Multimodality management of resectable gastric cancer: A review

Number of Examined Lymph Nodes as a Risk Factor for Recurrence in pT1N+ or pT2-3N0 Gastric Cancer

BACKGROUND/AIM

Japanese Gastric Cancer Treatment Guidelines do not recommend adjuvant chemotherapy after radical gastrectomy for pathological stage (p) T1N+ or pT2~3N0 gastric cancer. However, some patients experience disease recurrence. This study aimed to identify the risk factors for recurrence in pT1N+ or pT2-3N0 gastric cancer.

PATIENTS AND METHODS

The study included 157 patients with diagnosed pT1N+ or pT2-3N0 gastric cancer who underwent radical gastrectomy at our institution between January 2001 and December 2020. Clinicopathological data and surgical data were obtained. Independent prognostic factors were analyzed using a Cox proportional hazards regression model.

RESULTS

Thirteen patients (8.3%) experienced disease recurrence. Multivariate analysis revealed that the number of examined lymph nodes was an independent prognostic factor for recurrence-free survival (hazard ratio=10.90; 95% confidence interval=1.39-85.86; p=0.023). The group with ≤35 examined lymph nodes had significantly worse recurrence-free survival compared with the group with ≥36 examined lymph nodes (80.7% versus 98.7%; p=0.0005).

CONCLUSION

The number of examined lymph nodes (≤35) was an independent risk factor for recurrence after radical gastrectomy with pT1N+ or pT2-3N0 gastric cancer.

PD-L1 Expression Associated with Epstein-Barr Virus Status and Patients' Survival in a Large Cohort of Gastric Cancer Patients in Northern Brazil

Gastric cancer (GC) is a worldwide health problem, making it one of the most common types of cancer, in fifth place of all tumor types, and the third highest cause of cancer deaths in the world. There is a subgroup of GC that consists of tumors infected with the Epstein-Barr virus (EBV) and is characterized mainly by the overexpression of programmed cell death protein-ligand-1 (PD-L1). In the present study, we present histopathological and survival data of a thousand GC patients, associated with EBV status and PD-L1 expression. Of the thousand tumors analyzed, 190 were EBV-positive and the vast majority (86.8%) had a high relative expression of mRNA and PD-L1 protein (p < 0.0001) in relation to non-neoplastic control. On the other hand, in EBV-negative samples, the majority had a low PD-L1 expression of RNA and protein (p < 0.0001). In the Kaplan-Meier analysis, the probability of survival and increased overall survival of EBV-positive GC patients was impacted by the PD-L1 overexpression (p < 0.0001 and p = 0.004, respectively). However, the PD-L1 low expression was correlated with low overall survival in those patients. Patients with GC positive for EBV, presenting PD-L1 overexpression can benefit from immunotherapy treatments and performing the quantification of PD-L1 in gastric neoplasms should be adopted as routine.

SATB1-Mediated Upregulation of the Oncogenic Receptor Tyrosine Kinase HER3 Antagonizes MET Inhibition in Gastric Cancer Cells

MET-amplified gastric cancer cells are extremely sensitive to MET inhibition in vitro, whereas clinical efficacy of MET inhibitors is disappointing. The compensatory activation of other oncogenic growth factor receptors may serve as an underlying mechanism of resistance. In this study, we analyzed the role of HER receptors, in particular HER3 and its ligand heregulin, in this respect. This also included the chromatin-organizer protein SATB1, as an established regulator of HER expression in other tumor entities. In a panel of MET-amplified gastric carcinoma cell lines, cell growth under anchorage-dependent and independent conditions was studied upon inhibitor treatment or siRNA-mediated knockdown. Expression analyses were performed using RT-qPCR, FACS, and immunoblots. Signal transduction was monitored via antibody arrays and immunoblots. As expected, MET inhibition led to a growth arrest and inhibition of MAPK signaling. Strikingly, however, this was accompanied by a rapid and profound upregulation of the oncogenic receptor HER3. This finding was determined as functionally relevant, since HER3 activation by HRG led to partial MET inhibitor resistance, and MAPK/Akt signaling was even found enhanced upon HRG+MET inhibitor treatment compared to HRG alone. SATB1 was identified as mediator of HER3 upregulation. Concomitantly, SATB1 knockdown prevented upregulation of HER3, thus abrogating the HRG-promoted rescue from MET inhibition. Taken together, our results introduce the combined HER3/MET inhibition as strategy to overcome resistance towards MET inhibitors.

