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Previous issue date: 2017-11-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Oral cytopathology may be used to monitor individuals exposed to risk factor for
oral cancer. In this context, the study of field cancerization, a phenomenon
involved in the initial stages of oral carcinogenesis, has gained relevance for the
establishment of biomarkers that may identify individuals exposed to carcinogens
with the greatest risk for developing oral cancer. The first article of this study
aimed to compare cytopathological and histopathological characteristics of the
clinically normal mucosa adjacent to oral squamous cell carcinoma. The nuclear
area of cells obtained by cytological smear of this region was also analyzed and
compared to that of individuals without lesions but exposed to smoking and/or
alcohol and of patients not exposed to these risk factors. Ninety patients of both
sexes over 40 years old were included. In patients with carcinoma, in addition to
exfoliative cytology, tissue was obtained from the area adjacent to the tumor for
histopathological examination. In smears stained with Papanicolaou, the nuclei of
50 intermediate cells were measured. Both histological sections and cytological
smears were classified as low or high-risk. The sensitivity, specificity and
accuracy of the cytopathological diagnosis in relation to the histopathological
diagnosis, considered the gold standard, were 100, 75 and 75.86%, respectively.
The mean nuclear area was significantly lower (p<0.05) in the patients not
exposed to the risk factors in relation to the others. The cyto-histopathological
comparison of the area adjacent to oral cancer showed good sensitivity,
specificity and accuracy. In conclusion, this article demonstrated that nuclear
area can be used to detect early cellular changes in the oral mucosa exposed to
carcinogens and that mean percentage of nuclei larger than 100 ?m2 is the most indicated method for the assessment of these changes. The second article aimed
to assess genetic damage and cell proliferation rate in the field of cancerization,
i.e., the clinically normal mucosa adjacent to oral carcinoma. Cytologic smears
from the same scrapes used in the first article were stained with silver and with
the Feulgen reaction. The mean number of AgNORs/nucleus and micronuclei
(MN) was significantly higher (p<0.05) in the Tobacco/Alcohol and Oral Cancer
Groups than in the Control Group. Conversely, the mean number of NBUDs was
higher in the Control Group compared with the other groups. The number of
AgNORs/nucleus and MN/1,000 cells provide evidence of initial oral
carcinogenesis at field cancerization areas. Cutoff values for inclusion of
individuals exposed to carcinogens in longitudinal monitoring were ? 3.38
AgNORs/nucleus and/or ? 3 MN/1,000 cells. A prospective model including the
biomarkers assessed in this study was proposed. / A citopatologia bucal pode ser aplicada como m?todo de monitoramento em
indiv?duos expostos a fatores de risco ao c?ncer de boca. O campo de
canceriza??o, representando as etapas iniciais da carcinog?nese bucal, torna-se
uma ?rea atrativa ao estudo de biomarcadores que poder?o ser utilizados para
identificar indiv?duos expostos a carcin?genos com maior risco ao
desenvolvimento do c?ncer bucal. O primeiro artigo deste estudo visou comparar
as caracter?sticas citopatol?gicas e histopatol?gicas da mucosa clinicamente
normal adjacente ao carcinoma espinocelular bucal. Al?m disso, a ?rea nuclear
das c?lulas obtidas desta regi?o, por meio de esfrega?o citol?gico, foi
mensurada e comparada ? das c?lulas de indiv?duos sem les?o expostos ao
fumo e/ou ?lcool e a de pacientes n?o expostos a estes fatores de risco. Foram
inclu?dos 90 pacientes de ambos os sexos com idade superior a 40 anos. Nos
pacientes com carcinoma, al?m da citologia esfoliativa, foi obtido material para
exame histopatol?gico da ?rea adjacente ao tumor. Nos esfrega?os, corados
com Papanicolaou, foram mensurados os n?cleos de 50 c?lulas intermedi?rias.
Tanto os cortes histol?gicos, quanto os esfrega?os citol?gicos foram
classificados em baixo ou alto risco. Ao associar as caracter?sticas
citopatol?gicas e histopatol?gicas, verificou-se sensibilidade, especificidade e
acur?cia de 100%, 75% e 75,86%, respectivamente. A m?dia da ?rea nuclear foi
menor no grupo n?o exposto ao fumo e ao ?lcool, com diferen?a significativa
(p<0,05) em rela??o aos demais. A associa??o cito-histopatol?gica da ?rea
adjacente ao c?ncer bucal apresentou boa sensibilidade, especificidade e
acur?cia. Al?m disso, constatou-se que a ?rea nuclear ? pass?vel de ser utilizada para detectar altera??es celulares precoces na mucosa bucal exposta a
carcin?genos, sendo a m?dia percentual de n?cleos com mais de 100 ?m2 o
m?todo de avalia??o mais indicado. O segundo artigo objetivou avaliar o dano
gen?tico e a velocidade de prolifera??o celular no campo de canceriza??o, ou
seja, na mucosa clinicamente normal adjacente ao c?ncer bucal. Os esfrega?os
citol?gicos foram corados com a t?cnica das AgNORs e rea??o de Feulgen,
utilizando o mesmo raspado citol?gico obtido no primeiro artigo. A m?dia das
AgNORs/n?cleo e do micron?cleo (MN) dos grupos fumo/?lcool e carcinoma
bucal foi superior, com diferen?a estatisticamente significativa (p<0,05) em
rela??o ao grupo controle. Este, por sua vez, obteve m?dia superior de bot?es
nucleares (NBUDs) em rela??o aos grupos fumo/?lcool e carcinoma bucal.
Ambos os marcadores, n?mero das AgNORs/n?cleo e MN, evidenciaram a fase
inicial da carcinog?nese bucal, representada no campo de canceriza??o. Valores
iguais ou superiores a 3.38 AgNORs/n?cleo e/ou 3 MN/1000 c?lulas foram
identificados como ponto de corte ideal para incluir um indiv?duo exposto a
carcin?genos no monitoramento longitudinal. Um modelo prospectivo dos
marcadores foi sugerido.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/7884 |
| Date | 29 November 2017 |
| Creators | Paiva, Ricardo Losekann |
| Contributors | Salum, Fernanda Gon?alves, Silva, Vin?cius Duval da |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Odontologia, PUCRS, Brasil, Escola de Ci?ncias da Sa?de |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | -8096554818733665164, 500, 500, 600, -2070498469879244349, 2075167498588264571 |
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