Study that was just released: http://stm.sciencemag.org/content/9/394/eaah4477.full
Sulforaphane has been found to reduce and kill cancer cells. More details can be found in this video by Rhonda Patrick: https://www.youtube.com/watch?v=zz4YVJ4aRfg
Broccoli sprouts have high levels of sulforaphane. It is easy to grow them at home. There are many videos on youtube showing how to do it. I buy seeds on Amazon.