotherapy for incurable gastric cancer, in terms of survival, and this treatment approach should be carefully considered because of the high mortality rate associated with the disease. A large, randomized, prospective study is warranted to prove the benefit of non-curative resection in patients with incurable gastric cancer.

Clinical significance of incidental colonic 18F-FDG uptake on PET/CT images in patients with gastric adenocarcinoma

BACKGROUND AND OBJECTIVES

We assessed the ability of positron emission tomography-computed tomography (PET/CT) to detect synchronous colonic pathology and determined the significance of 18F-fluorodeoxyglucose (18F-FDG) activity in the colon of gastric cancer patients.

METHODS

A total of 239 gastric cancer patients who underwent PET/CT and colonoscopy preoperatively were included. FDG uptake patterns on PET/CT were classified as (1) group A, focal; (2) group B, diffuse; and (3) group C, no uptake. The PET/CT findings were compared with the results of concurrent colonoscopy.

RESULTS

In group A, a total of 123 polyps of >0 mm were observed. Of these, nine polyps were colonic adenocarcinomas and six were high-grade dysplasia. The incidence of colonic adenocarcinomas was significantly higher in group A than in the other two groups (p = 0.037). There was a significant correlation between SUVmax values and incidence of colonic polyps of >10 mm (r = 0.471, p = 0.04). The distribution pattern of SUVmax in polyps with adenoma (>10 mm) was less homogenous than in polyps (>10 mm) with adenocarcinoma.

CONCLUSIONS

The focal colonic FDG uptake in PET/CT requires colonoscopic confirmation. The suspicion of colonic malignancy increased in the presence of polyps >10 mm that showed a positive correlation with the SUVmax.

The impact of an increased application of critical pathway for gastrectomy on the length of stay and cost

Purpose

We developed a standardized critical pathway for gastric cancer surgery and then determined the increase of application, which resulted in an improvement in terms of measurable indices, such as hospital stay and cost.

Materials and Methods

A critical pathway was revised and used widely from the 2nd quarter of 2009. We collected clinical data, such as length of stay and complication rate, as clinical indices of quality prospectively. The total cost paid at the patient's discharge, as well as the daily hospital income, were calculated and compared by each quarter from January 2008 to December 2009.

Results

The application rate of critical pathway was 11.8% and 87.8% in 2008 and 2009, respectively. There were no perioperative deaths. There was no difference in the complication rates between 2008 and 2009 (P=0.45). However, the mean length of stay was significantly different between the 2 years (P<0.05). Although the total cost was not different, the daily hospital income was significantly higher in the latter year (P<0.05).

Conclusions

An increase in the application of critical pathway for gastrectomy resulted in significant decreases in length of stay and increases in the daily hospital income without a compromise on the clinical indices.

Morbidity and mortality after non-curative gastrectomy for gastric cancer in elderly patients

BACKGROUND AND OBJECTIVES

This study examined the surgical outcome of non-curative resection in elderly patients with gastric cancer.

METHODS

The study reviewed 278 patients who underwent non-curative resection for advanced gastric cancer. The clinicopathological features of elderly patients (≥ 75 years, n = 257) and younger patients (<75 years, n = 21) were compared.

RESULTS

Although no difference was observed in terms of preoperative performance, there were distinct differences in terms of albumin level, presence of symptoms, and the rate of comorbidities between the two groups. The postoperative morbidity and mortality rate did not differ between the two groups. Age, preoperative performance status, preoperative transfusion, and presence of comorbidity were not independent predictors of postoperative complications. However, the extent of gastric resection and combined resection were closely related to postoperative complications in patients with non-curative gastrectomy.

CONCLUSIONS

In a setting of non-curative resection for gastric cancer, age was not a limiting factor. Rather, the risk of postoperative morbidity should be considered carefully in total gastrectomy and combined resection.

Cumulative radiation exposure during follow-up after curative surgery for gastric cancer

OBJECTIVE

To quantify the cumulative effective dose (cED) of radiation due to repeated CT and PET/CT examinations after curative resection of gastric cancer and to assess the lifetime attributable risk (LAR) estimates based on Biological Effects of Ionizing Radiation VII models.

SUBJECTS AND METHODS

Patients who underwent a curative resection for gastric cancer between January 2006 and December 2006 and were followed-up until May 2010 were included in this study. The cED was calculated by using the dose-length product values and conversion factors for quantitative risk assessment of radiation exposure. cED and LAR were compared between early and advanced gastric cancer patients and among American Joint Committee on Cancer TNM stage groups (stage I, II, and III). The nonparametric Mann-Whitney U and Kruskal-Wallis tests, followed by a post-hoc analysis with Bonferroni adjustment, were employed as part of the statistical analysis.

