P53 tumor suppressor gene mutations in laryngeal cancer and in recurrent disease following radiation therapy

• Published in: Oral oncology 2002-04, Vol.38 (3), p.296-300
• Main Authors: Tjebbes, G.W.A, Kreijveld, P.A, Tilanus, M.G.J, Hordijk, G.J, Slootweg, P.J
• Format: Article
• Language: English
• Subjects: Aged; Biological and medical sciences; Diseases of the upper aerodigestive tract; DNA Mutational Analysis; DNA, Neoplasm - genetics; Ent and stomatology; Female; Gene Deletion; Genes, p53 - radiation effects; Head and neck squamous cell carcinoma; Humans; Laryngeal Neoplasms - genetics; Laryngeal Neoplasms - radiotherapy; Male; Medical sciences; Middle Aged; Neoplasm Recurrence, Local - genetics; Neoplasm Recurrence, Local - radiotherapy; Otorhinolaryngology. Stomatology; p53; Point Mutation; Radiation therapy; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Retrospective Studies; Sequencing based mutation analysis; Tumors; Upper respiratory tract, upper alimentary tract, paranasal sinuses, salivary glands: diseases, semeiology
• ISSN: 1368-8375; 1879-0593
• DOI: 10.1016/S1368-8375(01)00059-8

In this study we performed p53 sequencing based mutation analysis in laryngeal cancers and matched recurrent disease following irradiation. The question is if irradiation affects the DNA and introduces or deletes mutations so that p53 cannot be used as a clonal marker anymore. P53 mutations were identified in fresh-frozen laryngectomy specimens with either primary laryngeal cancers, treated by surgery and irradiation post-operative with local failure during follow-up, or with recurrent laryngeal cancers following primary irradiation. In 21 tumors the p53 status was analyzed by direct sequencing full-length mRNA through RT-PCR. DNA sequencing analysis of exons 2 through 11 was performed when RNA isolation could not be performed. The marker mutation identified in this way was detected by DNA sequencing of the corresponding exon in formalin-fixed deparaffinized tumor biopsy samples in respectively matched recurrent disease following surgery and irradiation or primary tumor before irradiation. DNA sequencing analysis of the corresponding exon of peripheral blood leukocytes excluded the presence of germline mutations or polymorphisms. In 16 out of 21 tumors (71%), a mutation was identified. Fifteen of these marker mutations were detected in the matched tumor biopsy sample (94%). The only case lacking the marker mutation probably was a second primary tumor. We conclude that we find no direct evidence for induction or loss of p53 mutations following irradiation. Consequently, p53 may be used as a diagnostic tool when histological examination fails, for example in discriminating between the presence of a second primary tumor in the same area versus recurrent disease.