Hi Jojoh,
Unfortunately side effects are common consequences of chemotherapy that affect individuals in different ways. The answer is yes that highly elevated levels of potassium can be detremental to your health butyour medical team is looking out for your welfare just by monitoring your blood levels. If these levels become significantly high then additional medication may be provided to you to decrease them.
Talk to your oncologist about your concerns and make them aware that you expect to be informed of any health issues and respective consequences. Also, do some research, be informed yourself so that you're able to ask all the right questions and get the responses that will help you.
Chemotherapy does tend to knock you around as it specifically acts on destroying dividing cells and as a result, will also act on those which are 'normal' and not tumour cells. Lysis of cells can increase potassium levels and these elevated levels happen to all of us. It's just that everyone's kidneys function differently to excrete potassium when it becomes too high.
I believe it's a tough time for you. I've just now got to some semblance of normality where I can return to work after being home for just on two years. And yes, recurrence is something we all think about. When it happens then you'll cross that bridge but for now, just stay focussed on getting through your therapy. You can make yourself loopy just be worrying about so many things which haven't even affected you yet.
You've mentioned your chemotherapy as consisting of four sessions. Is this to shrink the tumour prior to surgery (as the standard is 6)? Is a double mastectomy your choice or the expected surgical route that your doctor(s) have suggested?
Take one step at a time. We're all here to support you so you can vent as much as you want.
Kind regards,
Lilliana