Complete response of recurrent oral squamous cell carcinoma treated with cetuximab in combination with radiotherapy: A case series.

Salvage surgery for recurrent oral squamous cell carcinoma (OSCC) often leads to a poor quality of life (QOL). The present study described three cases that resulted in favorable locoregional control with cetuximab in combination with radiotherapy (Cmab + RT). Case 1 had regional recurrence of OSCC at the lower right mastoid area 4 months after primary surgery. Case 2 had regional recurrence of OSCC at the parotid area 7 months after primary surgery. Case 3 had local recurrence of OSCC at the masticatory muscle and Rouviere's lymph nodes 1 year and 3 months after primary surgery. In all cases, Cmab + RT was performed, and disease-free survival was confirmed 4 months, 2 years and 6 months, and 10 months after Cmab + RT, respectively. Immunohistochemically, all resected tumors had no expression of 110-kDa catalytic subunit of class IA phosphatidylinositol 3-kinase (PI3Kp110α). In conclusion, if salvage surgery for recurrent OSCC results in a significantly low QOL, then shifting to chemoradiotherapy may be appropriate as a treatment strategy. In addition, strong evidence indicated that PI3Kp110α expression is associated with Cmab therapy efficacy.