Prognostic significance of free peritoneal tumor cells in the peritoneal cavity before and after neoadjuvant chemotherapy in patients with gastric carcinoma undergoing potentially curative resection

Gastric Extent of Tumor Predicts Peritoneal Metastasis in Siewert II Adenocarcinoma

BACKGROUND

Whereas current guidelines recommend staging laparoscopy for most patients with potentially resectable gastric cancer, such a recommendation for patients with adenocarcinoma of the gastroesophageal junction (AEG) is lacking. This study sought to identify baseline clinicopathologic characteristics associated with peritoneal metastasis (PM) among patients with Siewert II AEG.

METHODS

Trimodality therapy-eligible patients with Siewert II AEG (2000-2015, single institution) were retrospectively identified. A composite PM outcome was defined as follows: (1) PM at staging laparoscopy; (2) PM diagnosed during neoadjuvant chemoradiation; or (3) PM ≤6 months postoperatively. Logistic regression was used to identify features associated with PM; bootstrapped analysis (Youden J) identified the distal tumor extension that best discriminated the composite outcome.

RESULTS

Of 188 patients, a composite PM outcome was observed in 26 of 188 (13.8%); 12 of 26 had positive staging laparoscopy, 10 of 26 experienced PM during chemoradiation, and 4 of 26 had PM ≤6 months postoperatively. Tumor extension below the GEJ was greater in patients with PM (median, 4.0 cm [interquartile range, 3.0-5.0] vs 3.0 cm [interquartile range, 2.0-3.0]; P < .001). All patients with PM had cT3 to cT4 tumors. Among patients with cT3 to cT4 tumors (n = 168 of 188; 89.4%), distal tumor extent (odds ratio, 1.67/cm; 95% CI, 1.23-2.28; P = .001) was independently associated with increased odds of PM. Gastric tumor extension ≥4 cm remained independently associated with PM (OR, 5.14; 95% CI, 2.11-12.53; P < .001) after adjustment for signet ring cell status.

CONCLUSIONS

Distal tumor extent beyond the GEJ is independently associated with increased odds of PM in patients with Siewert II AEG. Patients with extensive gastric involvement should therefore be considered for staging laparoscopy before trimodality therapy.

Efficacy of chemotherapy versus surgery as initial treatment for gastric cancer with positive peritoneal cytology

BACKGROUND

The prognosis of gastric cancer (GC) patients with positive peritoneal cytology (CY1) without other distant metastasis is poor, and there are no standard treatment strategies. Our study aimed to compare the survival outcomes of CY1 GC patients receiving chemotherapy or surgery as initial treatment.

METHODS

From February 2017 to January 2020, clinical and pathological data of patients diagnosed with CY1 GC without other distant metastasis in the Peking University Cancer Hospital was reviewed. Patients were divided into two groups: chemotherapy-initial group and surgery-initial group. In chemotherapy-initial group, patients received preoperative chemotherapy initially. According to the treatment response, the patients were divided into three subgroups: conversion gastrectomy group, palliative gastrectomy group, and further systematic chemotherapy group. In surgery-initial group, patients underwent gastrectomy followed by postoperative chemotherapy.

RESULTS

A total of 96 CY1 GC patients were included with 48 patients in each group. In chemotherapy-initial group, preoperative chemotherapy yielded an objective response rate of 20.8% and disease control rate of 87.5%. Conversion to CY0 after preoperative chemotherapy was obtained in 24 (50%) patients. The median overall survival was 36.1 months in chemotherapy-initial group and 29.7 months in surgery-initial group (p = 0.367). The median progression-free survival was 18.1 months in chemotherapy-initial group and 16.1 months in surgery-initial group (p = 0.861). The 3-year overall survival rates were 50.0% and 47.9%, respectively. In chemotherapy-initial group, twenty-four patients who converted to CY0 by preoperative chemotherapy and received surgery obtained a significantly better prognosis. The median overall survival was still not reached in these patients.

CONCLUSION

There was no significant difference in survival outcomes between chemotherapy-initial group and surgery-initial group. CY1 GC patients who converted to CY0 by preoperative chemotherapy and received radical surgery could obtain a favorable long-term prognosis. Further investigation should focus on preoperative chemotherapy to eliminate peritoneal cancer cell.

TRIAL REGISTRATION

This study is retrospectively registered.

Pre-therapeutic molecular biomarkers of pathological response to neoadjuvant chemotherapy in gastric and esophago-gastric junction adenocarcinoma: A systematic review and meta-analysis

PURPOSE

Multimodal treatment is the standard of care in patients with locally advanced gastric cancer. Unfortunately, the response rate after neoadjuvant treatment remains limited. The ability to predict the response has a potential to improve patient outcomes by promoting a more individualized approach. We sought to describe the current state of research in pre-treatment molecular biomarkers of response to neoadjuvant therapy in gastric adenocarcinoma available for testing before the initiation of treatment and to perform a systematic review and meta-analysis in order to summarize and evaluate the potential methods.

METHODS

A systematic MEDLINE, EMBASE and CENTRAL literature search was conducted to extract articles on potentially predictive molecular biomarkers of pathological response to neoadjuvant therapy in patients with gastric- and esophago-gastric junction adenocarcinoma. Fixed and random effects models were used to undertake the meta-analysis when appropriate.

RESULTS

Data on predictive biomarkers was reported in 38 studies. These articles described 47 biomarkers showing statistical significance. After evaluation of all reported biomarkers, 3 of them met the inclusion criteria for meta-analysis. The meta-analysis results indicate that >5 ​ng/mL pre-therapeutic serum concentration of carcinoembryonic antigen (CEA; norm <5 ​ng/mL) is significantly associated with tumor response (RR ​= ​5.13, 95% CI 2.53-10.43, P ​= ​0.026).

CONCLUSION

Previous studies describe a large number of candidate biomarkers. Our meta-analysis indicated pre-therapeutic serum concentration of CEA >5 ​ng/mL as a potential and easy-accessible biomarker available for use before initiation of treatment. However, it could be only an additional tool for complex qualification for neoadjuvant therapy.

Perspectives on the Management of Oligometastatic Disease in Esophago-Gastric Cancer

Gastric adenocarcinoma and esophageal cancer are the fifth and seventh most common cancer types worldwide. At the time of initial diagnosis, up to 50% of esophagogastric cancers present with distant metastatic lesions and are candidates for chemotherapy. Curative surgery in this stage is still an experimental approach. Only a small number of these metastatic patients show an oligometastatic disease with no uniform definition of what oligometastatic means in gastric cancer. Nevertheless, the question remains unanswered as to whether these patients are still candidates for curative concepts. Some studies have attempted to answer this question but have not been adequately designed to address the role of a curative-intended multimodal therapy in this setting. The current FLOT-5 is designed to potentially provide a definitive answer to the question of whether curatively intended surgery plays a role or is a disadvantage in this setting.

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.

Gastric cancer with positive peritoneal cytology: survival benefit after induction chemotherapy and conversion to negative peritoneal cytology

Background

The optimal treatment in patients with gastric cancer and peritoneal disease remains controversial. Some guidelines indicate palliative treatment only, while others consider surgical treatment in case of positive lavage cytology (CY+) or limited peritoneal disease. Here, we analyzed the role of peritoneal disease in patients with gastric cancer, and the prognostic relevance of response to neoadjuvant therapy.

Methods

In this retrospective cohort analysis, we analyzed patients with adenocarcinoma of the stomach or esophago-gastric junction from a single center operated between 2011 and 2019. According to histology and lavage cytology, patients were classified into four risk groups: (A) no peritoneal disease, (B) CY+ who converted to negative lavage cytology (CY−) after neoadjuvant chemotherapy, (C) CY+ without conversion after chemotherapy, and (D) patients with visible peritoneal metastasis.

Results

Overall, n = 172 patients were included. At initial presentation, n = 125 (73%) had no peritoneal disease, and about a third of patients (n = 47, 27%) had microscopic or macroscopic peritoneal disease. Among them, n = 14 (8%) were CY+ without visible peritoneal metastasis, n = 9 converted to CY− after chemotherapy, and in n = 5 no conversion was observed. Median overall survival was not reached in patients who had initially no peritoneal disease and in patients who converted after chemotherapy, resulting in 3-year survival rates of 65% and 53%. In contrast, median overall survival was reduced to 13 months (95% CI 8.7–16.7) in patients without conversion and was 16 months (95% CI 12–20.5) in patients with peritoneal metastasis without difference between the two groups (p = .364). The conversion rate from CY+ to CY− was significantly higher after neoadjuvant treatment with FLOT (5-fluorouracil plus leucovorin, oxaliplatin, and docetaxel) compared to ECF (epirubicin, cisplatin, and 5-fluorouracil) (p = 0.027).

