Cost-effectiveness analysis of chemotherapy for advanced gastric cancer in China

AIM

To assess the economics of various chemotherapeutic regimens for advanced gastric cancer (AGC), and to select the best cost-effective regimen for the common Chinese patients.

METHODS

Data source used in this study was the Chinese Biomedical Disk Database. Patients were diagnosed as AGC and any regimen was eligible. Outcome measures included median survival time (MST) and percentage of complete and partial response (CR+PR). Economic statistics was per capita direct medical cost (DMC) of a single cycle. TreeAge Pro Healthcare 2007 software was used to carry out cost-effectiveness and incremental cost-effectiveness analysis. Sensitivity analyses were applied by altering willingness-to-pay and annual discount rate, and also re-analyzed by excluding the studies with apparent heterogeneity.

RESULTS

Seven retrospective economics studies on 760 patients were included. 5-fluorouracil-based regimens were universal, and also some new agents were involved, such as docetaxel, paclitaxel, and oxaliplatin. By processing analysis, we could recommend etoposide, leucovorin and 5-fluorouracil (ELF) regimen as preference, with a DMC/MST ratio of 2543 RBM/11.7 mo and a DMC/CR+PR ratio of 2543 RMB/53.3%. Uracil-tegafur, etoposide and cisplatin (FEP) or 5-fluorouracil, adrimycin/epirubin and mitomycin (FAM) regimens could be regarded as optional first-line chemotherapy for AGC in common Chinese patients. With no regard for willingness-to-pay, the docetaxel, cisplatin and 5-fluorouracil (DCF) regimen could be chosen as either a first- or a second-line chemotherapy, with a DMC/CR+PR ratio of 9979 RMB/56.3%.

CONCLUSION

5-fluorouracial regimens are still considered the mainstream for AGC, while new agents such as taxanes are optional. More randomized clinical trials are required before any mandatory recommendation of certain regimens for patients with AGC in China is made.

Associations Between Gastric Cancer Risk and Virus Infection Other Than Epstein-Barr Virus: A Systematic Review and Meta-analysis Based on Epidemiological Studies

INTRODUCTION

Besides Helicobacter pylori and Epstein-Barr virus, other viruses might play potential roles in gastric carcinogenesis. This systematic review and meta-analysis was conducted to compare the prevalence of the viruses between gastric cancer (GC) and any controls.

METHODS

Comprehensive literature was searched up to January 25, 2019, and search was updated on April 6, 2020. The studies that compared the prevalence of viruses other than Epstein-Barr virus between GC and healthy or nonmalignant controls were eligible. Stata 12.0 software was used for heterogeneity tests and meta-analyses. Meanwhile, subgroup analysis, sensitivity analysis, and publication bias evaluation were performed where applicable. The power (1-β) was estimated by the PASS 11 software for each individual study.

RESULTS

A total of 41 eligible studies were included, concerning 11 kinds of viruses. Prevalence were significantly higher in GC for hepatitis B virus (odds ratio [OR] = 1.39, 95% confidence interval [CI] 1.11-1.75), human cytomegalovirus (OR = 2.25, 95% CI 1.14-4.43), human papillomavirus (HPV) (OR = 1.63, 95% CI 1.05-2.54), and John Cunningham virus (OR = 2.52, 95% CI 1.26-5.04). In subgroup analyses, HPV-16 infection was significantly associated with GC (OR = 2.42, 95% CI 1.00-5.83).

DISCUSSION

This study demonstrated that hepatitis B virus, human cytomegalovirus, HPV, and John Cunningham virus were more prevalent in GC. However, the causal relationship between their infection and risk of GC remains inconclusive, and further investigations are required.

Survival benefit and safety of no. 10 lymphadenectomy for gastric cancer patients with total gastrectomy

This study was aimed to evaluate the survival benefit and safety of No. 10 lymphadenectomy for gastric cancer patients with total gastrectomy.Splenic hilar lymph nodes (LNs) are required to be dissected in total gastrectomy with D2 lymphadenectomy. However, there has still not been a consensus in aspects of survival and safety on No. 10 LN resection.From January 2006 to December 2011, 453 patients undergoing total gastrectomy for gastric cancer were retrospectively analyzed. Patients were grouped according to No. 10 lymphadenectomy (10D+/10D-). Clinicopathologic characteristics were compared between the 2 groups. These patients had undergone a follow-up until January 2014. The overall survival, morbidity, and mortality rate were analyzed. Subgroup analyses which were stratified by the sex, age, tumor location, lymphadenectomy extent, curative degree, differentiation, tumor size, and TNM staging (ie, stages of tumor) were performed.There were 220 patients in 10D+ group, whereas 233 in 10D- group. In terms of prognosis, the baseline features between the 2 groups were almost comparable. The incidence of No. 10 LN metastasis was 11.82%. There was no difference in morbidity and mortality between the 2 groups. Significantly more LNs were harvested from patients in 10D+ group (P = 0.000). The estimated overall 5-year survival rates were 46.44% and 37.43% in 10D+ group and 10D- group respectively, which is not statistically significant (P = 0.3288). Although no statistical significance was found in the estimated 5-year survival rate, these data were obviously higher in patients with age >60 years, Siewert II/ III tumors, N1 status, or IIIa/IIIc stages when No. 10 lymphadenectomies were performed.Although the differences were obvious, the 5-year survival rates between the 2 groups did not reach statistical significances, which was probably caused by too small patient samples. High-quality studies with larger sample sizes are needed before stronger statement can be done. Until then, the No. 10 LNs' resection might be recommended in total gastrectomy with D2 lymphadenectomy with an acceptable incidence of complications.

