Toxicology of progestogens of implantable contraceptives for women

Breast Cancer Risk with Progestin Subdermal Implants: A Challenge in Patients Counseling

There is a steady global rise in the use of progestin subdermal implants, where use has increased by more than 20 times in the past two decades. BC risk has been reported with the older progestin only methods such as oral pills, injectables, and intrauterine devices, however, little is known about the risk with subdermal implants. In this review, we aim to update clinicians and researchers on the current evidence to support patient counseling and to inform future research directions. The available evidence of the association between the use of progestin subdermal implants and BC risk is discussed. We provide an overview of the potential role of endogenous progesterone in BC development. The chemical structure and molecular targets of synthetic progestins of relevance are summarized together with the preclinical and clinical evidence on their association with BC risk. We review all studies that investigated the action of the specific progestins included in subdermal implants. As well, we discuss the potential effect of the use of subdermal implants in women at increased BC risk, including carriers of BC susceptibility genetic mutations.

ProTox-II: a webserver for the prediction of toxicity of chemicals

Advancement in the field of computational research has made it possible for the in silico methods to offer significant benefits to both regulatory needs and requirements for risk assessments, and pharmaceutical industry to assess the safety profile of a chemical. Here, we present ProTox-II that incorporates molecular similarity, pharmacophores, fragment propensities and machine-learning models for the prediction of various toxicity endpoints; such as acute toxicity, hepatotoxicity, cytotoxicity, carcinogenicity, mutagenicity, immunotoxicity, adverse outcomes pathways (Tox21) and toxicity targets. The predictive models are built on data from both in vitro assays (e.g. Tox21 assays, Ames bacterial mutation assays, hepG2 cytotoxicity assays, Immunotoxicity assays) and in vivo cases (e.g. carcinogenicity, hepatotoxicity). The models have been validated on independent external sets and have shown strong performance. ProTox-II provides a freely available webserver for in silico toxicity prediction for toxicologists, regulatory agencies, computational and medicinal chemists, and all users without login at http://tox.charite.de/protox_II. The webserver takes a two-dimensional chemical structure as an input and reports the possible toxicity profile of the chemical for 33 models with confidence scores, and an overall toxicity radar chart along with three most similar compounds with known acute toxicity.

Use of the levonorgestrel-releasing intrauterine system in breast cancer patients

OBJECTIVE

To study the recurrence of breast cancer among patients who were using the levonorgestrel-releasing intrauterine system (LNG IUS).

DESIGN

A retrospective, controlled cohort analysis.

SETTING

Six Belgian hospitals.

PATIENT(S)

We identified 79 breast cancer patients who used the LNG IUS, and we selected a control group of 120 patients with no history of LNG IUS use and who were closely matched for age at diagnosis, tumor stage, tumor grade, and treatment modalities. Two subgroups were identified: [1] breast cancer patients who continued using the LNG IUS after diagnosis and [2] breast cancer patients who began using an LNG IUS after treatment for breast cancer.

INTERVENTION(S)

Patient's data were collected and survival analysis was performed.

MAIN OUTCOME MEASURE(S)

Breast cancer recurrence rate.

RESULT(S)

There was a recurrence rate of 21.5% (17/79) among LNG IUS users and of 16.6% (20/120) among the control group (adjusted hazard ratio, 1.86; 95% confidence interval, 0.86-4.00; no statistically significant difference). Subgroup analysis showed that women using the LNG IUS (n = 38) at the time of breast cancer diagnosis (and who continued its use) had a statistically significantly increased risk of recurrence (adjusted hazard ratio, 3.39; 95% confidence interval, 1.01-11.35) compared with patients in the control group. There was 47.4% (18/38) nodal involvement in this subgroup, and all patients who recurred had metastatic disease.

CONCLUSION(S)

Overall, we did not find an increased risk of breast cancer recurrence associated with use of the LNG-IUS. However, in a subgroup analysis of women who developed breast cancer while using an LNG IUS and who continued to use the LNG IUS, we found a higher risk of recurrence of borderline statistical significance. Additional research is needed to confirm or refute these findings.

Levonorgestrel pharmacokinetics in plasma and milk of lactating women who take 1.5 mg for emergency contraception

BACKGROUND

Progestin-only methods are among the contraceptive options available for breastfeeding women, however the doses of progestin used in emergency contraception (EC) have not been evaluated in nursing mothers. We therefore investigated the pharmacokinetics of 1.5 mg levonorgestrel (LNG) in lactating women.

METHODS

Twelve healthy exclusively breastfeeding volunteers received 1.5 mg LNG. Women refrained from nursing for 72 h after dosing and fed their infants with milk frozen beforehand. Serial blood and milk samples were collected for 120 h and assayed for LNG and sex hormone binding globulin.

