Evaluation of Different Doses of the Aromatase Inhibitor Letrozole for the Treatment of Ectopic Pregnancy and Its Effect on Villous Trophoblastic Tissue

Efficacy of letrozole for the treatment of tubal ectopic pregnancy: A meta-analysis

BACKGROUND

Tubal ectopic pregnancy (EP) is a life-threatening condition, especially if undiagnosed or misdiagnosed, tipically in low income countries and/or where women have limited access to health care. The current management protocol of tubal EP consists of either surgical management, or medical management with methotrexate. Recent studies, while few, have suggested that letrozole, an aromatase inhibitor, may play a role in the medical treatment of tubal EP.

OBJECTIVES

To evaluate the effectiveness of letrozole alone in the medical treatment of tubal EP.

SEARCH STRATEGY

Electronic databases were searched until 31 December 2023.

SELECTION CRITERIA

Retrospective or prospective studies reporting the treatment of tubal EP with letrozole alone were considered eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Pooled results were expressed as OR with 95 %CI. Heterogeneity was assessed using Higgins I2. Subgroup analysis was performed to compare outcomes according to time after intervention. Subgroup differences were checked through χ2 test.

RESULTS

A total of 152 patients were included. Seventy-nine patients (51.97 %) were treated with letrozole, 39 patients (16.54 %) with methotrexate, and 34 patients (31.49 %) underwent surgical treatment. Pooled data analysis supports the consistency of the effect of letrozole in reducing β-hCG over time at a comparable rate among studies, and that treatment with letrozole is superior to surgery and has the same efficacy as methotrexate. However, all the included studies were judged at high risk of bias in terms of study design, sample representativeness, and sampling technique. Furthermore, short and long term side effects were not reported in any of the included studies.

CONCLUSIONS

Letrozole is a promising alternative to methotrexate and surgical therapy in the treatment of tubal EP. Although this meta-analysis suggests efficacy and low hazard of the drug and encourages its application, the data available today remain extremely sparse, which weakens any claims that can be made, and is not sufficient to assert that letrozole is safe and effective in the treatment of EPs. There is an absolute need for randomized studies with accurate patient selection, fixed doses, large sample sizes, and reporting of short- and long-term side effects to refute or confirm this assumption.

Comparing the effectiveness of letrozole versus methotrexate for treatment of ectopic pregnancy: A randomized controlled trial

OBJECTIVE

To evaluate the efficacy of two different regimens of Letrozole, an aromatase inhibitor, in the management of ectopic pregnancy compared to methotrexate.

STUDY DESIGN

This randomized controlled trial was conducted on 88 women diagnosed with ectopic pregnancy with a baseline level of serum beta-human chorionic gonadotropin under 3000 mIU/mL between June 30, 2023, and December 30, 2023, at the Department of Obstetrics and Gynecology of the Vali-e-Asr Hospital affiliated with Tehran University of Medical Sciences. Participants were allocated into either methotrexate (n = 43), 5-day course Letrozole (n = 24), or 10-day course Letrozole (n = 21) treatments. The methotrexate group received a single dose of 50 mg/m2 dosage intramuscular methotrexate. The 5-day Letrozole group received a 2.5 mg Letrozole tablet three times daily for 5 days, whereas the 10-day Letrozole group received a 2.5 mg Letrozole tablet twice daily for 10 days. The primary outcome was the treatment response, defined as the achievement of a negative serum beta-human chorionic level without the need for additional methotrexate treatment or surgery. The secondary outcomes were the need for additional methotrexate dose or laparoscopic surgery intervention. The trial protocol was prospectively registered in ClinicalTrials.gov with code NCT05918718.

RESULTS

The treatment response rates in methotrexate, 5-day Letrozole, and 10-day Letrozole groups were 76.7 %, 75.0 %, and 90.5 %, respectively, with no significant differences between the groups (P-value = 0.358). A total of 10 (23.3 %) patients from the methotrexate group, 3 (12.5 %) from the 5-day Letrozole group, and 2 (9.5 %) from the 10-day Letrozole group required an additional methotrexate dose, with no significant differences between the groups (P-value = 0.307). Furthermore, only 3 (12.5 %) patients, all from the 5-day Letrozole group, were suspected of tubal rupture and underwent surgery (P-value = 0.016).

CONCLUSION

Our findings suggest Letrozole as a safe alternative to methotrexate in treating stable ectopic pregnancies, with a favorable treatment response rate. However, there is still a need for future larger studies to determine the applicability of Letrozole in the EP management. Also, the non-significant higher effectiveness of the 10-day Letrozole regimen than the 5-day Letrozole group underscores the need for future research to determine the optimal Letrozole regimen for the management of ectopic pregnancy.

A novel triad for the diagnosis of endometriosis, the short anogenital distance combines with high endometrial BCL2 and low endometrial FASL

OBJECTIVE

To investigate the anogenital distance from the upper verge of the anus to the posterior fourchette (AGDAF), FASL, and BCL2 combination as a reliable and non-invasive tool for the diagnosis of endometriosis.

METHODS

This study included 100 women with endometriosis and 50 women without endometriosis as the control group. All cases underwent history taking, body mass index (BMI) measurement, AGD measurement, and FASL and BCL2 immunohistochemical staining of the eutopic endometrial tissue.

RESULTS

This study included 150 women divided into endometriosis and control groups. Endometriosis cases significantly had shorter AGDAF, 22.9 ± 2.6 mm, compared with the control group, 27.3 ± 3.5 mm (P < 0.001). Lower FASL and higher BCL2 expression were associated with endometriosis (P < 0.001). The combined measurement of AGDAF (cut-off point 24.55 mm) with FASL and BCL2 was associated with endometriosis (P < 0.001). The combined diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of AGDAF, FASL, and BCL2 were 83%, 78%, 87.3%, and 69.6%, respectively. The area under the curve was greater for AGDAF, FASL, and BCL2 in combination than for individual measurements.

CONCLUSION

Combining short AGDAF with high BCL2 and low FASL is a highly sensitive, non-invasive diagnostic tool for endometriosis.