Clinical significance of putative markers of cancer stem cells in gastric cancer: A retrospective cohort study

Cancer stem cells (CSCs) are thought as the source of tumor maintaining and many CSCs markers have been identified. Regarding the heterogeneity in gastric cancer (GC), TNM stage is not enough to accurately predict the prognosis. The aim of this study was to investigate the clinical significance of CSCs markers (Lgr5, Oct4, CD133, EpCAM, CD54 and Sox2) and establish a new model based on these markers to accurately predict prognosis of GC. We retrospectively enrolled 377 GC tissues from January 2006 to October 2012 to perform immunohistochemistry (IHC), and 93 pairs of GC tissues and corresponding adjacent normal gastric tissues to perform quantitative PCR (qPCR) from December 2011 to October 2012. The clinicopathological and follow-up characteristics were collected. In IHC, Oct4, CD133 and EpCAM were independently related to tumor progression, while Sox2 were associated with well or moderate differentiation (all p<0.05). Cox regression showed that Oct4-EpCAM was an independently prognostic factor, indicating that double low expression of Oct4-EpCAM group had significantly better prognosis than control group (p=0.035). Regarding qPCR, CD133 was an independent prognostic factor, showing that the prognosis of patients with CD133 high expression was significantly worse than that of patients with CD133 low expression (p<0.001). The prognostic prediction accuracy of nomogram based on Oct4-EpCAM expression in IHC was significantly better than TNM stage alone (p=0.003). Low expressions of Oct4-EpCAM in IHC and CD133 in qPCR were favorable prognostic factors in GC. The nomogram based on Oct4-EpCAM was valuable in prognostic prediction of GC patients.

Cytotoxin-Associated Gene A-Negative Strains of Helicobacter pylori as a Potential Risk Factor of Pancreatic Cancer: A Meta-Analysis Based on Nested Case-Control Studies

OBJECTIVES

Risk of pancreatic cancer between Helicobacter pylori infected and noninfected persons is controversial, and therefore a meta-analysis was performed.

METHODS

PubMed was searched up to September 2014. Only population-based nested case-control studies comparing the serological prevalence of Helicobacter pylori between pancreatic cancer cases and cancer-free controls were eligible. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for pancreatic cancer risk between Helicobacter pylori infected and noninfected persons were estimated.

RESULTS

Five eligible nested case-control studies were included, with 1446 pancreatic cancer cases and 2235 cancer-free controls. On the whole, the proportion of pancreatic cancer cases among those infected with Helicobacter pylori was not significant different from those noninfected (OR, 0.99; 95% CI, 0.65-1.50; P = 0.96). Likewise, seropositivity of cytotoxin-associated gene A (CagA) showed nonsignificant association with pancreatic cancer (OR, 0.92; 95% CI, 0.65-1.30; P = 0.63). The CagA-positive virulent strains of Helicobacter pylori did not increase the risk of pancreatic cancer (OR, 0.97; 95% CI, 0.50-1.89; P = 0.93). However, CagA-negative nonvirulent strains of Helicobacter pylori had a significant increased risk for pancreatic cancer (OR, 1.47; 95% CI, 1.11-1.96; P = 0.008).

CONCLUSIONS

The CagA-negative non-virulent strains of Helicobacter pylori may be a potential risk factor of pancreatic cancer. High-quality prospective large-scaled studies are required for more conclusive results.

Comparison between gastric and esophageal classification system among adenocarcinomas of esophagogastric junction according to AJCC 8th edition: a retrospective observational study from two high-volume institutions in China

BACKGROUND

The new 8th TNM system attributes AEG Siewert type II to esophageal classification system. However, the gastric and esophageal classification system which was more suitable for type II remains in disputation. This study aimed to illuminate the 8th TNM-EC or TNM-GC system which was more rational for type II, especially for patients underwent transhiatal approaches.

