I'm currently undergoing chemotherapy for breast cancer. One of the drugs I am taking, Carboplatin, can damage the kidneys. They check my GFR prior to each infusion to make sure the kidneys are functioning ok. They adjust the dose lower if your GFR drops (and won't do the infusion if it is less than 60, I think).
I have one treatment left. My GFR was excellent, and compared to the numbers I have seen on this board, it is still excellent. However it dropped 10 points after my 3rd treatment (was 94, dropped to 84). The nurse said that I can have it retested tomorrow, as perhaps I was dehydrated - is it true that dehydration can affect the test markedly?
Is a 10 point drop in 4 weeks significant, or nothing to worry about?
My chemotherapy is to prevent recurrence - as of now I have no evidence of disease. I am considering not doing the last treatment. At some point the risks of treatment become greater than the risks of cancer recurrence. Of course I will discuss this with my onc, but I am curious if anyone has thoughts or feedback about this decision I have to make. Do I risk my kidneys or not? That is the question I have to answer for myself. Most of what I have read says "usually" the kidney function recovers...of course there are no guarantees. There is a good chance my cancer will never recur, so if I cause kidney damage, it may be for naught. Thanks for listening...I know no one can answer this question for me.
Don't worry too much about the GFR.It is actually an "e" GFR which stands for estimated. And it's not always that accurate in women. The amount of exercise you are getting, what you eat, and especially what you drink can seriously affect the number.