[Standards, options and recommendations for blood tumor markers in thyroid cancers].

Context: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centers (FNCLCC), the 20 French Cancer Centers and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery.

Objectives: To define, according to the definitions of the Standards, Options and Recommendations project, the characteristics of the main tumor markers in thyroid cancer and the potential role of these markers in the management of patients with this malignancy.

Methods: Data were identified by searching Medline and the personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to 55 independent reviewers, and to the medical committees of the 20 French Cancer Centers.

Results: The main recommendations are: 1) Thyroglobulin is a serum tumor marker for the monitoring of operated thyroid differentiated neoplasms (standard). 2) It is essential to know if the patient is under TSH stimulation or under thyroid suppression therapy to interpret thyroglobulin results (standard). 3) Thyroglobulin assay must be performed regularly during the monitoring of differentiated thyroid neoplasms (standard, level of evidence B2), should be coupled with the measurement of anti-thyroglobulin antibodies concentration using a sensitive method (standard, level of evidence B2). 4) Thyroglobulin assay should not be performed to detect or diagnose differentiated thyroid neoplasms (standard, level of evidence B2). 5) The methods used to assay thyroglobulin must have a limit of detection lower than 3 mug.l- 1 (standard, expert agreement). 6) Calcitonin is a marker for medullary thyroid cancer (standard). 7) Its assay, associated with RET gene study if indicated, enables medullary thyroid cancer to be diagnosed. 8) The pentagastrin test is essential to diagnose familial forms of medullary thyroid cancer. 9) All analyses for each patient must be performed in the same laboratory, using the same technique (standard, expert agreement). 10) Calcitonin and carcinoembryonic-antigen are serum markers for the monitoring of medullary thyroid cancer and allow the detection of recurrent disease (standard).