[briggsbio]

That depends on the cancer and depends on the approach (structural, genetic, or immunological).

The difficulty in cancer treatment is that you're dealing with a natural biological process gone awry. It's not like viral or bacterial infections, where you're fighting something off. You're dealing with aggregations of unwanted mutations and cellular proliferation (over simplification warning).

Chemotherapy is less trying to alter a process than it is dropping a bomb in the body and hoping that you kill the cancer before killing the patient. There are some incredibly effective chemotherapy agents that will never make it to market because they are just too toxic.

Gene therapy approaches are making promising moves, but it is very early.

There are some pretty cool structural approaches, such as protein conjugated nanotubes that lyse cancer cells under infrared light (Stanford and Oklahoma researchers), but these too are early, and for only specific tumor types.

Cancer is a huge problem that takes a multifaceted, case-by-case approach. Lots of tools in the tool shed, and it's growing every year. I feel in my heart that one day in the future, cancer will be called "the biggest problem of the last generation." But there is much work to be done.