The clinical importance of a transcription reverse-transcription concerted (TRC) diagnosis using peritoneal lavage fluids in gastric cancer with clinical serosal invasion: a prospective, multicenter study

Utility of Molecular Analysis of Peritoneal Fluid in Staging Laparoscopy of Advanced Esophagogastric Junction and Gastric Cancer Prior to Neoadjuvant Treatment

PURPOSE

Molecular analysis of peritoneal fluid in staging laparoscopy of gastric cancer is performed to improve the detection of free intraperitoneal tumor cells. Nevertheless, its significance is controversial, especially in patients with negative cytology but positive molecular analysis. The aim of this study was to analyze the sensitivity of molecular analysis and its prognostic value.

METHODS

A retrospective analysis from April 2011 to October 2019 was performed. Cytology (Cyt) and molecular analysis were analyzed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) of the carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) tumor makers.

RESULTS

During the study period, 138 staging laparoscopies were performed. Macroscopic carcinomatosis was found in 12.3%. Of the remaining 87.7%, 9.9% were Cyt + and 11.6% were Cyt- RT-PCR + . Of the latter, 9 responded to chemotherapy and underwent radical surgery. The sensitivity of cytology and molecular analysis was 0.70 and 0.76, respectively (p = 0.67). The 2-year overall survival (OS) of Cyt- RT-PCR + vs. Cyt + was similar (p = 0.1). The 2-year OS of Cyt-RT-PCR + subgroup who underwent radical surgery vs. Cyt-RT-PCR- patients was similar (p = 0.69), but disease-free survival was shorter in the first group (p = 0.005).

CONCLUSION

Our results show that the sensitivity of molecular analysis is similar to that of cytology. The prognostic value of positive molecular analysis was similar to positive cytology in terms of 2-year overall survival, except in the subgroup of operated patients in whom the overall survival was similar to that of those with a negative molecular analysis, albeit with a shorter disease-free survival.

Prognostic value of molecular cytology by one-step nucleic acid amplification (OSNA) assay of peritoneal washings in advanced gastric cancer patients

Peritoneal dissemination is a common form of gastric cancer (GC) recurrence, despite surgery with curative intent. This study aimed to evaluate the prognostic value of intraperitoneal lavage One-Step Nucleic Acid Amplification (OSNA) assay in advanced GC patients. OSNA assay targeting CK-19 mRNA was applied to detect free cancer cells (FCC) in intraperitoneal lavage samples obtained during gastrectomy. A total of 82 GC patients were enrolled to investigate the correlation between OSNA assay and patient's prognosis. Of the 82 patients, OSNA assay was positive in 25 (30.5%) patients. The median OS in OSNA positive patients was significantly lower than in OSNA negative patients (19 vs 45 months). Positive OSNA assay result was a significant unfavourable prognostic factor in both, univariable (HR 3.45, 95% CI 0.95-12.48; p = 0.0030) and multivariable analysis (HR 3.10, 95% CI 1.22-8.54; p = 0.0298). Positive OSNA assay in intraperitoneal lavage is a valuable indicator of poor survival in advanced GC patients after multimodal treatment. After further confirmation on larger sample size, OSNA assay of peritoneal washings could be considered an adjunct tool to conventional cytology, the current gold standard, to provide precise intraoperative staging and additional prognostic information.

Risk Assessment and Preventive Treatment for Peritoneal Recurrence Following Radical Resection for Gastric Cancer

As the most common recurrence pattern after radical gastric cancer resection, peritoneal recurrence is a major cause of mortality, which affects the prognosis of patients to a very large extent. Peritoneal status and risk of peritoneal recurrence can be evaluated by peritoneal lavage cytology, photodynamic diagnosis, imaging examination, and pathologic analysis. Presently, there is no standard approach for preventing peritoneal recurrence after radical surgery; furthermore, controversies exist regarding the effects of some preventive methods. Among the preventive methods, there are high expectations about the potential of preoperative therapy, surgical skill improvement, hyperthermic intraperitoneal chemotherapy, and postoperative treatment to reduce the incidence of peritoneal recurrence after radical gastrectomy. This study aimed to analyze the results of previous studies on the risk assessment and preventive methods of peritoneal recurrence after radical gastrectomy in recent years. We hope to provide references for better approach to clinical diagnosis and treatment strategies for peritoneal recurrence after radical gastrectomy.

