Many publications on breast implants are heavily sponsored by the industry.
I must confess that I, myself, was also offered a grant from the industry, but I would have had to sign an agreement that I could never publish anything without their consent. I refused that. That's not ethical. It's not done by the industry for medicine, but for medical devices it seems to be more harsh in these kinds of subjects than others.
There are very few well-granted studies performed because it's difficult to get a grant for such studies. You have to go to CIHR, which is difficult for such a not well-developed field.