Monitoring estrogen level

[Nguyen]

Just something to think about for ER+ patient:

Does anyone happen to monitor estradiol (precursor to estrogen) level while under endocrine (letrozole, anastrozole, etc) treatment? My wife cancer returns while being treated with Femara (letrozole). I happened to notice the estradiol level has been going up in conjunction with tumour marker CA27.29. While this may be a coincident, this MIGHT indicate that one of the reason for recurrence is NOT because the cancer cells have found a way to grow without (or minimal need) of estrogen, but because the body has found (after a while) away to produce more estrogen despite a particular form of endocrine treatment.

The implication of this ONE data point is that for ER+ tumour, while under endocrine treatment, monitor estrogen (estradiol, estrone, and estrone sulfate) level along side with tumour marker or CT scan. If the tumour returns or progresses, look at the resulting data before giving up on endocrine treatment.

Some years ago we were indecisive about removing the ovaries (not needed since she was induced into menopause via chemotherapy), this estradiol elevation data pushes us over the edge of having an oophorectomy. The ovaries (main source), adrenal glands, fat tissues, food intake are sources of estrogen.

Nguyen

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Linda's treatment history:
01/2005 - current: Herceptin (readded) and Femara
07/2004: It returned again via several small nodules in the lung
10/2002: NED (via CT and CA27.29)!
10/2001 - 01/2005: Femara, (Fosamax)
12/2000 - 10/2001: Herceptin and Navelbine
12/2000: lung metastatic was diagnosed (a few small nodules)
02/1998 - 12/2000: Daily Tamoxifen
05/1997 - 04/1998: Modified Radical Mastectomy, many many cycles of chemo regiments (CAF,Taxol, Carpoplatin, Thiotepa, Navelbine, Taxotere), including HDC, and radiation
05/1997: First diagnosed with BC stage 3A, ER+, PR+, HER2 +, poorly differetiated, nuclear grade 3.