METHODS

We collected the database of patients with AEG who underwent radical surgical resection from two high-volume institutions in China: West China Hospital (N = 773) and Xi Jing Hospital of Fourth Military University (N = 637). The cases were randomly matched into 705 training cohort and 705 validation cohort. All the cases were reclassified by the 8th edition of TNM-EC and TNM-GC. The distribution of patients in each stage, the hazard ratio of each stage, and the separation of the survival were compared. Multivariate analysis was performed using the Cox proportional hazard model. Comparisons between the different staging systems for the prognostic prediction were performed with the rcorrp.cens package in Hmisc in R (version 3.4.4. http://www.R-project.org/ ). The validity of these two systems was evaluated by Akaike information criterion (AIC) and concordance index (C-index).

RESULTS

By univariate analysis, the HRs from stage IA/IB to stage IV/IVB were monotonously increased according to TNM-GC scheme in both cohorts (training 2.63, 3.91, 5.02, 8.64, 15.51 and 29.64; validation 1.54, 3.55, 4.91, 7.14, 11.67, 18.71 and 48.32) whereas only a fluctuating increased tendency was found when staged by TNM-EC. After the multivariate analysis, TNM-GC (P < 0.001), TNM-EC (P = 0.001) in training cohort and TNM-GC (P < 0.001) TNM-EC (P < 0.001) in the validation cohort were both independent prognostic factors. The C-index value for the TNM-GC scheme was larger than that of TNM-EC system in both training (0.721 vs. 0.690, P < 0.001) and validation (0.721 vs. 0.696, P < 0.001) cohorts. After stratification analysis for Siewert type II, the C-index for TNM-GC scheme was still larger than that of TNM-EC in both training (0.724 vs. 0.694, P = 0.005) and validation (0.723 vs. 0.699, P < 0.001) cohorts.

CONCLUSIONS

The 8th TNM-GC scheme is superior to TNM-EC in predicting the prognosis of AEG especially for type II among patients underwent transhiatal approaches.

Necessity of harvesting at least 25 lymph nodes in patients with stage N2-N3 resectable gastric cancer: a 10-year, single-institution cohort study

A minimum of 15 lymph nodes (LNs) has been recommended as an adequate number for radical gastrectomy for gastric cancer (GC). This study aimed to investigate whether the harvesting of at least 25 LNs was a better criterion for stage N2-3 GC based on the 10-year experience of a high-volume hospital. A total of 1363 patients who underwent radical gastrectomy for gastric cancer between 2000 and 2010 were included in this study. The relationship between the number of lymph nodes examined during gastrectomy and overall survival (OS) was analyzed. In multivariate analysis, the numbers of LNs examined (P = 0.001) and N stage were confirmed as 2 of the independent prognostic factors. A larger proportion of N2/N3a/N3b patients was observed in the group with ≥20 LNs examined. The cutoff of ≥25 LNs examined exhibited a significantly lower hazard ratio (HR) than other LN cutoffs among N2-N3 diseases, but the cutoff was not significantly superior to other cutoffs in patients with N0 and N1 disease (HR, 0.64, 0.62, and 0.53 for N2, N3a, and N3b, respectively). The 5-year OS rates were 58.59% and 32.77% for N2 and N3 diseases, respectively, with ≥25 LNs examined, which represents a significant improvement over 15-24 LNs examined (52.48% and 21.67% for N2 and N3 stages, respectively). Among patients with stage N2-N3 GC, harvesting at least 25 LNs may represent a superior cutoff for radical gastrectomy and could yield better survival outcomes.

Outcomes of surgical treatment for gastric cancer patients: 11-year experience of a Chinese high-volume hospital

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. We report our experience with surgery-related parameters and survival outcomes at a single Chinese center. This study analyzed patients following gastric resection between 2000 and 2010, and overall survival was the primary end point. In this study, 1,936 patients who underwent gastrectomy were collected from 2000 to 2010. Curative gastrectomy (R0 resection) was performed in 86.6 % of patients. D1/D1+ lymphadenectomy was frequently performed from 2000 to 2005, and the proportion of D2/D2+ lymphadenectomy increased after 2006. The number of harvested lymph nodes was 10.1 ± 6.0 in 2000 and increased to 28.0 ± 10.5 in 2010. Serosa-invasive lesions (pT4) accounted for 67.9 % of all cases. The 1-year overall survival (OS), 2-year OS, and 3-year OS rates were 89, 74, and 63 %, respectively. Multivariate analysis identified R status, tumor location, macroscopic type, and tumor stage (pT stage and pN stage) as the independent risk factors for overall survival. The prognosis of gastric cancer patients in China remains dismal. To improve the survival outcomes, further efforts toward early detection and multi-disciplinary treatment are needed.

