Rising Breast Cancer CA27.29 Markers

[BNOD]

My wife diagnosed 16 Dec '05---Merry Christmas--with IDC, 1.4 cm 20% DCIS, er/pr + her-2-, grade 3,no lvsi, node negative(sentinel node) lumpectomy with clear margins. Prognosis at that time was GREAT a stage 1.  Now she has completed 4 chemo cycles of A/C 2 weeks apart on 9 May '06 and about to start radiation.  In March '06 her pre-chemo CA 27.29 marker was 28 she was tested in April '06 after 2 A/C cycles and it rose to 48---her last treatment was 9 May and blood drawn on 25 May---CA27.29 remained high at 58---Onco ordered a PET scan conducted last Fri---now on pins and needles waiting for the results.  Much I've read over the weekend lead me to believe this particular marker has a relatively high false positive rate especially in light of chemo and radiation and should not be tested for until treatment concluded.   Thoughts Please. Nick

[bobbi58]

A related discussion, breast cancer to lung cancer? was started.

[BNOD]

PET scan came back in yesterday----All is Normal

[CCF-RN,MSN-rf]

Dear bnod:  The CA 27.29 test was approved by the FDA in 1996 as a tumor marker test for breast cancer.  Unfortunately the test has turned out to be neither "sensitive" nor "specific."  That means that there are both high numbers of false negative and false positive results.  So a negative result is not necessarily negative and a positive result is not necessarily positive.  Many centers do not do this test for this reason.  Further, there is no evidence that "catching and treating" metastasis based on a blood test (before any symptoms) will improve survival or quality of life.  When this test is used it is mostly in the setting of known metastatic disease to follow the value in response to treatment.

[BNOD]

the May ca27.29 was 50 not 58