Conclusion

Conversion of CY+ to CY− after neoadjuvant chemotherapy with FLOT is a significant prognostic factor for a better overall survival. Surgical treatment in well-selected patients should therefore be considered. However, peritoneal recurrence remains frequent despite conversion, urging for a better local control.

Circulating methylated THBS1 DNAs as a novel marker for predicting peritoneal dissemination in gastric cancer

Objectives

Thrombospondin 1 (THBS1) is known to play a key role in tumor metastasis, and aberrant DNA methylation is one of the mechanisms regulating THBS1. The present study investigated whether methylated THBS1 in circulating cell‐free DNA from preoperative peritoneal lavage fluid (PPLF) and peripheral blood could be used as a potential biomarker for predicting peritoneal dissemination in gastric cancer (GC) patients.

Methods

The status of THBS1 methylation was detected by quantitative methylation‐specific PCR (MSP) in tumor tissues, paired PPLF, and serum from 92 GC patients. The correlation between methylated THBS1 levels and peritoneal dissemination of GC was studied, and its diagnostic value for predicting peritoneal dissemination was clarified by the receiver operating characteristic (ROC) curve.

Results

Aberrant THBS1 methylation in tumor tissues was significantly higher than that in paracancerous normal tissues (p < 0.0001). No THBS1 methylation was found in 40 healthy controls, and partial methylation was detected in 3 of 48 patients with chronic non‐atrophic gastritis. The frequency of THBS1 methylation in pairing PPLF and serum from 92 GC patients was 52.2% (48/92) and 58.7% (54/92), respectively. The results of methylated THBS1 in pairing PPLF and serum were similar to those of tumor tissues. Aberrant THBS1 methylation in tumor tissues and pairing PPLF or serum was closely related to peritoneal dissemination, tumor progression, and poor prognosis (all p < 0.0001).

Conclusion

Circulating methylated THBS1 DNAs in PPLF/serum may predict peritoneal dissemination, a potential poor prognostic factor for GC patients.

Clinical Significance of Peritoneal Fluid Examination for Free Cancer Cells in Patients Qualified for Surgery for Gastric Cancer

Background: Peritoneal lavage cytology in patients with gastric cancer may correlate with an unfavorable prognosis. This study evaluated the presence of free cancer cells in the peritoneal lavage of a population of patients with gastric cancer and its correlation with the outcome of surgical treatment.

Methods: One hundred patients diagnosed with gastric or gastrointestinal junction adenocarcinoma underwent surgery. In all patients, a cytological and immunohistochemical analysis of peritoneal lavage was performed. Based on the presence of free cancer cells (fcc) at the cytological and immunohistochemical examination of peritoneal lavage, patients undergoing surgery for gastric cancer were divided into two groups: fcc (+) and fcc (–).

Results: A total of 100 patients, 37 women, and 63 men with a median age of 65 years were included in the study. In the entire study group, 16 (16%) patients were positive for the presence of free cancer cells (fcc +) at peritoneal lavage examination. However, in the group of patients who underwent gastrectomy, fcc (+) was found in 10 out of 77 (13%) patients. The presence of cancer cells in peritoneal lavage was a strong predictive factor in an unfavorable outcome after surgery, and 1-year and 2-year patient survival was 34 and 0% in fcc (+) patients and 79 and 59% in fcc (–), respectively. Moreover, the presence of free cancer cells was associated with a five-fold increased risk of death within 2 years after surgery. When analyzing the group of patients undergoing R0/R1 surgery, this difference was even more significant (p < 0.0001).

Conclusions: The presence of free cancer cells in peritoneal lavage may significantly affect the outcome of patients with gastric cancer. Radical surgery in patients with free cancer cells in the peritoneal lavage did not result in a survival advantage. Identification of free cancer cells could help for a better stratification of gastric cancer patients, identifying those patients who could better benefit from a radical surgical treatment, finally improving long-term survival.

The role of laparoscopic staging for the management of gastric cancer

AİM Staging laparoscopy enables us to perform palliative treatment, neo-adjuvant therapy for curative resection or direct curative resection and making a decision with minimal morbidity by avoiding from unnecessary laparotomies. In the present study, the importance of staging lapafoscopy was retrospectively investigated by using clinical and pathologic data. METHODS Data of 70 out of 350 patients who underwent diagnostic laparoscopy due to gastric cancer at Surgical Oncology department between August 2013 and January 2020 were retrospectively analyzed. RESULTS Peritoneal biopsy was positive for malignity in 41 (58.5%) and negative in 29 (41.5%) of the patients who underwent SL. Peritoneal cytology (PC) results were negative in 32 (45.7%) patients and positive in 38 (54.3%) patients. Peritoneal biopsy and cytology results were concurrently positive in 35 patients and concurrently negative in 26 patients. CONCLUSİONS In conclusion, even the most developed imaging methods cannot provide 100% staging, therefore SL plays an important role in treatment of gastric cancer and laparoscopic staging is essential as a simple, inexpensive, safe and well tolerated method in patients who have the suspicion of peritoneal disease and who cannot be clearly evaluated with pre-operative methods.

Peritoneal Lavage Cytology Following Neoadjuvant Chemotherapy for Gastric Adenocarcinoma: Low Yield in Detecting Peritoneal Metastases

BACKGROUND

Peritoneal lavage cytology (PLC) can detect advanced disease in gastric adenocarcinoma (GC); however, routine practice remains controversial. Furthermore, the effect of neoadjuvant chemotherapy (NAC) on cytological detection of carcinomatosis is unknown.

METHODS

Using a 2012-2020 prospective database, we retrospectively reviewed patients with GC who underwent NAC followed by a staging laparoscopic peritoneal lavage with or without biopsy of suspicious peritoneal nodules. PLC results were considered discordant if they did not align with the peritoneal biopsy results. Patients with benign peritoneal cytology (Cyt-) or biopsy results who had postoperative time to carcinomatosis of <6 months were considered to have diagnostic failure of peritoneal lavage.

RESULTS

Fifty-five patients with GC who underwent NAC followed by staging diagnostic laparoscopy with peritoneal lavage were identified. The majority of the patients in the cohort had Cyt- lavage (89.1%). Of the patients who underwent resection, 76.1% had T3 or greater disease on final pathology and 66% had nodal metastases. In 23 patients (41.8%) who had both peritoneal lavage and biopsy, four cases (17.4%) had discordant results. Diagnostic failure rate was 20% at 6 months and 42.2% at 12 months. The median time to carcinomatosis in patients who were Cyt- or biopsy negative was 7.9 months.

CONCLUSION

PLC after NAC has a high diagnostic failure rate and inaccurately predicts carcinomatosis in 20% of patients with GC. Novel methods for identifying cytology positive GC after NAC should also be developed and evaluated, since the risk of peritoneal dissemination is high.

Flow cytometry-based analysis of tumor-leukocyte ratios in peritoneal fluid from patients with advanced gastric cancer

Background

The frequency of tumor cell dissemination in the peritoneal cavity is critically related to the progression of peritoneal metastases (PM). Recently, flow cytometry (FCM) has been successfully used to detect tumor cells in malignant effusions.

Methods

A total of 143 single cell suspensions derived from ascites or peritoneal lavages from patients with advanced gastric cancer (GC) were stained with monoclonal antibodies to CD45 and to CD326 as well as 4,6‐diamidino‐2‐phenylindole (DAPI) and FVS780. Using FCM, tumor‐leukocyte ratio (TLR) were calculated from CD45(−)CD326(+) tumor cell counts/ CD45(+)CD326(+) leukocyte counts in DAPI (+) FVS780(−) gated area. In 54 patients, the ratios of CD11b(+), CD4(+) and CD8(+) cells in CD45(+) leukocytes were evaluated in parallel.

Results

TLR of 69 patients with PM were significantly higher than those of 74 without PM (p < .001) and log(TLR) showed strong correlation with peritoneal cancer index scores in 51 PM (+) patients (r = 0.439). TLR in PM (+) patients also correlated with the ratio of CD11b (+) myeloid cells (r = 0.547), and correlated inversely with those of CD4(+) (r = −0.490) and CD8(+) T cells (r = −0.648). In PM (−) patients who underwent gastrectomy, TLR never exceeded 0.1% in patients with primary GC without serosal involvement (<T4). However, TLR in patients with T4 GC were significantly higher (p < .05) and peritoneal recurrence occurred in 6/8 patients whose TLR exceeded 0.1%.

