His main interests are clinical management of rare cancers, especially sarcomas and cancers of unknown primary site and methodology of early phase clinical trials. He is coordinator of numerous clinical trials assessing new drugs in rare cancers and urological cancers. Prof Penel is a member of the American Society of Clinical Oncology, the European Society for Medical Oncology and the French Society of Cancer.

Prof Penel is the author or co-author of over 240 publications in medical oncology.