A review of the risk factors for endometrial carcinoma

Cadmium exposure and endometrial cancer risk: A large midwestern U.S. population-based case-control study

Estrogen-mimicking chemicals, such as cadmium, may be associated with increased susceptibility to hormone-dependent cancers, though supporting data are sparse, particularly for endometrial cancer. The Health and Environmental Exposure Research (HEER) study worked with the Arkansas Central Cancer Registry, Iowa Cancer Registry and Missouri Cancer Registry to obtain names of women diagnosed with endometrial cancer who were willing to be contacted for participation in our case control study. Voter registration lists from Iowa and Missouri were used to randomly select similarly aged women as represented in the case population. Participants were interviewed by telephone to obtain information on known or suspected endometrial risk factors. Urine kits were sent to participants for home collection and returned for analysis. Our case-control study consisted of 631 incident cases of endometrial cancer diagnosed from January 2010 to October 2012 and 879 age-matched population-based controls, ages 18-81 years (mean age 65 years). We quantified cadmium amounts in urine and standardized these values through creatinine adjustment. Using data from all survey completers, we developed a multivariable model for endometrial cancer. Creatinine-adjusted cadmium concentration was added to this model. Odds ratio (OR) and 95% confidence intervals (CIs) for endometrial cancer were calculated. After multivariable adjustment, higher creatinine-adjusted cadmium exposure was associated with a statistically significant increase of endometrial cancer risk (OR: 1.22; 95% CI: 1.03-1.44). Our results provide evidence that cadmium may increase the risk of endometrial cancer, possibly through estrogenic effects.

Saline infusion sonohysterography: technique, indications, and imaging findings

OBJECTIVE

To review the technique, indications, and common imaging findings regarding saline infusion sonohysterography.

METHODS

The literature on saline infusion sonohysterography was reviewed. Pertinent images from our institution are presented to illustrate common imaging findings.

RESULTS

From the literature review, we summarize the various clinical scenarios in which saline infusion sonohysterography is useful and give examples from our clinical practice.

CONCLUSIONS

Saline infusion sonohysterography is a useful procedure for evaluation of endometrial and subendometrial abnormalities.

Increased endometrial thickness in women with hypertension

OBJECTIVE

We noticed an increase in endometrial thickness in women with hypertension who were treated with a combination of medications, including beta-blockers. The purpose of this study was to examine whether the endometrium of hypertensive women is thicker than that of healthy women and to determine whether endometrial thickening in hypertensive women is directly related to the antihypertensive beta-blocker treatment.

STUDY DESIGN

We compared 3 groups of postmenopausal patients as follows: (1) women with a history of essential hypertension treated with a combination of medications, including beta-blockers; (2) women with a history of hypertension treated with a combination of medications that did not include beta-blockers; and (3) healthy women without hypertension. All patients were interviewed and examined, blood tests were performed, and endometrial thickness in the anterior-posterior diameter was measured by vaginal ultrasonography. Among the exclusion criteria were diabetes or an abnormal fasting blood glucose level, obesity, hormonal medication or replacement hormonal therapy during the previous 6 months, and a history of hormonal disturbances, infertility, or polycystic ovary syndrome.

RESULTS

Of 45 hypertensive women enrolled in the study, 22 were treated with a beta-blocker combination medication and 23 were treated with other antihypertensive medications. They were compared with 25 healthy women. There was no statistically significant difference in endometrial thickness between women treated with medications, including beta-blockers, and those who were treated with other hypotensive agents. Twenty percent of women with hypertension and none of the healthy women had endometrium >5 mm thick (P <.017; odds ratio, 8.22; 95% confidence interval, 1.22-infinity).

CONCLUSION

Twenty percent of hypertensive postmenopausal women were found to have increased endometrial thickness. However, we were unable to substantiate an association between the type of treatment administered, whether beta-blockers were included, and the increase in endometrial thickness.

Adipose tissue distribution in postmenopausal women with adenomatous hyperplasia of the endometrium

OBJECTIVE

To investigate body fat distribution in postmenopausal women with adenomatous and atypical hyperplasia of the endometrium.

METHODS

A prospective population-based case control study was performed in a health care county in Sweden. General obesity, as reflected by body mass index (BMI), and adipose tissue distribution, expressed as waist to hip circumference ratio (WHR), were evaluated in a cohort of 367 postmenopausal women who underwent dilatation and curettage because of uterine bleeding. The study group consisted of 29 women with adenomatous or atypical hyperplasia of the endometrium. The controls consisted of 49 age-matched postmenopausal women randomly selected from the computerized population register of the same region.

RESULTS

The frequency of endometrial adenomatous and atypical hyperplasia in postmenopausal women with bleeding was 7.2%. In the total population of postmenopausal women the incidence of these endometrial lesions was 44 per 100,000 per year. Body weight (P = 0.039), BMI (P = 0.007), and WHR (P = 0.022) were higher in postmenopausal women with endometrial adenomatous and atypical hyperplasia than in controls. In multivariate analysis only BMI remained statistically associated with adenomatous hyperplasia (P = 0.012).

