Underutilization of Staging Laparoscopy Prior to Neoadjuvant Systemic Therapy in Gastric Cancer.

[BACKGROUND] Radiographically occult peritoneal carcinomatosis (PC) is a major concern in gastric cancer; hence staging laparoscopy (SL) is recommended prior to initiating treatment, particularly neoadjuvant systemic therapy (NST). However, compliance may vary and could result in understaging. We sought to evaluate the utilization of SL in patients with gastric cancer referred to academic institutions.

[PATIENTS AND METHODS] This is a multi-institution retrospective study of patients with a diagnosis of gastric/gastroesophageal junction (GEJ) Siewert 3 adenocarcinoma who received treatment between 2010 and 2022. Demographics, tumor characteristics, treatment, and recurrence data were collected. Descriptive statistics and multivariate analysis were performed.

[RESULTS] A total of 280 patients with gastric/GEJ cancer were identified, of which 75 (26.8%) had clinical stage IV disease and were excluded. Of the remaining 205 patients, 74 (36.1%) underwent upfront surgery and 131 (63.1%) underwent NST. Only 39 (29.8%) patients in the NST group underwent SL, of whom 15(38.4%) were found to have peritoneal metastases; 12 (80%) had gross PC and 3 (20%) had positive cytology. Among patients who underwent surgical resection after NST (n = 77), 26 (33.7%) experienced disease recurrence with a median time to recurrence of 11.6 months. The peritoneum (n = 10/26, 38.5%) was the most common site of recurrence.

[CONCLUSIONS] Compliance with SL prior to NST is poor (29.8%), and in the group that underwent SL, 38% of patients were upstaged due to presence of peritoneal metastases. These findings are significant, as the management and prognosis of peritoneal metastases are drastically different. Various factors could lead to poor compliance with SL, hence better compliance and alternate approaches to reliably detect PC are needed.