BRAFV600E genetic testing should be recommended for Bethesda III or V thyroid nodules based on fine-needle aspiration

The preoperative diagnosis of thyroid nodules now routinely includes BRAF(V600E) genetic testing in most provincial and municipal hospitals in China. This study identified the most suitable patients of thyroid nodule for BRAFV600E genetic testing. We retrospectively collected data of patients from the Hospital Information System that had undergone fine needle aspiration biopsy (FNAB) from May 2019 to December 2021. Data of FNAB, BRAF(V600E) genetic testing, and post-surgical pathological diagnosis were collected. A total of 12,392 patients were included in this study. Among them, 7,010 patients underwent solely FNAB, while 5,382 patients had both FNAB and BRAF(V600E) genetic testing. In the FNAB group, 2,065 thyroid nodules were surgically removed, with a 93.12% malignancy rate. In the FNAB+BRAF group, 2,005 nodules were dissected, and the malignancy rate was 98.20%. However, it was evident that in the subgroups, the combination of FNAB and BRAF(V600E) genetic testing only benefited Bethesda III (p<0.001) and V (p=0.001) nodules. Overall, the combination of FNAB with BRAF(V600E) genetic testing significantly improved the malignancy rate of surgical thyroid nodes at our hospital when compared to FNAB alone. The subgroup analysis showed that BRAF(V600E) genetic testing only benefited Bethesda III and V nodules. These findings provide a clinical reference for rationally selecting the most suitable population for BRAF(V600E) genetic testing.