The Significance of the CLDN18-ARHGAP Fusion Gene in Gastric Cancer: A Systematic Review and Meta-Analysis

Objective: The objective of this study was to summarize the clinicopathological characteristics of the CLDN18-ARHGAP fusion gene in gastric cancer patients. Background: The CLDN18-ARHGAP26 fusion gene is one of the most frequent somatic genomic rearrangements in gastric cancer, especially in the genomically stable (GS) subtype. However, the clinical and prognostic meaning of the CLDN18-ARHGAP fusion in gastric cancer patients is unclear. Methods: Studies that investigated CLDN18-ARHGAP fusion gastric cancer patients were identified systematically from the PubMed, Cochrane, and Embase databases through the 28th of February 2020. A systematic review and meta-analysis were performed to estimate the clinical significance of CLDN18-ARHGAP fusion in patients. Results: A total of five eligible studies covering 1908 patients were selected for inclusion in the meta-analysis based on specified inclusion and exclusion criteria. Several fusion patterns were observed linking CLDN18 and ARHGAP26 or ARHGAP6, with the most common type being CLDN18/exon5-ARHGAP26/exon12. The survival outcome meta-analysis of the CLDN18-ARHGAP fusion gene showed that it was associated with overall survival outcomes in gastric cancer (HR, 2.03, 95% CI 1.26-3.26, P < 0.01, random-effects). In addition, diffuse gastric cancer had a greater proportion of CLDN18-ARHGAP fusions than intestinal gastric cancer (13.3%, 151/1,138 vs. 1.8%, 8/442; p < 0.001). Moreover, gastric cancer patients with the CLDN18-ARHGAP fusion gene are more likely to be female or have a younger age, lymph node metastasis and advanced TNM stages. Conclusion: The CLDN18-ARHGAP fusion is one of the molecular characteristics of diffuse gastric cancer and is also an independent prognostic risk factor for gastric cancer. In addition, it is also related to multiple clinical characteristics, including age, sex, lymph node metastasis and tumor stage. However, the mechanism of the CLDN18-ARHGAP fusion gene and potential targeted therapeutic strategies need further exploration.

High mortality from hepatic, gastric and esophageal cancers in mainland China: 40 years of experience and development

The disability-adjusted life-years caused by hepatic, gastric and esophageal cancers in mainland China are among the highest in the world. During the past four decades, improvements in primary prevention of these cancers, particularly in the isolation of risk factors, have been a nationwide goal, and secondary prevention has also been advanced. Nationwide primary preventative measures, including active vaccination against hepatitis B virus in neonates, consensus on screening and eradication of Helicobacter pylori, and quality improvement of dietary and drinking water, have been performed. Additionally, serum alpha-fetoprotein and endoscopic screening were developed and implemented as efficient secondary preventative measures for early diagnosis. Substantial strides toward cancer prevention were taken and have resulted in improved risk factors identification and more efficient screening in mainland China. Despite a reduction, HBV prevalence remained relatively high, potentially contributing to the increase in hepatic cancer-induced mortality. Because the slight decrease in H. pylori prevalence was not associated with an increase in the proportion of early diagnosis of gastric cancer, gastric cancer mortality appeared stable. Esophageal cancer incidence and mortality was reduced, principally due to the improvement in dietary habits and quality, as well as nutritional status. Nationwide isolation of risk factors and the implementation of high-risk candidate screening have been useful approaches to control mortality due to hepatic, gastric and esophageal cancers, and must be continued to secure a future reduction in mortality.

Prognostic Score System Using Preoperative Inflammatory, Nutritional and Tumor Markers to Predict Prognosis for Gastric Cancer: A Two-Center Cohort Study

INTRODUCTION

Gastric cancer (GC) is the fourth leading cause of cancer-related death worldwide. Our study aimed to investigate the prognostic value of preoperative inflammatory, nutritional and tumor markers and develop an effective prognostic score system to predict the prognosis of GC patients.

METHODS

We retrospectively analyzed 1587 consecutive GC patients who received curative gastrectomy from two medical centers. A novel prognostic score system was proposed based on independently preoperative markers associated with overall survival (OS) of GC patients. A nomogram based on prognostic score system was further established and validated internally and externally.

RESULTS

Based on multivariate analysis in the training set, a novel BLC (body mass index-lymphocyte-carbohydrate antigen 19-9) score system was proposed, which showed an effective predictability of OS in GC patients (log-rank P < 0.001). Moreover, receiver-operating characteristic (ROC) analysis showed that BLC had better performance in predicting OS than the traditional prognostic markers. The C-index of the BLC based-nomogram was 0.710 (95% CI 0.686-0.734), and the areas under ROC curves for predicting 3- and 5-year OS were 0.781 (95% CI 0.750-0.813) and 0.755 (95% CI 0.723-0.786), respectively, which were higher than those of tumor node metastasis (TNM) staging system alone. The calibration curve for probability of 3- and 5-year OS rate showed a good fitting effect between prediction by nomogram and actual observation. Verification in the internal and external validation sets showed results consistent with those in the training set.

CONCLUSIONS

The BLC combining inflammatory, nutritional and tumor markers was an independent prognostic predictor for GC patients, and the nomogram based on BLC could accurately predict the personalized survival of patients with GC.

