Very interesting. Another result showing how increased NAD+ levels 'benefit' cancer cells casting a shadow on the idea of NAD+ boosting supplementation to increase healthspan and lifespan. But then, it's not like this means that heightened NAD+ levels cause cancer. Just that it is plausible that it makes it more aggressive, once you have it.
Why doubt? It only proves that supplements work as indented in prolonging eycariotic cell life. Its just that you don't want everything in your body to be boosted, just some - cancer is just one of those, you don't want various constituents of your body flora influenced as well, like parasites, harmful microbiota etc.
In either way, I'm pretty excited by all the recent findings and breakthroughs in both fields - longevity and figuring out cancer.