Association between Lymphovascular Invasion and Recurrence in Patients with pT1N+ or pT2–3N0 Gastric Cancer: a Multi-institutional Dataset Analysis

Purpose

Patients with pathological stage T1N+ or T2–3N0 gastric cancer may experience disease recurrence following curative gastrectomy. However, the current Japanese Gastric Cancer Treatment Guidelines do not recommend postoperative adjuvant chemotherapy for such patients. This study aimed to identify the prognostic factors for patients with pT1N+ or pT2–3N0 gastric cancer using a multi-institutional dataset.

Materials and Methods

We retrospectively analyzed the data obtained from 401 patients with pT1N+ or pT2–3N0 gastric cancer who underwent curative gastrectomy at 9 institutions between 2010 and 2014.

Results

Of the 401 patients assessed, 24 (6.0%) experienced postoperative disease recurrence. Multivariate analysis revealed that age ≥70 years (hazard ratio [HR], 2.62; 95% confidence interval [CI], 1.09–7.23; P=0.030) and lymphatic and/or venous invasion (lymphovascular invasion (LVI): HR, 7.88; 95% CI, 1.66–140.9; P=0.005) were independent prognostic factors for poor recurrence-free survival. There was no significant association between LVI and the site of initial recurrence.

Conclusions

LVI is an indicator of poor prognosis in patients with pT1N+ or pT2–3N0 gastric cancer.

Intraoperative Blood Loss is Associated with Shortened Postoperative Survival of Patients with Stage II/III Gastric Cancer: Analysis of a Multi-institutional Dataset

BACKGROUND

The influence of intraoperative blood loss (IBL) on postoperative long-term outcomes of patients with gastric cancer is controversial. Here, we used a large multicenter dataset from nine institutes to evaluate the prognostic impact of IBL on patients with stage II/III gastric cancer.

METHODS

The study analyzed 1013 patients with stage II/III gastric cancer who underwent gastrectomy without preoperative treatment and intraoperative transfusion. Patients were equally divided into learning and validation cohorts using a table of random numbers. The optimal cutoff value of IBL to predict recurrence was determined using the learning cohort, and the prognostic significance of the proposed cutoff was validated using the second cohort.

RESULTS

The optimal cutoff value of IBL determined with the learning cohort using the receiver operating characteristic curve analysis was 330 ml. In the validation cohort, IBL > 330 ml was significantly associated with high body mass index, total gastrectomy, and postoperative complications, but not disease stage and the frequency of adjuvant chemotherapy. The disease-free and disease-specific survival rates of patients in the IBL > 330 ml (IBL-high) group were significantly shorter compared with those in the IBL ≤ 330 ml group. IBL-high was identified as an independent prognostic factor of disease recurrence (hazard ratio 1.45, 95% confidence interval 1.01-2.09, P = 0.0420). The hazard ratio of the IBL-high group was greater in the surgery-alone subgroup compared with that of the postoperative adjuvant-chemotherapy subgroup.

CONCLUSIONS

Our analysis of a multicenter dataset indicates that IBL adversely influenced long-term outcomes of patients with stage II/III gastric cancer.

Preoperative Albumin-Bilirubin Grade Predicts Recurrences After Radical Gastrectomy in Patients with pT2-4 Gastric Cancer

BACKGROUND

The albumin-bilirubin (ALBI) score was initially developed for assessing liver dysfunction severity and was suggested to have prognostic value in patients with hepatocellular carcinoma. We aimed to evaluate the prognostic impact of ALBI grade in patients with advanced gastric cancer (GC) after radical gastrectomy.

METHODS

This study included 283 patients who underwent radical gastrectomy for pT2-4 GC without preoperative treatment. ALBI was calculated as follows: (log₁₀ bilirubin (μmol/L) × 0.66) + (albumin (g/L) × -0.0852) and categorized into grades 1 (≤-2.60), 2 (-2.60<, ≤-1.39) and 3 (-1.39<).

RESULTS

The median ALBI score was -2.96, and a number of patients in ALBI grades 1, 2 and 3 were 228, 55 and 0, respectively. Patients with ALBI grade 2 had a lower administration rate of adjuvant chemotherapy than those with ALBI grade 1, whereas no significant differences were found in morbidity rate and disease stage. The ALBI grade 2 group was more likely to have shorter disease-specific and disease-free survival compared with the ALBI grade 1 group. Multivariable analysis identified ALBI grade 2 as an independent prognostic factor for disease-free survival (hazard ratio 1.97, 95% confidence interval 1.10-3.47, p = 0.0242). Survival differences between ALBI grade 1 and 2 groups were increased in the patient subset that received adjuvant chemotherapy. ALBI grade 2 was correlated with a shortened duration of administration of postoperative S-1 adjuvant.

