Aluminum in deodorant — is it giving us cancer or what? My perimenopausal self needs the antiperspirant aspect not offered in natural alternatives.—Bridget Sweaty Pits
No, or at least not based on data.
The source of this discussion is the observation that breast cancer often appears in areas of the breast close to the armpit. Aluminum is toxic in some concentrations, in some settings, so the suggestion was made (see linked paper above) that these products might be responsible.
That suggestion isn’t seen supported in the data. In a systematic review from 2016, the authors identified two small case-control studies, neither of which showed this relationship (the point estimate was actually in the other direction). Case-control studies are not the best, so this isn’t some kind of ironclad proof, but it definitely does not support this observation.
A somewhat scathing 2008 article convened a set of experts to evaluate the possibility of this claim. They titled their article “The use of deodorants/antiperspirants does not constitute a risk factor for breast cancer.” They end with “After analysis of the available literature on the subject, no scientific evidence to support the hypothesis was identified and no validated hypothesis appears likely to open the way to interesting avenues of research.”
In other words: you can stop thinking about this.