D2 plus para-aortic lymphadenectomy versus standardized D2 lymphadenectomy in gastric cancer surgery

PURPOSE

To evaluate the survival benefits and safety of D2 plus para-aortic lymphadenectomy (D2 + PALD) for gastric carcinoma.

METHODS

Patients with gastric carcinoma, who agreed to undergo D2 + PALD between February 2001 and December 2003, were allocated to the D2 + PALD group, and compared with a control group who underwent D2 lymphadenectomy. Patients were followed up until August 2007.

RESULTS

Sixty-two patients were allocated to the D2 + PALD group, and a concurrent 55 patients were allocated to the D2 group. The mean follow-up period was 57.6 (range 43.0-77.6) months, with 11.1% lost to follow-up. The morbidity and mortality rates were 24.2% and 0% in the D2 + PALD group, and 27.3% and 1.8% in the D2 group, respectively. The overall 3- and 5-year survival rates were 77.5% and 65.8% in the D2 + PALD group, and 73.2% and 66.1% in the D2 group, respectively, without a significant difference. The frequency of metastasis to the para-aortic lymph nodes (PALN) was 8.1%. The logistic regression revealed that PALN metastasis was correlated to metastasis of No. 8a and No. 9 lymph nodes (P = 0.021 and P = 0.030, respectively).

CONCLUSION

Although D2 + PALD can be performed safely with an acceptable incidence of complications when performed by well-trained gastrointestinal surgeons, its survival benefits are not significantly greater than those of D2 lymphadenectomy. Therefore, routine D2 + PALD should not be recommended.

Difference Between Signet Ring Cell Gastric Cancers and Non-Signet Ring Cell Gastric Cancers: A Systematic Review and Meta-Analysis

Background: There is controversy about the characteristics and prognostic implications of signet ring cell gastric cancers and non-signet ring cell gastric cancers. Objective: This study aims to evaluate clinicopathological characteristics and prognoses of signet ring cell carcinoma (SRCC) and non-signet ring cell carcinoma (NSRCC) of stomach. Methods: Studies compared between SRCC and NSRCC of the stomach after gastrectomy and published before September 1st, 2020, in the PubMed, Cochrane, and Embase databases, were identified systematically. Results: A total of 2,865 studies were screened, and 36 studies were included, with 19,174 patients in the SRCC group and 55,942 patients in the NSRCC group. SRCC patients were younger in age (P < 0.001), less likely to be male patients (P < 0.001), more afflicted with upper third lesions (P < 0.001), and presenting with more Borrmann type IV tumors (P = 0.005) than NSRCC patients. Lymph nodes metastasis was similar between SRCC and NSRCC patients with advanced tumor stage (OR: 0.86, 95% CI: 0.671.10, P = 0.23), but lower in the SRCC than NSRCC patients with early tumor stage (OR: 0.73; 95% CI: 0.560.98, P = 0.02). SRCC patients had comparable survival outcomes with NSRCC patients for early gastric cancers (HR: 1.05, 95% CI: 0.651.68, P < 0.001) but had significantly poor prognosis for patients with advanced tumor stage (HR: 1.50, 95% CI: 1.281.76, P < 0.001). Conclusions: Signet ring cell carcinomas of the stomach are an increasingly common histopathological subtype of gastric cancers. These kinds of patients tend to be younger in age and more often female. Although, signet ring cell gastric cancer is a negative prognostic factor for patients with advanced stage. The difference is that for early stage of signet ring cell gastric cancers, it has low lymph nodes metastasis rate and comparable prognosis with non-signet ring cell cancers.

Prevalence of atrophic gastritis in southwest China and predictive strength of serum gastrin-17: A cross-sectional study (SIGES)

A hospital-based cross-sectional study in SIGES project was conducted during 2016.5-2017.5 in West China Hospital. It was aimed to observe the prevalence of atrophic gastritis (AG) in southwest China, and assess the diagnostic strength of serum gastrin-17 (G-17) in predicting AG in Chinese population. Asymptomatic healthy controls from health check-up, cancer-free patients with unspecific upper gastrointestinal symptoms, and histologically proven gastric cancer patients were eligible, if serum pepsinogen-I (PG-I), PG-II, and G-17 were detected. AG status was classified by the accredited cutoffs of PG-I (<70 ug/L) and PG-I/II ratio (<3). Totally, healthy controls (n = 9,425), symptomatic patients (n = 671) and gastric cancer patients (n = 305) were simultaneously observed, in which the prevalence of AG in southwest China were estimated as 15.9/1,000, 28.3/1,000, and 55.7/1,000 persons, respectively. The age-specific prevalence of AG in healthy controls showed a significantly uphill trend (p for trend <0.001). Higher level of serum G-17 was significantly associated with increased risk of AG in healthy population (15-30 pmol/L, aOR = 20.67, 95% CI 9.17-46.55; >30 pmol/L, aOR = 314.41, 95% CI 166.10-595.12). Throughout the progression of stomach diseases, the diagnostic strength of serum G-17 for AG showed a downhill trend across more advanced situations. In despite of that, serum G-17 displayed a good performance in predicting AG in the entire cross-sectional population (AUC = 0.92, 95% CI 0.89-0.94; SEN = 85.5%; SPE = 93.2%; LR+ = 12.55; LR- = 0.11). Population in southwest China had intermediate prevalence of AG, while the prevalence was increased over age or disease progression. High level of serum G-17 might be a reliable non-invasive measurement to predict AG in southwest Chinese population.