CONCLUSIONS

ALBI grade serves as a simple and promising predictive factor for disease-free and disease-specific survival in patients with pT2-4 GC after radical gastrectomy.

CT volumetry for gastric adenocarcinoma: association with lymphovascular invasion and T-stages

Purpose

To determine whether gross tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography could predict presence of lymphovascular invasion and T-stages.

Results

Gross tumor volume increased with the lymphovascular invasion (r = 0.426, P < 0.0001) and T stage (r = 0.656, P < 0.0001). Univariate analysis showed gross tumor volume could predict lymphovascular invasion (P < 0.0001). Multivariate analyses indicated gross tumor volume as an independent risk factor of lymphovascular invasion (P = 0.026, odds ratio = 2.284). The Mann-Whitney U test showed gross tumor volume could distinguish T2 from T3, T1 from T2–T4a, T1–T2 from T3–T4a and T1–T3 from T4a (P = 0.000). In the development cohort, gross tumor volume could predict lymphovascular invasion (cutoff, 15.92 cm³; AUC, 0.760), and distinguish T2 from T3 (cutoff, 10.09 cm³; AUC, 0.828), T1 from T2-T4a (cutoff, 8.20 cm³; AUC, 0.860), T1-T2 from T3-T4a (cutoff, 15.88 cm³; AUC, 0.883), and T1-T3 from T4a (cutoff, 21.53 cm³; AUC, 0.834). In validation cohort, gross tumor volume could predict presence of lymphovascular invasion (AUC, 0.742), and distinguish T2 from T3 (AUC, 0.861), T1 from T2-T4a (AUC, 0.859), T1–T2 from T3–T4a (AUC, 0.875), and T1–T3 from T4a (AUC, 0.773).

Materials and Methods

360 consecutive patients with gastric adenocarcinoma were retrospectively identified. Gross tumor volume was evaluated on multidetector computed tomography images. Statistical analysis was performed to determine whether gross tumor volume could predict presence of lymphovascular invasion and T-stages. Cutoffs of gross tumor volume were first investigated in 212 patients and then validated in an independent 148 patients using area under the receiver operating characteristic curve (AUC) for predicting lymphovascular invasion and T-stages.

Conclusions

Gross tumor volume of resectable gastric adenocarcinoma at multidetector computed tomography demonstrated capability in predicting lymphovascular invasion and distinguishing T-stages.

The value of FDG-PET in the staging of gastric adenocarcinoma: A single institution retrospective review

BACKGROUND

The value of FDG-PET in the staging of gastric adenocarcinoma (GA) has been subject to debate.

METHODS

We performed a retrospective review of GA patients between 2006 and 2014 and identified those who had a CT and FDG-PET before initiating treatment. CT and FDG-PET images were analyzed by a blinded body radiologist and nuclear physician, respectively. Disease stage was assessed, looking at primary tumor (PT), locoregional (LLN) and distant lymph node disease (DLN), and metastasis (M).

RESULTS

We identified 608 patients who had biopsy-proven GA and 207 (34.0%) had a CT and FDG-PET as part of their staging work-up. Of these, imaging from 166 (27.3%) patients was available for review. CT identified PT, LLN, DLN, and M in 120 (72.3%), 84 (50.6%), 25 (15.1%), and 32 (19.3%) patients, respectively; while FDG-PET identified PT, LLN, DLN, and M in 125 (75.3%), 78 (47.0%), 41 (24.7%), and 27 (16.3%) of patients, respectively. FDG-PET up-staged 31 (18.7%) patients while it down-staged 17 (10.2%) patients. Of patients who were up-staged, 20 (64.5%) developed progressive disease.

CONCLUSIONS

Our findings support the use of FDG-PET as a valuable adjunct to CT in the staging of GA, as it changed the stage in 48 (28.9%) patients. J. Surg. Oncol. 2016;113:640-646. © 2016 Wiley Periodicals, Inc.

