Can cancer be treated? Can we really cure cancer? Borrowing some of their strategies directly from the immune system, researchers have recently developed several experimental therapies that, used alone or in combination, promise to revolutionise cancer care in the coming years.
What’s in the pipeline of cancer treatments:
Scientists, using biotechnology, took a cue from the natural immune system to create these artificial molecules. Like antibodies that search for and destroy invading microorganisms, monoclonal antibodies seek out tumour cells and latch onto their surfaces, then shut them down. Some are armed with radioactivity or other toxins that are inserted into tumours to annihilate them.
For this approach, scientists are using viruses as their model. The theory is that, since disease-causing viruses insert their own genetic material into a cell’s DNA, why can’t harmless viruses be used to enter and repair a cell by carrying unflawed DNA into it? Mapping the human genome has advanced this technology. There have already been promising studies in cancer patients.
These preparations are used to stimulate or replenish a patient’s immune system by injecting substances known as biological response modifiers. These molecules help to fight disease by, for example, nudging certain white blood cells to go after tumour cells more aggressively. The immune system needs this extra push because it may not detect cancer cells which arise from normal body cells and therefore may not arise the alarm.
One reason a tumour can spread so wildly is that it produces protein molecules called growth factors that stimulate angiogenesis, the growth of blood vessels. The aim of this therapy, now in clinical trials, is to shrivel the blood-vessel lifelines, causing the tumour to shrink and disappear. The hope is that anti-angiogenesis drugs will have few side effects since adults don’t normally need to produce new blood vessels.