[Conditionally replicative adenoviruses: a second wind for cancer gene therapy].

Cancer gene therapy has offered many hopes but its first use in humans revealed some pitfalls and at least three main problems: lack of efficacy and specificity of current vectors to deliver therapeutic genes, poor diffusion of the therapeutic effects inside the tumor (absence of bystander effect), poor distribution of the vectors injected inside the tissue. To address some of these issues, several teams have developed tumor selective replicating adenoviruses, some of them being already in the clinic. First results are promising but complementary studies are needed to define if these agents will take place in the therapeutic armentorium against cancer.