Back in 2014, I posted on sleep apnea's correlation with Apoe4 (viewtopic.php?f=4&t=366&p=2999#p2999
). They discovered that those with Apoe4 were thinner, not the typical body type associated with sleep apnea. Dr. Bredesen mentions on his cognoscopy list to rule out sleep apnea. For me, treatment has eliminated late afternoon tiredness and sleeping wake-ups. Treatment per the NYU study seem to forestall AD 5 years, but it wasn't clear to me that the white matter deficits were reversed.
Sleep apnea elevates cancer risks, but this might be easily skewed as both are associated with obesity. I haven't seen Apoe4 separately linked to breast cancer.