New Long-Term Follow-Up Study Demonstrates that Afirma GEC Benign Nodules Behave Similarly to Nodules with Benign Cytology


Brigham and Women’s Hospital compared long-term follow-up results of greater than 1-year for thyroid nodules with indeterminate cytology and a benign GEC result to nodules with a benign cytology diagnosis. The data demonstrate that GEC Benign nodules may be safely followed similarly to nodules with benign cytology.


Methodology: Retrospective study with a median follow-up of 13 months and up to 40 months of a consecutive series of 95 nodules with indeterminate cytology and benign GEC results compared to an independent prospective series of 1,224 consecutive nodules with benign cytology. The following variables were compared between the benign GEC and cytology groups:

  • Nodule growth (defined as ≥ 20% increase in 2 dimensions, or ≥ 50% increase in volume)
  • Frequency of repeat FNA
  • Frequency of surgical resection



Nodule growth: The rate of nodule growth was similar in both groups. Even after adjusting for co-variates such as multinodularity, cystic content, and duration of follow-up no statistically significant differences were found.

Frequency of repeat FNA’s: Repeat FNAs were less common in benign GEC patients (6.9%) than in benign cytology patients (16.8%) (P < 0.05).

Frequency of surgical resection: Surgical resection was more common in patients with a benign GEC result (14.3%) than in benign cytology patients (1.4%) (P < 0.01).

Author’s Conclusions:

“Benign GEC nodules and benign cytology nodules show similar growth during follow up, suggesting comparable clinical behavior.”

“These data provide a strong indication that treating benign GEC nodules similarly to those with benign cytology is appropriate.”