Occurrence of BRAF mutations in a Polish cohort of PTC patients - preliminary results.
BACKGROUND
Genetic alterations involving the mitogen-activated protein kinase (MAPK) pathway are frequently demonstrated in papillary thyroid cancer (PTC). BRAF(V600E), the most frequent mutation in adult patients, is present in approximately 50% of PTC. Most clinical studies have demonstrated an association of BRAF(V600E) mutation with aggressive clinicopathological characteristics and high tumour recurrence, although the results are controversial. In this study we present the preliminary results of BRAF mutation frequence in a group of 88 Polish patients with papillary thyroid cancer (PTC) and relate it to the outcome all DTC patients operated in 2004 and 2005. BRAF (V600E) mutation was diagnosed in 38 (43%) of cases.


METHODS
The presence of BRAF mutation was evaluated in 88 PTC tumours. DNA was isolated from tissue parafin blocks, and the mutation V600E was evaluated by sequence analysis with an AbiPrism 377 and 3130 xl genetic analyzer (Life Technologies). Statistical analysis was carried out with the use of SPSS 12 software. The chi² and Kaplan-Meyer survival analysis were performed.


RESULTS
From all analyzed clinico-pathological factors, only older age positively correlated with BRAF mutation frequency (p = 0.0017). Lymph node/distant metastases, multifocality, and extra-thyroid extension did not correlate with BRAF status. One cancer related death and two reccurences were observed in the BRAF+ group while one relapse was diagnosed in the BRAF- group.


CONCLUSIONS
Although many studies document BRAF mutation as a prognostic factor in PTC our results underline that it is too early to consider it as a routine clinical predictive factor.
Department of Oncological and Reconstructive Surgery, MSC Memorial Cancer Centre and Institute of Oncology, Gliwice Branch, Poland. aczarniecka@io.gliwice.pl
Agnieszka
A
Czarniecka
Dagmara
D
Rusinek
Ewa
E
Stobiecka
Jolanta
J
Krajewska
Monika
M
Kowal
Aleksandra
A
Kropińska
Jadwiga
J
Zebracka
Małgorzata
M
Kowalska
Jan
J
Włoch
Adam
A
Maciejewski
Daria
D
Handkiewicz-Junak
D000328:Adult; D000367:Age Factors; D002277:Carcinoma; D002291:Carcinoma, Papillary; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011044:Poland / Q000453:epidemiology; D011379:Prognosis; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000235:genetics / Q000556:secondary