Serum thyroglobulin is a poor diagnostic biomarker of malignancy in follicular and Ḧurthle-cell neoplasms of the thyroid

Suh, Insoo; Vriens, Menno R.; Guerrero, Marlon A.; Griffin, Ann; Shen, Wen T.; Duh, Quan-Yang; Clark, Orlo H.; Kebebew, Electron

doi:10.1016/j.amjsurg.2009.08.030

« Previous Next »The American Journal of Surgery
Volume 200, Issue 1 , Pages 41-46, July 2010

Serum thyroglobulin is a poor diagnostic biomarker of malignancy in follicular and Ḧurthle-cell neoplasms of the thyroid

Insoo Suh, M.D.
- Department of Surgery, University of California, San Francisco, 513 Parnassus Ave., Box 0470, San Francisco, CA 94143-0470, USA
- Corresponding author. Tel.: +1-415-476-1239; fax: +1-415-502-1259
Menno R. Vriens, M.D., Ph.D.
- Department of Surgery, University of California, San Francisco, 513 Parnassus Ave., Box 0470, San Francisco, CA 94143-0470, USA
Marlon A. Guerrero, M.D.
- Department of Surgery, University of California, San Francisco, 513 Parnassus Ave., Box 0470, San Francisco, CA 94143-0470, USA
Ann Griffin, Ph.D.
- Cancer Center Registry, University of California, San Francisco, CA, USA
Wen T. Shen, M.D.
- Department of Surgery, University of California, San Francisco, 513 Parnassus Ave., Box 0470, San Francisco, CA 94143-0470, USA
Quan-Yang Duh, M.D.
- Department of Surgery, University of California, San Francisco, 513 Parnassus Ave., Box 0470, San Francisco, CA 94143-0470, USA
Orlo H. Clark, M.D.
- Department of Surgery, University of California, San Francisco, 513 Parnassus Ave., Box 0470, San Francisco, CA 94143-0470, USA
Electron Kebebew, M.D.
- Department of Surgery, University of California, San Francisco, 513 Parnassus Ave., Box 0470, San Francisco, CA 94143-0470, USA

Received 15 June 2009; received in revised form 17 August 2009

Abstract

Background

Serum thyroglobulin (Tg) is the most accurate biomarker for thyroid cancer recurrence. However, some clinicians measure preoperative Tg as a diagnostic cancer marker despite lack of supporting evidence. We examined whether Tg accurately predicts malignancy in follicular or Hürthle-cell neoplasms.

Methods

We reviewed 366 patients who underwent thyroidectomies for follicular/Hürthle-cell neoplasms. We compared Tg in malignant versus benign tumors by univariate and receiver-operator characteristic analyses. We also examined several Tg-derived indices that normalized Tg to known confounding factors including nodule size, thyroid function, and type of Tg assay.

Results

Thirty-nine patients met inclusion criteria for analysis. There were no differences between malignant (n = 16) and benign (n = 23) lesions in Tg or any of the normalized indexes. Receiver-operator characteristic analysis revealed an area under the curve of .59. Lesions with Tg levels greater than 500 μg/L had a positive predictive value of .75.