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Lymphogenic metastatic spread of auricular VX2 carcinoma in New Zealand white rabbits.

INTRODUCTION
The auricular VX2 carcinoma of the New Zealand white rabbit serves as an animal model for human squamous cell carcinomas of the head and neck region (HNSCC), since both tumors tend to metastasize lymphatically, leading to early lymph node and subsequent distant metastasis. The aim of this study was to examine the pattern of lymphogenic metastatic spread in untreated auricular VX2 carcinomas, since the resulting knowledge potentially could help in the development of new treatment strategies for human HNSCC.


MATERIALS AND METHODS
VX2 carcinomas were implanted into both ears of 22 New Zealand white rabbits. The animals were sacrificed at days 7, 14, 21, 28 or 32 after tumor implantation, followed by a detailed histopathological examination of their head and neck lymph nodes.


RESULTS
On day 7 after tumor implantation 25% of the animals had metastases in the parotid lymph node, which is the first draining lymph node of the tumor region. This number rose to 87.5% by day 28. At this time 12.5% of all animals also had an additional metastasis in the second echelon node.


CONCLUSION
A reproducible metastatic spread into the first draining lymph node could be demonstrated for the auricular VX2 carcinoma of the New Zealand white rabbit. The VX2 carcinoma therefore appears to be a highly suitable animal model for studying the sentinel node concept in the context of human HNSCC.