Cisplatin superior to carboplatin in adjuvant radiochemotherapy for locally advanced cancers of the oropharynx and oral cavity.

BACKGROUND AND
PURPOSE: The optimal radiochemotherapy regimen for squamous cell carcinoma of the head and neck (SCCHN) is controversial. In most cases, platin-based chemotherapy regimens are used. However, uncertainty exists whether cisplatin or carboplatin is the better choice. This retrospective study compared radiochemotherapy with either cisplatin or carboplatin in patients with locally advanced SCC of the oropharynx and oral cavity. PATIENTS AND METHODS: Concurrent chemotherapy consisted of two courses of cisplatin (20 mg/m(2) on days 1-5 and days 29 - 33; n = 65) or two courses of carboplatin (AUC 1.5 on days 1-5 and days  29 - 33; n = 41). Both regimens were retrospectively compared for locoregional control (LRC), overall survival (OS), and toxicity. Thirteen additional potential prognostic factors were evaluated including age, gender, ECOG performance status, tumor site, histologic grade, T/N category, AJCC stage, year of treatment, extent of resection, interval between surgery and RT, completion of chemotherapy, and radiotherapy breaks.
RESULTS: The 3-year LRC rates were 85% in the cisplatin group and 62% in the carboplatin group, respectively (p = 0.004). The 3-year OS rates were 78% and 51%, respectively (p = 0.001). Acute toxicity (mucositis, skin toxicity, nausea/vomiting, renal toxicity, hematologic toxicity) and late toxicity (xerostomia, neck fibrosis, skin toxicity, lymph edema) rates were not significantly different between the two groups. On multivariate analysis, better LRC was significantly associated with cisplatin (p < 0.001), an ECOG performance status of 0-1 (p = 0.001), and an interval between surgery and RT of ≤ 6 weeks (p = 0.001). Improved OS was significantly associated with cisplatin (p < 0.001) and completion of chemotherapy (p = 0.002).
CONCLUSION: For adjuvant radiochemotherapy of patients with locally advanced cancer of the oropharynx and oral cavity, cisplatin appears preferable to carboplatin as it resulted in better outcomes without increased toxicity.