Outcome of neoadjuvant chemotherapy (NACT) with paclitaxel plus carboplatin and oral metronomic chemotherapy (OMCT) in patients with technically unresectable oral cavity squamous cell carcinoma (SCC).

Abstract

e18034 Background: NACT is often used in technically unresectable oral cavity SCC to improve resection rate. NACT regimen based on combination of maximum tolerated doses (MTD) and metronomic chemotherapy will debulk the tumor and subsequently inhibit angiogenesis which may overcome drug resistance of MTD schedule. We assessed outcome and tolerance of this combination as NACT in patients with technically unresectable oral cavity SCC. Methods: This is retrospective analysis of prospectively maintained data. Fourteen patients having technically unresectable oral cavity SCC received NACT with paclitaxel (175mg/m2) plus carboplatin (AUC5) every 3 weekly (MTD schedule) and OMCT (methotrexate 9mg/m2 once a week, celecoxib 200mg twice daily and erlotinib 150mg once daily). Patient were assessed clinically and radiologically after minimum of two cycles for surgery. Kaplan-Meier method was used for survival analysis. We report resectability, survival and tolerance of this regimen. Results: Median age of the patients was 38 years, and twelve patients (85%) were male. Twelve (85%) and two (15%) patients had buccal mucosa and oral tongue primary, respectively. AJCC 2017 stage IVA and IVB disease was present in twelve (85%) and two (15%) patients, respectively. Reason for technical unresectabilty was skin edema above zygoma in five (36%), high infratemporal fossa involvement in five (36%), nodal encasement of major vessels in two (14%) and posterior extent of oral tongue tumor into oropharynx in two (14%) patients. Median number of NACT administered were three. Tumor of nine patients (65%; 95% CI = 39%-89%) were deemed resectable after NACT. Eight patients underwent surgery and tumor of one patient showed pathologic complete response. Median follow up was 14.6 months (95% CI = 14.1 - 15 months). Median progression free survival was 11.4 months (95% CI = 7.9 – 15 months). Median overall survival (OS) was not reached while OS at 15 months was 63.5% (95% CI = 37.8% - 89.2%). Common grade 3/4 toxicities (CTCAE 5.0) were neutropenia in eight (57%), thrombocytopenia in three (21%), febrile neutropenia, hypokalemia and diarrhoea in two patients (14%) each. Two patients required in-patient supportive care for adverse events. Conclusions: Paclitaxel and carboplatin along with OMCT is well tolerated and less resource intensive regimen which leads to favorable resection rate and survival in patients with technically unresectable oral cavity SCC.