1040P - The Impact of Induction Chemotherapy on Cisplation Dose Intensity During Chemo-Radiotherapy (CTRT) in Oropharyngeal Squamous Cell Cancer (OPC)

Abstract

ABSTRACT Background Induction (IC) with TPF (Taxotere, Cisplatin, 5-FU) has been associated with improved outcome in advanced head and neck squamous cell cancer patients (pts). Full dose of cisplatin (300 mg/m2) during CTRT has been demonstrated to impact on patients' outcome. The aim of the current study is to investigate whether the IC could impact on cisplatin dose intensity during CTRT in a homogeneous population of OPC. Materials and methods The study population consisted of 101 pts with stage III-IV OPC treated from 07/2004 to 12/2011 with IC (n = 53) plus CTRT or CTRT alone (n= 48). IC consisted of TPF, while weekly 50 mg/m2 or 3-weekly 100 mg/m2 cisplatin was administered concurrently with RT (planned chemotherapy dose = 300 mg/m2; planned RT dose = 66-70 Gy, 3DRT or IMRT with a conventional or accelerated fractionation). Carboplatin substituted cisplatin in case of creatinine clearance less than 60 mL/min. HPV status, concurrent cisplatin dose intensity and RT overall treatment time (OTT) were analyzed. Results Stage IV pts were 100% in the IC group and 83% in CTRT, while HPV positive OPCs were detected in 58% and 63% of the cases respectively. TPF median number of cycles was 3, with induction cisplatin median dose administered of 200 mg/ m2. RT median total dose administered was 70 Gy in both group. Accelerated fractionated RT was adopted in 65% of CTRT alone group and in 21% of IC group. Two pts (1 in each group) did not complete CTRT because of cardiovascular events. Mean and median dose intensity of cisplatin concurrent to RT in the IC group was 77.7% and 75% (35%-100%) while in CTRT group was 86% and 91.7% (33%-100%), with a p value = 0.014. In 11 pts (21%) treated with IC and only in 1 pts (2%) treated with CTRT alone cisplatin was substituted with carboplatin. No different cisplatin dose intensity was identified in HPV positive versus HPV negative cases. Prolonged OTT (longer than 5 days) was observed in two patients in IC group due to sepsis and severe mucositis as well as in one patient in CTRT group due to machine failure. Conclusions Concurrent cisplatin dose intensity was significantly reduced in pts receiving IC compared to CTRT alone, irrespective of HPV status. Whether this has an impact on the results of IC followed by full dose CT/RT has to be clarified. Disclosure All authors have declared no conflicts of interest.