The Multidisciplinary Team Conference's Decision on M-Staging in Patients with Gastric- and Gastroesophageal Cancer is not Accurate without Staging Laparoscopy

Risk factors associated with peritoneal carcinomatosis of gastric cancer in staging laparoscopy: A systematic review and meta-analysis

Background

The optimal indications of staging laparoscopy in gastric cancer to detect peritoneal carcinomatosis are still controversial. We performed this systematic review and meta-analysis to quantify the relevance of the preoperative factors with peritoneal carcinomatosis to explore the indications of staging laparoscopy.

Materials and methods

Systematic searches were conducted using Medline, Embase, and the Cochrane Library in December 2021. On the basis of calculating the odds ratio (OR) of each factor, we quantified the association between the risk factors and peritoneal carcinomatosis such as clinical T/N stage, Borrmann type, and tumor markers, using meta-analysis with a random-effects model.

Results

A total of 21 case-control studies and one cohort study were obtained. T stage, N stage, and differentiation degree were most widely studied, with OR values of 2.96 (95% CI: 1.87–4.69), 1.22 (95% CI: 0.86–1.73), and 1.91 (95% CI: 1.42–2.56), respectively. Among all the factors, elevated CA125 (OR = 19.45, 95% CI: 4.71–80.30), Borrmann type IV (OR = 7.68, 95% CI: 3.62–16.27), and large tumor diameter (OR = 5.12, 95% CI: 2.55–10.31) had the highest OR. In particular, CA125 had the best predictability for peritoneal carcinomatosis but was only mentioned by three articles.

Conclusions

There was a cognitive gap between the awareness and importance of risk factors for peritoneal carcinomatosis. In addition to T4 stage, patients with factors with high OR, such as Borrmann type IV, large tumor diameter, and elevated CA125, should undergo staging laparoscopy.

Predicting peritoneal carcinomatosis of gastric cancer: A simple model to exempt low-risk patients from unnecessary staging laparoscopy

Background

Peritoneal carcinomatosis (PC) of gastric cancer indicates a poor outcome and is mainly diagnosed by staging laparoscopy (SL). This study was designed to develop a risk stratification model based on the number of risk factors to exempt low-risk patients from unnecessary SL.

Methods

This was a retrospective cohort study based on a single institution between January 2015 and December 2019. SL is indicated for patients of advanced locoregional stage, and clinicopathologic characteristics of 535 consecutive patients were included. PC-associated variables were identified by logistic regression analysis. A risk stratification model based on the number of risk factors was constructed, and we defined its predictive value with a receiver operating characteristic (ROC) curve and negative predictive value.

Results

In total, 15.9% of included patients were found to have PC during SL. Borrmann type IV, elevated CA125, and tumour diameter ≥5 cm were independent risk factors of PC. These three factors combined with cT4 were selected as predictive factors, and the number of predictive variables was significantly related to the possibility of PC (2.0%, 12.8%, 20.0%, 54.2%, and 100%, respectively). When the cutoff value is more than one predictive factor, the negative predictive value is 98.0%, with an area under the curve of 0.780. This model could exempt 29.8% of unnecessary SL compared to the indication of the current NCCN guideline.

Conclusions

We constructed a simple model to predict the probability of PC using the number of predictive factors. It is recommended that patients without any of these factors should be exempt from SL.

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.

Role of staging laparoscopy for gastric cancer patients

Staging laparoscopy (SL) is frequently carried out in patients with advanced gastric cancer. However, some clinical questions are being debated and consensus must be obtained. With this aim, a literature search of PubMed/MEDLINE was carried out using the keywords "gastric cancer," "SL," and "diagnostic laparoscopy". Articles published online up to February 2019 were analyzed, focusing on the following questions. (i) What is an adequate indication for SL? (ii) How do you carry out SL? (iii) Does SL provide accurate information about peritoneal dissemination? (iv) Is the yield of SL different by tumor location? (v) Is SL a safe procedure? (vi) Is "repeat SL" needed? (vii) Does SL provide oncological benefit? Results provided the following responses: (i) In Western countries, clinically resectable advanced tumor is an indication for SL. Terms to be introduced for adequate indication include "location," "type 4 (linitis feature)," "large tumor," "equivocal computed tomography (CT] findings," and "lymph node swelling". (ii) Exploration of the entire peritoneal cavity is preferable. (iii) Detection rate of peritoneal disease is 43%-52% in Japanese institutions and 7.8%-40% in other countries. False-negative findings during SL were 0%-17%, and 10%-13% when limited to cytology. (iv) Yield of SL was higher in gastric cancer compared with esophagogastric junctional tumor. (v) SL-related complications were estimated to occur in 0.4%. (vi) Repeat SL is important after treatment. (vii) If the efficacy of neoadjuvant chemotherapy for patients with P0CY1 is established, SL can provide oncological benefit. SL can be carried out safely and effectively. Considering the prevalence of neoadjuvant treatment, the role of SL will become more important.