Assessment of indocyanine green fluorescence lymphography on lymphadenectomy during minimally invasive gastric cancer surgery: a systematic review and meta-analysis

BACKGROUND

In recent years, indocyanine green fluorescence lymphography has been introduced for lymphatic mapping in gastric cancer surgery. The aim of this study was to investigate the efficacy of ICGFL in lymph node dissection during minimally invasive surgery for gastric cancer.

METHODS

A systematic review of electronic databases including PubMed, Embase, Web of Science, the Cochrane Library, and China National Knowledge Infrastructure was performed from the inception to January 2021 for all studies comparing ICGFL with non-ICGFL in GC patients undergoing minimal access gastrectomy. The primary outcome was the total number of harvested lymph nodes. The secondary endpoints were the number of metastatic LNs, operative time, estimated blood loss, and postoperative complications. The registration number of this protocol is PROSPERO CRD42020203443.

RESULTS

A total of 13 studies including 1882 participants were included. In this meta-analysis, the use of ICGFL was associated with a higher number of harvested LNs (40.33 vs. 33.40; MD = 6.93; 95%CI: 4.28 to 9.58; P < 0.0001; I2 = 86%). No significant difference was found between the ICGFL and control groups in terms of metastatic LNs (2.63 vs. 2.42; MD = 0.21; 95%CI: -0.46 to 0.87; P = 0.54; I2 = 0%). In addition, the use of ICGFL could be safely performed without increasing the operative time (P = 0.49), estimated blood loss (P = 0.26) and postoperative complications (P = 0.54).

CONCLUSION

The use of ICGFL may be a useful tool facilitating complete lymph node dissection during minimally invasive GC resection. However, more high-quality RCTs with large sample size are needed to validate this issue.

Deep Convolutional Neural Network Based on Computed Tomography Images for the Preoperative Diagnosis of Occult Peritoneal Metastasis in Advanced Gastric Cancer

We aimed to develop a deep convolutional neural network (DCNN) model based on computed tomography (CT) images for the preoperative diagnosis of occult peritoneal metastasis (OPM) in advanced gastric cancer (AGC). A total of 544 patients with AGC were retrospectively enrolled. Seventy-nine patients were confirmed with OPM during surgery or laparoscopy. CT images collected during the initial visit were randomly split into a training cohort and a testing cohort for DCNN model development and performance evaluation, respectively. A conventional clinical model using multivariable logistic regression was also developed to estimate the pretest probability of OPM in patients with gastric cancer. The DCNN model showed an AUC of 0.900 (95% CI: 0.851-0.953), outperforming the conventional clinical model (AUC = 0.670, 95% CI: 0.615-0.739; p < 0.001). The proposed DCNN model demonstrated the diagnostic detection of occult PM, with a sensitivity of 81.0% and specificity of 87.5% using the cutoff value according to the Youden index. Our study shows that the proposed deep learning algorithm, developed with CT images, may be used as an effective tool to preoperatively diagnose OPM in AGC.

Superiority of lymph node ratio-based staging system for prognostic prediction in 2575 patients with gastric cancer: validation analysis in a large single center

This study aimed to evaluate the prognostic significance of node ratio (Nr), the ratio of metastatic to retrieved lymph nodes, and to investigate whether a modified staging system based on Nr can improve prognostic ability for gastric cancer patients following gastrectomy. A total of 2572 patients were randomly divided into training set and validation set, and the cutoff points for Nr were produced using X-tile. The relationships between Nr and other clinicopathologic factors were analyzed, while survival prognostic discriminatory ability and accuracy were compared among different staging systems by AIC and C-index in R program. Patients were categorized into four groups as follows: Nr0, Nr1: 0.00-0.15, Nr2: 0.15-0.40 and Nr3: > 0.40. Nr was significantly associated with clinicopathologic factors including macroscopic type, tumor differentiation, lymphovascular invasion, perineural invasion, tumor size, T stage, N stage and TNM stage. Besides, for all patients, Nr and TNrM staging system showed a smaller AIC and a larger C-index than that of N and TNM staging system, respectively. Moreover, in subgroup analysis for patients with retrieved lymph nodes < 15, Nr was demonstrated to have a smaller AIC and a larger C-index than N staging system. Furthermore, in validation analysis, Nr, categorized by our cutoff points, showed a larger C-index and a smaller AIC value than those produced in previous studies. Nr could be considered as a reliable prognostic factor, even in patients with insufficient (< 15) retrieved lymph nodes, and TNrM staging system may improve the prognostic discriminatory ability and accuracy for gastric cancer patients undergoing radical gastrectomy.

