Intravenous chemotherapy with cisplatin for regional lymph node metastases of auricular VX2 carcinoma.

Introduction: The VX2 carcinoma is well established as a useful model for studies on treatment of primary tumors of various locations including the rabbit's auricle; however, limited experience exists on the treatment modalities of lymph node (LN) metastases. In this investigation we studied the frequency and extent of lymphogenic metastatic spread of auricular VX2- carcinomas and their response to systemic chemotherapy. Materials and Methods: Induction of a right-sided auricular VX2-carcinoma in 17 healthy New Zealand white rabbits was followed by ablation of the right auricle and intravenous application of 1mg/kg KG CDDP (cisdiamminedichloroplatinum (II) ) dissolved in 2ml NaCl via the left-sided auricular vein in 10 rabbits (group 1), while 7 rabbits (group 2) remained untreated. After a 24-day follow-up period, animals of both groups were sacrificed and the regional draining LN as well as the lungs were isolated and examined histopathologically. Results: Group 1. Following intravenous cisplatin therapy (ICT), 6/10 animals showed no vital tumor cells within LN metastases of the first draining LN station, while 4/10 animals had necrotic LN metastases limited to the parotideal LN. Group 2. All 7 animals showed necrotic LN metastases of the first and second draining LN station as well as pulmonary metastases. Conclusion: The auricular VX2-carcinoma, characterized by frequent lymphogenic metastatic spread and response of LN metastases to ICT, offers an excellent animal model for further studies on the optimised treatment of lymphogenic metastatic spread in HNSCC. The VX2-carcinoma of the New Zealand white rabbit resembles the human head and neck squamous cell carcinoma (HNSCC) in its growth behavior since it tends to metastasize lymphatically (1). The auricular VX2- carcinoma is characterized by its easy accessibility and observation. This location has been successfully used for intra-arterial embolization (2,3) and the VX2-carcinoma is well established as a model for transcatheter arterial embolization for gynecological tumors (4). Moreover isolated perfusion of tumors transplanted into the hindlimb (5), transcatheter arterial chemoembolization with