Resumo:
Background: The BRAFV600E mutation is the most prevalent mutation in
patients diagnosed with papillary thyroid cancer (PTC). The clinical meaning of
Hashimoto's thyroiditis (HT) associated with PTC has been studied, and so its
association with BRAFV600E mutation. Objective: Evaluate the prevalence of
BRAFV600E mutation in PTC associated with HT and its association with clinical and
pathological features. Methods: Retrospective study of unicentric transversal section
with consecutive PTC on patients treated at Hospital São Rafael - Monte Tabor,
Salvador, Bahia. Clinical and pathological data were gathered through analysis of
electronic and physical records. Polymerase chain reaction was done in order to
amplify the exon 15 of BRAF gene through DNA extracted from paraffin-embedded
tumor tissue post thyroidectomy. PCR readings were done and the presence of
BRAFV600E mutation was confirmed through direct sequencing. Results: 43 patients
diagnosed with PTC were studied. Among those, 17 (39,4%), were simultaneously
diagnosed with HT. within the latter, 7 were confirmed carriers of the BRAFV600E
mutation through genetic study, and 10 (66,7%) were BRAFV600E negative. The
presence of these two conditions and the BRAFV600E mutation were confronted. Chi square test provided a significant negative association (p:0,008). In a multivariate
logistic regression analysis, this relation was independent (p:0,024). Conclusions: The
coexisting presence of HT and PTC may be an independent protective factor to the
BRAFV600E mutation.
