Sugar, on its own, has downsides. As someone who has been very careful about what I eat (and failing often, admittedly because... cravings), fruit juice is pretty bad for you. Even blended fruit can be bad for you. The reason is that you can "drink" far more than you will typically eat. How many oranges does it take to make a glass of juice? Say it's 5-7 for a full glass. Now what is the chance you will eat 5-7 oranges? Yes, of course, you get the fiber if you eat them and it makes you full, but the point is that you would never naturally consume all that sugar in one sitting, nor should you consume it in pure juice form either.

That being said, most reports about sugar's impact on caner are fairly anecdotal. Consider that eggs have been good, bad, good, bad, good, bad, good bad and now they are super healthy for you for some reason. Butter was the bane of all evil, now it's considered healthy when in moderation. The old rule of thumb still applies: just about anything in moderation.

The moral of the story is eat responsibly. Maybe it's good for cancer, maybe it's bad but without you relegating yourself to drinking filtered water and eating/drinking nothing else then you can pretty much guarantee that someone, somewhere, has an opinion about how your diet is impacting your [insert malady here].