Cancer is one of those diseases that cause dread in its victims and their families. Though many are treatable or even curable, many others are not and there is great pressure on medics to offer any source of hope the those suffering from hard to treat varieties of the disease.
And modern cancer drugs are often very expensive:
...the average cancer drug costs in excess of $100 000 (£75 000; €85 000) per year of treatment...
This makes decisions about whether health systems can afford them very controversial.
But a recent editorial in the BMJ claims than many modern cancer drugs get approved despite the fact that the evidence that they work is very weak. The editorial argues (quoting a recent European study that extended work done on approvals by the USA's FDA and reached similar conclusions):
In their study of cancer drugs approved by the European Medicines Agency between 2009 and 2013, 57% (39/68) had no supporting evidence of better survival or quality of life when they entered the market. After a median of 5.9 years on the market, just six of these 39 (15%) agents had been shown to improve survival or quality of life.
Although we are approving cancer drugs at a rapid pace, few come to market with good evidence that they improve patient centred outcomes. If they do, they often offer marginal benefits that may be lost in the heterogeneous patients of the real world. Most approvals of cancer drugs are based on flimsy or untested surrogate endpoints, and postmarketing studies rarely validate the efficacy and safety of these drugs on patient centred endpoints.
It looks like our fear of cancer is giving drug companies an easy path to the approval of marginal or useless drugs.
Is it true that most modern cancer drugs offer minimal benefits in the real world?