Aaron Robinson1, David Schneider1, Rebecca Sippel1, Herbert Chen2. 1. Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. 2. Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama. Electronic address: herbchen@uab.edu.
Abstract
BACKGROUND: Follicular thyroid cancer is the second most common thyroid cancer, accounting for 10%-15% of all cases. Follicular thyroid carcinomas (FTCs) can be classified into two subtypes: classic (C), which exhibit both vascular and capsular invasion and minimally invasive (MI), which only has limited capsular invasion. Both types, like most well-differentiated thyroid cancers, are traditionally treated the same: a completion thyroidectomy usually followed by radioiodine ablation. We hypothesize that MI-FTC may behave more like a benign follicular adenoma rather than C-FTC and may not require total thyroidectomy and radioiodine. METHODS: A prospective thyroid database was screened for patients with follicular cell tumors. Data on recurrence rates, disease-free survival, and requirement for follow-up surgery and/or radioiodine were compared. Disease-free survival was determined by the Kaplan-Meier method. Analysis of variance and chi-square test were used to evaluate other factors. RESULTS: In total, there were 419 benign adenomas (87%), 21 MI-FTCs (4.5%), and 41 C-FTCs (8.5%). Patients with adenomas were younger (P = 0.035) and were more likely to be female (P = 0.001). Importantly, the 16-y disease-free survival was 100% in the adenoma group, 100% in the MI-FTC group, and 36.6% in the C-FTC group (P < 0.0001). CONCLUSIONS: MI-FTCs behave similar to adenomas with 100% disease-free survival with up to 16 y of follow-up. These data suggest MI-FTCs could be potentially treated by thyroid lobectomy alone like follicular adenomas and perhaps should be classified as a distinct clinical entity.
BACKGROUND:Follicular thyroid cancer is the second most common thyroid cancer, accounting for 10%-15% of all cases. Follicular thyroid carcinomas (FTCs) can be classified into two subtypes: classic (C), which exhibit both vascular and capsular invasion and minimally invasive (MI), which only has limited capsular invasion. Both types, like most well-differentiated thyroid cancers, are traditionally treated the same: a completion thyroidectomy usually followed by radioiodine ablation. We hypothesize that MI-FTC may behave more like a benign follicular adenoma rather than C-FTC and may not require total thyroidectomy and radioiodine. METHODS: A prospective thyroid database was screened for patients with follicular cell tumors. Data on recurrence rates, disease-free survival, and requirement for follow-up surgery and/or radioiodine were compared. Disease-free survival was determined by the Kaplan-Meier method. Analysis of variance and chi-square test were used to evaluate other factors. RESULTS: In total, there were 419 benign adenomas (87%), 21 MI-FTCs (4.5%), and 41 C-FTCs (8.5%). Patients with adenomas were younger (P = 0.035) and were more likely to be female (P = 0.001). Importantly, the 16-y disease-free survival was 100% in the adenoma group, 100% in the MI-FTC group, and 36.6% in the C-FTC group (P < 0.0001). CONCLUSIONS:MI-FTCs behave similar to adenomas with 100% disease-free survival with up to 16 y of follow-up. These data suggest MI-FTCs could be potentially treated by thyroid lobectomy alone like follicular adenomas and perhaps should be classified as a distinct clinical entity.
Authors: Samuel Chan; Katarina Karamali; Anna Kolodziejczyk; Georgios Oikonomou; John Watkinson; Vinidh Paleri; Iain Nixon; Dae Kim Journal: Eur Thyroid J Date: 2020-01-28