It does not surprise me that introduction of small particulates to any orifice on a daily basis would increase cancer risk. Household dust increases cancer risk.
The cover up orchestrated by Johnson&Johnson here, however, is the deplorable story.
I'm just a simple man, but I don't understand how a fine-grained powder, even entering the vagina, could cause ovarian cancer. This very long article spends only two paragraphs asking that question, with no answer.
Sounds like pesudo-statistical lawyering. This woman has cancer and she used talc every day of her life, ergo the talc is to blame.
One might ask why asbestos causes mesothelioma. Maybe the mechanisms are similar. Although talc is obviously less effective. But if there's increased risk, the lack of mechanistic understanding doesn't negate the evidence.
We already know why asbestos causes mesothelioma. Asbestos can form very small particles that go deep into the lung (there is good relationship between particle size and how deep it penetrates into the lung). Asbestos contains iron and the iron can promote free-radical formation, thus DNA damage and thus cancer. Yes, I'm simplifying it, but that's what I remember from my toxicology classes long ago.
I don't think it's odd to question the toxicity of talcum powder. Talcum powder used to contain asbestos, but doesn't any longer. We have good evidence that the newer talc doesn't cause lung cancer.
So an obvious question is, if talc doesn't cause lung cancer, why would it cause ovarian cancer? Of course, different tissue, different effect, but it raises doubt.
Maybe talc does cause ovarian cancer by some as-yet-discovered mechanism, but I wouldn't blame anyone for thinking it either coincidental (lots of people get ovarian cancer who never use talc) or due to something else.
I was under the impression that the cause was chronic inflammation resulting from recruitment and activation of macrophages and other immune cells to site of the fibres [1]. Chronic inflammation causes cancer on its own independent of external factors like free radical formation.
Well, I should have added details. You are correct that asbestos that doesn't contain iron can still cause cancer through a hypothesized inflammatory mechanism.
Honestly, I don't we know the exact mechanism, but have some theories that seem to fit.
And that, perhaps cryptically, was my point. Why should any chemically inert mineral cause cancer? But some apparently do, regardless. Inflammation seems most plausible.
That link says what I'm saying: it's not clear that this is really happening.
> Many studies in women have looked at the possible link between talcum powder and cancer of the ovary. Findings have been mixed, with some studies reporting a slightly increased risk and some reporting no increase. Many case-control studies have found a small increase in risk. But these types of studies can be biased because they often rely on a person’s memory of talc use many years earlier. Two prospective cohort studies, which would not have the same type of potential bias, have not found an increased risk.
Even if there is a correlation, there might not be a cause and effect relationship.
For example, it's known that female reproductive cancers are associated with the levels of various female sex hormones. Female sex hormones also affect the vaginal lining and external genitalia (in particular, moisture levels). It might be that women who are prone to ovarian cancer due to hormone levels also have a vaginal/labial situation that makes them more likely to apply powder to keep the area dry. If that were the case, you'd see a correlation with no cause and effect relation whatsoever.
(just an illustration... I'm not claiming this is what's going on, but I'd probably try to argue something like that if I were a lawyer for J&J).
However, if the coverup of the correlation is as described in the article, that would be a bad, bad thing.
I wonder if this is going to end up like the breast implant thing, with lawyers getting rich and companies in bankruptcy before we take a step back and realize the law is way ahead of the science.
The cover up orchestrated by Johnson&Johnson here, however, is the deplorable story.