Treatment Outcome of Cetuximab Compared with Cisplatin during Radical Radiotherapy for Locally Advanced Head and Neck Cancer

Objectives: To assess whether cetuximab (C225) is equivalent to cisplatin (CDDP) with concurrent radical radiotherapy (RT) for locally advanced head and neck squamous cell carcinoma (LAHNSCC) by comparing the treatment outcome of two patient cohorts treated in our institute. Methods: Patients with LAHNSCC treated with weekly C225 and intensity-modulated radiotherapy (IMRT) with radical dose 70 Gy between March 2008 and June 2014 were retrospectively reviewed. Another cohort of patients with LAHNSCC treated with weekly CDDP and IMRT was selected for comparison, with matched age, sex, and primary tumour site. Treatment outcomes including crude local control rate, median duration of locoregional control, median overall survival, and toxicities were compared. Results: The study cohort comprised 20 (95.2%) males and 1 (4.8%) female in each treatment arm. Their median age was similar in each cohort with 67 years in C225 group and 65 years in CDDP group. The median number of cycles received was 6 in C225 group versus 5 in CDDP group. Crude local control rate was 52.3% (11/21) in C225 group versus 61.9% (13/21) in CDDP group. The median duration of locoregional control was 15 months in C225 group and 48 months in CDDP group (hazard ratio [HR] = 1.19; 95% confidence interval [CI], 0.71-3.39; p = 0.747). The median overall survival was 27 months in C225 group versus 49 months in CDDP group (HR = 1.21; 95% CI, 0.48-3.07; p = 0.678). Acute severe skin toxicity (>= grade 3) was observed in 19% (n = 4) of the C225 group and 0% (n = 0) of the CDDP group, while 38.1% (n = 8) of the CDDP group had grade 2 radiation dermatitis versus 14.3% (n = 3) of the C225 group. Two patients in the C225 group developed a grade 4 acute skin reaction with full-thickness dermis ulceration and bleeding. No grade 4 skin toxicity was observed in the CDDP group. Severe bone marrow toxicity (>= grade 3) occurred in 4.8% (n = 1) of the CDDP group, and CDDP-induced vomiting (grade 1-2) developed in 14.3% (n = 3) of patients and none had grade 3 or above toxicity. No bone marrow toxicity or vomiting occurred with C225 treatment. More treatment-induced renal toxicity was observed in the CDDP cohort (42.9%) compared with the C225 cohort (9.5%). Conclusion: The results showed a trend of superior treatment outcomes for CDDP than C225 when combined with radical IMRT. If patients had good tolerance, CDDP concurrent with IMRT remains the standard of care for the treatment of LAHNSCC. C225 should be reserved for patients with poor functional status who cannot tolerate CDDP or where there are contraindications. In general, C225 concurrent with RT is well-tolerated, but there is a chance of grade 4 skin reactions. Prevention, early detection, and management of skin reaction to C225 are therefore vital. Whenever possible, C225 or CDDP should be added to radical RT for LAHNSCC for a gain in clinical outcome since evidence has shown poorer treatment results with RT alone.