Cancer will directly affect about one in three of us at some time in our lives. Many more will be touched indirectly as friends and relatives are lost to this devastating collection of often lethal diseases. For years, the only serious treatments for cancer have been surgery, radiotherapy and chemotherapy – slicing, burning and poisoning as some doctors put it. The side effects of such treatments are often worse than the disease itself because of the collateral damage inflicted on the healthy cells of the body.
The prospect of a “paradigm shift” in cancer treatment could hardly be more welcome, then. The hope comes from “immunotherapy”, where the immune system that normally protects us against invading viruses and microbes is stimulated to attack a spreading tumour.
Cancer specialists are cautiously optimistic that immunotherapy could open a new front in the now infamous “war on cancer” declared as long ago as 1971, when President Nixon signed the National Cancer Act, and revitalised in 2009 with President Obama urging scientists to find a “cure for cancer in our time”.
In making cancer immunotherapy its breakthrough of the year, the journal Science emphasises that it does not want to give patients false hope – given the field’s long history of expectations raised and then dashed. But at the same time, the journal makes it clear that a corner has been turned.
As with many medical breakthroughs, however, it may be years yet before patients see real benefits from immunotherapy. And some types of cancer may not respond at all to the treatments we can expect in the coming decade.
Early results from the first clinical trials involving artificial antibodies are promising, but hardly a cause for jubilation. The lives of most patients in the trials seem to have been extended by just a few months – a significant, but still only incremental improvement.
There is also always the risk of drug resistance. Tumours are complex communities of genetically diverse cells that can rapidly evolve to form breakaway rebels resistant to any new drug or treatment.
Even so, there is an inescapable logic to an attempt to use the body’s own defence system to attack tumour cells. Cancer immunotherapy is a technique which holds out much promise. We can only hope that it is fulfilled.