Conclusion

TLR in peritoneal fluid reflects tumor burden and the immune environment in peritoneal cavity. Multicolor FCM may provide additional information which can be used for the treatment of the patients with PM.

Predicting Peritoneal Dissemination of Gastric Cancer in the Era of Precision Medicine: Molecular Characterization and Biomarkers

Gastric cancer (GC) is a leading cause of worldwide cancer-related death. Being a highly heterogeneous disease, the current treatment of GC has been suboptimal due to the lack of subtype-dependent therapies. Peritoneal dissemination (PD) is a common pattern of GC metastasis associated with poor prognosis. Therefore, it is urgently necessary to identify patients at high risk of PD. PD is found to be associated with Lauren diffuse type GC. Molecular profiling of GC, especially diffuse type GC, has been utilized to identify molecular alterations and has given rise to various molecular classifications, shedding light on the underlying mechanism of PD and enabling identification of patients at higher PD risk. In addition, a series of diagnositc and prognostic biomarkers of PD from serum, peritoneal lavages and primary GCs have been reported. This comprehensive review summarizes findings on the multi-omic characteristics of diffuse type GC, the clinical significance of updating molecular classifications of GC in association with PD risk and research advances in PD-associated biomarkers.

Laparoscopic HIPEC for Low-Volume Peritoneal Metastasis in Gastric and Gastroesophageal Adenocarcinoma

BACKGROUND

We seek to determine whether laparoscopic hyperthermic intraperitoneal chemoperfusion (LS-HIPEC) improves overall survival (OS) in patients with gastric and gastroesophageal adenocarcinoma and low-volume peritoneal metastasis compared with standard of care treatment.

PATIENTS AND METHODS

We reviewed data from a prospectively maintained database of patients with gastric and gastroesophageal adenocarcinoma to identify patients with radiologically occult carcinomatosis or positive peritoneal cytology, no evidence of distant metastasis, and without disease progression during initial chemotherapy or observation. Univariate and multivariable analyses were performed to evaluate the impact of LS-HIPEC on OS.

RESULTS

We identified 25 patients who underwent LS-HIPEC and 27 treated with a standard of care approach due to patient (33.3%) or provider (51.9%) preference or financial limitations/lack of insurance coverage (14.8%). Resection was ultimately performed in 28% of LS-HIPEC patients and no standard care patients. At a median follow-up of 18.9 months, median OS was 24.7 (IQR 20.8-34.2) months in LS-HIPEC patients and 21.3 (IQR 12.3-23.1) months in standard care patients (p = 0.08). Three-year OS in the LS-HIPEC group was 19.1%, compared with 9.6% (p = 0.08). Patients who underwent resection had a median OS of 25.3 (IQR 22.6-47.1) months compared with 21.3 months in standard care patients (p = 0.05).

CONCLUSIONS

Neoadjuvant LS-HIPEC for the treatment of low-volume peritoneal disease in gastric and gastroesophageal cancer patients did not significantly improve OS compared with standard care. Multiinstitutional studies are necessary to further elucidate the benefit of LS-HIPEC for this patient population.

A cohort study and meta-analysis of the evidence for consideration of Lauren subtype when prescribing adjuvant or palliative chemotherapy for gastric cancer

Background

The association between the survival or efficacy of chemotherapy and the Lauren subtype of gastric cancer (GC) remains unclear. We aimed to clarify whether patients with different Lauren subtypes have different survival after treatment with systemic chemotherapy: intestinal gastric cancer (IGC) patients survived better than patients with mixed type gastric cancer (MGC) or diffuse gastric cancer (DGC) after treatment with systemic chemotherapy.

Patients & methods

Relevant studies for the meta-analysis were identified through searching Pubmed, Embase, Cochrane and Ovid up to March 2020. We also included our own prospectively collected cohort of patients that were followed over a 10-year period. Sub-group and sensitivity analyses were also performed.

Results

In our prospective cohort, the overall survival (OS) of IGC patients receiving systemic chemotherapy (chemoIGC) [median OS 5.01 years, interquartile range (IQR) 2.63-6.71] was significantly higher than that of DGC patients receiving the same chemotherapy (chemoDGC) (median OS 1.33 years, IQR 0.78-3.33, p = 0.0001). After adjusting for age, gender and cancer stage, there was a significant difference in OS in patients treated with chemotherapy based on the Lauren classification of GC {hazard ratio (HR) for OS of the IGC versus DGC 0.33, [95% confidence interval (CI), 0.17-0.65; p < 0.001]}. In the IGC patients, the adjusted HR associated with chemotherapy was 0.26 (95% CI, 0.12-0.56; p = 0.001), whereas the association was 0.64 (95% CI, 0.30-1.33; p = 0.23) in the DGC patient group.In our meta-analysis, 33 studies comprising 10,246 patients treated with systemic chemotherapy (chemoIGC n = 4888, chemoDGC n = 5358) met all the selection criteria. While we accounted for much of the heterogeneity in these studies, we found that chemoIGC patients showed significantly improved OS [HR, 0.76 (95% CI, 0.71-0.82); p < 0.00001] when compared with similarly treated chemoDGC patients.

Conclusion

Our results support the consideration of Lauren subtype when prescribing systemic chemotherapy for GC, particularly for MGC or DGC, which may not benefit from chemotherapy. Lauren classification should be considered to stratify chemotherapy regimens to GC patients in future clinical trials, with particular relevance to MGC or DGC, which is more difficult to treat with current regimens.

Effects of Neoadjuvant Chemotherapy Toxicity and Postoperative Complications on Short-term and Long-term Outcomes After Curative Resection of Gastric Cancer

BACKGROUND

Whether neoadjuvant chemotherapy (NAC) increased the risk of postoperative morbidities for patients with locally advanced gastric cancer (GC) is unknown. Whether neoadjuvant chemotherapy toxicity (NCT) and postoperative complications (POCs) correlate with short-term and long-term outcomes also remains unclear. We aimed to evaluate the role of NAC on the development of POCs, as well as the impact of NCT and POCs on postoperative and oncologic outcomes in curatively resected GC treated with NAC.

METHODS

This study retrospectively reviewed 230 patients who underwent curative gastrectomy for locally advanced GC (clinically T3/4 or N+) after NAC between 2006 and 2016. Five hundred patients undergoing upfront and curative surgery were selected as a control group. After matching, the incidence of POCs was compared between two groups. In the NAC group, clinicopathological characteristics of patients who experienced POCs were compared to those who did not. Logistic and Cox multivariate regression analyses were used to examine factors associated with POCs, disease-free survival (DFS), and overall survival (OS).

RESULTS

Following matching, 230 and 230 patients treated with surgery plus NAC and upfront surgery remained, respectively. The incidence of POCs was 28.7% and 24.3%, respectively (p = 0.290). In the NAC group, NCT (OR [odds ratio] 22.968, 95% CI [confidence interval] 2.948-> 99, p = 0.003) and operation time (OR 1.006, 95% CI 1.001-1.011, p = 0.021) were independent predictive factors of POCs. NCT did not affect oncologic outcomes. The Cox regression model demonstrated that POCs were independently associated with worse DFS (HR [hazard ratio] 2.128, 95% CI 1.240-3.653, p = 0.006) but not OS for patients treated with NAC.

CONCLUSIONS

The administration of NAC is not associated with an elevated risk of POCs. For patients treated with NAC, NCT is an independent predictor of POCs, but does not affect oncologic outcomes. POCs is independently associated with worse DFS but not OS. NAC should be considered a safe approach in patients who have locally advanced GC. Strategies to minimize chemotherapy toxicity and postoperative morbidities associated with NAC are warranted.

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.

Staging laparoscopy and peritoneal cytology in patients with early stage gastric adenocarcinoma

Background

Staging laparoscopy and peritoneal cytology can detect occult metastatic disease prior to treatment of gastric cancer. The yield of peritoneal staging in patients with early stage disease is lacking. We assess the yield of peritoneal staging in early stage gastric cancer and its impact on survival.

Methods

Data were obtained from a prospective database of patients who underwent staging laparoscopy and peritoneal cytology for gastric cancer at our institution between July 1995 and July 2018. Clinical stage was determined by endoscopic ultrasound, and early stage was defined as cT1-2 and cN0. Rates of positive cytology and carcinomatosis at time of laparoscopy were obtained. Univariate analyses were used to compare groups, and Kaplan-Meier survival analyses were used to assess survival outcomes.