Novel Biomarkers of Gastric Adenocarcinoma: Current Research and Future Perspectives

Simple Summary

Gastric cancer is characterized by poor survival rates despite surgery and chemotherapy. Current research focuses on biomarkers to improve diagnosis and prognosis, and to enable targeted treatment strategies. The aim of our review was to give an overview over the wide range of novel biomarkers in gastric cancer. These biomarkers are targets of a specific treatment, such as antibodies against human epidermal growth factor receptor 2. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are vascular endothelial growth factor, programmed cell death protein 1, and Claudin 18.2. There is a vast number of biomarkers based on DNA, RNA, and protein expression, as well as detection of circulating tumor cells and the immune tumor microenvironment.

Abstract

Overall survival of gastric cancer remains low, as patients are often diagnosed with advanced stage disease. In this review, we give an overview of current research on biomarkers in gastric cancer and their implementation in treatment strategies. The HER2-targeting trastuzumab is the first molecular targeted agent approved for gastric cancer treatment. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are VEGF and Claudin 18.2. Expression of MET has been shown to be a negative prognostic factor in gastric cancer. Targeting the PD-1/PD-L1 pathway with immune checkpoint inhibitors has proven efficacy in advanced gastric cancer. Recent technology advances allow the detection of circulating tumor cells that may be used as diagnostic and prognostic indicators and for therapy monitoring in gastric cancer patients. Prognostic molecular subtypes of gastric cancer have been identified using genomic data. In addition, transcriptome profiling has allowed a comprehensive characterization of the immune and stromal microenvironment in gastric cancer and development of novel risk scores. These prognostic and predictive markers highlight the rapidly evolving field of research in gastric cancer, promising improved treatment stratification and identification of molecular targets for individualized treatment in gastric cancer.

Prognostic impact of lymph node micrometastasis in patients with gastric cancer

PURPOSE

The clinical significance of lymph node micrometastasis (LNMM) remains controversial in gastric cancer (GC). In this study, we investigated the prognostic impact of LNMM in patients with GC.

METHODS

A total of 624 patients with pathologically lymph node metastasis-negative (pN0) and N1 status (pN1) who underwent gastrectomy between 2004 and 2018 were enrolled in this retrospective study. The diameter of tumor cell clusters in metastatic lymph nodes was measured in 120 patients with pN1 GC.

RESULTS

Patients with lymph node tumors < 1500 μm in diameter (LNMM) had a significantly better prognosis than those with tumors ≥ 1500 μm in diameter (p = 0.012; log-rank test). Cox's proportional hazards model revealed that LNMM (p = 0.016), several dissected lymph nodes (p = 0.049), and the provision of adjuvant chemotherapy (p = 0.002) were independent prognostic factors for the overall survival of patients with pN1 GC. There was no significant difference in the overall survival between patients with LNMM who received chemotherapy and those who did not (p = 0.332).

CONCLUSIONS

LNMM is associated with a favorable prognosis and maybe an independent prognostic marker in patients with pN1 GC. LNMM in GC may be considered a factor preventing adjuvant chemotherapy.

Free cancer cells in gastric cancer - methods of detection, clinical and prognostic importance (meta-analysis)

Gastric cancer (GC) is one of the most common malignant cancers worldwide. Intraperitoneal dissemination is the typical mechanism of the formation of metastases in GC. The diagnosis of the presence of intraperitoneal free cancer cells (IFCCs) is treated equally to the M (metastasis) category according to the 8^th edition of the TNM classification by the American Joint Committee on Cancer. IFCCs are cells which have detached from the primary tumour through exfoliation into the peritoneal cavity. The source of IFCCs may be iatrogenic due to improper surgical technique during resection of the tumour and may lead to intraperitoneal dissemination. Cytological examination of peritoneal lavage is considered as a gold standard in the confirmation of the presence of IFCCs; however, its sensitivity is very low. In order to increase the sensitivity and reliability of the examination, molecular biology techniques should be applied. In the case of detection of the presence of IFCCs in patients with GC, the patient should be qualified for chemotherapy, or possibly the use of hyperthermic intraperitoneal chemotherapy should be considered.

