Cisplatin Every 3 Weeks Versus Weekly With Definitive Concurrent Radiotherapy for Squamous Cell Carcinoma of the Head and Neck.

<bold>Background: </bold>Concurrent chemoradiotherapy is an established component of the nonoperative management of locally advanced head and neck squamous cell carcinoma (HNSCC), but the standard dose of 100 mg/m2 cisplatin every 3 weeks is associated with clinically significant toxicity. Interest in a more tolerable regimen has led to the widespread use of weekly lower dose cisplatin, but few randomized trials have compared these approaches.<bold>Methods: </bold>We examined outcomes of patients with stage III-IVb HNSCC treated with definitive intent chemoradiotherapy using either high-dose cisplatin (HDC) or low-dose cisplatin (LDC), using population-based Veterans Affairs data. In an intent-to-treat analysis, patients were assigned to the HDC vs LDC group according to the dose of their first cycle. Variables potentially influencing treatment decisions including cancer site, stage, smoking/alcohol use, and comorbidities were used to generate propensity scores (PS) for the use of HDC. We compared overall survival (OS) by treatment group using Cox regression, adjusting for PS. We then determined the risk of toxicities using PS-adjusted logistic regression.<bold>Results: </bold>A total of 2901 patients were included in the analysis; 2200 received HDC (mean initial dose 100 mg/m2). The mean initial dose of LDC was 40 mg/m2. After PS adjustment, HDC was not associated with improved OS over LDC (hazard ratio = 0.94, 95% confidence interval = 0.80 to 1.04). Adjusting for PS, HDC was associated with an increased risk of acute kidney injury, neutropenia, dehydration/electrolyte disturbance, and hearing loss.<bold>Conclusion: </bold>In this large, population-based study of US military veterans, LDC was associated with similar survival to HDC in the nonoperative definitive management of locally advanced HNSCC of the oral cavity, oropharynx, and hypopharynx/larynx. HDC was associated with statistically significantly more toxicity than LDC. Adoption of LDC may reduce toxicity burden while maintaining OS. [ABSTRACT FROM AUTHOR]