Oral contraceptives and neoplasia.

PIP: Some of the available data concerning the suspected association between oral contraceptive (OC) use and the development of cancer is surveyed, and the attempt is made to evaluate possible associations between OCs and human neoplasia in light of pregnancy risk or benefit of oral contraception. The principal investigative methods in humans include various epidemiologic approaches, and the methodologies most often used are case reports (tumor registries), disease rates and trends, case-control studies, and cohort studies. These methods cannot prove a causal relationship between exposure to a possible carcinogen and the occurrence of disease. Consistent positive or negative evidence, confirmed by multiple epidemiologic approaches, can be used to guide physicians and regulatory agencies in formulating policy for the clinical use of OCs. Both the progestogen-only and the combined OCs have been shown to have a protective effect on the development of benign breast disease with this protective effect not appearing until 2 years of use. Long-term combined OC use appears to be related to the development of benign liver neoplasia, and this risk increases with the dose of the steroid and the age of the user. These lesions are quite rare but may be life threatening because of potential spontaneous rupture and hemorrhage. Long-term postmenopausal use of estrogens appears to increase significantly the risk of developing endometrial hyperplasia and adenocarcinoma of the endometrium. Estrogens appear to be related to the growth of pre-existing uterine leiomyomas. Endocervical cells under the influence of progestogens may develop adenomatous changes, and these benign changes have on occasion been misinterpreted as carcinoma.^ieng

Endometrial histologic changes in post-menopausal breast cancer patients using tamoxifen.

OBJECTIVE: The aim of this study was to evaluate the effect of tamoxifen on the endometrium of post-menopausal women with breast cancer and to examine the relationship between ultrasonography, hysteroscopy and histopathologic changes. METHOD: Included in this longitudinal study were 303 post-menopausal women taking 20 mg daily of tamoxifen. Hysteroscopy was performed in 83 patients with an endometrial thickness of only >or=5 mm and 34 with vaginal bleeding also. Forty-five asymptomatic patients (control group) underwent hysteroscopies. RESULT: The most frequent outcome in patients with endometrial thickness of only >or=5 mm was an atrophic endometrium in an empty cavity (79.5%) whereas simple hyperplasia (35.3%) was found in women with vaginal bleeding. Carcinoma was diagnosed in seven cases (5.9%). In the control group, no endometrial cancer was found. CONCLUSION: This study suggests that patients with a thickness >5 mm should be offered a whole hysteroscopic evaluation, whenever bleeding is reported.

Uterine changes during tamoxifen therapy.

Tamoxifen used for adjuvant therapy in breast cancer, has a complex and unclear action on endometrium and myometrium. Many authors demonstrated endometrial proliferous changes in peri and post menopausal women. Our study shows the development of myomas in three patients without uterine pathology before tamoxifen therapy, and the increase of a polip and a myoma after tamoxifen therapy. Moreover, we observed the development of a myoma in a patient after one year tamoxifen in association with LH-RH analogue therapy. It is necessary to continue our study with a larger number of patients to assess the hyperplasic effect of tamoxifen.

Tumor induction in monkeys after administration of dimethylhydrazine.

1,2-Dimethylhydrazine (DMH) was administered subcutaneously to nine Macaca fascicularis monkeys (6 males and 3 females) at doses of 16 mg/kg body weight, three times a month for two years. Colon cancer was detected in two male monkeys after total DMH doses of 1080 and 3696 mg (528 and 400 mg/kg body wt., respectively). A uterine tumor was induced in one female monkey which received 3648 mg of DMH (608 mg/kg body wt.). Latent periods of tumor development were 34, 47 and 55 weeks, respectively. Histologically, the colon tumors had the structure of adenocarcinoma in both cases and the uterine tumor was diagnosed as fibromyoma.