Can Vegan and HIIT workouts move the needle? Not sure. I have been physically fit practically my entire adult life, don't smoke, drink, never been a big meat eater and have been an avid runner up to the point my lower back can't take it anymore so now its brisk walking. Still very active, etc, etc and yet, still recently diagnosed with 3+3 Gleason, GG1. I think overall things like this will certainly help your overall health and you will feel better, but honestly, just not sure at this point. Sleep quality, amount of stress, diet and exercise and general frame of mind and environmental conditions all go into it.....and if vegan and HIIT make you feel better about yourself whos to say it will not help keep it at bay. That said, I think most of what is attributed to keeping things in check is annecdotal