@carlynic FYI, I noted with interest that an AK (actinic keratosis, common precancer from chronic sun exposure) developed on my chest, about 7-8 weeks into Brinsupri treatment. Years ago my dermatologist prescribed a tube of fluorouracil topical to be used on such spots for in-between visits. In other words, AK are not new to me and sadly they are more common than I'd like to admit. I'm on every 6 month skin checks. Anyway, I applied it as directed, the spot scabbed over and fell off. I plan to have the dermatologist check it soon.

Given our increasing age, it's hard to know what caused this. Was it the Brinsupri? Years of sun on fair skin? Genetics? A mix of everything or something else? We read about so many co-morbidities here that it’s tough to sort out what causes what. So I stay alert to subtle changes and keep moving forward.