Alternative Protein Tests for Avastin

Hello, in 2006 my mom was diagnosed with stage IV ovarian cancer.  As a result of the tumor she needed a stent placed in her ureter and one of her kidneys is <10% functional.  She often has blood in her urine, her urologist believes due to the stent.  She had been on Avastin for about 6 months and her oncologist decided a month ago to take her off due to high protein levels in her urine.  Her urologist thinks the urine test could be skewed too much by the blood.  The protein levels in her blood are acceptable.  My question is: are there any other tests to assess how the Avastin is effecting her kidneys?  Is there a type of blood test that can be used reliably?  Thank you for any information you can provide, Jon

[Annekathryn Goodman, M.D.]

Hi There,
thank you for this important question.  I agree with JR's comments. I would say that ultimately, the oncologist knows the patient the best and I defer to their judgement.

in addition to protein in the urine, blood test determinants of kidney function (creatinine and glomerular filtration rate (GFR)), and analysis of urine sediment help to understand kidney function.

urine sediment is a microscopic look at the urine to see if parts of the tubules in the kidneys are being sloughed.

Ultimately a kidney specialist (nephrologist) could weigh in on the kidney function question.


here is an informative link on this:

http://www.merck.com/mmhe/sec11/ch142/ch142c.html

best wishes

[jr1971]

Hey Jon

I spoke to my wife's doctor about this and he said that they are looking for specific markers that identify Kidney damage. I am sure that your Mom's doctors, knowing her condition will be able to monitor her condition and rather than refuse treatment because of seeing protein or blood in the urine they should be able to treat and monitor changes between treatments.

My wife's urine contained blood last week but they still treated her with Avastin. I would ask the doctors exactly what there criteria is for giving/not giving Avastin as she progresses through treatment.

Clearly the issue with Kidneys is a critical one. If the Kidney does not function properly it can cause the drugs to remain in the system and damage the kidney further, this cycle could lead to the Kidney not functioning at all. I believe that this is quite critical with Avastin.

The specific test to look out for is "creatinine". The levels of creatinine indicate how well the kidney is functioning. They are likely to be looking at this as a guide to treating your Mom.

Jon

[jonm505]

Hi JR,

Thanks again for posting.

To boil down the issue, Genentech tells doctors to measure protein using dipstick urine analysis (Which blood will cause a "false positive" of sorts, its a simple test using strips like you would to test the pH of a pool).  Her oncologist does not see any point in exploring alternative testing because that is what Genentech says to do.  Her urologist has looked at her blood work and urine tests (and believes her kidney is doing OK) and has tried to talk to the oncologist, but the oncologist won't budge.

Just an FYI, I saw you mention creatinine; on Genentech's website they said a study showed that there wasn't a good correlation between Creatinine testing and 24 hour urine sample protein.  I'm not sure what it means exactly, but perhaps its something worth bringing up with your wife's doctor. (Link: section 5.8 of the pdf.. http://www.gene.com/gene/products/information/pdf/avastin-prescribing.pdf)

She's been hospitalized for the weekend because the drug she was forced to switch to is absolutely wreaking havoc on her blood and platelet counts.  I hope the Avastin works for your wife and she can stay on it.  If your doctor can shed anymore light on this issue..specifically the Creatinine test being sufficient..that would be excellent.  Unfortunately her doctor is the only show in town, hence why I'm here.  Thanks again,

Jon