Nearly 50 years since war on cancer was declared, declarations of victory remain a distant prospect. Here, six cancer researchers assess the lie of the land.
By Helen Coleman  Twitter: @HelenColemanQUB
By David A. Sanders  Twitter: @DavidSandersRep
By William G. Kaelin
Jr  By Jalees Rehman  Twitter: @jalees_rehman
By Ian Olver  Twitter: @iolver
By Bissan Al-Lazikani  Twitter: @bissanao