Does treatment ever speed up death? Given that chemo is super hard on the body I imagine it could? That might just account for your use of “mostly”, though.
It would depend on the treatment. In my case I had neoadjuvant radiation followed by chemo, then surgery, capped off with more chemo to kill any cancer cells that might have tried to make a dash for it. I would assume that while the radiation treatment elevated my risk for future cancers, the greater risk was my 10 hour surgical procedure.
No, it can't explain that; but the rise is very small. On the per 100,000 mortality graphs divided into the age cohorts, the under fifty mortality is almost a flat line. There is something there, but it doesn't seem like a huge alarm.