BACKGROUND: Lymph node metastasis in the head and neck region with occult primary cancer are a fairly rare tumor entity in head and neck cancer. Tumor biological parameters as well as mechanism and cause for the development of this so called "cancer of unknown primary" (CUP) are not well investigated in head and neck cancer. Mutations of the p53 tumor suppressor gene are the most prevalent genetic alteration of human malignancies and show an incidence of up to 50% in head and neck cancer. For a further tumor biological definition of CUP the p53 status was determined. METHODS: Twenty-three archival formalin fixed paraffined CUP of an occult squamous cell carcinoma of the head and neck region were examined. In all cases a primary cancer was never diagnosed. The DNA extracted from the tumor material was amplified with specific primers for exon 4-9 of the p53 gene and subsequently sequenced. RESULTS: None of the 23 CUP cases showed a mutation or polymorphism in exon 4-9 of the p53 gene. CONCLUSIONS: The total absence of p53 mutations in the so called mutational "hot spots" shows a significant difference to the frequency of primary tumors of the head and neck region. May be this tumor biological characterisation helps to further elucidate the growth behaviour of CUP in the head and neck region and the reason for their development.
BACKGROUND: Lymph node metastasis in the head and neck region with occult primary cancer are a fairly rare tumor entity in head and neck cancer. Tumor biological parameters as well as mechanism and cause for the development of this so called "cancer of unknown primary" (CUP) are not well investigated in head and neck cancer. Mutations of the p53tumor suppressor gene are the most prevalent genetic alteration of humanmalignancies and show an incidence of up to 50% in head and neck cancer. For a further tumor biological definition of CUP the p53 status was determined. METHODS: Twenty-three archival formalin fixed paraffined CUP of an occult squamous cell carcinoma of the head and neck region were examined. In all cases a primary cancer was never diagnosed. The DNA extracted from the tumor material was amplified with specific primers for exon 4-9 of the p53 gene and subsequently sequenced. RESULTS: None of the 23 CUP cases showed a mutation or polymorphism in exon 4-9 of the p53 gene. CONCLUSIONS: The total absence of p53 mutations in the so called mutational "hot spots" shows a significant difference to the frequency of primary tumors of the head and neck region. May be this tumor biological characterisation helps to further elucidate the growth behaviour of CUP in the head and neck region and the reason for their development.