Analysis Of Risk Factors Of Positive Peritoneal Cytology In Patients Treated For Gastric Cancer – Preliminary Report*

Abstract

Presence of free gastric cancer cells in the peritoneal cavity of patients who underwent surgical treatment for gastric cancer is a negative prognostic factor and caused rapid disease recurrence, manifested as peritoneal metastases. Positive peritoneal cytology despite lack of visible peritoneal metastases was regarded as M1 class in the TNM classification (7 th edition) in 2010. the aim of the study was to analyze factors associated with positive peritoneal cytology and identify groups of patients in whom diagnostic laparoscopy plus peritoneal lavage in the diagnostic process could affect therapeutic decisions. material and methods. The study enrolled patients with gastric cancer who underwent surgical treatment at the Department of Surgery, Wielkopolskie Oncology Center in Poznań. During the laparotomy, after opening of the peritoneal cavity, 200 ml of physiological saline at 37°C was administered in the tumor region. After this fluid was mixed, 100 ml of lavage fluid was collected. This fluid was subsequently spun many times to obtain sediment for cytology and immunohistochemistry investigation using anti-BerEp-4, CK 7/20, and B72.3. Results of peritoneal cytology were analyzed jointly with clinical factors -patient's age, sex and pathology factors -tumor invasion, involvement of lymph nodes, histological grade, histological type according to Lauren and localization of the cancer in the stomach. Results. Analysis of the peritoneal fluid for presence of free cancer cells was done in 51 patients. Positive peritoneal cytology was found in 12 (23.5%) patients. In the group of patients with positive cytology, all patients had T3/T4 tumors and all were found to have lymph node metastases, while G3 cancer was found in 83.3% of patients. In patients with positive cytology, diffuse gastric cancer according to Lauren predominated (9 of 12 patients, 75%), while in patients with negative cytology -intestinal type (20 of 39 patients, 51.2%). In the group of patients with positive histology, the whole stomach was involved by the cancer process in 7 of 12 patients (58.3%), while in the group with negative histology, in 29 of 39 patients the tumor was located in the gastric body and prepyloric part (74.4%). conclusions. Based on this study we can conclude that determinants of positive peritoneal cytology include: tumor stage T3/T4, N+, G3, cancer located in the whole stomach, diffuse histological type according to Lauren.

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

“…The majority of the included studies used T4 as a criterion, and T4's relevance with PC is also consistent with the "seed and soil" hypothesis, which states that more free cancer cells exfoliated from the tumor penetrating serosa could lead to PC (34). However, if all three studies with CY1 only were included in the analysis, then OR (95% CI) was 1.65 (0.79-3.44), which means that there is no statistical difference (19,21,22). Yoshida et al found the occurrence of CY1 or P1 in five of the 1,509 patients with early gastric cancer, and pathological analysis revealed that the primary tumor invaded the submucosa and metastasized to the regional lymph nodes through the lymph vessels; they speculated that tumor cells may metastasize to the peritoneal cavity through the lymphatic system rather than by breaking through the plasma (35).…”

“…Five studies, with 1,427 patients, from 2015 to 2020 were included ( 15 , 16 , 19 , 24 , 30 ). The sample size of the studies changed from 51 to 804.…”

“…Eleven studies, with 3,877 patients, from 2008 to 2020 were included (10,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). The sample size of the studies varied from 49 to 879.…”

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

“…Comparable results were identified (risk difference: 0.32; 95% CI: 0.19–0.44; n=600 patients; I 2 =55%; p <0.00001) when analyzing studies that evaluated oncologic stages according to the UICC/AJCC system 7 th edition 26,31,38,59,97.…”

Treatment of peritoneal metastases from gastric carcinoma

“…In Poland, positive cytology is detected in 24% of all patients initially scheduled for radical surgery [40]. Factors that are predictive for positive cytology of peritoneal fluid include: stage T3/4, lymph node involvement, grade score G3, infiltration by the tumour of the entire stomach and indications of a diffuse type of GC by Laurén classification.…”