Addition of nuclear DNA content to the AMES risk-group classification for papillary thyroid cancer

The purpose of this study was to prospectively assess whether nuclear DNA content added prognostic value to existing risk factors in patients with papillary thyroid cancer.

Nuclear DNA content was measured both on the fine needle aspiration material and the surgical specimen in 73 patients with primary or recurrent papillary thyroid cancer. We modified the existing age of patient, presence of distant metastases, extent and size of the tumor (AMES) risk-group classification to include DNA ploidy with AMES (DAMES). Patients with euploid tumors that were AMES low risk were considered to be DAMES low risk; patients with euploid tumors that were AMES high risk became intermediate risk, and patients with aneuploid tumors that were AMES high risk became DAMES high risk.

Forty-eight patients were in the DAMES low-risk group. Recurrences and/or distant metastases developed in only four (8%) of these patients. Twenty-two patients were in the DAMES intermediate-risk group. Twelve (55%) of the intermediate-risk group had residual, recurrent, or distant metastatic disease, with one death from cancer at 120 months. Three patients were in the DAMES high-risk group. Distant metastases developed in all three patients, who died within 24 months from thyroid cancer. A statistically significant difference existed in the development of recurrence/metastases or death from cancer in the DAMES high-risk group compared with the other risk groups combined.

Nuclear DNA content adds prognostic value to the existing AMES risk-group classification. Because DNA analysis on fine needle aspiration correlated well with the surgical specimen DNA analysis, this modified classification can be used perioperatively to further individualize the treatment of patients with papillary thyroid cancer.