A better prognostic stratification for the 8th edition of the AJCC staging system of gastric cancer by incorporating pT4aN0M0 into stage IIIA

INTRODUCTION

The aim of this study was to analyze the prognosis of gastric cancer patients categorized as pT4aN0M0, pT1N3aM0/pT2N2M0/pT3N1M0 of stage IIB and stage IIIA and to compare the optimistic prognostic stratification between the AJCC 8th edition staging system and the AJCC modified 8th (m8th) edition staging system by incorporating pT4aN0M0 into stage IIIA.

MATERIAL AND METHODS

A total of 1770 patients who underwent gastrectomy were enrolled in this study. The homogeneity, the discriminatory ability, the monotonicity of the gradient assessments, and the discriminatory ability of the AJCC 8th and m8th edition staging systems were compared by using the likelihood ratio χ2 test, a linear trend χ2 test, the Akaike information criteria (AIC) and Bayesian information criterion (BIC) calculations, respectively.

RESULTS

For patients staged IIB, the 5-year survival rate of the patients categorized as pT4aN0M0 were significantly worse than that of the patients categorized as pT1N3aM0/pT2N2M0/pT3N1M0 (59.9% vs. 72.4%, P = 0.036). By contrast, the prognoses of the patients between the pT4aN0M0 category and those staged IIIA were analogous (59.9% vs. 61.5%, P = 0.693). Compared with the 8th edition system, the modified 8th edition staging system had a better homogeneity (higher likelihood ratio χ [2] score, 441.17 vs. 436.24), discriminatory ability, monotonicity of gradients (higher linear trend χ2 score, 436.78 vs. 416.15) and smaller AIC (10364.98 vs. 10369.91) and BIC values (10447.13 vs. 10452.06).

CONCLUSIONS

The prognosis of pT4aN0M0 was poorer than those of pT1N3aM0, pT2N2M0, and pT3N1M0, which were staged IIB. There is a better prognostic stratification for the AJCC 8th edition staging system of gastric cancer by incorporating pT4aN0M0 into stage IIIA.

Advanced gastric cancer: the value of systemic and intraperitoneal chemotherapy

Several possibilities in treating advanced gastric cancer exist. Radical surgery associated with chemotherapy represents the cornerstone. Which one is more effective among neoadjuvant, adjuvant or perioperative chemotherapy is still a matter of debate. Several innovative results showed the necessity to keep increasingly into consideration the intraperitoneal administration of chemotherapies. Moreover, classical drugs and their ways of administration should be combined with the new ones to improve results. Lastly the prevention of recurrence should be considered: one possibility is to administer intraperitoneal chemotherapy earlier in the therapeutic algorithm. (www.actabiomedica.it)

Detection value of free cancer cells in peritoneal washing in gastric cancer: a systematic review and meta-analysis

Intraperitoneal free cancer cells in gastric adenocarcinoma are associated with a poor outcome. However, the true prognostic value of intraperitoneal free cancer cells is still unclear, leading to a lack of consensus in the management of gastric cancer. The aim of the present study is to perform a systematic review and meta-analysis to analyze intraperitoneal free cancer cells-positive patients with regard to tumor oncologic stage, recurrence, grade of cellular differentiation, and survival rates and to analyze the clinical significance of intraperitoneal free cancer cells with regard to prognosis. Databases were searched up to January 2016 for prognostic factors associated with intraperitoneal free cancer cells, including oncologic stage, depth of neoplasm invasion, lymph nodal spread, differentiation grade of the tumor, and recurrence and survival rates. A total of 100 studies were identified. Meta-analysis revealed a clear association between intraperitoneal free cancer cells and a poor prognosis. intraperitoneal free cancer cells -positive patients had higher rates of nodal spread (risk difference: 0.29; p<0.01), serosal invasion (risk difference: 0.43; p<0.01), recurrence (after 60 months of follow-up, risk difference: 0.44; p<0.01), and mortality (after 60 months of follow-up, risk difference: 0.34; p<0.01). Intraperitoneal free cancer cells are associated with a poor outcome in gastric cancer. This surrogate biomarker should be used to guide therapy both prior to and after surgery.