Gastric adenocarcinoma: the role of Helicobacter pylori in pathogenesis and prevention efforts

Gastric cancer is the third most common cause of cancer deaths in the world, prompting high-risk countries like South Korea and Japan to establish nationwide screening programmes. Helicobacter pylori is linked to the majority of gastric adenocarcinoma cases and to the vast majority of non-cardia gastric adenocarcinomas. Several studies have demonstrated the effectiveness of 'test-and-treat' programmes for H. pylori infection to prevent gastric cancer in high-risk populations. While this strategy has gained momentum, providers in low-risk developed countries may be unaware of the risk individual patients face, particularly those who have emigrated from high-risk regions and members of economically disadvantaged minority groups. Rapidly evolving science in recent years has made it difficult for clinicians to keep up with the current best practices. This article reviews the epidemiology of H. pylori and gastric cancer, screening and diagnostic tests and the current treatment regimens for clinicians.

Combination of preoperative platelet/lymphocyte and neutrophil/lymphocyte rates and tumor-related factors to predict lymph node metastasis in patients with gastric cancer

OBJECTIVE

Lymph node (LN) metastasis is widely accepted as a poor prognosis indicator in patients with gastric cancer. An accurate preoperative prediction of LN status is of crucial importance for the planning treatment. The aim of the present study was to assess the predictive value of the preoperative platelet/lymphocyte (PLR) and neutrophil/lymphocyte rates (NLR) on the LN metastasis in gastric cancer patients and to develop a new preoperative score system to predict LN metastasis.

PATIENTS AND METHODS

A total of 492 operable patients with gastric cancer were enrolled in our study. The clinical utility of the PLR and NLR was evaluated by receiver operating characteristic (ROC) curves. The logistic analysis was used to identify the independent parameters associated with LN metastasis. Then, a score system including those independent parameters that can be detected preoperatively was established, which was also tested by an ROC curve.

RESULTS

The ideal cutoff values for predicting LN metastasis were 1.59 for NLR and 155.67 for PLR according to the ROC curve. Multivariate analyses showed that both PLR and NLR are significantly associated with LN metastasis independent of depth of invasion, lymphatic invasion, macroscopic type, and tumor size. The area under the ROC curve of the score system was 0.830 (95% confidence interval 0.782-0.878), showing a reliable ability to evaluate the status of nodal involvement.

CONCLUSION

Preoperative PLR and NLR are useful biomarkers to predict LN metastasis and the score system in our study may serve as a reliable instrument to predict LN metastasis in gastric cancer patients.

Correlation between preoperative endoscopic ultrasound and surgical pathology staging of gastric adenocarcinoma: A single institution retrospective review

BACKGROUND

Recent evidence validates the effectiveness of neoadjuvant chemotherapy in the treatment of gastric adenocarcinoma. Endoscopic ultrasonographic (EUS) staging has been proposed as a useful adjunct in this setting.

METHODS

We performed a retrospective review of patients treated at our institution for gastric adenocarcinoma between July 2005 and January 2014. We identified patients referred for EUS before surgery as part of a prospective treatment plan. Histopathologic staging was compared to EUS staging, with a focus on T- and N-stage. Agreement between the two modalities was examined using kappa-statistics.

RESULTS

We identified 614 patients with biopsy-proven gastric adenocarcinoma; 145 underwent curative-intent surgery. Surgical pathology and EUS results were available from 69 patients. The accuracy of EUS for the evaluation of T- and N-stage was 44.9% and 56.5%, respectively. EUS demonstrated greater concordance with histopathology at evaluating T-stage (κ = 0.3469) than N-stage (κ = 0.1316). EUS underestimated T- and N-stage in 40.8% and 30.4% of patients, respectively.

CONCLUSION

EUS seems to correlate poorly with pathology in the preoperative staging of gastric adenocarcinoma. In the majority of inaccurate cases, EUS underestimates T-stage and N-stage, limiting its utility in the neoadjuvant setting.

Targeted therapy for advanced gastric cancer: A review of current status and future prospects

In the West in particular, the vast majority of gastric cancer (GC) patients present with advanced-stage disease. Although combination chemotherapy is still the most important component of treatment for these patients, it confers a modest survival advantage. Recently, increased knowledge of the key molecular signaling pathways involved in gastric carcinogenesis has led to the discovery of specific molecular-targeted therapeutic agents. Some of these agents such as trastuzumab and ramucirumab have changed the treatment paradigm for this disease. In this paper, we will summarize the current clinical status of targeted drug therapy in the management of GC.

Towards curative therapy in gastric cancer: Faraway, so close!