Results

Eight hundred sixty-seven patients underwent staging laparoscopy and peritoneal cytology; 56 were defined as early stage. Age was 61 ± 12 years, 66.4% were male, and 62.3% were white. Of the patients with early stage disease, 17.9% had either gross carcinomatosis (10.7%) and/or positive peritoneal cytology (10.9%). All cases of peritoneal disease were in patients with cT2 disease. There were no differences in age, gender, or race based on peritoneal disease (all p > 0.05). The presence of carcinomatosis or positive cytology significantly affected overall survival (p < 0.001), regardless of clinical T or N stage.

Conclusions

Peritoneal staging identifies metastatic disease in a significant number of patients with early stage disease. Given its poor prognosis and alternate therapy options, independent staging laparoscopy and peritoneal cytology should be considered in patients with early stage gastric adenocarcinoma.

Dealing with the gray zones in the management of gastric cancer: The consensus statement of the İstanbul Group

The geographical location and differences in tumor biology significantly change the management of gastric cancer. The prevalence of gastric cancer ranks fifth and sixth among men and women, respectively, in Turkey. The international guidelines from the Eastern and Western countries fail to manage a considerable amount of inconclusive issues in the management of gastric cancer. The uncertainties lead to significant heterogeneities in clinical practice, lack of homogeneous data collection, and subsequently, diverse outcomes. The physicians who are professionally involved in the management of gastric cancer at two institutions in Istanbul, Turkey, organized a consensus meeting to address current problems and plan feasible, logical, measurable, and collective solutions in their clinical practice for this challenging disease. The evidence-based data and current guidelines were reviewed. The gray zones in the management of gastric cancer were determined in the first session of this consensus meeting. The second session was constructed to discuss, vote, and ratify the ultimate decisions. The identification of the T stage, the esophagogastric area, imaging algorithm for proper staging and follow-up, timing and patient selection for neoadjuvant treatment, and management of advanced and metastatic disease have been accepted as the major issues in the management of gastric cancer. The recommendations are presented with the percentage of supporting votes in the results section with related data.

The Incidence of Free Peritoneal Tumor Cells before and after Neoadjuvant Chemotherapy in Gastroesophageal Junction Cancer

Context

The utility of peritoneal washing cytology in patients with gastroesophageal junction cancer has not been thoroughly evaluated.

Aims

The study aimed to determine the incidence of free peritoneal tumor cells by peritoneal washing cytology before and after neoadjuvant chemotherapy using conventional cytopathological methods and immunohistochemical staining for the analysis of peritoneal washings.

Settings and Design

A prospective study conducted at a single tertiary referral hospital.

Materials and Methods

Patients with gastroesophageal junction cancer and without suspicion of intra- or extraabdominal metastases before the staging laparoscopy were prospectively and consecutively enrolled. Peritoneal washing cytology was performed at staging laparoscopy (primary cytology) and after neoadjuvant chemotherapy during robot-assisted or open resection (secondary cytology). Peritoneal fluid samples were analyzed by conventional cytology and an immunohistochemical panel.

Results

Overall, 81 patients met the primary inclusion criteria. During primary cytology, positive cytology without overt metastases (C1M0) was detected in three patients (3.8%) while five patients (6.3%) had overt intra-abdominal metastases but negative cytology (C0M1). None of the patients with C1M0 underwent surgery due to extra-abdominal (n = 1) or intra-abdominal metastases (n = 2), and the overall survival was 4, 7, and 14 months. During secondary cytology, no patients with free peritoneal tumor cells were identified, but seven patients were classified as C0M1 (10.9%).

Conclusions

The incidence of C1M0 was 3.8% and 0% before and after neoadjuvant chemotherapy, respectively in patients with gastroesophageal junction cancer. Free peritoneal tumor cells were not identified in several patients with intra-abdominal metastases suggesting that peritoneal washing cytology with conventional cytology and immunohistochemical staining lack sensitivity.

Detection of free intraperitoneal tumour cells in peritoneal lavage fluid from patients with peritoneal metastasis before and after treatment with pressurised intraperitoneal aerosol chemotherapy (PIPAC)

AIMS

In this study, we investigated whether free intraperitoneal tumour cells (FITC) were detectable in ascites or peritoneal lavage fluid (PLF) from patients with peritoneal metastasis (PM) before and after treatment with pressurised intraperitoneal aerosol chemotherapy (PIPAC).

METHODS

Ascites or PLF retrieved at the first and third PIPAC procedures was analysed by conventional cytology, carcinoembryonic antigen (CEA) and total protein concentration, and quantitative reverse transcriptase PCR (qRT-PCR) for mRNA expression of CEA, epithelial cell adhesion molecule (EpCAM) and cancer antigen 125 (CA-125). Conventional cytology and qRT-PCR were also performed in a negative control group (benign PLF specimens and inflammatory ascites). The treatment response was compared with the histological response based on repeated peritoneal biopsies evaluated by the Peritoneal Regression Grading Score (PRGS).

RESULTS

Thirty-five patients with PM of various origins were included from 2015 to 2016. At the first PIPAC procedure, FITC were detected by conventional cytology (sensitivity 0.58, specificity 1.00), CEA protein (cut-off 0.4 µg/L, sensitivity 0.71), CEA mRNA (sensitivity 0.75, specificity 1.00), EpCAM mRNA (sensitivity 0.71, specificity 1.00) and CA-125 mRNA (sensitivity 0.43, specificity 1.00). The combination of CEA/EpCAM mRNA had a sensitivity of 0.88 and a specificity of 1.00. The evaluation of ascites or PLF retrieved at the third PIPAC procedure failed to detect treatment response, when compared with the histological PRGS.

CONCLUSIONS

The evaluation of CEA and EpCAM mRNA detects FITC with a high sensitivity and an excellent specificity, but is not useful for response evaluation in patients treated with PIPAC.

TRIAL REGISTRATION NUMBER

NCT02320448.

Review and Update on the Role of Peritoneal Cytology in the Treatment of Gastric Cancer

BACKGROUND

Positive peritoneal cytology (Cyt+) even in the absence of macroscopic disease is associated with poor prognosis in patients with gastric cancer and deemed as M1 disease. Recent years have seen advancements in the evaluation strategies for peritoneal washings and management of patients with Cyt+. The aim of this review was to describe the newest paradigms in the management of patients with gastric cancer who have Cyt+ without macroscopic peritoneal metastases.

METHODS

A comprehensive literature review was performed to identify studies on the management of gastric cancer and thereby to summarize relevant information on the accuracy of various diagnostic tests and controversies involved in the treatment of patients with Cyt+.

RESULTS

Although conventional cytology remains the standard technique for assessment of peritoneal washings, it is limited by low sensitivity. The role of immunohistochemistry and molecular techniques for the assessment of peritoneal washings is evolving. Although systemic chemotherapy remains the standard of care for patients with Cyt+ disease, the role of gastrectomy, intraperitoneal chemotherapy, extensive intraperitoneal saline lavage, and hyperthermic intraperitoneal chemotherapy is being evaluated.

CONCLUSIONS

Clinical decision-making in patients with Cyt+ remains controversial given the seemingly technical resectable albeit biologically unresectable or aggressive disease that portends an overall poor prognosis. Current management strategies are evolving, and further studies are needed to develop an optimal treatment strategy for these patients.

Evolving Treatment Strategies and Outcomes in Advanced Gastric Cancer with Peritoneal Metastasis

Gastric cancer (GC) has a predilection to metastasize to the peritoneum, denoting a poor prognosis. Treatment strategies available for advanced GC have significantly evolved over time and can be categorized into systemic, regional, and surgical. Although systemic therapies have been the mainstay for the treatment of advanced GC, their ability in achieving long-term survival in patients with peritoneal involvement is modest at best. This article describes advances in combined modality treatment of peritoneal metastases, specifically with an emphasis on peritoneal-directed therapies.

Extensive intraperitoneal lavage to eliminate intraperitoneal tumor cells in gastrectomy with D2 lymphadenectomy for gastric cancer

INTRODUCTION:

Survival in gastric cancer is often limited by peritoneal carcinomatosis, which supposedly develops from serosal tumor infiltration or tumor cell spread during gastrectomy with lymphadenectomy. To eliminate peritoneal tumor cells, extensive intraperitoneal lavage (EIPL) has been suggested. Impressive results have been achieved in Japanese trials. In this trial, we assessed EIPL in Western patients.

