Testosterone metabolism in endometrial cancer

Is there an altered steroid profile in patients with endometrial carcinoma?

BACKGROUND

Besides the well-known association between endometrial carcinoma (EC) and unopposed estrogen, androgens also may play a role in this respect; however, previous studies on endogenous estrogens and androgens in patients with EC and control subjects have yielded mostly divergent results, probably because of the use of poorly defined control groups.

METHODS

Circulating steroid and pituitary hormones and sex hormone-binding globulin were measured in patients with EC and matched control groups of either patients with nonmalignant postmenopausal bleeding (hospital control subjects) and healthy, symptom-free women (nonhospital control subjects).

RESULTS

Patients with EC had higher serum levels of adrenal C21 and C19 steroids, estrogens, and biologically active testosterone than nonhospital control subjects, whereas the hospital control subjects constituted an intermediate group in this respect.

CONCLUSIONS

The results clearly indicate an altered steroid homeostasis, probably reflecting an increased "adrenal drive" in patients with EC. The results also stress the necessity of using strictly defined, healthy, symptom-free control subjects instead of the frequently used hospital control subjects when studying more subtile endocrine aberrations.

Estrone sulphate plasma levels in postmenopausal women with and without endometrial cancer

Plasma estrone sulphate ( E1S ) and estrone (E1) concentrations were determined in healthy postmenopausal women and in postmenopausal women with endometrial cancer, matched for body weight, age, and years since menopause. E1S levels (mean +/- SD) were significantly higher (P less than 0.05) in cancer patients with normal weight (511 +/- 200 pg/ml) than in control subjects (303 +/- 99 pg/ml). E1S levels were also higher in obese cancer patients (691 +/- 328 pg/ml) than in obese control subjects (610 +/- 139 pg/ml). Both cancer groups showed similar plasma E1 levels as compared with their respective controls. The E1S /E1 ratio was higher in both groups of cancer patients than in control subjects. These data suggest that estrogen conjugates should be taken into account during studies on estrogen balance and endometrial cancer.

Peripheral aromatization as a risk factor for breast and endometrial cancer in postmenopausal women: a review

In menopause, estrogens are produced almost exclusively through peripheral aromatization of androgens, especially androstenedione. Obesity increases the production rate of estrogens by means of the same mechanism. In postmenopause, plasma levels of SHBG diminish significantly. Obesity even further decreases the levels of SHBG, thus increasing "free" E2 available to target tissues. The increase in circulating estrogenic activity in menopause, whether as a result of obesity or of ingestion of estrogens, implies a risk factor for endometrial and breast cancer not only because of the permissive and stimulating effects of estrogens but also due to the special circumstance that they may act on target tissues in the almost absolute absence of the "protecting effect" of progesterone. The modifications performed by obesity on the values of SHBG and circulating estrogens are reversible, since they tend to normalize with weight loss.

Synthesis of catechol estrogens by human uterus and leiomyoma

Homogenates of human endometrial, myometrial and leiomyoma tissues were incubated with (2,4,6,7-3H)-estradiol and tritiated catechol estrogens were isolated and identified. Though 2- and 4-hydroxylations were about the same in endometrium, 4-hydroxylation was two to four fold higher than 2-hydroxylation in myometrium and leiomyoma. However, endometrium showed greater capacity to form both 2- and 4-hydroxyestrogens than the other two tissues. Both 2- and 4-hydroxylations were significantly less than in myometrium. In view of the reports indicating that inhibitors of catechol 0-methyl transferase (COMT) might act as antineoplastic agents due to their interference with t-RNA methylases and since catechol estrogens inhibit COMT, the present results suggest that endogenous synthesis of catechol estrogens may play an important role in the pathophysiology of uterine leiomyoma.

Serum androgens and estrogens in postmenopausal women with and without endometrial cancer

Thirty-five consecutive patients with adenocarcinoma of the endometrium and an equal number of control subjects matched to the cancer patients for age and percentage of ideal weight were studied prospectively. In the cancer patients, the mean +/- SE serum androstenedione, testosterone, estrone (E1) and estradiol (E2) levels were 503 +/- 34 pg/ml, 224 +/- 22 pg/ml, 38.7 +/- 3.6 pg/ml, and 14.5 +/- 0.9 pg/ml, respectively. Similar concentrations were found in the control subjects. Body weight and percentage of ideal weight showed highly significant correlations (P less than 0.001) with E1 and E2 but not with the androgen concentrations in either group. The heavier patients had higher E1 and E2 levels. Age and years since menopause did not correlate with any of the hormonal levels. The cancer patients with overt diabetes tended to be more obese and have higher estrogen levels than did the nondiabetic subjects. Those with a history of prior estrogen usage were more slender and had lower endogenous estrogens than the nonusers. Twenty-three of the cancer patients (66%) had a presumed risk factor(s) for the development of this tumor, that is, excess body weight, high endogenous estrogen levels, or a history of prior estrogen usage. These data support the concept that conditions which lead to continued, unopposed estrogen stimulation may be associated with malignant transformation of the endometrium.

Estradiol and testosterone levels in the peripheral and ovarian circulations in patients with endometrial cancer

Estradiol and testosterone levels in the peripheral and ovarian circulation of patients with endometrial cancer and of postmenopausal women were studied. These levels proved to be the same in the two groups. The ovaries of neither group secreted estradiol. The testosterone level in the ovarian circulation of all examined women was four times higher than that in the peripheral circulation, thus indicating the ovarian origin of testosterone.

Kinetics of testosterone metabolism in normal postmenopausal women and women with breast cancer

The constant infusion and single injection techniques were utilized to study the kinetics of 3H-testosterone (T) metabolism in posmenopausal women with and without breast cancer. The metabolic clearance rates (mean +/- SEM) for normal postmenopausal women were 578 +/- 82 and 644 +/- 128 1/24 has obtained by the constant infusion and single injection techniques, respectively. The corresponding results for the women with breast cancer (patients) are 644 +/- 25 and 617 +/- 106 1/24 h. The single injection technique yielded values for rate constants (units) and volumes of distribution (1); K1 = 37.5 +/- 1.6 for the normals and 34.5 +/- 1.9 for the patients, K = 76.6 +/- 5.1 for the normals and 71.1 +/- 1.6 for the patients, V1 = 7.9 +/- 2.2 for the normals and 8.7 +/- 1.4 for the patients and V2 = 7.0 +/- 1.5 for the normals and 6.4 +/- 1.2 for the patients. The constant infusion technique yielded values for the conversion ratios for the transformation of T to several products; 4-androstene-3,17-dione/T of 0.02 +/- 0.003 for normals and 0.03 +/- 0.002 for patients, 5alpha-dihydrotestosterone/T of 0.02 +/- 0.002 for normals and 0.03 +/- 0.002 for patients, estrone/T of 0.04 +/- 0.01 for normals and 0.04 +/- 0.01 for patients, estradiol-17beta/T of 0.02 +/- 0.005 for normals and 0.03 +/- 0.005 for patients and estrone sulfate/T of 0.16 +/- 0.02 for normals and 0.24 +/- 0.06 for patients. The T plasma concentrations and production rates were similar for the two groups of subjects. Hence there were no significant differences between the normals and the patients for all the kinetic parameters. It was determined that all the estradiol being produced in postmenopausal women could be coming from circulating T.