There is an ongoing debate over what actually causes the observed cancer increase from eating (some) meats, and which meats it applies to. Some studies suggest the issue is red meat in general, not cured meats; others focus on a more vague "processed meat" category. (This is made even more confusing by the US habit of selling cured meats labelled as "uncured", which was touched on in the article.)

We do know that nitrites can turn into cancer causing chemicals, but we also know that they do so in low quantities, and that a lot of things in our diet contain nitrites. The "cured-labelled-as-uncured" American bacon gets its nitrites from celery, which contains a lot, yet celery doesn't seem to be causing a lot of cancer. There are some vague theories about how "nitrites in plants are special!", but so far, every attempt to study that has shown the reverse as far as I'm aware.

So in my view, the situation is confusing, but there is certainly evidence that bacon causes cancer. What I don't really buy is the idea that it's obviously the nitrites. It's great that parma hams are made without them, but there's no study (nor is there likely to ever be a study) that says "good news, eating parma hams has 0% impact on your risk of cancer". Especially since they probably do give you cancer, if all the studies showing links to red meat are borne out.

But eh. Maybe it does lower your risk. :) But I think if I was worried about it, I'd skip all bacon, given how nonexistent the evidence is to suggest nitrite-free bacon is actually healthy.