Good question! It is very hard to tell what percentage targeted therapy is successfull at present. Among gene net, it is possible for tumors to bypass the blocked target and continu growing, which depends on how you block the target, blocking one signal pathway to the target or changing the functional conformation of the target protein.

Incase of solid tumors the most used target is IGF and VEGF to regulate angiogenesis; there by tumor growth. if both signal molecules are blocked it is found the size of the tumor is limited to some millimeters in vivo.

What next in this therapy? After limiting the size to a particular limit how they continue the completion of therapy? That i cant find in any journals.

Can any one give an idea about the rest in this process?

I do agree and on has to be clear that cancer cell are not completely destroyed by targeting the signal pathway, the next step in this therapy is to induce apoptosis by drugs such as gemcitabine, paclitaxel etc... here comes the role for p53 alternative or complementary pathways in this process. Fas/FasL signaling system has also been presented by some literature's. and I think by this means we can prolong the patients life yet a complete cure is a matter of question ???? Can we ?

So I think the pathway-targeted drug discovery may be the powerful method.