METHODS:

This prospective trial included patients with non-metastatic gastric adenocarcinoma undergoing gastrectomy with D2 lymphadenectomy. Peritoneal fluid samples at laparotomy, after lymphadenectomy, and after EIPL were analyzed for tumor cells using cytology and EpCAM antibodies. The primary endpoint was peritoneal conversion rate (PCR; proportion of patients in whom EIPL eliminated tumor cells after lymphadenectomy). Secondary endpoints were peritoneal release rate (PRR; proportion of patients with peritoneal tumor cells after gastrectomy/lymphadenectomy among all patients without cells before gastrectomy/lymphadenectomy) and prevalence of peritoneal tumor cells before resection. EIPL was considered ineffective if PCR ⩽ 0.2 and warranted further exploration if PCR ⩾ 0.5. Clinicaltrials.gov identifier is NCT01476553.

RESULTS:

The trial was stopped early because tumor cells after gastrectomy/lymphadenectomy were detected in only 3/27 (11.1%) patients. In none of these did EIPL eliminate tumor cells (PCR 0, 95% confidence interval [CI] 0%-12.5%). In 8/27 (29.6%) patients, tumor cells were detected after EIPL. PRR was 11.1% (95% CI 2.4%-29.2%). There were no perioperative complications higher than Clavien-Dindo grade 3a.

CONCLUSIONS:

In Western patients, free peritoneal tumor cells after gastrectomy with D2 lymphadenectomy for gastric cancer were detected only sporadically. Although based on few cases, the findings suggest that EIPL spreads tumor cells into the peritoneal cavity, thus being potentially harmful. Therefore, EIPL cannot be generally recommended.

Neoadjuvant Therapy Improves Outcomes in Locally Advanced Signet-Ring-Cell Containing Esophagogastric Adenocarcinomas

BACKGROUND

Only a few studies have analyzed multimodal treatment concepts in the subgroup of signet-ring-cell containing upper gastrointestinal (GI) cancer. Recent retrospective, multicentric data favor primary resection without neoadjuvant chemotherapy for gastric signet-ring-cell containing carcinomas (SRCs). We compared the outcomes of primarily resected carcinomas with neoadjuvantly treated, locally advanced esophagogastric SRCs.

METHODS

A total of 310 patients with esophagogastric SRC-staged cT3/4/Nany/Many from a prospective unicentric database were included in this study; 192 (61.9%) received neoadjuvant therapy (NEO group) and 118 (38.1%) were primarily resected (RES group).

RESULTS

Overall, 128 (41.3%) patients presented with adenocarcinoma of the esophagogastric junction (AEG) and 182 (58.7%) presented with gastric cancer. Neoadjuvant therapy was significantly associated with resection in curative intent (NEO: 91.1%; RES: 75.4%; P = 0.001), improved (y)pT category (P = 0.035), improved (y)pN category (P < 0.001), and R0 resections (curative intent cohort: 76.0% in NEO vs. 60.7% in RES; P = 0.010), among others, but not with postoperative complications. Overall survival was significantly improved by neoadjuvant treatment {median survival 28.5 months (95% confidence interval [CI] 14.4-39.6) vs. RES: 14.9 months (10.6-17.5); P < 0.001}, as well as in subgroups (AEG and gastric tumors, R0-resected patients, and patients with and without relevant comorbidities). Independent prognostic factors were neoadjuvant therapy (hazard ratio [HR] 0.66; P = 0.023), pT4 category (HR 1.71; P = 0.041), pN2 category (HR 1.86; P = 0.013), pN3 category (HR 2.40; P < 0.001), pM1 category (HR 1.95; P = 0.003), age > 70 years (HR 1.79; P = 0.006), gastric localization (HR 0.69; P = 0.032), American Society of Anesthesiologists classification 3/4 (HR 1.71; P = 0.004), and incomplete resection R1/2 (HR 1.6; P = 0.014).

CONCLUSIONS

Our results demonstrate a survival advantage for advanced-stage esophagogastric SRC patients by neoadjuvant treatment.

Prognostic significance of peritoneal lavage cytology in staging gastric cancer: systematic review and meta-analysis

BACKGROUND

Peritoneal cytology has been used as a part of the cancer staging of gastric cancer patients. The primary aim of this systematic review was to evaluate the value of peritoneal cytology as part of the staging of gastric cancer and survival prediction. The second aim was to establish if positive cytology may be modified by neoadjuvant therapy, to improve prognosis.

METHODS

An electronic literature search was performed using Embase, Medline, Web of Science, and Cochrane library databases up to January 2016. The logarithm of the hazard ratio (HR) with 95% confidence intervals (CI) was used as the primary summary statistic. Comparative studies were used, and the outcome measure was survival in three groups: (1) positive versus negative cytology at staging laparoscopy immediately preceding surgery; (2) effect of neoadjuvant therapy on cytology and survival; and (3) positive cytology in the absence of macroscopic peritoneal disease was compared with obvious macroscopic peritoneal disease.

RESULTS

Pooled analysis demonstrated that positive cytology was associated with significantly reduced overall survival (HR, 3.46; 95% CI, 2.77-4.31; P < 0.0001). Interestingly, negative cytology following neoadjuvant chemotherapy was associated with significantly improved overall survival (HR, 0.42; 95% CI, 0.31-0.57; P < 0.0001). The absence of macroscopic peritoneal disease with positive cytology was associated with significantly improved overall survival (HR, 0.64; 95% CI, 0.56-0.73; P < 0.0001).

CONCLUSION

This study suggests that patients with initial positive cytology may have a good prognosis following neoadjuvant treatment if the cytology results change to negative after treatment.

Risk of peritoneal metastases in patients who had negative peritoneal staging and received therapy for localized gastric adenocarcinoma

BACKGROUND

Positive peritoneal cytology (+PCyt) or gross carcinomatosis (GPC) carries a poor prognosis. Laparoscopic staging to detect +PCyt/GPC is recommended for all ≥T1b gastric adenocarcinoma (GAC). The natural history of patients with GAC who have baseline -PCyt and then undergo multimodality therapy is not well documented, particularly for the risk of subsequent GPC.

METHODS

We identified 238 GAC patients with baseline -PCyt who were followed for the development of peritoneal carcinomatosis (PC). Standard statistical methods were employed.

RESULTS

Of 238 patients, 192 had attempted surgery after preoperative therapy. Of these, 13 patients (6.8%) had GPC and one had liver metastases, thus surgery was aborted. We followed 164 patients who had an R0 resection. The median follow-up duration was 3.4 (range, 0.6-18) years. The rate of PC was 13.4%, (22/164 patients) and the median time to PC was 15.6 months. Female gender was associated with PC on multivariate analysis. The 5-year OS rate for patients without subsequent PC was 75%. Conclusion Even with baseline -Cyt, ∼25% of patients develop PC following multimodality therapy. Patients who do not develop PC have an excellent OS rate. Further research is warranted to detect PC at baseline by the use of biomarkers.

Peritoneal recurrence in gastric cancer following curative resection can be predicted by postoperative but not preoperative biomarkers: a single-institution study of 320 cases

To determine the risk factors for peritoneal recurrence in gastric cancer patients after curative resection, we included 320 patients with stage I-III primary gastric cancer between January 2008 and June 2012. Data on each patient's surgical and pathological information, preoperative and postoperative tumor markers were collected and analyzed retrospectively. The risk factors for peritoneal recurrence were investigated by univariate and multivariate analysis. In patients with peritoneal recurrence, advanced T or N stage, low differentiation, vascular/lymphatic invasion, perineural invasion, and elevated postoperative CEA/CA19-9 were more common than in patients without peritoneal recurrence. Patients with peritoneal recurrence showed a worse overall survival (OS) compared to those without peritoneal recurrence. In addition, patients with peritoneal recurrence within the first year had a worse OS compared to those with recurrence after 1 year. The univariate and multivariate analyses revealed that elevated number of metastatic lymph nodes and elevated postoperative CEA and CA19-9 were three independent risk factors for peritoneal recurrence in gastric cancer patients. For patients with N3 stage and high postoperative CEA and CA19-9, we found an initial steep slope within approximately 1 year and a subsequent gentle slope in the risk curve. Combined receiver operating characteristic curve analysis using the three independent risk factors for peritoneal recurrence yielded an area under the curve value of 0.73 with 73.7% sensitivity and 64.2% specificity. Therefore, the risk factors may be associated with peritoneal recurrence after curative resection in selected gastric cancer patients.

