The biological actions of estrogens on skin

Topical Estrogen Accelerates Hair Regrowth in Mice After Chemotherapy-Induced Alopecia by Favoring the Dystrophic Catagen Response Pathway to Damage

Estrogen receptor ligands are important modulators of skin physiology and are involved in the control of normal hair follicle cycling. Here, we have studied the effects of topically applied 17-beta-estradiol on pathologic hair follicle cycling as seen during chemotherapy-induced alopecia, one of the major unresolved problems of clinical oncology. For this study we employed a well-established murine model that mimics chemotherapy-induced alopecia in humans. For precisely quantifying the area of hair loss and hair regrowth in this model in vivo, we developed a simple planimetric assay (dotmatrix planimetry). We show that topical 17-beta-estradiol significantly alters the cycling response of murine follicles to cyclophosphamide, whereas the estrogen antagonist ICI 182.780 exerted no such effects. Initially, topical 17-beta-estradiol enhanced chemotherapy-induced alopecia significantly by forcing the follicles into the dystrophic catagen response pathway to hair follicle damage, whereas follicles treated by ICI 182.780 or vehicle shifted into the dystrophic anagen response pathway. Consequently, the regrowth of normally pigmented hair shafts after chemotherapy-induced alopecia was significantly accelerated in the 17-beta-estradiol treated group. Our data encourage one to explore topical estrogens as a potential stimulant for hair re-growth after chemotherapy-induced alopecia.

The utility of estrogen receptor and progesterone receptor immunohistochemistry in the distinction of metastatic breast carcinoma from other tumors in the liver

CONTEXT

The distinction of metastatic breast adenocarcinoma (MBA) to the liver from hepatocellular carcinoma (HCC), cholangiocarcinoma (CC), and metastatic adenocarcinoma from other sites may require the use of immunohistochemistry. The use of antibodies directed against estrogen receptor (ER) and progesterone receptor (PR) has been suggested to help make this distinction.

OBJECTIVE

To examine the utility of ER and PR immunohistochemistry in the distinction of MBA from HCC, CC, and other metastatic adenocarcinomas in the liver.

METHODS

Ninety-two previously characterized hepatic neoplasms were identified, including HCC (n = 14), CC (n = 16), and metastatic tumors from breast (n = 17), colorectal (n = 14), pancreatic (n = 15), and esophageal/gastric (n = 16) origins. For all cases of metastatic tumor, the primary tumor was reviewed to verify the diagnosis. All tumors were graded as well, moderately, or poorly differentiated. Estrogen receptor and PR immunohistochemical staining was performed on all cases and evaluated by 2 pathologists.

RESULTS

Immunoreactivity for ER was identified only in MBA, with 6 (35%) of 17 cases positive. Positive immunoreactivity for PR was not restricted to MBA, but was seen in HCC, CC, esophageal/gastric, and pancreatic metastases. Positive immunostaining with PR was nearly as frequent in poorly differentiated carcinomas of nonbreast origin (3/16 cases, 19%) as in poorly differentiated breast carcinomas (2/8 cases, 25%).

CONCLUSION

Progesterone receptor exhibited poor specificity and sensitivity for the distinction of MBA from HCC, CC, and other metastatic adenocarcinomas. Estrogen receptor exhibited poor sensitivity for MBA, although the specificity was good. The finding that PR positivity was present with a similar frequency in poorly differentiated tumors of breast and nonbreast origin limits the usefulness of this marker. Therefore, ER and PR staining have limited utility in the distinction of MBA from HCC, CC, and other metastatic adenocarcinomas in the liver.