Weekly Versus Triweekly Cisplatin in the Treatment of Patients with Head and Neck Cancer Receiving Concurrent Radiation Therapy

Abstract

Standard of care for patients with head and neck squamous cell carcinoma (HNSCC) has historically consisted of cisplatin delivered every 3 weeks with concurrent radiotherapy. In an effort to reduce toxicity, weekly doses of cisplatin have been given to certain patients in hopes of lowering toxicity burden without compromising results. Recent randomized data from a single institution in an Asian, mostly post-operative population have suggested that weekly treatment may be inferior to triweekly. This study was performed to compare the outcomes between weekly and triweekly cisplatin dosing with concurrent radiotherapy in HNSCC patients. Between July 2011 and January 2016, 144 patients with HNSCC receiving radiotherapy with concurrent chemotherapy were retrospectively analyzed. Patients with primary cutaneous squamous cell carcinoma were excluded. All patients received intensity-modulated radiotherapy. Standard dosing was 70 Gray (Gy) in the definitive setting and 60 Gy in the post-operative setting. The study included 60 patients scheduled to receive weekly cisplatin (30 mg/m2, 40 mg/m2, or 50 mg fixed dosing) and 84 scheduled to receive triweekly cisplatin (100 mg/m2). Demographic and treatment data was collected from the electronic record. Poor oncologic outcomes were evaluated by using chi-squared tests. The Kaplan-Meier method was performed using the log-rank test to calculate two-year overall survival (OS) and two-year progression free survival (PFS) between the two groups. Median follow-up time was 31 months (range 3-73 months). Patients receiving weekly dosing were older than those receiving triweekly (63 v 56, p<.001), otherwise patients were well balanced. The patient population was 90% White. The most common primary subsites were oropharynx (65%) and larynx (24%). The most common stage was IVA (73%). Fifty-three percent of patients were positive for p16 and 24% were post-operative. The data shows a trend towards significance in the weekly cisplatin group requiring a radiation treatment break due to side effects (p= 0.055). No significance was shown for patients requiring a radiation treatment break greater than 5 days (p= 0.473), chemotherapy delay (p= 0.329), completion of planned chemotherapy cycles (p= 0.201), hospitalization (p= 0.154), or weight loss greater than 10% of pre-treatment body weight (p= 0.493). 2-year OS in the weekly and triweekly groups was 82% and 85%, respectively (p= 0.722). 2-year PFS in the weekly and triweekly groups was 77% and 81%, respectively (p= 0.480). Both weekly and triweekly cisplatin are appropriate options when combined with concurrent radiotherapy in HNSCC patients. Neither dosing schedule shows a difference in survival outcomes or treatment tolerance. Although non-randomized, our results suggest that optimal chemotherapy schedules deserve further study.