Patterns of EGFR, HER2, TP53, and KRAS mutations of p14arf expression in non-small cell lung cancers in relation to smoking history.

Mutations in the tyrosine kinase domain of the epidermal growth factor receptor EGFR are common in non-small cell lung cancer (NSCLC) of never smokers, whereas HER2 mutations are rare. We have analyzed EGFR and HER2 mutations and the expression of the two products of the CDKN2A gene (p14(arf) and p16(INK4a)) in 116 NSCLC that have been previously analyzed for TP53 and KRAS mutations in relation to smoking history of patients. EGFR mutations were detected in 20 of 116 (17%) tumors, whereas five (4.

The TP53 mutation, R337H, is associated with Li-Fraumeni and Li-Fraumeni-like syndromes in Brazilian families.

A TP53 germline mutation, R337H, has been previously described in children from southern Brazil with adrenocortical tumours but no documented familial history of other cancers. Here, we have screened for TP53 mutation 45 Brazilian unrelated individuals with family histories fulfilling the clinical definitions of Li-Fraumeni (LFS) or Li-Fraumeni-like (LFL) syndromes. Mutations were found in 13 patients (28.

TP53 and KRAS mutation load and types in lung cancers in relation to tobacco smoke: distinct patterns in never, former, and current smokers.

TP53 mutations are common in lung cancers of smokers, with high prevalence of G:C-to-T:A transversions generally interpreted as mutagen fingerprints of tobacco smoke. In this study, TP53 (exons 5-9) and KRAS (codon 12) were analyzed in primary lung tumors of never (n = 40), former (n = 27), and current smokers (n = 64; mainly heavy smokers). Expression of p53, cyclooxygenase-2 (Cox-2), and nitrotyrosine (N-Tyr), a marker of protein damage by nitric oxide, were analyzed by immunohistochemistry.

TP53 mutations in squamous-cell carcinomas of the conjunctiva: evidence for UV-induced mutagenesis.

Squamous cell carcinoma of the conjunctiva is associated with sun exposure and often occurs in HIV-positive individuals. We have analysed TP53 mutations in 21 cases of squamous cell carcinoma and 22 controls with benign conjunctival lesions from a region (Uganda, Africa) with a high prevalence of heavy sun exposure and HIV infection. TP53 mutations were detected in 11 cases (52%) and 3 controls (14%).

Human papillomavirus type 16 and TP53 mutation in oral cancer: matched analysis of the IARC multicenter study.

TP53 mutations were analyzed in 35 human papillomavirus (HPV) type 16 DNA-positive cancers of the oral cavity and oropharynx and in 35 HPV DNA-negative cancers matched by subsite, country, sex, age, and tobacco and alcohol consumption. Wild-type TP53 was found more frequently in cancer specimens that contained HPV16 DNA than in those that did not. All 14 HPV16 DNA-positive cancers in HPV16 E6 antibody-positive patients contained wild-type TP53, compared with 50% of corresponding HPV DNA-negative cancers (matched odds ratio, infinity; 95% confidence interval, 1.