Search

Background To enforce the evidence for causality between high-risk human papillomavirus (hrHPV) infections and neck squamous cell carcinoma from unknown primary (NSCCUP) and provide biological basis for treatment de-intensification, we searched for TP53 mutations in association with HPV status. Methods TP53 mutations were searched for by amplification of exons 4 to 10. Results Of the 70 NSCCUP, 27 (39%) harbored HPV infection. TP53 sequencing resulted in the identification of 19 patients harboring single mutations including 16 disruptive alterations (84%). The association of TP53 mutations and HPV could be evaluated in 48 NSCCUP including those with disruptive mutation in any exon (n = 16) and those without mutations but with complete sequence of exons 4 to 9 (n = 32): no disruptive mutations were found in the 17 HPV-driven NSCCUP but in 16 of the 31 non-HPV-driven NSCCUP (P = .0002). Conclusion In a fraction of cases, NSCCUP is an HPV-driven entity harboring wild-type TP53 gene or nondisruptive TP53 mutations. HPV-driven NSCCUP might benefit from treatment de-intensification.

Gastrointestinal stromal tumors (GISTs), tumors characterized by c-KIT mutations, are the most frequent mesenchymal tumors of the digestive tract. The stomach is the most commonly involved site. Localization, size and mitotic rate are reliable predictors of survival and the two milestones of GISTs treatment are surgery and imatinib. This article is aimed to report the data of an audit, carried out on the morphological and clinical aspects of the disease and to review the present knowledge on GISTs. A total of 172 patients with GISTs (M : F=1 : 1; mean age 65 years) were recruited. The stomach was the most frequently involved site. In 50% of the cases the tumor was smaller than 5 cm, whereas major symptoms were observed in 43% of the cases. Predictors of progressive disease were present only in a small percentage of cases but the disease was in the metastatic phase in over 25% of the cases at diagnosis. Familial aggregation was rare but a consistent share of the patients (21%) had other synchronous or metachronous cancers. The most frequent mutations were in-frame deletions and point mutations of c-KIT exon 11. This report confirms in part the available data on GIST in a consecutive series of patients recruited in Italy and shows that only large collaborative multicenter studies provide data sound enough to enable making reasonable clinical and therapeutic choices, and suggests that, as a measure of secondary prevention, a diagnostic definition should be obtained in all submucosal lesions of the GI tract and that GIST patients should be screened for second tumors.

Gefitinib and erlotinib were shown to be particularly effective in a clinically selected subpopulation of non-small cell lung cancer patients (NSCLC): adenocarcinoma histology, non-smoking status, Asian origin and female gender have been associated with improved clinical benefit compared to the unselected NSCLC population. The aim of the present study was to investigate the prognostic and predictive role of EGFR and KRAS analysis in advanced lung adenocarcinomas, selected according to clinical features associated to better response to EGFR tyrosine kinase inhibitors (TKIs), namely female gender and non-smoker or former light smoker status.EGFR and KRAS mutations and EGFR FISH status were assessed in 67 surgical samples.EGFR and KRAS mutations were found in 16 (26.7%) and 12 (17.9%) patients, respectively. FISH analysis was positive in 34 (56.7%) patients. EGFR-mutated patients showed significantly longer survival when treated with EGFR TKIs (p = 0.002, hazard ratio (HR) = 0.036, 95% confidence interval (CI): 0.004 -0.303). KRAS mutations was found to be an independent negative prognostic factor in multivariate analysis (p = 0.008, HR = 3.52, 95% CI: 1.39-8.9). The prognostic value of EGFR FISH status was not confirmed in multivariate analysis (p = 0.048, HR = 0.47, 95%CI: 0.22-0.99).In a group of clinically selected patients, EGFR and KRAS analysis was able to define distinct molecular subsets of lung adenocarcinoma.

A large body of evidence strongly suggests that the p53 tumor suppressor pathway is central in reducing cancer frequency in vertebrates. The protein product of the haploinsufficient mouse double minute 2 (MDM2) oncogene binds to and inhibits the p53 protein. Recent studies of human genetic variants in p53 and MDM2 have shown that single nucleotide polymorphisms (SNPs) can affect p53 signaling, confer cancer risk, and suggest that the pathway is under evolutionary selective pressure ( 1 – 4 ). In this report, we analyze the haplotype structure of MDM4, a structural homolog of MDM2, in several different human populations. Unusual patterns of linkage disequilibrium (LD) in the haplotype distribution of MDM4 indicate the presence of candidate SNPs that may also modify the efficacy of the p53 pathway. Association studies in 5 different patient populations reveal that these SNPs in MDM4 confer an increased risk for, or early onset of, human breast and ovarian cancers in Ashkenazi Jewish and European cohorts, respectively. This report not only implicates MDM4 as a key regulator of tumorigenesis in the human breast and ovary, but also exploits for the first time evolutionary driven linkage disequilibrium as a means to select SNPs of p53 pathway genes that might be clinically relevant.