Análise epidemiológica, molecular e citogenética do câncer de hipofaringe em Goiânia

• Autor(a) principal: Costa, Cesar Augusto Sam Tiago Vilanova
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/3572
• topic: Câncer de hipofaringe; Epidemiologia; Citogenética; HPV,; Genotipagem molecular; Hypo pharynx cancer; Epidemiology; Ccytogenetics; HPV; Molecular genotyping; MORFOLOGIA::CITOLOGIA E BIOLOGIA CELULAR

Hypo pharynx is the under region of pharynx and serves both respiratory and digestive tract, acting as a passageway to air and food. It’s composed by squamous nonkeratinized epithelial tissue. Statistical studies indicates that 85 to 90% of neoplasies rush pyriform sinus and are characterized by fast dissemination and metastization. Epidemiological trends of hypo pharynx cancer in Goiania on period 1998 to 2003 analyzing data derived from Cancer Registry of Association for Cancer Combat of Goias, shows that the relative survival rate for men diagnosed with hypo pharynx cancer was 38% past 60 months while women presented a survival rate of 100%. Surgery was the treatments that present fewer rates (34%) and chemotherapy was associated to the most survival rate (54%). Patients that use tobacco presented a survival rate of 43% while non-tabagists present a rate of 60% of surviving. Relative survival rate for patients diagnosed with hypo pharynx tumor was 38% and estimated censure for 5 years was just 5%. Survival rate was extremely decreased due to 45% of cases were diagnosed in advanced stages of disease. It is important to point out that preventive campaign is important to evade the increasing of these pathologies that are related to behavior of tabagism and etilism. Present study also evaluates cytogenetically individuals diagnosed with hypo pharynx cancer. Cytogenetic analysis of exfoliated cells is largely used to evaluate cytotoxic and genotoxic alterations on people exposed to potentially mutagens. A number of 36 individuals were analyzed, representing case group, and 36 healthy individuals composed control group. Data was collected and analysis was performed to estimate main nuclear alterations. Standard protocols were adopted to collect and counting cells. Micronuclei test was used to determinate the frequency of cytotoxic and genotoxic alterations. Besides than micronuclei others alterations like broken-eggs, binucleated cells and piknotic nuclei are good markers of cell alterations because they are resulted from cytotoxic events frequently related to occupational exposure. Behaviors like tabagism, etilism and exposition time were also investigated to correlate cells alterations. The correlation between micronuclei frequencies of case and control group test doesn’t show statistic difference. Broken egg and binucleated cells were the most observed anomalies on case group and showed up significant statistic difference (p=0.03). Results indicates a high grade of cytotoxic anomalies on individuals with hypo pharynx cancer, specially in tabagists and chronic etilists individuals, behaviors that are correlated to induct and promote tumors in susceptible people due their capabilities to affect cell cycle. Studies about relationship between Human Papillomavirus (HPV) and cancer development are performed since 80’s. Although the correlation of HPV and cervical cancer are well established, the possible role of HPV and head and neck cancer are still unclear. Among controversial factors of HPV and carcinogenesis of squamous epithelial cells, there is a viral incidence that oscillates from 0 to almost 100% on studies that includes a myriad of viral genome detect methods, such Blotting and PCR. Importance of HPV infection and epithelial carcinogenesis is related to capabilities of High risk HPV 16 and 18 to promote cell alterations, by tumor suppressor proteins inactivation, tumor suppressor genes blockage and insertions of HPV oncogenes. On present study, HPV detection and typing was performed on tumors derived from hypo pharynx of 24 patients diagnosed with cancer (CID-O: C12,0 to C13,9). All samples was submitted to PCR with generic primers MY09/11 and GP05/06, as specific primers to HPV 6, 11, 16, 18, 33, 35, 45 and 58. Results shows that on 9 of 24 samples, HPV were detected by generic primers (a rate of 37,5%) and HPV types 16, 18 and 45 were identified, with a sample presenting coinfection of HPV 16 and 18.