Cetuximab for the treatment of locally advanced and recurrent/metastatic oral cancer: An investigation of distant metastasis

The aim of this retrospective study was to assess the efficacy and safety of cetuximab therapy for patients with locally advanced (LA) and recurrent/metastatic (R/M) oral squamous cell carcinoma (OSCC), with a specific focus on distant metastases (DMs). Data from 21 patients with unresectable LA and R/M OSCC treated with cetuximab therapy in our department between December, 2012 and July, 2015 were reviewed. The endpoint was the time-to-progression and the assessments made were tumor response rate, progression-free survival (PFS), overall survival (OS) and safety. The overall response rate was 57.1%, with a complete response (CR) rate of 33.3%. The overall median PFS and OS were 5.5 and 8.0 months, respectively. For patients with DMs, the overall response rate was 60.0%, with a CR rate of 40.0%. The median PFS and OS were 3.8 and 5.8 months, respectively. In addition, improved 1-year OS was observed following approval of cetuximab, although the differences between the group of patients treated after that time and historical controls were not statistically significantly (P=0.246). Grade 3-4 adverse events included infusion reaction (4 cases), neutropenia, hypophosphatemia, upper gastrointestinal hemorrhage, liver toxicity and mucositis (1 case each). There was one cetuximab-related death due to interstitial pneumonia. An acne-like rash was observed in all cases, but no grade 3 or 4 rash was reported. Hypomagnesemia was observed in 10 cases. Our results suggest that cetuximab may display significant therapeutic efficacy in patients with unresectable LA and R/M OSCC, including those with DMs.