Two cases of metastatic malignant carcinoid tumor in elderly women contained significant amounts of estrogen receptor (19 and 32 femtomoledmg protein) as shown by Scatchard-plot analysis of a dextran-coated charcoal assay, inhibition of binding by an estrogen analog (67 and 63%) and highaffinity binding (Kd = 6.8 and 2.6 x 1W"' M). The demonstration of estrogen receptor in malignant carcinoid tumor expands the spectrum of non-breast or non-gynecologic neoplasms that contain the receptor. The significance of estrogen receptor in such tumors is uncertain; it may represent aberrant derepression of the gene for estrogen receptor protein in a malignant tumor.
Cancer 45293-296, 1980.
H E MEASUREMENT of estrogen receptor protein in
T breast carcinomas is a valuable procedure to predict the response to hormonal therapy. Patients whose carcinomas contain estrogen receptor are much more likely to respond than patients whose tumors do not contain the receptor." Estrogen receptor protein has also been detected in a variety of carcinomas of non-breast origin. Some of these, such as ovarian"* or endometriaPJ4 carcinoma, are either sources of estrogen or target organs. Other sites of tumors that have been reported to contain estrogen receptor protein, such as the kidney,".'" stomach,X or melanocytes (malignant are not known to be involved in estrogen metabolism. The significance of estrogen receptor in these cases is unclear, regarding both the biology of the tumor and possible response to hormonal therapy.
The presence of estrogen receptor in malignant tumors of non-breast origin warrants further investigation. We report here Z cases of an additional type of neoplasm, malignant carcinoid tumor, that contains estrogen receptor.
Case Reports
Case 1 A 65-year-old white woman developed left hip and groin pain. Two days before admission, she noticed a midline, From the