Helicobacter pylori infection, atrophic gastritis, and pancreatic cancer risk: A meta-analysis of prospective epidemiologic studies

BACKGROUND

To investigate the associations of Helicobacter pylori (Hp) infection and atrophic gastritis (AG) with pancreatic cancer risk.

METHODS

A literature search in PubMed was performed up to July 2017. Only prospective cohort and nested case-control studies enrolling cancer-free participants were eligible. Incident pancreatic cancer cases were ascertained during the follow-up. The risks of pancreatic cancer were compared between persons infected and noninfected with Hp, or between those with and without AG status at baseline. Odds ratios (ORs) or hazard ratios were combined. Subgroup and sensitivity analyses were performed, and publication bias was estimated.

RESULTS

Three cohort studies and 6 nested case-control studies, including 65,155 observations, were analyzed. The meta-analyses did not confirm the association between pancreatic cancer risk and Hp infection (OR = 1.09, 95% confidence interval [CI] = 0.81-1.47) or AG status (OR = 1.18, 95% CI = 0.80-1.72). However, particular subpopulations potentially had increased risks of pancreatic cancer. Cytotoxin-associated gene A (CagA)-negative strains of Hp might be a causative factor of pancreatic cancer (OR = 1.30, 95% CI = 1.05-1.62), but a sensitivity analysis by leave-one-out method did not fully warrant it (OR = 1.20, 95% CI = 0.93-1.56). In 1 nested case-control study, AG at stomach corpus in Hp-negative subpopulation might have increased risk of pancreatic cancer, but with a poor test power = 0.56. Publication biases were nonsignificant in the present meta-analysis.

CONCLUSION

Based on current prospective epidemiologic studies, the linkage of pancreatic cancer to Hp infection or AG status was not warranted on the whole. Nevertheless, prospective studies only focusing on those specific subpopulations are further required to obtain better power.

The Value of Palliative Gastrectomy for Gastric Cancer Patients With Intraoperatively Proven Peritoneal Seeding

The aim of this study was to evaluate the survival benefit of palliative gastrectomy for gastric cancer patients with peritoneal seeding proven intraoperatively and to identify positive predictive factors for improving survival.The value of palliative resection for gastric cancer patients with peritoneal metastasis is controversial.From 2006 to 2013, 267 gastric cancer patients with intraoperatively identified peritoneal dissemination were retrospectively analyzed. Patients were divided into resection group and nonresection group according to whether a palliative gastrectomy was performed. Clinicopathologic variables and survival were compared. Subgroup analyses stratified by clinicopathologic factors and multivariable analysis for overall survival were also performed.There were 114 patients in the resection group and 153 in nonresection group. The morbidities in the resection and nonresection groups were 14.91% and 5.88%, respectively (P = 0.014). There, however, was no difference in mortality between the 2 groups. The median survival time of patients in the resection group was longer than in nonresection group (14.00 versus 8.57 months, P = 0.000). The median survivals among the patients with different classifications of peritoneal metastasis were statistically significant (P = 0.000). Patients undergoing resection followed by chemotherapy had a significantly longer median survival, compared with that of patients who had chemotherapy alone, those who had resection alone, or those who had not received chemotherapy or resection (P = 0.000). Results of subgroup analyses showed that except for P3 patients and patients with multisite distant metastases, overall survival was significantly better in patients with palliative gastrectomy, compared with the nonresection group. In multivariate analysis, P3 disease (P = 0.000), absence of resection (P = 0.000), and lack of chemotherapy (P = 0.000) were identified as independently associated with poor survival.Palliative gastrectomy might be beneficial to the survival of gastric cancer patients with intraoperatively proven P1/P2 alone, rather than P3. Postoperative palliative chemotherapy could improve survival regardless of operation and should be recommended.