Prognostic significance of intraoperative macroscopic serosal invasion finding when it shows a discrepancy in pathologic result gastric cancer

Purpose

Depth of wall invasion is an important prognostic factor in patients with gastric cancer, whereas the prognostic significance of intraoperative macroscopic serosal invasion (mSE) findings remain unclear when they show a discrepancy in pathologic findings. This study, therefore, assessed the prognostic significance of mSE.

Methods

Data from cohort of 2,835 patients with resectable gastric cancer who underwent surgery between 1990 and 2010 were retrospectively reviewed.

Results

The overall accuracy of mSE and pathologic results was 83.4%. The accuracy of mSE was 75.5% in pT2. On the other hand, the accuracy of pT3 dropped to 24.5%. According to mSE findings (+/–), the 5-year disease-specific survival (DSS) rate differed significantly in patients with pT2 (+; 74.2% vs. –; 92.0%), pT3 (+; 76.7% vs. –; 91.8%) and pT4a (+; 51.3% vs. –; 72.8%) (P < 0.001 each), but not in patients with T1 tumor. Multivariate analysis showed that mSE findings (hazard ratio [HR], 2.275; 95% confidence interval [CI], 1.148–4.509), tumor depth (HR, 6.894; 95% CI, 2.325–20.437), nodal status (HR, 5.206; 95% CI, 2.298–11.791), distant metastasis (HR, 2.881; 95% CI, 1.388–6.209), radical resection (HR, 2.002; 95% CI, 1.017–3.940), and lymphatic invasion (HR, 2.713; 95% CI, 1.424–5.167) were independent predictors of 5-year DSS rate.

Conclusion

We observed considerable discrepancies between macroscopic and pathologic diagnosis of serosal invasion. However, macroscopic diagnosis of serosal invasion was independently prognostic of 5-year DSS. It suggests that because the pathologic results could not be perfect and the local inflammatory change with mSE(+) could affect survival, a combination of mSE(+/–) and pathologic depth may be predictive of prognosis in patients with gastric cancer.

Prognostic Significance of Molecular Analysis of Peritoneal Fluid for Patients with Gastric Cancer: A Meta-Analysis

Background

Accurately distinguishing serosal invasion in patients with gastric cancer (GC) prior to surgery can be difficult. Molecular analysis of peritoneal fluid (MAPF) for free cancer cells with higher sensitivity than other methods; however, its prognostic value for GC remains controversial, precluding its application in clinical practice.

Methods

PubMed, EMBASE and other databases were systematically searched. Thirty-one studies were eligible for the meta-analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled for overall survival (OS), disease-free survival (DFS) and peritoneal recurrence-free survival (PRF).

Results

The current meta-analysis focused on patients with GC and negative cytological diagnoses. The results showed that positive MAPF status (MAPF⁺) led to poorer prognoses for OS (HR 2.59, 95% CI 1.99–3.37), DFS (HR 4.92, 95% CI 3.28–7.37) and PRF (HR 2.81, 95% CI 2.12–3.72) compared with negative MAPF status (MAPF^-). Moreover, among the patients with GC who received curative treatment, the MAPF⁺ patients had poorer prognoses for OS (HR 3.27, 95% CI 2.49–4.29), DFS (HR 3.90, 95% CI 2.74–5.57) and PRF (HR 5.45, 95% CI 3.70–8.03). A meta-analysis of multivariate-adjusted HRs demonstrated that MAPF⁺ status was an independent prognostic factor for patients with GC who underwent curative treatment (OS: HR 2.19, 95% CI 1.47–3.28; PRF: HR 3.44, 95% CI 2.01–5.87). Using the identical target genes (CEA, CEA/CK20) as molecular markers, the patients with GC who were MAPF⁺ had significantly worse prognoses for OS (CEA: HR 3.03, 95% CI 2.29–4.01; CEA/CK20: HR 4.24, 95% CI 2.42–7.40), DFS (CEA: HR 3.99, 95% CI 2.24–7.12; CEA/CK20: HR 4.31, 95% CI 1.49–2.48) and PRF (CEA: HR 4.45, 95% CI 2.72–7.31; CEA/CK20: HR 6.46, 95% CI 3.62–11.55) than the patients who were MAPF^-.

