Controversies are still seen in the histological differential diagnosis of hyperplasia and well-differentiated endometrial carcinoma. Prediction of endometrial cancer in patients with hyperplasia with atypia, with the available markers has not been reliable yet. Hence these patients require more attention in the clinical management. Endometrial hyperplasia is proliferation of endometrial glands resulting in a higher gland : stroma ratio. Cytological atypia, which may progress to or co-exist with endometrial cancer and other pathological changes, result from estrogen stimulation unopposed by progesterone. Biomarkers whose expression is altered in cases of endometrial hyperplasia or cancer such as progesterone receptor, insulin-like growth factor I, retinaldehyde dehydrogenase type II, and secreted frizzled-related protein 4, seem to be promising to use as early-stage tumor markers. Mutation of PTEN is present in 83% of endometrial adenocarcinoma cases, making it the most frequent early molecular genetic alteration in type 1 endometrial tumors, which are generally associated with hyperplasia. p53 gene mutation is not found in endometrial hyperplasia, but researchers have detected this mutation in 20% of cases of endometrial carcinoma and 90% of cases of serous endometrial tumors. Cyclooxygenase-2 is important in tumorogenic transformation of hyperplasia. Expression of cyclooxygenase-2 decreases apoptosis, increases angiogenesis, and is related to invasiveness. Cyclooxygenase-2 expression increases significantly in cases of well-differentiated endometrial adenocarcinoma. Prostaglandin E2 is known to regulate aromatase gene expression and is the product of cyclooxygenase-2. The data about aromatase inhibitors are promising; in breast cancer patients, treatment with tamoxifen induces uterine abnormalities as early as 3 months after the initiation of therapy. In contrast, these abnormalities are not seen in patients who receive aromatase inhibitors and switched therapy after tamoxifen withdrawal may reverse tamoxifen-associated endometrial thickening.
In order to assess a possible influence of endogenous opioids upon gonadotrophin secretion in women, we examined the effects of i.v. administration of 10 mg naloxone, a specific opiate antagonist, in ten normal menstruating women, in thirteen women with amenorrhoea and/or hyperprolactinaemia and in two women with putative deficiency of gonadotrophin-releasing hormone (GnRH). In thirteen subjects, a saline vehicle control study (randomized order of administration) was also performed. In the normal women, naloxone failed to elicit changes in serum gonadotrophin levels when administered during the early follicular phase of the menstrual cycle. However, significant increments of LH were observed from 30 to 165 min following naloxone administration during the late follicular phase. Similar LH responses occurred in the amenorrhoeic and hyperprolactinaemic women. There was a tendency towards a concomitant increment in FSH levels, which reached statistical significance variably from 60 to 105 min post-naloxone. The LH response to naloxone in individual subjects showed a significant (P less than 0.01) quadratic (U-shaped) relationship to the log basal oestradiol concentration. No response to naloxone was observed in the two patients with GnRH deficiency despite a brisk response to an exogenous GnRH bolus. Taken together, these data suggest that central nervous system inhibitory opioid pathways may be involved in the regulation of LH secretion in normal women and that excessive production of endogenous opioids may play a role in the pathophysiology of some amenorrhoeic conditions.
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