Prognostic significance, diagnosis and treatment in patients with gastric cancer and positive peritoneal washings. A review of the literature

Peritoneal dissemination is a common consequence of a relapse following a radical surgical treatment of gastric cancer. The development of the disease in the peritoneum depends not only on its stage, but also on free cancer cells exfoliated from the tumor mass or from involved lymph nodes, and which are capable of being implanted in the peritoneum. According to the latest TNM (7 edition; 2010) classification, patients with free cancer cells in the peritoneal washings qualify for stage IV of the disease. Patients in whom free cancer cells were found during the operation - have a recurrence of gastric cancer - mainly in the peritoneum, and the majority of them die within two years of the diagnosis. To properly assess the prognosis, it is vital to determine the stage of cancer by additionally assessing the washings for the presence of free cancer cells before taking a therapeutic decision. This also allows identifying those patients who require different medical procedures to obtain the best treatment results possible. Medical literature describes various methods of examining peritoneal washings aimed at detecting free cancer cells. The methods apply different cancer cell detection rates, sensitivity and specificity in prediction of a peritoneal relapse. Oncological Departments performing the evaluation of the washings employ non-standard methods of treatment in this group of patients and the results presented are promising.

The value of staging laparoscopy in gastric cancer

Treatment options for patients with gastric cancer (GC) are based on tumor staging and resectability. Although only surgery provides improved survival, resection is contraindicated and should be avoided in the presence of intra-abdominal disease stage M1 (liver, peritoneal, or non-local lymph node metastases). Thus, a detailed and precise evaluation is imperative for optimal treatment. Staging laparoscopy (SL) constitutes a major tool in the accurate diagnosis of several types of cancers, including GC. SL presents several critical advantages: it can diagnose intra-abdominal disease; serve as a complement to other imaging studies; allow for biopsies; facilitate intraoperative ultrasound evaluations; allow for sampling of peritoneal fluid for cytological examination; and serve as an option for the administration of intraperitoneal chemotherapy. Although considered and advocated as a very useful asset in the pre-treatment cancer-staging arsenal, the wider application of SL has been long debated. The purpose of our study was to evaluate the contribution of laparoscopy to GC staging.

Changing Trends in Gastric Cancer Surgery

Gastric cancer is one of the most common causes of cancer-related death. It requires multimodal treatment and surgery is the most effective treatment modality. Radical surgery includes total or subtotal gastrectomy with lymph node dissection. The extent of lymphadenectomy still remains controversial. Eastern surgeons have performed D2 or more extended lymphadenectomy while their Western colleagues have performed more limited lymph node dissection. However, the trend has been changing in favour of D2 lymph node dissection in both hemispheres. Currently, D2 is the recommended type of lymphadenectomy in experienced centres in the west. In Japan, D2 lymph node dissection is the standard surgical approach. More extensive lymphadenectomy than D2 has not been found to be associated with improved survival and generally is not performed. Bursectomy and splenectomy are additional controversial issues in surgical performance, and trends regarding them will be discussed. The performance of bursectomy is controversial and there is no clear evidence of its clinical benefit. However, a trend toward better survival in patients with serosal invasion has been reported. Routine splenectomy as a part of lymph node dissection has largely been abandoned, although splenectomy is recommended in selected cases. Minimally invasive surgery has gained wide popularity and indications for minimally invasive procedures have been expanding due to increasing experience and improving technology. Neoadjuvant therapy has been shown to have beneficial effects and seems necessary to provide a survival benefit. Diagnostic laparoscopy should be kept in mind prior to treatment.

The Importance of Extensive Intraoperative Peritoneal Lavage as a Promising Method in Patients with Gastric Cancer Showing Positive Peritoneal Cytology Without Overt Peritoneal Metastasis and Other Therapeutic Approaches

Peritoneal invasion is more common and has a worse prognosis in gastric cancer than most of other intestinal cancers. Advanced gastric cancers have a poor course in terms of the development of peritoneal carcinomatosis and prognosis, even if the curative resection has been performed. Patients usually die within the first 2 years of the postoperative period mainly due to peritoneal metastasis. It is, therefore, essential to eradicate intraperitoneal free cancer cells to prevent peritoneal recurrences. A standard therapy has not been developed yet for patients with gastric cancer with a positive peritoneal cytology or a gross peritoneal metastasis. Curative resection following neoadjuvant chemotherapy, postoperative oral S-1 chemotherapy, intraoperative intraperitoneal chemotherapy (IPC), and extensive intraoperative peritoneal lavage (EIPL)-IPC are recommended as therapeutic approaches. Although there is a limited number of studies on EIPL, which is a promising and exciting method in this patient population, unexpected results of survival have been demonstrated. We consider that the results of ongoing and further studies would lead to an extensive use of EIPL, which is a simple and easy method which can be applied anywhere and anytime, in patients with advanced gastic cancer and/or peritoneal cytology positive but peritoneal metastasis negative (CY+/P0) gastric cancer.

Seventh tumor-node-metastasis staging of gastric cancer: Five-year follow-up

Seventh tumor-node-metastasis (TNM) classification for gastric cancer, published in 2010, introduced changes in all of its three parameters with the aim to increase its accuracy in prognostication. The aim of this review is to analyze the efficacy of these changes and their implication in clinical practice. We reviewed relevant Literature concerning staging systems in gastric cancer from 2010 up to March 2016. Adenocarcinoma of the esophago-gastric junction still remains a debated entity, due to its peculiar anatomical and histological situation: further improvement in its staging are required. Concerning distant metastases, positive peritoneal cytology has been adopted as a criterion to define metastatic disease: however, its search in clinical practice is still far from being routinely performed, as staging laparoscopy has not yet reached wide diffusion. Regarding definition of T and N: in the era of multimodal treatment these parameters should more influence both staging and surgery. The changes about T-staging suggested some modifications in clinical practice. Differently, many controversies on lymph node staging are still ongoing, with the proposal of alternative classification systems in order to minimize the extent of lymphadenectomy. The next TNM classification should take into account all of these aspects to improve its accuracy and the comparability of prognosis in patients from both Eastern and Western world.

Positive Peritoneal Lavage Cytology -Implications for Staging and Management of Gastric Cancer

The survival rates of gastric cancer patients with cytology-positive peritoneal lavage fluid without macroscopic dissemination (CY+/P-) is the same as that of patients with overt peritoneal metastasis.The 5-year survival rate of such patients is only 2%. The current study aims to highlight its significance in the staging of gastrointestinal malignancies and its implications for patient care. Prospective nonrandom analysis of peritoneal wash cytology in patients with gastrointestinal malignancies was conducted in the department of Surgical Gastroenterology, Nizams Institute of Medical Sciences, Hyderabad from January 2012 to June 2013. Descriptive statistics and ANOVA variance analysis was performed to estimate incidence, risk factors and the effect of surgery in causing peritoneal dissemination of malignancy. A total of 60 patients with operable gastric cancer underwent peritoneal lavage for evaluation of malignant cells. The incidence of Positive peritoneal lavage cytology was 8.3% (5/60).Four patients with positive lavage fluid belong to T3 stage (11.7%, p-0.309).Poorly differentiating and mucinous tumors had a higher incidence of positive cytology (18.1% and 25%).None of the patients with positive cytology had positive resection margin. Tumors with advanced T stage, lymph nodal involvement, lympho-vascular and perineural invasion have higher incidence of positive peritoneal cytology. Surgical handling has a negligible effect in peritoneal dissemination of tumor. Large scale studies are warranted to validate the findings and define it's role in management of gastric cancer.

Proactive Management for Gastric, Colorectal and Appendiceal Malignancies: Preventing Peritoneal Metastases with Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

An integrated treatment strategy using peritonectomy procedures plus hyperthermic intraperitoneal chemotherapy (HIPEC) is now a clinical standard of care in selected patients with peritoneal metastases and primary peritoneal tumors. This comprehensive approach can offer many patients, who hitherto had no hope of cure, a good quality of life and survival despite limited morbidity. The increasingly successful results and chance of interfering in the natural history of disease has prompted research to develop for some clinical conditions a therapeutic strategy designed to prevent malignant peritoneal dissemination before it becomes clinically evident and treat it microscopically (tertiary prevention). The main factor governing successful cytoreductive surgery and predicting outcome is the extent of peritoneal spread assessed with the peritoneal cancer index (PCI). In peritoneal metastases from colorectal and gastric cancer the PCI score acquires a specific role acting as the cut-off between patients who can undergo curative surgery or palliation. Long-term results show that the only group enjoying favorable results are patients with limited disease (a statistical minority). By applying to appropriately selected patients with primary malignancies a proactive management strategy including HIPEC we can treat patients with microscopic peritoneal dissemination and therefore at PCI 0. Among treated conditions pseudomyxoma peritonei enjoys the best results. But a major future advance comes from identifying among lesions at major risk of pseudomyxoma.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in gastric cancer

Gastric cancer associated peritoneal carcinomatosis (GCPC) has a poor prognosis with a median survival of less than one year. Systemic chemotherapy including targeted agents has not been found to significantly increase the survival in GCPC. Since recurrent gastric cancer remains confined to the abdominal cavity in many patients, regional therapies like aggressive cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been investigated for GCPC. HIPEC has been used for three indications in GC- as an adjuvant therapy after a curative surgery, HIPEC has been shown to improve survival and reduce peritoneal recurrences in many randomised trials in Asian countries; as a definitive treatment in established PC, HIPEC along with CRS is the only therapeutic modality that has resulted in long-term survival in select groups of patients; as a palliative treatment in advanced PC with intractable ascites, HIPEC has been shown to control ascites and reduce the need for frequent paracentesis. While the results of randomised trials of adjuvant HIPEC from western centres are awaited, the role of HIPEC in the treatment of GCPC is still evolving and needs larger studies before it is accepted as a standard of care.