Conclusion/Significance

The above results demonstrate that MAPF could be a prognostic indicator for patients with GC who have a negative cytological diagnosis and/or are receiving curative treatment. MAPF could provide clinicians with additional prognostic information that could aid in developing individualized treatment plans prior to surgery. The widely used target genes CEA, CEA/CK20 were confirmed to be valuable MAPF markers for predicting the prognosis of GC.

Free intraperitoneal tumor cells and outcome in gastric cancer patients: a systematic review and meta-analysis

PURPOSE

Despite continuously improving therapies, gastric cancer still shows poor survival in locally advanced stages with local recurrence rates of up to 50% and peritoneal recurrence rates of 17% after curative surgery. We performed a systematic review with meta-analyses to clarify whether positive intraperitoneal cytology (IPC) indicates a high risk of disease recurrence and poor overall survival in gastric cancer.

METHODS

Multiple databases were searched in December 2014 to identify studies on the prognostic significance of positive intraperitoneal cytology in gastric cancer, including: Medline, Biosis, Science Citation Index, Embase, CCMed and publisher databases. Hazard ratios (HR) and associated 95% confidence intervals (CI) were extracted from the identified studies. A meta-analysis was performed using a random-effects model on overall survival, disease-free survival and peritoneal recurrence free survival.

RESULTS

A total of 64 studies with a cumulative sample size of 12,883 patients were included. Cytology, quantitative real time polymerase chain reaction (PCR) or both were performed in 35; 21 and 8 studies, respectively. Meta analyses revealed free intraperitoneal tumor cells (FITC) to be associated with poor overall survival in univariate (HR 3.27; 95% CI 2.82 - 3.78]) and multivariate (HR 2.45; 95% CI 2.04 - 2.94) analysis and poor peritoneal recurrence free survival in univariate (4.15; 95% CI 3.10 - 5.57) and multivariate (3.09; 95% CI 2.02 - 4.71) analysis. Subgroup analysis showed this effect to be independent of the detection method, Western or Asian origin or the time of publication.

CONCLUSIONS

FITC oder positive peritoneal cytology is associated with poor survival and increased peritoneal recurrence in gastric cancer.

Clinical importance of a transcription reverse-transcription concerted (TRC) diagnosis using peritoneal lavage fluids obtained pre- and post-lymphadenectomy from gastric cancer patients

PURPOSE

Our previous study demonstrated that a transcription reverse-transcription concerted (TRC) diagnosis using peritoneal lavage fluids at laparotomy was a potential prognostic factor for gastric cancer patients; however, the clinical importance of a TRC diagnosis from peritoneal lavage fluids after lymphadenectomy remains unclear.

METHODS

TRC amplification targeting CEA mRNA was utilized to detect free cancer cells before and after lymphadenectomy during gastric cancer resection. Of 120 patients who underwent curative gastrectomy for cT2-T4 gastric cancer, 38 whose peritoneal lavage samples were collected pre- and post-lymphadenectomy were eligible for analysis.

RESULTS

Six (16.0 %) patients had CEA positivity before lymphadenectomy (pre-CEA), whereas nine (23.7 %) had CEA positivity after lymphadenectomy (post-CEA). Post-CEA was significantly correlated with higher pathological N-stage. Moreover, the positive post-CEA group had significantly worse relapse-free survival than the negative post-CEA group (p = 0.001). Cox multivariate analysis revealed that post-CEA positivity was a significant predictor of poor relapse-free survival (p = 0.012). It was also a predictor of distant metastasis, but not specific for peritoneal recurrence.

