A phase II trial of modified FOLFOX6 as first-line therapy for adenocarcinoma of an unknown primary site

Purpose The aim of the study was to assess the clinical activity and toxicity of oxaliplatin and leucovorin in combination with bolus and continuous infusional 5-fluorouracil administered every 2 weeks (modified FOLFOX-6 regimen) to patients with adenocarcinoma of an unknown primary site (ACUP). Methods Previously untreated ACUP patients were treated with oxaliplatin (100 mg/m 2 ) and leucovorin (200 mg/m 2 ) as a 2-h infusion followed by bolus administration of 5-fluorouracil (400 mg/m 2 ) and continuous infusion of 5-fluorouracil (2400 mg/m 2 ) every 2 weeks. Results A total of 23 patients were enrolled and treated with a modified FOLFOX-6 regimen between May 2009 and November 2014. This trial was terminated before the scheduled enrollment due to poor accrual. A total of 134 cycles of mFOLFOX-6 were administered to 23 patients. The median number of cycles of mFOLFOX-6 was 5 (range 1–12). Among 20 patients whose tumor responses were evaluable, seven patients showed a partial response (no complete response), with an objective response rate of 35.0 %. The median duration of response was 3.9 months (range 3.0–19.8). The median progression-free survival and overall survival were 3.0 and 9.5 months, respectively (95 % confidence interval 1.4–6.7 months and 4.8–26.4 months, respectively). Treatment-related toxicity was manageable. Conclusions mFOLFOX-6 showed modest activity in treatment-naïve patients with ACUP. A future, prospective large-scale study incorporating a parallel molecular prediction marker study is warranted.