Is conversion therapy possible in stage IV gastric cancer: the proposal of new biological categories of classification

Conversion therapy for gastric cancer (GC) has been the subject of much recent attention. It is defined as a surgical treatment aiming at an R0 resection after chemotherapy for tumors that were originally unresectable or marginally resectable for technical and/or oncological reasons. However, the indications for resection remain to be clarified. In the present review, we focus on the biology and heterogeneous characteristics of stage IV GC and propose new categories of classification. Stage IV GC patients can be divided based on the absence (categories 1 and 2) or presence (categories 3 and 4) of macroscopically detectable peritoneal dissemination, which has a different biological outcome compared to hematological metastasis. Category 1 is defined oncologically as stage IV but the metastasis is technically resectable. Category 2 includes a marginally resectable metastasis or patients for whom the operation would not necessarily be the best choice. Category 3 includes a potentially unresectable metastasis of peritoneal dissemination that is only macroscopically detectable. Category 4 includes noncurable metastasis with peritoneal and other organ metastasis. The indications for conversion therapy might include the patients from category 2, some patients from category 3 and a very small number of patients from category 4. The longer survival can be expected for patients corresponding to categories 1, 2 and, to a lesser extent, 3, while the treatment of other patients focuses on "care." The provision of conversion therapy for stage IV GC patients might be one of the main roles of surgical oncologists in the near future.

Prognosis of gastric adenocarcinoma patients with various burdens of peritoneal metastases

BACKGROUND

Peritoneal metastases (PM) in patients with gastric adenocarcinoma (GAC) may be identified by diagnostic laparoscopy (DL) or imaging (I). Although prognosis is poor, some patients have excellent outcome. We compared the overall survival (OS) of patients in 3 groups: those with positive cytology (CY+) by DL (DL-CY+), those with gross PM (GPM) by DL (DL-GPM+) and with GPM obvious on I (I-GPM+).

METHODS

146 GAC patients were identified. The Kaplan-Meier analysis, univariate, and multivariate Cox proportional hazards regression models were employed.

RESULTS

Patients were primarily men (67%), with good ECOG scores (0-1; 89%), had DL (84%), had poorly differentiated GAC (92%), and had received chemotherapy (89%). The median OS for all patients was 15 months (5% CI, 12.9-18.2 months). The DL-CY+ group had median OS of 22.5 months (95% CI, 15-29.3 months). Patients with I-GPM+ had four times the risk of death than those with DL-CY+ (P < 0.001) and patients with DL-GPM+ had two times the risk of death than those with DL-CY+ (P = 0.001). At 36 months, all DL-GPM+ and I-GPM+ had died but 8 patients with DL-CY+ remained alive.

CONCLUSIONS

Some GAC patients with DL-CY+ have long OS; therefore, novel strategies to further prolong their OS are needed.

Noncurative Resection for Gastric Cancer Patients: Who Could Benefit? : Determining Prognostic Factors for Patient Selection

BACKGROUND

Resections have long been recommended for patients with incurable gastric cancer. However, high morbidity rates and more efficient chemotherapy regimens have demanded more accurate patient selection. The aim of this study was to analyze the results of gastric cancer patients treated with noncurative resection in a single cancer center.

METHODS

Medical charts of patients treated with a noncurative resection between January 1988 and December 2012 were analyzed. Individuals who had M1 disease were included, along with those with no metastasis but who had an R2 resection. Morbidity, mortality, and survival prognostic factors were analyzed.

RESULTS

In the period, 192 patients were resected, 159 with previously diagnosed metastatic disease and the other 33 having resection with macroscopic residual disease (R2). A distal gastrectomy was performed in 117 patients and a total resection in 75, with a more limited lymph node dissection in 70 % of cases. A multivisceral resection was deemed necessary in 42 individuals (21.9 %). Overall morbidity was 26.6 % and 60-day mortality was 6.8 %. Splenectomy was the only independent prognostic factor for higher morbidity. Median survival was 10 months, and younger age, distal resection, and chemotherapy were independent prognostic factors for survival. A prognostic score obtained from these factors identified a 20-month median survival in patients with these favorable characteristics.

CONCLUSION

Noncurative surgery may be considered in selected gastric cancer patients as long as it has low morbidity and allows the realization of chemotherapy.

Tumor regression and survival after perioperative MAGIC-style chemotherapy in carcinoma of the stomach and gastroesophageal junction

BACKGROUND

We assessed the effectiveness of perioperative MAGIC-style chemotherapy in our series focused on the tumor regression grade and survival rate.

METHODS

We conducted a retrospective study of 53 patients following a perioperative regimen of epirubicin, cisplatin, and fluorouracil or capecitabine (ECF/X). Forty-four (83 %) neoplasias were located in the stomach and 9 (17 %) were located at the esophagogastric junction. Perioperative chemotherapy completion, resection, TNM staging, the tumor regression grade (Becker's classification) and survival were analyzed.

RESULTS

Forty-five patients (85 %) completed the 3 preoperative cycles. R0 resection was achieved in 42 (79 %) patients. Thirty-five (66 %) patients completed the 3 postoperative cycles. Nine carcinomas (17 %) were considered major responders after preoperative chemotherapy. With multivariate analysis, only completion of perioperative chemotherapy (HR: 0.25; 95%CI: 0.08 - 0.79; p = 0.019) was identified as an independent prognostic factor for disease-specific survival. However, the protective effect of perioperative therapy was lost in patients with ypT3-4 and more than 4 positive lymph nodes (HR: 1.16; 95%CI: 1.02 - 1.32; p = 0.029). The tumor regression grade (major vs minor responders) was at the limit of significance only with univariate analysis. The 5-year overall and disease-specific survival rates were 18 % and 22 % respectively.

CONCLUSIONS

The percentage of major responder tumors after preoperative chemotherapy was low. Completion of perioperative ECF/X chemotherapy may benefit patients with gastric carcinomas that do not invade the subserosa with few positive lymph nodes.

Current status of management of malignant disease: current management of gastric cancer

Despite a continually decreasing incidence trend, gastric cancer remains a high-risk malignancy. Symptoms are often unspecific, and upper gastrointestinal endoscopy is the key modality for diagnosing early and intermediate-stage disease. Surgeons play a critical role in guiding and managing multiple aspects of gastric cancer diagnosis and care. Potentially curable gastric adenocarcinoma has to be free of distant metastasis and should be staged through endoscopic ultrasound and computed tomography. Early (T1N0) gastric cancer can be considered for endosopic mucosal resection or submucosal dissection. All other M0 stage groups should be evaluated for preoperative chemotherapy or chemoradiation followed by resection through a multidisciplinary approach. Laparoscopic staging, complete (R0) resection, and extended lymphadenectomy (D2 dissection) are critical operative components that optimize curability during gastrectomy. The morbidity potential after gastrectomy remains high; splenectomy and distal pancreatectomy should be avoided if possible to minimize postoperative complications. Laparoscopic gastric cancer resections are increasingly pursued and have not shown disadvantages to open gastrectomy as long as oncologic principles are followed. For the palliation of specific symptoms in patients with incurable gastric cancer, operative interventions should be applied selectively if less invasive modalities are insufficient and only if a meaningful benefit can be expected from a resection or bypass procedure. Prophylactic total gastrectomy should be considered for individuals at risk for hereditary diffuse-type gastric cancer through germline E-cadherin gene mutations. Surgeons engaging in gastric cancer care are expected to provide specialty expertise in order to plan and deliver appropriate care, minimize postoperative morbidity, and optimize resulting survival.

