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

Abstract

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.

Keywords: Aromatase inhibitors; Clinical efficacy; Conservative treatment; Ectopic pregnancy; Letrozole.