Adenocarcinoma of unknown primary site

To Treat or Not to Treat Poorly Differentiated Adenocarcinoma of Unknown Origin

This case illustrates that although advances have been made with diagnosis and treatment of adenocarcinoma of unknown origin with targeted therapy, more research needs to be done on poorly differentiated adenocarcinoma that initially presents with extensive metastases. In this patient’s case, it was beneficial and ethical to reduce the toxicity and emotional burden and thus limit further investigation into her adenocarcinoma. However, it is imperative to recognize that only a small subset of adenocarcinoma of unknown origin are responsive to current therapies and more research is required for the many cases that present with poorly differentiated adenocarcinoma and widespread metastasis.

Les carcinomes de primitif inconnu

PURPOSE

Carcinoma of unknown primary site is a common clinical syndrome, accounting for 2% of cancer patients. Diagnosis is a recurrent challenge for internists. Treatment is difficult and prognosis is still poor. This review presents one synthesis of diagnosis strategies and therapeutic trials. It envisages the interest of new molecular biology methods as well as therapeutic perspectives.

CURRENT KNOWLEDGE AND KEY POINTS

Pathologic examination completed with immunohistochemical tests, and, depending on cases, with electron microscopy, cytogenetics, and molecular biology is a key-point for diagnosis. Diagnosis work-up, based on histological type and on individualization of some clinical presentation, proceeds in three steps. Positron emission tomography is recommended when a curative treatment is planed, particularly in cases of isolated metastasis. Functional status analysed using the performance status and simple biologic parameters (serum lactate dehydrogenase, serum alkaline phosphatase) permit us to assess prognosis. Chemotherapy is offered for patients with a good general health status.

FUTURE PROSPECTS AND PROJECTS

Further evaluation of positron emission tomography, as well as cost-benefit analyses, is warranted. Further randomised trials are necessary to determine the optimal chemotherapy regimen in good-risk patients and the interest of chemotherapy in patients with poor-risk disease. Gene expression profiling and proteomic evaluation, as well as pharmacogenomic offer new investigation fields.