The Prognostic Impact of Extent of Vascular Invasion in Follicular Thyroid Carcinoma

Abstract

Background Encapsulated angioinvasive follicular thyroid carcinoma (EAFTC) is associated with an increased risk of distant metastasis and reduced survival compared to minimally invasive follicular thyroid carcinoma (MIFTC). There is controversy regarding the extent of surgery and adjuvant radioactive iodine therapy for angioinvasive follicular thyroid carcinoma when stratified by number of foci of angioinvasion. Methods All follicular thyroid carcinoma cases from 1990–2018 were identified from a thyroid cancer database. Primary outcomes were distant metastasis‐free survival (DMFS) and disease‐specific survival (DSS) with factors of interest being age, gender, tumour size, treatment, foci of angioinvasion and histological subtype. Results A total of 292 cases were identified; 139 MIFTC, 141 EAFTC and 12 widely invasive follicular thyroid carcinoma (WIFTC). Over a follow‐up period of 6.25 years, DMFS was significantly reduced (p < 0.001) with 14.2% (EAFTC) and 50% of WIFTC developing metastasis. The risk of metastasis in EAFTC with ≥ 4 foci of angioinvasion was 31.7% (HR = 5.89, p = 0.004), 6.3% for EAFTC with < 4 foci of angioinvasion (HR = 1.74, p = 0.47), compared to 3.6% MIFTC. Age ≥ 50 years (HR = 4.24, p = 0.005) and tumour size (HR = 1.27, p = 0.014) were significantly associated with increased risk of distant metastasis. DSS was reduced significantly (p < 0.001), with 7.8% EAFTC patients dying of disease. For EAFTC patients, DSS was 96.8% for < 4 foci and 82.6% for ≥ 4 foci of angioinvasion (p = 0.003). Conclusion EAFTC is at increased risk of distant metastasis related to the extent of angioinvasion. Tumours with < 4 foci of angioinvasion should be considered for a total thyroidectomy, particularly in older patients.

Prognosis and influencing factors of follicular thyroid cancer

“…Due to the vascular invasiveness of FTC, it is more likely to metastasize to distant organs and not only to regional lymph nodes 25 . Some studies have indicated that WIFTC is a poorer prognosis than MIFTC, which is consistent with our study 26,27 . Other research has found no significant difference in disease‐free survival between patients with MIFTC who underwent thyroidectomy alone and those who received thyroidectomy and radioiodine therapy after thyroidectomy 28 .…”

“… 25 Some studies have indicated that WIFTC is a poorer prognosis than MIFTC, which is consistent with our study. 26 , 27 Other research has found no significant difference in disease‐free survival between patients with MIFTC who underwent thyroidectomy alone and those who received thyroidectomy and radioiodine therapy after thyroidectomy. 28 This is another evidence of the better prognosis of MIFTC.…”

The Effect of Radioiodine Therapy on the Prognosis of Differentiated Thyroid Cancer with Lung Metastases

“…Research has demonstrated that targeted therapy with TKIs can improve clinical outcomes in TCLM patients [ 34 , 35 ]. These factors are essential for assessing the risk of thyroid cancer recurrence [ 36 , 37 , 38 ].…”

High rates of aggressive features in young Vietnamese females with papillary thyroid carcinoma: Associations with preoperative risk factors

“…These findings diverge from some recent literature reporting lower rates of capsular invasion (around 30%) [6,21] and nodal metastases (15%-50%) in similar cohorts [22][23][24] . The elevated incidence of capsular breach indicates more aggressive tumor behavior, with implications for increased extrathyroidal extension and lymphatic spread [25,26] .…”