RESULTS

LNG concentrations peaked in plasma and in milk 1-4 h and 2-4 h after dosing, respectively. Concentrations in milk (M) paralleled those in plasma (P) but were consistently lower (mean M:P ratio 0.28). Estimated infant exposure to LNG is 1.6 microg on the day of dosing (1 microg in the first 8 h), 0.3 microg on the second day and 0.2 microg on the third day.

CONCLUSIONS

Nursing mothers may need EC. These results suggest that to limit infant exposure to the period of maximum LNG excretion in milk, mothers should discontinue nursing for at least 8 h, but not more than 24 h, after EC.

Failure of Implanon contraception in a patient taking carbamazepin for epilepsia

Until now, no pregnancies have been reported in association with the implantable hormonal contraceptive Implanon (Organon, Roseland, NJ, USA), resulting in a pearl index of 0. We present a 24-year-old patient who conceived despite the correct application of Implanon for one and a half year. The patient was concurrently taking carbamazepin for epilepsia. Special care should be taken to patients demanding hormonal contraceptives while taking carbamezepin. Even Implanon seems to possibly fail in this combination.

Genotoxicity of hormonal steroids

Hormonal steroids have a widespread use in medicine and their side effects are continuously debated. The possible genotoxic activity of steroids has been the subject of many investigations. The natural estrogens estradiol, estrone and estriol are generally negative in the ICH core battery of tests, but several positive results have been obtained when using additional endpoints of genotoxicity. The genotoxic activity of the 4-hydroxy metabolites of estradiol and estrone is well established. The synthetic steroidal estrogens have a comparable profile of negative and positive test results. Cyproterone acetate and some of its analogues have a special position within the group of progestins. Their genotoxic potential has been established. Other progestins are generally negative in the routine tests. Anti-glucocorticoids, anti-progestins, corticosteroids, androgens, anabolics and anti-androgens appear to be devoid of genotoxic activities. The genotoxic potential of estradiol, estrone and cyproterone acetate with its analogues may play no role under normal physiological and therapeutic conditions. The metabolic conditions that are needed for the formation of DNA-reactive metabolites and oxygen radicals may not be present in humans. Epidemiological cancer data seem to support this view. The importance of thresholds in the dose-effect-relationship of genotoxicity data and their use in risk assessment is discussed.

Comparison of a levonorgestrel-releasing intrauterine device versus expectant management after conservative surgery for symptomatic endometriosis: a pilot study

OBJECTIVE

To determine whether the frequency and severity of dysmenorrhea are reduced in women with symptomatic endometriosis in whom a levonorgestrel-releasing intrauterine device (Lng-IUD) is inserted after operative laparoscopy compared with those treated with surgery only.

DESIGN

Open-label, parallel-group, randomized, controlled trial.

SETTING

A tertiary care and referral center for patients with endometriosis.

PATIENTS(S)

Parous women with moderate or severe dysmenorrhea undergoing first-line operative laparoscopy for symptomatic endometriosis.

INTERVENTION(S)

Randomization to immediate Lng-IUD insertion or expectant management after laparoscopic treatment of endometriotic lesions. Proportions of women with recurrence of moderate or severe dysmenorrhea in the two study groups 1 year after surgery and overall degree of satisfaction with treatment. Moderate or severe dysmenorrhea recurred in 2 of 20 (10%) subjects in the postoperative Lng-IUD group and 9/20 (45%) in the surgery-only group. Thus, a medicated device inserted postoperatively will prevent the recurrence of moderate or severe dysmenorrhea in one out of three patients 1 year after surgery. A total of 15/20 (75%) women in the Lng-IUD group and 10/20 (50%) in the expectant management group were satisfied or very satisfied with the treatment received.

CONCLUSION(S)

Insertion of an Lng-IUD after laparoscopic surgery for symptomatic endometriosis significantly reduced the medium-term risk of recurrence of moderate or severe dysmenorrhea.

Pathogenetic and diagnostic aspects of siliconosis

Silicones have an adverse effect on human health well beyond that suggested by the recent superficial public controversy. The evidence for immune responses to injected/implanted silicones is extensive, detailed, often very specific, and not at all new. Comprehending the immunopathogenicity, realized and potential, of silicone has grown as our general understanding of the immune system has developed. Several major issues in furthering this comprehension pertain to the nature of the essential epitope, special risk of silicones to women, and definition of the chronic disease complex so evident clinically, one defying classification within currently traditional disease categories and states. The commentary presented here emphasizes the immunopathic evidence, explores the question of the essential epitope, estimates the minimal threshold of silicone load for immune reactivity, presents a profile of autoantibodies for siliconosis, and calls attention to specific silicone-based female contraceptive modalities. The silicone content of personal care products, not always revealed by retail package labeling, is explored as a potential sensitizing factor in the environment.