Abstract
BACKGROUND: In patients with locally advanced unresectable gastric or gastroesophageal junction adenocarcinoma, conversion therapy has shown suboptimal efficacy, typically resulting in stable disease (SD) or progressive disease (PD) leading to low surgical conversion rates and unfavorable prognosis. This study seeks to assess the efficacy and safety of superselective transarterial chemoembolization (SSTACE) in treating this specific patient cohort. METHODS: This retrospective cohort study analyzed patients diagnosed with locally advanced unresectable gastric cancer (GC) or gastroesophageal junction (GEJ) adenocarcinoma at the Affiliated Hospital of North Sichuan Medical College between January 2019 and March 2025. All of them underwent a single session of SSTACE, followed by an assessment of surgical resectability one month later. Patients considered resectable underwent gastrectomy with D2 lymphadenectomy, while those deemed unresectable continued with palliative chemotherapy regimens consistent with their pre-SSTACE systemic protocols. The primary endpoint was R0 resection rate, with secondary endpoints, including the postoperative complication rate, tumor regression rate post-chemoembolization, and pathological complete response (pCR) rate. RESULTS: This retrospective study analyzed 16 patients who underwent SSTACE. Tumor regression was observed in 12 patients, eight of whom met the criteria for partial response. In addition, 12 patients who exhibited regression subsequently achieved R0 resection. Pathological complete response (pCR) was observed in three patients. In terms of safety, all adverse events related to SSTACE in the cohort were manageable. The most common adverse events were nausea (43.8%, 7/16), vomiting (37.5%, 6/16), and abdominal pain (37.5%, 6/16). No instances of hepatic dysfunction were reported. In addition, none of the surgical patients experienced major postoperative complications. CONCLUSIONS: SSTACE could potentially offer a novel therapeutic approach for patients with locally advanced unresectable GC or GEJ cancer who have shown limited response to systemic chemotherapy/immunotherapy, characterized by SD or PD. This treatment may increase the likelihood of achieving surgical conversion and R0 resection rates while upholding a favorable safety profile.