CONCLUSIONS

General obesity, but neither upper nor lower body fat distribution, was characteristic of postmenopausal women with adenomatous and atypical hyperplasia of the endometrium. Overall obesity is a risk factor for these endometrial precancerous lesions, as it is also claimed to be for endometrial cancer.

Female reproductive profile in a fertile, genetically obese line of rats

The female reproductive profile of a fertile genetically obese line of rats, named beta, is characterized. Hypophysis, ovaries, oviducts, and uteri weights do not differ from those of nonobese controls. Histological features in ovary, uterus, and vagina in beta line and alpha controls are similar, in agreement with classical descriptions in the subject. Vaginal opening, number of estrus, number of corpora lutea at ovulation time, and pregnancy patterns (i.e., ovary weight, number of corpora lutea, sites of implantation, and living fetuses, as well as productivity, fertility, litter size, and preweaning mortality) show no significant differences between obese and nonobese animals. From a reproductive standpoint, obese beta line would behave as nonobese. Up to now beta would represent the only fertile genetically obese line of rats, appearing as a profitable biological model to widen and deepen reproductive analysis on obesity.

Immunohistochemical study of the human 17 beta-hydroxysteroid dehydrogenase and steroid receptors in endometrial adenocarcinoma

17 beta-Hydroxysteroid dehydrogenase (17HSD) and estrogen (ER) and progestin (PR) receptors were analyzed immunohistochemically in tissue specimens of 66 patients with endometrial adenocarcinoma. Plasma steroid concentrations were correlated to immunohistochemical data. 17HSD was detected in 48% of the specimens and was stained in the cytoplasm of epithelial cells. The tissues were characterized by a heterogeneous staining pattern for 17HSD. In some patients, intensively stained epithelial cell clusters were seen, indicating that local factors were responsible for the expression of the protein. Poorly differentiated adenocarcinoma specimens tended to have no 17HSD more frequently than did well or moderately differentiated tissues. ER and PR were detectable in 24% and 28% of patients, respectively, and were localized in the nuclei of epithelial and stromal cells. There was a significant correlation between 17HSD and PR staining and an inverse correlation between plasma progesterone concentrations and 17HSD staining. This is contrary to the data obtained with normal endometrium. The main reason for this inverse relation between endometrial 17HSD staining and plasma progesterone concentrations was that, in some postmenopausal patients with low plasma progesterone concentrations, intense staining for 17HSD was detectable in the endometrial carcinoma specimens. This indicates a major difference in the regulation of 17HSD expression in endometrial adenocarcinomas, compared with normal tissues of premenopausal women.

Squamous cell carcinoma of the endometrium presenting as peritonitis with small bowel obstruction

Squamous carcinoma primary in the endometrium has been rarely reported. Diagnosis of this condition requires adherence to strict histologic criteria. Most patients are postmenopausal at presentation, and long-term survival is poor. We present a patient with peritonitis and small bowel obstruction. Chemotherapy was given after disease recurrence and was ineffective. Receptor data and serum markers were obtained.

Regulation of epidermal growth factor and insulin-like growth factor I receptors by estradiol and progesterone in normal and neoplastic endometrial cell cultures

Growth factors are polypeptides which regulate cell proliferation through binding to specific receptor proteins. Normal and neoplastic human endometrium have been shown to express epidermal growth factor (EGF) and insulin-like growth factor I (IGF-1) receptors. Endometrial cell cultures were used to test modulation of EGF and IGF-1 receptors in response to steroid hormones. Endometrial gland and stroma cells were separated by enzymatic dispersion and were incubated in medium containing estradiol (10, 100, or 1000 pg/ml) or progesterone (1, 10, or 100 ng/ml) followed by radioligand assays. Normal endometrial cultures (n = 6) treated with estradiol demonstrated 40% less EGF binding than control cultures (P less than 0.05), while IGF-1 binding was unaffected. Stromal cells treated identically decreased in only one treatment group. Progesterone treatment stimulated a significant increase in EGF and IGF-1 receptors in gland cultures. Cultures derived from adenocarcinoma (n = 2) demonstrated decreased EGF binding compared with normal endometrium (P less than 0.05). Carcinoma cells treated with progesterone resulted in a dose-dependent increase in EGF binding over control (P less than 0.05). These data illustrate effects of steroid hormones upon growth factor receptors in human endometrium, and suggest involvement of growth factors in the regulation of normal and neoplastic endometrial growth.

