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Estrogen receptors in nasopharyngeal angiofibromas
Abstract:
Nasopharyngeal angiofibromas, which occur exclusively in pubescent males, are frequently treated with estrogens in an effort to decrease their size and vascularity. It has been presumed by some that estrogen has a direct effect on the tumor itself. Others have felt that hormone acts by affecting the pituitary-gonadal axis. In this study, six male patients with nasopharyngeal angiofibromas had their tumors analyzed for estrogen receptors and none were found. Despite this fact, two of these patients treated with estrogens showed clinical evidence of a decrease in tumor size and vascularity. This response occurring in the absence of estrogen receptors suggests that the action of estrogen on nasopharyngeal angiofibromas is indirect. Alternatively these tumors may be testosterone dependent and the administration of estrogen suppresses the normal male testosterone levels, with a resultant reduction in tumor size and vascularity. Twenty-four patients with nasopharyngeal angiofibroma have been treated at the University of Virginia in the past 22 years. The average blood loss at operation was 1900 cc. When estrogens were administered preoperatively in 3 patients, the average blood loss was 1135 cc. Those patients who received no estrogens averaged 2000 cc blood loss. These figures do not reflect the size or extent of the disease, both of which greatly influence blood loss.
Insights
Estrogen treatment may reduce nasopharyngeal angiofibromas indirectly by suppressing testosterone, as tumors lack estrogen receptors. This suggests a hormonal, rather than direct, effect on tumor growth.
Area of Science:
- Otolaryngology
- Endocrinology
- Oncology
Background:
- Nasopharyngeal angiofibromas (NA) exclusively affect pubescent males.
- Estrogen therapy is used to reduce NA size and vascularity.
- The mechanism of estrogen's action on NA is debated: direct tumor effect vs. pituitary-gonadal axis modulation.
Purpose of the Study:
- To investigate the presence of estrogen receptors in NA.
- To explore the indirect mechanism of estrogen action on NA.
- To evaluate the effect of estrogen administration on surgical blood loss in NA patients.
Main Methods:
- Analysis of estrogen receptors in six male NA patient tumors.
- Clinical observation of tumor response to estrogen therapy.
- Comparison of surgical blood loss in NA patients with and without preoperative estrogen administration.
Main Results:
- No estrogen receptors were detected in the analyzed NA tumors.
- Two patients showed clinical reduction in tumor size and vascularity despite the absence of estrogen receptors.
- Preoperative estrogen administration in three patients was associated with reduced average blood loss (1135 cc) compared to those without (2000 cc).
Conclusions:
- Estrogen's effect on NA is likely indirect, possibly via suppression of testosterone levels.
- The absence of estrogen receptors suggests testosterone dependency of NA.
- Estrogen administration may reduce surgical blood loss in NA patients, though further studies are needed to control for disease extent.