Prognostic Significance of Tumor Size in 2405 Patients With Gastric Cancer: A Retrospective Cohort Study

The clinical prognostic significance of tumor size (Ts) in gastric cancer remains under debate. This study aims to evaluate the prognostic value of Ts in gastric cancer patients undergoing gastrectomy. A total of 2405 patients with gastric cancer, all having received radical resection, were enrolled in this retrospective study from 2000 to 2011. Patients were categorized by minimum P value from log-rank χ2 statistics using X-tile. The relationships between Ts and other clinicopathologic characteristics were analyzed, and the survival prediction accuracy was also compared between Ts and T stage. Patients were divided into 5 groups, according to which Ts stage and TsNM stage system were proposed. Ts, an independent prognostic factor identified by univariate and multivariate survival analysis, was significantly associated with sex, age, tumor location, macroscopic type, tumor diffferentiation, vessel invasion, perineural invasion, T stage, N stage, and TNM stage. Compared with T stage system, Ts stage system was found no superiorities in survival prediction. However, for patients with lymph node metastasis and patients with age ≥60, Ts stage system revealed a significant improvement of predictive accuracy in subgroup survival analysis. Furthermore, TsNM stage (c-index = 0.783) system was found to be superior to TNM stage (c-index = 0.743) system in prognostic prediction accuracy (P < 0.05). Ts is significantly correlated with gastric cancer progression, which can be regarded as a reliable prognostic factor, and the TsNM stage system may improve the prognostic prediction accuracy in gastric cancer patients.

Strategies to improve treatment outcome in gastric cancer: a retrospective analysis of patients from two high-volume hospitals in Korea and China

China has high incidence of gastric cancer (GC). However, the treatment outcomes of China were unsatisfactory compared to those of Korea. We performed this study to compare tumour characteristics, treatment parameters, and survival outcomes of GC patients between Korea and China based on the databases of two high-volume hospitals, with the aim of identifying indicators of GC prognosis. Data of patients undergoing gastrectomy for GC from 2006 to 2010 were analysed retrospectively. Subgroup survival analyses, stratified by clinicopathologic factors and multivariable analyses, were performed. The interactive roles of chemotherapy and D2 lymphadenectomy for overall survival were also investigated. Among 1365 Chinese and 4981 Korean patients, the proportion of early cancer detection in Chinese patients was much lower relative to that of Korean patients. There were no significant differences between countries in terms of surgical morbidity and mortality. The overall 5-year survival rates were 54.3% and 81.4%; when stratified by clinicopathologic factors, the survival were generally statistically higher in Korean patients. Gender, age, T stage, N stage, extent of lymphadenectomy, radicality of surgery, resection type, and chemotherapy were independently associated with survival in patients without metastasis. Survival rates for stage II and III GC differed significantly between the two countries, but this difference was eliminated among patients who underwent D2 lymphadenectomy or received chemotherapy. These treatments were given to patients with advanced-stage diagnoses (approximately 20% and 80% of patients, respectively). Treatment type was selected as independent prognostic factors in stage I-III and D2/D2+, with chemotherapy resulting in the best prognosis. Many differences in GC tumour characteristics exist between two countries. Early cancer detection and standardized treatment in Korea contribute to superior survival rates. Promotion of an early screening program, training and dissemination of standard D2 lymphadenectomy, and appropriate applications of chemotherapy would improve survival outcomes.

Learning curve for gastric cancer patients with laparoscopy-assisted distal gastrectomy: 6-year experience from a single institution in western China

Laparoscopy-assisted distal gastrectomy (LADG) is widely used for gastric cancer (GC) patients nowadays. This study aimed to investigate the time trend of outcomes so as to describe the learning curve for GC patients with LADG at a single medical institution in western China over a 6-year period.A total of 246 consecutive GC patients with LADG were divided into 5 groups (group A: 46 patients from 2006 to 2007; group B: 47 patients in 2008; group C: 49 patients in 2009; group D: 73 patients in 2010; and group E: 31 patients in 2011). All surgeries were conducted by the same surgeon. Comparative analyses were successively performed by Mann-Whitney U test or Student t test among the 5 different groups for the clinical data, including clinicopathologic characteristics, surgical parameters, postoperative course, and survival outcomes, through which the learning curve was described.There were no differences in the baseline information among the 5 groups (P > 0.05), and the proportion of advanced GC patients with LADG slightly increased from 58.7% to 77.4% during the 6 years. Besides, the proportion of D2/D2+ lymphadenectomy and the number of retrieved lymph nodes gradually grew from 60.9% to 80.6% and from 20.0 to 28.8, respectively. In addition, the operation time decreased from 299.2 to 267.8 minutes, while the estimated blood loss dropped from 175.2 to 146.8 mL. Furthermore, some surgical parameters (surgical duration and blood loss) and postoperative course (such as postoperative complications, the time to ambulation, to first flatus, and to first liquid intake as well as the length of hospital stay) were all observed to be significantly different between group A and other groups (P < 0.05), illustrating a similar downward trend and remaining stable to form a plateau after 46 cases in group A. However, no difference on overall survival was found among these 5 groups, and multivariate analysis indicated that factors, such as age, tumor differentiation, tumor size, and T stage as well as N stage, were independent prognostic factors for patients with LADG.Improvement on surgical parameters and postoperative course can be seen over the past years, and the cutoff value of the learning curve of LADG for surgeons with rich experience in open operation might be 46 cases.