A systematic review and meta-analysis of gastric cancer treatment in patients with positive peritoneal cytology

Gastric cancer patients with positive peritoneal cytology as the only marker of metastatic disease have poor prognoses. There is no universal consensus on the most appropriate treatment regimen for this particular patient group. We reviewed and analyzed published data to determine the optimal treatment regimen for patients with peritoneal cytology-positive gastric adenocarcinomas. Six electronic databases were explored [PubMed, Cochrane (Systematic Reviews and Controlled Trials), PROSPERO, DARE, and EMBASE]. The primary outcome was overall survival with secondary outcomes including patterns of recurrence and treatment-related morbidity. Six studies were included for data extraction. There was no significant heterogeneity between studies. The use of S1 monotherapy was associated with a significant survival benefit (HR 0.48; 95% CI 0.32-0.70; p = 0.0002). Intraoperative intraperitoneal chemotherapy (IIPC) with adjuvant chemotherapy showed a trend toward improvement in overall survival (HR 0.70; 9 % CI 0.47-1.04; p = 0.08). A recent randomized controlled trial examining extensive intraperitoneal lavage (EIPL) with IIPC showed a significant improvement in overall survival (5-year overall survival, 43.8% for EIPL-IPC group compared with 4.6% for IPC group). However, these promising results need to be validated in larger prospective randomized trials.

Differential impact of the neutrophil-lymphocyte ratio on the survival of patients with stage IV gastric cancer

BACKGROUND AND AIM

The neutrophil to lymphocyte ratio (NLR) may be related to progression in several cancers. The aim of this study was to investigate the impact of pretreatment NLR in advanced gastric cancer on the prognosis of the patients stratified by metastatic pattern.

METHODS

We retrospectively investigated clinical data from 191 patients with stage IV gastric cancer who had undergone surgery for primary gastric cancer between 1997 and 2010 at the Department of Surgical Oncology of Osaka City University.

RESULTS

All patients had unresectable metastatic factors including peritoneal metastasis (P) and liver metastasis (H). Sixty-one (32%) patients had more than two unresectable factors. We determined a cutoff value of 2.5 for the NLR to be optimal to discriminate the patient's characteristics and divided patients into low (<2.5) and high (>2.5) NLR group for subsequent analysis. In the low NLR group, long survival was found in patients with H, P, or multiple site metastases.

CONCLUSION

Our results suggest that NLR well reflects the progression of critical metastasis and surgical resection might improve prognosis for patients with low NLR. In conclusion, NLR might be used as a predictive marker to decide on surgical therapy for patients with Stage IV gastric cancer.

Flow Cytometric Quantification of Intraperitoneal Free Tumor Cells is a Useful Biomarker in Gastric Cancer Patients with Peritoneal Metastasis

BACKGROUND

The frequency of intraperitoneal free tumor cells (IPTC) is considered to reflect the severity of peritoneal metastasis (PM). We quantified the relative number of IPTC against leukocytes in peritoneal fluid and evaluated its clinical relevance in gastric cancer (GC) patients, particularly those with PM.

METHODS

Cells recovered from ascites or peritoneal lavage fluid were immunostained with monoclonal antibodies (mAb) to CD45 and CD326 (EpCAM). Using flow cytometry (FACS), CD326(+) and CD45(+) cells were classified as either tumor cells (T) or leukocytes (L) and the T/L ratio (TLR) was calculated in a total of 506 samples obtained from 300 patients with GC and 33 patients with liver cirrhosis (LC).

RESULTS

Median (M) of the TLR of the initial samples obtained from 199 patients with PM(+) GC was 1.32 % (0-1,868.44 %), which was significantly higher than that in patients with PM(-) GC (M = 0 %, 0-0.35 %; n = 101) or LC (M = 0 %, 0-0.031 %; n = 33). In 104 PM(+) patients who received combination chemotherapy including intraperitoneal paclitaxel, the TLR was repeatedly measured in peritoneal fluid obtained from the port. In these patients, the TLR showed a strong correlation with clinical features as well as cytological findings and carcinoembryonic antigen messenger RNA status. Finally, the median survival time of the 11 patients with initial TLR > 10 % was significantly shorter than that of the 52 patients with TLR < 10 % (271 vs. 627 days; p = 0.0002).

CONCLUSION

The TLR excellently reflected tumor burden in the peritoneal cavity, and could be a reliable biomarker to determine the outcome, as well as the effectiveness, of chemotherapy in patients with PM(+) GC.

Clinical significance of cytological status of peritoneal lavage fluid during intraperitoneal chemotherapy for gastric cancer with overt peritoneal dissemination

BACKGROUND

A positive cytology of peritoneal lavage fluid (CY1) is a poor prognostic factor in patients with gastric cancer (GC). We have recently reported that CY1 often changes to negative (CY0) following combination chemotherapy including intraperitoneal (IP) paclitaxel (PTX), which results in marked prolongation of survival in GC patients with peritoneal dissemination (P1).

METHODS

A total of 95 P1 GC patients who received combination chemotherapy with S-1 and intravenous and IP PTX were enrolled. Peritoneal lavage fluid was periodically examined cytologically at the start of every cycle of chemotherapy, and the impact of CY status on patient outcome was retrospectively evaluated.

RESULTS

Seventy-three (76.8%) of 95 patients were diagnosed as CY1 before initial treatment. Median survival time (MST) of the CY1 group was significantly shorter than that of the CY0 group (19.1 vs. 32.5 months, P = 0.033). Cytological status changed from CY1 to CY0 in 68 (93.2%) of 73 CY1 patients during the whole treatment period and MST of patients who showed a negative change was significantly longer than that of the unchanged group (20.0 vs. 13.0 months, P = 0.0017). In 64 patients who achieved CY0 by IP PTX regimen, the median time to achieve CY0 was 1.4 months, and patients who achieved a negative change within 1 month showed a particularly good outcome (MST = 26.1 months).

CONCLUSIONS

Periodic cytological examination of peritoneal lavage fluid is clinically useful to evaluate the efficacy of treatment as well as to predict the outcome of patients with P1 GC.

The clinical significance of potentially curative resection for gastric cancer following the clearance of free cancer cells in the peritoneal cavity by induction chemotherapy

PURPOSE

The aim of this study was to evaluate the significance of the conversion of the peritoneal cytology from positive to negative following induction chemotherapy in relation to the prognosis after subsequent resection for gastric cancer.

METHODS

This retrospective study was conducted using a prospectively maintained database. A total of 47 patients with free cancer cells in the peritoneal cavity, as evaluated by staging laparoscopy, but no other evidence of distant metastasis, who underwent induction chemotherapy followed by surgery were enrolled in the study. Then, the clinicopathological factors and survival in the study subjects were assessed.

RESULTS

The median survival time and 5-year overall survival rate of the 47 study participants were 20.4 months and 25.0 %, respectively. In 23 of the patients, the peritoneal cytology converted from positive to negative after the induction chemotherapy, and a microscopically margin-negative gastrectomy was performed. The median survival time of 30.4 months and the 5-year survival rate of 34.6 % of these patients was significantly more favorable than the corresponding values of 15.0 months and 17.6 % in the patients who had persistently positive cytology (P = 0.03).

CONCLUSION

Based on our findings, the clearance of free cancer cells in the peritoneal cavity by induction chemotherapy improves the prognosis of patients following subsequent gastrectomy.

The critical role of peritoneal cytology in the staging of gastric cancer: an evidence-based review

Positive peritoneal cytology (Cyt+) is an important staging tool for patients with locally advanced gastric cancer. The objective of this review is to evaluate the current literature regarding cytology evaluation in patients with gastric cancer and to provide recommendations on the inclusion of this powerful prognosticator in patients with this disease. A literature search was performed for recent and pertinent studies evaluating peritoneal cytology in patients with gastric adenocarcinoma. Peritoneal cytology as the only evidence for M1 disease is present in up to 10% of patients with locally advanced gastric cancer; survival in the setting of Cyt+ is dismal when gastrectomy is the first line of therapy. Improved survival is associated with response to chemotherapy indicated by conversion to negative cytology, good performance status, and antral tumors. Highly select patients with Cyt+ treated with gastrectomy show improved survival in only some of the available studies. There are high quality studies that support the routine practice of peritoneal cytology evaluation in patients with locally advanced gastric cancer. The role of gastrectomy remains unclear in patients with Cyt+ and clinical trials are needed to define the best treatment option for this select group of patients.