Is Familial Nonmedullary Thyroid Cancer A More Aggressive Type of Thyroid Cancer?

Objectives: Familial non-medullary thyroid cancer (FNMTC) is a distinct entity, increasingly diagnosed. By lacking an accurate genetic diagnostic test, its diagnosis is currently clinically based, with an ongoing debate over whether it has a more aggressive clinical behavior than sporadic non-medullary thyroid cancer (SNMTC). We seek to compare in this study, the clinicopathological variables, and the outcome of FNMTC versus SNMTC patients. Methods: We retrospectively searched a database of 465 patients that underwent thyroidectomy at Assaf Harofeh Medical Center (91.4% between 1990 and 2019) for demographics, risk factors, medical history, diagnostic workup, primary treatment, follow-up, and disease outcome data. We compared 47 FNMTC versus 321 SNMTC patients, and FNMTC patients with ≥2 (n = 34) versus ≥3 (n = 13) first-relative affected members. Results: There were no significant differences in demographics, histopathology, TNM stage, treatment, and disease outcome between the FNMTC and SNMTC groups. The T2 and T4 tumor stage in the ≥3-member group were 25% and 8.3% compared to 0% and 0% in the two-member group (P =.02 and P = ns, respectively). Also, LN involvement was significantly higher in the ≥3-member group (61.6% vs. 24.2%, respectively; P =.036). Conclusion: FNMTC is not a more aggressive disease than SNMTC, but this may not apply for the ≥3-affected-relatives group. A large multicenter study including only families with three or more affected relatives is needed. Until then, a family history of NMTC should not be overlooked. Level of Evidence: 3/5 Laryngoscope, 131:E677–E681, 2021.