Although recent diagnostic and therapeutic advances have substantially improved the survival of patients with gastric cancer (GC), the overall prognosis is still poor. Surgery is the only curative treatment and should be performed in experienced centers. Due to high relapse following surgery, complementary and systemic treatment aimed at eradicating micrometastasis should be performed in most cases. Cytotoxic treatments are effective in downstaging locally advanced cancer, but different sensitivities and toxicities probably exist in different GC subtypes. Current treatment protocols are based primarily on clinical data and histological features, but molecular biomarkers that would allow for the prediction of treatment responses are urgently needed. Understanding how host factors are responsible for inter-individual variability of drug response or toxicity will also contribute to the development of more effective and less toxic treatments.

Postoperative adjuvant chemotherapy with S-1 alters recurrence patterns and prognostic factors among patients with stage II/III gastric cancer: A propensity score matching analysis

BACKGROUND

A phase 3 evidence indicates that S-1 adjuvant is beneficial among East Asian patients with stage II/III gastric cancer (GC). However, little is known about the changes in prognostic factors and recurrence patterns after it has become widespread as a standard of care. The present study compared prognostic factors of patients with stage II/III GC treated with or without S-1 adjuvant with formulate appropriate risk stratification strategies.

METHODS

We enrolled 171 patients with stage II/III GC, 92 patients who underwent gastrectomy alone, and 79 patients treated with S-1 adjuvant. To balance more strictly the essential variables including stage of progression, we conducted propensity score analysis and 70 pairs of patients were generated from each group. Prognostic factors were compared between the groups and initial recurrence patterns were investigated to explore reasons for the change.

RESULTS

In concordance with the previous phase 3 trial, overall and recurrence-free survival were better for the S-1 adjuvant group. In the surgery alone group, carcinoembryonic antigen ≥ 5 ng/mL, total gastrectomy, vessel invasion, pT4, and stage 3 were identified as significant prognostic factors. In striking contrast, macroscopic tumor size ≥ 50 mm was the only significant prognostic factor for the S-1 adjuvant group. The lower overall recurrence rate of the S-1 adjuvant group was attributable mainly to a significant decrease of peritoneal recurrence.

CONCLUSION

Prognostic factors changed substantially after implementation of S-1 adjuvant treatment. Macroscopic tumor size should be considered for patient stratification and selection of treatment options for patients with stage II/III GC.

The photodynamic effect of far-red range phthalocyanines (AlPc and Pc green) supported by electropermeabilization in human gastric adenocarcinoma cells of sensitive and resistant type

INTRODUCTION

Electroporation (EP) is commonly applied for effective drug transport thorough cell membranes based on the application of electromagnetic field. When applied with cytostatics, it is called electrochemotherapy (ECT) - a quite new method of cancer treatment. A high-voltage pulse causes the formation of temporary pores in the cell membrane which create an additional way for the intracellular drug transport. In the current work, EP was effectively merged with the already known photodynamic therapy (PDT) to selective photosensitizers' delivery to diseased tissue. The application of electroporation can reduce the dose of applied drug.

RESEARCH OBJECTIVE

The aim of research was to evaluate the effectiveness of photodynamic reaction using two near infrared cyanines (AlPc and Pc green) combined with electroporation in two human gastric adenocarcinoma cell lines.

MATERIALS AND METHODS

Two human cell lines - EPG85-257P (parental) and EPG85-257RDB (resistant to daunorubicin) - of gastric cancer were used. The effect of two photosensitizers (aluminum 1,8,15,22-tetrakis(-phenylthio)-29H,31H-phthalocyanine chloride and Phthalocyanine green) was investigated. The efficiency of EP parameters was assessed by propidium iodide uptake. The viability assay was applied to analyse EP, PDT and EP-PDT effect. Cyanine localization was determined by confocal microscopy. Immunocytochemical evaluation of manganese superoxide dismutase and glutathione S-transferase-pi was determined after applied therapies.

RESULTS

PDT in combination with EP affected the viability of EPG85-257P and EPG85-257RDB cells negatively while both cyanine were used. The most evident changes were observed in the following concentrations: 15, 10 and 5μM. The optimal field strength for enhanced EP-PDT was 800 and 1200V/cm. AlPc distributed selectively in the lysosomes of parental cell line.

CONCLUSIONS

PDT, enhanced by EP, caused decreased viability when compared to the application of PDT alone. Both phthalocyanines found to be more effective after electroporation. Due to the low concentration of light-sensitive compounds and safety of electroporation itself, a treatment plan can be an alternative therapeutic modality against gastric adenocarcinomas.