Our best weapons against cancer are not magic bullets

Vinay Prasad in Nature:

Earlier this month, the American Cancer Society announced its latest figures on cancer incidence and mortality1. These included the largest drop ever observed in national cancer statistics, which several media outlets seized on. Cancer death rates in the United States peaked in 1990, and in 2008–17 fell by about 1.5% per year. Between 2016 and 2017, the drop was slightly larger: 2.2%. This is undeniably good news.

But our optimism must be tempered by other measures of population health — particularly declining life expectancy.

The reason behind the large drop is a decrease in mortality for lung cancer — without lung cancer, the rate is still about 1.5%. Several reactions to the Cancer Society’s news heralded advances in precision treatments. Yet much of the continued reduction in mortality is due to the lower incidence of lung cancer, or a reduction in new cases per year. And new drugs cannot cause that. The two major therapeutic advances for treating this cancer — genome-targeted therapies and immunotherapy — are currently approved for the worst-off individuals: those with advanced or metastatic disease. Exciting technologies that uncover genetic drivers of cancer and unleash the immune system against it make headlines, but I think we must be careful not to give customized treatments too much credit, and I have been outspoken about my work to pin down the impact of these therapies. We would do better to focus on public-health strategies that are less glamorous.

More here.