[Clinical practice guidelines: Standards, Options and Recommendations for the diagnosis of carcinomas of unknown...

The "Standards, Options and Recommendations" (SOR) project, which started in 1993, is a collaboration between the Federation of French Cancer Centers (FNCLCC), the 20 French Regional 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 the outcome of cancer patients.

To define Clinical Practice Guidelines (CPG) for the diagnosis of carcinomas of unknown primary site.

The methodology is based on a literature review and critical appraisal by a multidisciplinary group of experts who define the CPGs according to the definitions of the Standards, Options and Recommendations project. Once the guidelines has been defined, the document is submitted for review by independent reviewers.

The main recommendations for the diagnosis of carcinomas of unknown primary site are: 1) Diagnostic strategy should aim to identify anatomoclinical entities of carcinomas of unknown primary site for which there is a specific treatment. For other anatomoclinical entities, identification of the primary tumour has no impact on the prognostic or therapeutic consequences, thus a systematic complete assessment is unnecessary. 2) An immunohistochemical investigation for the diagnosis should be performed using an appropriate panel of specific antibodies. This should enable the diagnosis of lymphoma, melanoma, germ cell tumour and sarcoma to be eliminated and the diagnosis of prostate, breast, ovary, thyroid or neuroendocrine tumours to be positively identified. 3) A sample can be frozen to enable typing, cytogenetic and, particularly, molecular biological studies to be performed later. 4) The clinician and pathologist should compare their opinions before and after the pathological diagnosis.