Rare cancers: Common approaches to improve the management of different entities [Cancers rares: Des entités différentes, des problématiques communes]

摘要

Rare cancers are better defined by their incidence (< 3/100 000 per year) than by their prevalence. Rare cancers include various types of cancer: intrinsically rare cancers (sarcomas, primary CNS tumours, cancers of the endocrine system, and cancers of the biliary tract); sub-entities of frequent cancers (male breast cancer, non epithelial ovarian cancers, apocrine carcinomas, MALT lymphomas); genetically determined cancers; and cancers occurring during pregnancy or in organ transplant recipients. Although widely different, these cancers raise common questions and problems: 1) the limitation of preclinical studies in relation with insufficient preserved tumour samples, the rarity of preclinical models, and the poor interest for preclinical pharmacology; 2) the limited number of comprehensive "expert" centres (less than 10-15 in Europe), emphasizing the role of networks; 3) the difficulties in conducting clinical and therapeutic studies due to the small number of concerned patients and methods available to run studies in rare populations. Effective support appears necessary to improve both research on these rare cancers and their management (constitution and maintenance of databases on this topic, constitution of virtual tumour banks, harmonization of the diagnostic procedures, especially regarding pathology and imaging, and "academic" support for clinical studies. Paris University Hospitals include more than 20 comprehensive centres dedicated to almost all rare cancers; these centres are useful for the implementation and evaluation of such methodological and logistic support.