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

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.

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.

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).

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.

3/5 Laryngoscope, 131:E677-E681, 2021.