RESULTS

The overall median cED was 57.8 mSv (interquartile range [IQR], 43.9-74.7). The cED was significantly higher in the advanced (median, 67.0; IQR, 49.1-102.3) than in the early gastric cancer group (median, 52.3; IQR, 41.5-67.9) (p < 0.001), and increased as the TNM stage increased. For radiation exposure, 62% of all patients received an estimated cED of over 50 mSv, while 11% of patients received over 100 mSv. The median LAR of cancer incidence was 0.28% (IQR, 0.20-0.40) and there were significant differences between the early gastric cancer and advanced gastric cancer group (p < 0.001) as well as among the three TNM stage groups (p = 0.015). The LAR of cancer incidence exceeded 1% in 2.4% of the patients.

CONCLUSION

The cED increases proportionally along with tumor stage and, even in early gastric cancer or stage I patients, cED is much higher than that found among the general population. Considering the very good prognosis of early gastric cancer after curative surgery, the cED should be considered when designing a postoperative follow-up CT protocol.

Long-term outcomes after laparoscopy-assisted gastrectomy for advanced gastric cancer: a large-scale multicenter retrospective study

BACKGROUND

Recently, the number of laparoscopic procedures for gastric cancer has increased rapidly. Laparoscopic surgery is reported to have many advantages over open gastrectomy with oncologic safety in early gastric cancer. However, there were few reports on long-term outcomes of laparoscopy-assisted gastrectomy (LAG) for advanced gastric cancer (AGC). The aim of this study was to investigate long-term survival outcomes after LAG for AGC.

METHODS

The data of 1,485 patients who underwent LAG between April 1998 and December 2005 by ten surgeons at ten hospitals were collected retrospectively. Among them, 239 patients who were diagnosed with AGC on final pathologic examination were enrolled in the present study to investigate long-term clinical outcomes.

RESULTS

The ratio of male to female patients was 151:88 and the mean age was 57.1 years. One hundred ninety-three subtotal gastrectomies, 41 total gastrectomies, and 5 proximal gastrectomies were performed. D1 + α, D1 + β, and D2 lymph node dissections were performed for 14, 62, and 163 cases, respectively. The median follow-up period was 55.4 months. The overall 5-year survival rate of the 239 AGC patients was 78.8% and the disease-specific 5-year survival rate was 85.6%. The 5-year survival rates of the TNM staging system's (7th ed.) stages were 90.5% (stage Ib, n = 86), 86.4% (stage IIa, n = 53), 78.3% (stage IIb, n = 44), 52.8% (stage IIIa, n = 24), 52.9% (stage IIIb, n = 24), and 37.5% (stage IIIc, n = 8) (p < 0.001).

CONCLUSION

The long-term survival outcome rates of LAG for AGC in the present study were comparable to those previously reported for open gastrectomy. Based on the present results, a well-designed phase III trial comparing LAG and open gastrectomy for AGC will be needed to affirm the validity of LAG for AGC.

Comparative study of complete and partial omentectomy in radical subtotal gastrectomy for early gastric cancer

PURPOSE

Curative surgery for patients with advanced or even early gastric cancer can be defined as resection of the stomach and dissection of the first and second level lymph nodes, including the greater omentum. The aim of this study was to evaluate the short- and long- term outcomes of partial omentectomy (PO) as compared with complete omentectomy (CO).

MATERIALS AND METHODS

Seventeen consecutive open distal gastrectomies with POs were initially performed between February and July in 2006. The patients' clinicopathologic data and post-operative outcomes were retrospectively compared with 20 patients who underwent open distal gastrectomies with COs for early gastric cancer in 2005.

RESULTS

The operation time in PO group was significantly shorter than that in CO group (142.4 minutes vs. 165.0 minutes, p=0.018). The serum albumin concentration on the first post-operative day in PO group was significantly higher than CO group (3.8 g/dL vs. 3.5 g/dL, p=0.018). Three postoperative minor complications were successfully managed with conservative treatment. Median follow-up period between PO and CO was 38.1 and 37.7 months. All patients were alive without recurrence until December 30, 2009.

CONCLUSION

PO during open radical distal gastrectomy can be considered a more useful procedure than CO for treating early gastric cancer. To document the long-term technical and oncologic safety of this procedure, a large-scale prospective randomized trial will be needed.