Iodine-labeled tamoxifen uptake in primary human breast carcinoma.
Assessing tumor uptake and retention of (123)I-labeled tamoxifen (TX) could increase our understanding of TX's action and the mechanisms involved in resistance to the drug.


METHODS
Nine untreated primary breast carcinoma patients underwent whole-body planar and tomographic (SPECT) imaging 30 min and 4-5 h after injection of 185 MBq (123)I-TX. Tumor-to-normal tissue uptake ratios (T/N) derived from SPECT images were related to estrogen receptor (ER) and progesterone receptor (PR) status.


RESULTS
In 4 of 9 patients, all of whom were ER+/PR+, (123)I-TX tumor uptake was clearly depicted. In 2 of them, involved axillary lymph nodes were also visualized. T/N consistently increased over time. All ER+/PR- and ER-/PR- tumors as well as 2 ER+/PR+ tumors were (123)I-TX-.


CONCLUSIONS
These preliminary findings suggest that (123)I-TX is preferentially taken up in alpha-ER+/PR+ breast tumors known to be more likely to respond to endocrine treatment.
Van de Wiele
C
C
Divisions of Nuclear Medicine, Medical Oncology, and Oncological Gynaecology and Department of Anatomopathology, Ghent University Hospital, Ghent, Belgium.
Cocquyt
V
V
VandenBroecke
R
R
De Vos
F
F
Van Belle
S
S
Dhaene
K
K
Slegers
G
G
Dierckx
R A
RA
D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging / Q000378:metabolism; D018275:Carcinoma, Lobular / Q000000981:diagnostic imaging / Q000378:metabolism; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007457:Iodine Radioisotopes; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D013629:Tamoxifen / Q000493:pharmacokinetics* / Q000627:therapeutic use; D015899:Tomography, Emission-Computed, Single-Photon
D007457:Iodine Radioisotopes; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen