2 labs, 2 different measurements

[saraheltorky]

hi, im misha's wife sarah. we have a question regarding the way labs measure tumor markers. no one here, including our dr and the lab technicians can answer our question(honestly, not kidding...typical of egypt). the lab we normally get blood work done at measures AFP in IU/ml(11.5). the lab we got our 2nd opinion blood test done at used ng/ml(17.4). are they using the same measurement and calling it different things? i know ng/ml seems to be standard in north america, and iv never seen AFP measured in IU/ml anywhere in all our reading online. are they the same thing? anyone have any thoughts?

[Scott]

I definitely would not make decisions based on two measurements in different units from two different labs!

See this definition of IU, or International Unit: http://www.medterms.com/script/main/...rticlekey=9650

[dadmo]

sarah:
Welcome. I just took this from a tc cancer web site. "Please note that AFP is normally less than about 5 ng/ml, but cancer cannot be assumed until it is over 25 ng/ml." Everyplace I checked measures in ng/ml but I'm sure you can do a converson from one to the other, it should just be a matter of some math formula. You may have seen this site already but check out the informaton they have. http://tcrc.acor.org/.

[Scott]

I'm sure you can do a converson from one to the other, it should just be a matter of some math formula.

...except that an "IU" varies depending on what is being measured.

[Scott]

According to one source, for AFP, "1 IU/ml is equivalent to 1.21 ng/ml." Assuming that's accurate, your two readings are 13.9 ng/mL and 17.4 ng/mL (but still from different labs).