Specific imaging of hormone-dependent mammary carcinoma in nude mice with [131I]-anti-estriol 3-sulfate antibody.

We tried to put the estrogen metabolite to use in tumor imaging. The antibody against estriol 3-sulfate (E3 3-S), which was one of the major metabolites of estrogen in hormone-dependent mammary carcinoma, was prepared and the tissue distribution and imaging of human breast carcinoma with anti-E3 3-S antibody (Ab) were studied in nude mice. In hormone-dependent breast carcinoma, MCF-7,-bearing nude mice, [125I] anti-E3 3-S Ab localized in tumor with the percentage injected dose/g of 9.29 +/- 3.01 (mean +/- SD). This value was significantly high compared with that in hormone-independent breast carcinoma, MDA-MB-231,-bearing nude mice. At 72 h after the administration of [125I]anti-E3 3-S Ab to MCF-7 bearing mice, tumor/blood, tumor/liver and tumor/muscle ratios were 0.49, 5.02 and 6.83, respectively. These ratios were supposed to be enough for imaging. In radioimmunoscintigraphy, a MCF-7 tumor was clearly visualized at 120 or 168 h post-injection of [131I]anti-E3 3-S Ab.