Gastric Carcinoma—a New Biomarker Peritoneal Fluid Lavage Cytology

Presence of free gastric cancer cells in the peritoneal cavity of patients who undergo surgical treatment for gastric cancer is considered as a negative prognostic factor. It manifests as peritoneal metastasis and causes rapid recurrence of diseases. The aim of this study was to analyse factors associated with positive peritoneal cytology and identify patients in whom diagnostic peritoneal lavage could affect therapeutic decisions. The study enrolled patients with gastric cancer who underwent surgical treatment at the Department of General and Minimal Invasive Surgery, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, over a period of 18 months from November of 2017 to May of 2019. During the laparotomy, 200 mL of physiological saline at 37 °C was administered in the tumour region. About 100 mL fluid was recovered from several regions of the abdominal cavity which was sent to the Department of Pathology where the samples were processed by liquid-based cytology technique. Results of peritoneal cytology were analysed jointly on the basis of clinical and pathological factors. Analysis of the peritoneal fluid for presence of free cancer cells was done in 52 patients. Positive peritoneal cytology was found in 9 (17.3%) patients. In the group of patients with positive cytology, all patients had T4 tumours and all were found to have lymph node metastases, whilst as grade 3 cancer was found in 55.5% patients. In patients with positive cytology, diffuse gastric cancer was seen in 7 out of 9 patients (77.7%), whilst in patients with negative cytology, intestinal type was seen in 41 of 43 patients (95.3%). Amongst the 9 patients with positive peritoneal cytology, 7 (77.7%) patients had tumour located in the distal part, and one (11.1%) patient had tumour located in the proximal part, whilst the lone patient with diffuse involvement of the stomach was also positive for malignant peritoneal cells. Based on this study, we can conclude that determinants of positive peritoneal cytology include tumour stage (T4), positive nodal status (N +). Knowing the peritoneal cytology status can alter the treatment strategy and can vary from curative to a palliative one and vice versa.