Age-related factors in cancers of the breast, ovary, and endometrium

The most central epidemiological feature of cancers of the breast, ovary and endometrium is the enormous protective effect of menopause. Simple mathematical "models" of the age-incidence of these tumours suggests that their incidence by age 70 would be between 4 and 8-fold increased if women continued to menstruate into old age. Using the notion of "effective cell-cycle time" to explain this phenomenon, different "models" are constructed for each of these three tumour sites and shown to provide an excellent description of most of the known epidemiology of each of the cancers, and to provide a basis for predicting the long-term effects of various factors on the risk of these diseases. In particular, the model suggests that 5 years of combination-type oral contraceptive use will approximately halve the lifelong risk of both ovarian cancer and endometrial cancer.

Serum estrogens and androgens in women with endometrial carcinoma

Fifty-two postmenopausal women with newly diagnosed endometrial carcinoma and 58 postmenopausal age-matched controls were studied concerning serum levels of estrone, total estrone, estradiol, androstenedione, testosterone, dehydroepiandrosterone and its sulphate, sex steroid hormone binding globulin, follicle stimulating hormone, and luteinizing hormone. The patients had a higher mean serum level of estradiol (P = 0.006) and a lower level of follicle stimulating hormone (P = 0.001) than the controls and the significant differences remained after the number of years since the menopause and body index had been taken into account. As the serum levels of steroid hormone binding globulin tended to be lower among patients than among controls (P = 0.084), the difference in the biological effect of estradiol between the two groups was probably greater than the difference in serum concentrations would indicate. No significant difference in the ratio of estrone to androstenedione or in the mean serum level of androstenedione was found between patients and controls. These data support the role of estrogen in the etiology of endometrial carcinoma.

Occult, high-risk endometrial cancer

In a series of 173 consecutive patients with endometrial cancer treated by a fixed protocol 62 tumors (36%) appear "estrogen independent," i.e. there is no history of estrogen ingestion and no recognized risk factors such as obesity or diabetes mellitus. A high proportion of these tumors are of advanced stage and grade. Prognosis is poorer and mortality higher than for "estrogen-dependent" tumors. Twenty-two tumors were truly occult (no spontaneous vaginal bleeding). Factors which identify this high-risk group are described and the reasons for delay in diagnosis discussed. Spread by intraperitoneal dissemination is considered a major factor in the poorer prognosis. Cytology of peritoneal washings is a useful diagnostic and prognostic aid. An estrogen provocation test is suggested as a means of earlier recognition which could reduce mortality in this group.

A novel approach to the analysis of risk factors in endometrial carcinoma

Early diagnosis of endometrial carcinoma enables one to achieve a cure rate of 80%. The purpose of this study is to characterize the patients who are prone to develop adenocarcinoma by simple epidemiologic and clinical data. The data of 109 consecutive patients who developed adenocarcinoma were compared with those of 146 control hysterectomy patients using logistic regression analysis. The following characteristics of patients who developed adenocarcinoma were identified: parity (P less than 0.0001), diabetes mellitus (P less than 0.003), hypertension (P less than 0.0001), obesity (P less than 0.0006), treatment with exogenous estrogen (P less than 0.001), and second primary tumor. The logistic regression formula classified correctly 77% of all patients to their actual group. The study showed that the relative risk of a patient to develop adenocarcinoma can be estimated from simple and readily available epidemiologic and clinical data.

Detection of postmenopausal women at risk for endometrial carcinoma by a progesterone challenge test

Currently, there exists no convenient, inexpensive screening test for the detection of postmenopausal women at risk for developing adenocarcinoma of the endometrium. After the administration of a progesterone challenge test (PCT) to asymptomatic postmenopausal women, the presence or absence of withdrawal bleeding may aid in detecting premalignant lesions of the endometrium. Of 30 such women who had endometrial sampling followed by a PCT, 25 had no withdrawal bleeding and all had nonpathologic histology. Five patients exhibited withdrawal bleeding. Of these five, three had unsuspected adenomatous hyperplasia (p less than 0.001). It is concluded that a PCT may be a reliable screening test for detecting those women at greater risk for developing endometrial hyperplasia or adenocarcinoma.

The selective use of vaginal hysterectomy in the management of adenocarcinoma of the endometrium

Vaginal hysterectomy was performed in 56 patients with Stage I adenocarcinoma of the endometrium who were selected because of obesity or major medical problems that placed the patient at high risk for morbidity and death with an abdominal operation. Seventy percent of the patients were hypertensive and 29% were diabetic. The median weight for the 56 patients was 211 pounds. Ten patients who were age 40 or younger were included, and all showed signs of polycystic ovary syndrome. This subgroup of patients was significantly more obese, with a median weight of 331 pounds. Adjuvant radiation therapy was used in 32 of the 56 patients. There was one postoperative death from a pulmonary embolus, but there were few other major complications. The actuarial survival probability was 94% for all patients. With grade 1 tumors, the 5-year survival rate was 98%; with grade 2 tumors, it was 78%; and with grade 3 tumors, it was 84%. Although we do not recommend that vaginal hysterectomy become routine, it has cure rates comparable to those with abdominal hysterectomy and should be considered in patients who are a poor surgical risk, particularly patients with grade 1 tumors.