Genetic predisposition has been suggested as a cofactor for cancer aetiology and a polymorphism in TP53 codon 72 has been associated as a susceptibility factor for several cancers. Nasopharyngeal carcinoma is a rare neoplasia in western civilizations and genetic predisposition might play an important role in its development. We evaluated the linkage of the polymorphic variants (Arg/Pro) on TP53 codon 72 with nasopharyngeal cancer development in a case-control study with 392 individuals from a northern Portuguese population, including 107 patients with nasopharyngeal carcinoma and 285 healthy controls. This study revealed a three-fold risk for carriers of Pro/Pro genotype either against carriers of Arg/Arg (OR=2.62; 95% CI=1.10-6.30; P=0.016) or total Arg carriers (OR=2.67; 95% CI=1.21-5.90; P=0.012). Moreover, step-wise logistic regression analysis identified Pro/Pro genotype (OR=3.1; 95% CI=1.3-7.3; P=0.009), age >49 at diagnosis (OR=2.5; 95% CI=1.6-4.0; P<0.001) and male gender (OR=2.7; 95% CI=1.6-4.4; P<0.001) as predictive factors for the development of nasopharyngeal carcinoma. These results confirm the data from Asiatic populations suggesting that Pro/Pro genotype represents a stable risk factor for nasopharyngeal carcinoma development in Portugal and that TP53 codon 72 polymorphism can contribute as a genetic susceptibility marker, providing additional information to improve the knowledge about nasopharyngeal carcinoma aetiology.
Transoral laser microsurgery, alone or with neck dissection and adjuvant therapy, is an efficient procedure for treatment of laryngeal cancer in different stages. To the best of our knowledge, this is the first study reporting transoral laser microsurgery outcomes in the Portuguese population.
The anatomical complexity of the temporal bone and the close associations with vital structures make it difficult to perform tumor resection with margins of safety and thus, tumor relapses are almost always local. A high level of suspicion is crucial for early diagnosis, and stringent and prolonged follow-up after treatment is essential for diagnosis and timely treatment of recurrances.
Variations in the genome sequence of Epstein-Barr Virus (EBV) are thought to lead to differential interaction with host cells, immune evasion, and transformation. The discussion regarding EBV strains as having a geographic or disease-association has been increasing and the majority of studies are performed in Asiatic populations. We developed a case-control study with 139 individuals, including 96 subjects with different malignancies and 43 healthy individuals, from the North region of Portugal. We have used PCR protocols for the characterization of EBV strains (type A or B) based on EBNA3C genome variation and for the LMP1 30bp-deletion variants (wt-LMP1 or del-LMP1). Our study showed that type A is the most prevalent in our population (100% of healthy controls, 96.9% of aHSCT patients, 90.8% of HNSCC patients, and 94.9% of NPC patients) and that type B was significantly associated with NPC (P = 0.019; RR = 8.90). Regarding the LMP1 30bp-deletion, we found a similar distribution of both wt- and del-LMP1 variants in controls and dispare results in cases: del-LMP1 was more frequent in aHSCT and HNSCC patients (64.7% and 63.2%, respectively) and wt-LMP1 in NPC patients (100%). In fact, the study reveals that wt-LPM1 was significantly associated with NPC (P < 0.001; RR = 18.4). Hence, our study showed that EBV type B and wt-LMP1 variant seem to be associated with NPC in our population, with a clear disease-association for wt-LMP1. These results contribute for the knowledge of EBV genetic diversity among Caucasian populations.
The tumor necrosis factor-alpha (TNF-α) is a strong proinflammatory cytokine produced by the activated macrophages in the immune response to viral infections. A common polymorphism on the promoter region of TNFA gene (-308G >A) has been associated with different susceptibilities to the development of several diseases including viral-associated neoplasias. Data suggest that the A allele has been associated with higher levels of TNF-α and, therefore, leads to increased risk of cancer development. We have performed a case-control study considering the role of the -308G >A polymorphism in 750 individuals from the northern region of Portugal, including 123 patients with nasopharyngeal carcinoma (NPC) and 627 healthy individuals. Our study revealed an increased frequency of the -308A TNFA allele in patients with NPC. The statistical analysis for recessive model revealed that -308AA genotype is associated with increased risk for the development of NPC (odds ratio = 2.46; 95% confidence interval, 0.98-6.17; p = 0.047); moreover, this effect was stronger in undifferentiated types, which are virtually 100% caused by the Epstein-Barr virus (odds ratio = 2.75; 95% confidence interval, 1.09-6.90; p = 0.025). These results reveal that in our population -308 TNFA AA genotype can represent a risk marker for NPC development and contributes for the definition of genetic susceptibility profiles for individuals at risk of development of a viral infection and associated neoplasia.
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