Association of BRAF V600E Mutation with Tumor Recurrence in a Small Sample of Filipino Patients with Papillary Thyroid Cancer in a Single Center

Abstract

Background and Objective. Epidemiological studies have shown that Filipinos have a higher prevalence of welldifferentiated thyroid cancer and a higher rate of recurrence. The BRAF V600E mutation has been proposed as a potential prognostic marker in aggressive papillary thyroid cancers. In this study, we determined whether this mutation is a risk factor for tumor recurrence in papillary thyroid cancer among Filipinos.

Methods. We conducted an age and sex-matched case-control study of patients with papillary thyroid cancer; we had two groups – with and without tumor recurrence – of 14 patients each, with at least a 5-year follow-up. We extracted the DNA samples from the patients’ (paraffin-embedded) tumor biopsy tissue blocks from thyroidectomy specimens, then detected the BRAF V600E mutation using polymerase chain reaction. The McNemar’s test for difference of proportions in paired data was used to determine the association of BRAF V600E mutation with recurrence.

Results. The BRAF V600E mutation was found in 57.14% of all cases. We found a prevalence of 64.29% among those with recurrence and 50.00% among those without recurrence, with no significant difference between the two groups (p = 0.688).

Conclusion. Our study showed the BRAF V600E mutation was not associated with recurrence. We encountered
several limitations: we had limited data regarding molecular methodologies in the Philippine setting, we had a small sample size, and therefore we could not study other parameters (e.g., tumor characteristics, lymph node metastasis, stage of disease). We hope that this paves the way for future studies and collaborations to establish the role of BRAF V600E in Filipinos with papillary thyroid tumor recurrence.