CONCLUSIONS

These findings demonstrated that post-CEA positivity in a TRC diagnosis was a potential predictor of disease recurrence, but not a specific predictor of peritoneal recurrence.

Novel imaging strategies for upper gastrointestinal tract cancers

Accurate pretherapeutic imaging is the cornerstone of all cancer treatment. Unfortunately, modern imaging modalities have several unsolved problems and limitations. The differentiation between inflammation and cancer infiltration, false positive and false negative findings as well as lack of confirming biopsies in suspected metastases may have serious negative consequences in cancer patients. This review describes some of these problems and challenges the use of conventional imaging by suggesting new combined strategies that include selective use of confirming biopsies and complementary methods to detect microscopic cancer dissemination.

Prognostic prediction in gastric cancer patients without serosal invasion: comparative study between UICC 7(th) edition and JCGS 13(th) edition N-classification systems

OBJECTIVE

T-stage and N-stage have been proven to be the most important factors influencing survival in gastric cancer patients, and have been accepted for use in the Japanese Classification of Gastric Carcinoma (JCGC) and the Union International Cancer Control (UICC-TNM) staging systems. The purpose of this study was to compare the prognostic values of the different N classification systems in gastric cancer patients without serosal invasion.

METHODS

We retrospectively compared the clinicopathological results of 1,115 patients with primary gastric cancer who underwent curative gastric resection.

RESULTS

Serosal invasion was identified in 212 of 1,115 patients (19.0%), and it was associated with lymph node metastasis according to the JCGC(13th) (P<0.001) and TNM(7th) (P<0.001) systems. The 5-year survival rate for the serosal invasion-negative patients (78.2%) was significantly higher than that for the serosal invasion-positive patients (31.1%) (P<0.001). Multivariate Cox regression survival analysis showed that depth of invasion (P=0.013), 13(th) JCGC PN stage (P<0.001), and 7(th) TNM PN stage (P<0.001) were independent prognostic factors for serosal invasion-negative gastric cancer patients.

CONCLUSIONS

The prognosis of gastric cancer patients with serosal invasion is very poor. Both the 13(th) JCGC and 7(th) TNM N-staging systems were able to accurately estimate the prognosis of gastric cancer patients, but the 7(th) TNM system was simpler and easier to use.

Diagnostic laparoscopy with 5-aminolevulinic-acid-mediated photodynamic diagnosis enhances the detection of peritoneal micrometastases in advanced gastric cancer

OBJECTS

Recently, we reported that diagnostic laparoscopy with photodynamic diagnosis using oral 5-aminolevulinic acid (ALA-PDD) is a promising tool for diagnosing early peritoneal metastases in gastric cancer. The present study evaluated the usefulness of adding ALA-PDD to conventional diagnostic laparoscopy and assessed the association of the ALA-PDD results with peritoneal fluid cytology and molecular diagnostic testing.

METHODS

Diagnostic laparoscopy using sequential white light (WL) and ALA-PDD observations was performed in 52 advanced gastric cancer patients, and the sensitivity of ALA-PDD for detecting peritoneal disease was compared to WL. Peritoneal fluid samples from the same patients were also subjected to cytological examination and molecular diagnosis using a transcription-reverse transcription concerted reaction (TRC).

RESULTS

Twenty-four of the 52 patients (46%) had no macroscopic evidence of peritoneal metastases on WL examination; however, ALA-PDD detected dissemination in 5 of these 24 patients (21%) (pd-P). Cytological examination was negative in 4 of the 5 pd-P patients, and molecular testing using TRC was negative in 3 of the 5 pd-P patients.

CONCLUSIONS

This study demonstrated that diagnostic laparoscopy with ALA-PDD improved the sensitivity for the detection of peritoneal metastases. ALA-PDD may be a useful technique for the preoperative staging of advanced gastric cancer and can complement examinations of peritoneal lavage fluids.