Optimal perioperative therapy for incidental gallbladder cancer (OPT-IN): A randomized phase II/III trial-ECOG-ACRIN EA2197.

TPS620 Background: Gallbladder carcinoma (GBC) is a rare disease with a poor prognosis, with an overall estimated 5-year survival rate of 5-13%. Approximately 70% of gallbladder cancers in the US are found incidentally on pathologic analysis after elective cholecystectomy for presumed benign disease. Current management guidelines for incidental gallbladder cancer (IGBC) recommend re-resection for T1b, T2, and T3 lesions, which entails a partial hepatectomy and lymph node dissection. Up to 75% of patients have residual locoregional disease and 20% have disseminated disease at the time of re-resection, both factors strongly associated with poor prognosis and inoperability, respectively. For those who undergo re-resection, the recurrence rate at one year can be as high as 40%. Therefore we designed a Phase II/III trial to assess the benefit of a perioperative chemotherapy approach around the re-resection procedure compared to standard of care adjuvant therapy alone. Methods: We have enrolled 18 of 186 planned patients (Phase III design) on study NCT 04559139/EA2197. Current eligibility criteria include: Incidentally diagnosed T2 / T3 gallbladder cancer with no evidence of metastatic disease or inoperable locoregional disease. At randomization, patients must be within 12 weeks of their index cholecystectomy. Patients are randomized 2:1 to receive perioperative chemotherapy with gemcitabine and cisplatin vs adjuvant therapy alone. The primary endpoint is overall survival. Secondary endpoints include resectability, presence of residual disease, and progression-free survival. Clinical trial information: 04559139 .