Written by Reich O, Regauer S. | 05 October 2008

Department of Obstetrics and Gynaecology, Medical University of Graz, Graz, Austria.

PURPOSE OF REVIEW: Low-grade endometrial stromal sarcomas are steroid receptor positive tumors with slow tumor progression and high recurrence rates, which lack established treatment protocols. We present an update on hormonal therapy options. RECENT FINDINGS: In the past, hormonal therapy consisted of progestins for advanced/recurrent/metastatic low-grade endometrial stromal sarcomas. Aromatase inhibitors and gonadotropin-releasing hormone analogues have become new effective alternatives for first and second line treatment. The high recurrence rates after short disease free intervals in low-grade endometrial stromal sarcoma patients were partly due to inadvertent growth stimulation during estrogen-containing hormone replacement therapy and tamoxifen treatment, which - according to current knowledge - are contraindicated. Recently, hormonal therapy has been introduced for the prevention of recurrences. Aromatase inhibitors are becoming the treatment of choice, since progestins are poorly tolerated due to side effects. The effective duration of preventive hormonal therapy is still undetermined. SUMMARY: Hormonal therapy with progestins, aromatase inhibitors and gonadotropin-releasing hormone analogues has become an effective treatment alternative to radiation and chemotherapy for low-grade endometrial stromal sarcoma patients. Preventive hormonal therapy is of particular interest in the setting of concomitant endometriosis.

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Written by Suzy Johnson | 16 October 2007

From PubMed

The use of drugs, which inhibit estrogen biosynthesis, is an attractive treatment for postmenopausal women with hormone-dependent breast cancer. Estrogen deprivation is most specifically achieved using inhibitors which block the last stage in the biosynthetic sequence, i.e., the conversion of androgens to estrogens by the aromatase enzyme.

Recently, a new generation of aromatase inhibitors has been developed. Among these, letrozole (Femara) appears to be the most potent. When given orally in milligram amounts per day to postmenopausal women, the drug almost totally inhibits peripheral aromatase and causes a marked reduction in circulating estrogens to levels that are often undetectable in conventional assays. Similarly, neoadjuvant studies demonstrate that letrozole substantially inhibits aromatase activity in both malignant and nonmalignant breast tissues, and markedly suppresses endogenous estrogens within the breast cancers. These studies also illustrate anti-estrogenic and anti-proliferative effects of letrozole in estrogen receptor (ER)-rich tumors. Thus, tumor expression of progesterone receptors and the cell-cycle marker Ki67 is significantly and consistently reduced with treatment.

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Written by Suzy Johnson | 16 October 2007

From PubMed

The use of drugs, which inhibit estrogen biosynthesis, is an attractive treatment for postmenopausal women with hormone-dependent breast cancer. Estrogen deprivation is most specifically achieved using inhibitors which block the last stage in the biosynthetic sequence, i.e., the conversion of androgens to estrogens by the aromatase enzyme.

Recently, a new generation of aromatase inhibitors has been developed. Among these, letrozole (Femara) appears to be the most potent. When given orally in milligram amounts per day to postmenopausal women, the drug almost totally inhibits peripheral aromatase and causes a marked reduction in circulating estrogens to levels that are often undetectable in conventional assays. Similarly, neoadjuvant studies demonstrate that letrozole substantially inhibits aromatase activity in both malignant and nonmalignant breast tissues, and markedly suppresses endogenous estrogens within the breast cancers. These studies also illustrate anti-estrogenic and anti-proliferative effects of letrozole in estrogen receptor (ER)-rich tumors. Thus, tumor expression of progesterone receptors and the cell-cycle marker Ki67 is significantly and consistently reduced with treatment.

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Written by Suzy Johnson | 16 October 2007

Abstract from PubMed

The female genital tract is hormonally responsive, and consequently some tumors, which arise within in it, may be treated at least in part, with hormonal manipulation. The range of responses in clinical trials and case reports will be reviewed. Many of these diseases are too rare for clinical trial testing, and in some cases evidence is anecdotal at best. Recurrences of ovarian cancer have been treated with tamoxifen and megesterol acetate with variable response rates from 0 to 56%.

The favorable toxicity profile of aromatase inhibitors led to trials of these agents for the treatment of relapsed epithelial ovarian cancer. These agents have proved tolerable with minor response rates but a significant disease stabilization rate, which may be prolonged in a minority of cases. It is unclear if these responses may be predicted by estrogen receptor expression or aromatase expression. Anastrazole has also been tried in combination with an EGFR receptor-inhibitor, again showing minor responses but possibly an increase in TTT in some patients. Granulosa cell tumors of the ovary are rare, hormonally sensitive tumors, with reported responses to a variety of hormonal manipulations, including aromatase inhibition. In addition, combined endocrine blockade, including aromatase inhibition, has been tried with reports of success. Endometrial cancers, particularly type I lesions, are often treated with hormonal manipulation, most commonly with progestins, but also with antiestrogens such as tamoxifen. A trial of aromatase inhibition in the treatment of recurrent endometrial cancer showed minimal responses. Endometrial stromal sarcoma, an uncommon uterine malignancy, has shown response to hormonal treatments, with multiple case reports of efficacy of aromatase inhibition. Despite the rarity of some of these tumor types, rare tumor study groups, such as within the Gynecologic Oncology Group, should make an effort to prospectively define the utility of these treatments.

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