Temporal trends in referrals of RET gene carriers for neck surgery to a tertiary surgical center in the era of international management guidelines.

PURPOSE

Thirty years into the genomic era, this study sought to explore events that helped transform the clinical landscape of hereditary medullary thyroid cancer (MTC).

METHOD

This retrospective analysis of prospectively collected data included all RET carriers referred to a tertiary center for neck surgery that was performed between 1986 and 2021, using descriptive statistics and Poisson regression analysis.

RESULTS

Altogether, 496 RET carriers were referred for thyroidectomy (388 carriers) or neck reoperation (108 carriers). Of these, 44 carriers had highest risk mutations (p.Met918Thr), 164 carriers high risk mutations (p.Cys634Arg/Gly/Phe/Ser/Trp/Tyr/insHisGluLeuCys), 116 carriers moderate-high risk mutations (p.Cys609/611/618/620/630Arg/Gly/Phe/Ser/Tyr) and 172 carriers low-moderate risk mutations (p.Glu768Asp, p.Leu790Phe, p.Val804Leu/Met, or p.Ser891Ala). Three event clusters drove referral numbers upward: a string of first reports of causative RET mutations between 1993 and 1998; the international consensus guidelines for diagnosis and therapy of MEN type 1 and type 2 in 2001; and the revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma in 2015. Referrals for neck reoperation declined sluggishly over 30 years, ending in 2018. Index patients continued to be referred into 2021. Referrals for thyroidectomy, grouped in 5-year increments, peaked in 1996-2000 for carriers of highest and high risk mutations, and in 2006-2010 for carriers of moderate-high and low-moderate risk mutations, some 10 years later.

CONCLUSION

International management guidelines are critical in building and increasing the pressure towards screening of sporadic-appearing disease and offspring of known gene families by encompassing the complete disease spectrum early on.