When a patient presents with abnormal vaginal bleeding around or after menopause, part of a physician's work up includes taking a tiny sample of the uterine lining, called an endometrial biopsy. Pathologists then examine this tiny biopsy and characterize the cells and tissue architecture they see under the microscope. A common finding is "endometrial hyperplasia." Simply put, pathologists diagnose endometrial hyperplasia when they see too much cell proliferation and thickening of the inside lining of the uterus in the biopsy sample. The pathologists then go one step further and describe whether the biopsy sample has "atypia" or not (is "non-atypic"). If the pathologist sees atypical cells, there is an approximately 30% chance that the endometrial hyperplasia will progress to endometrial cancer. If there is no atypia, then the chance is much lower- 5%.
Dr. Hashim, Dr. Ghayaty, and Dr. Rakhawy of Mansoura University in Egypt wanted to know more about how to treat patients with endometrial hyperplasia without atypia. In the past, physicians have used progestin pills to treat non-atypical endometrial hyperplasia. However, the progesterone IUD (they studied the Mirena) may be a great option since it gets the progesterone to just the right spot! The authors conducted a meta-analysis of all the studies they could find that explored oral progestins versus Mirena IUD for non-atypical endometrial hyperplasia. They found seven randomized trials that included a total of 766 women. Different studies used different progesterone pills and for different lengths of time, but the study authors pulled out the data to learn how the pills compared to the IUD after 3, 6, 12, and 24 months of use. Their main concern was whether the treatment fixed the abnormalities found in the original biopsy sample when the doctor did a repeat biopsy sample after 3, 6, 12, and 24 months of treatment. The results were very consistent: at all of the time points, the IUD outperformed the progesterone pills. The IUD even outperformed the pills more and more over time.
In addition to looking at the results of the new pathology specimens over time, the authors also compared the two treatments on rates of irregular vaginal bleeding and rates of hysterectomy (surgical removal of the entire uterus). There was no difference between the two groups on irregular bleeding, but this outcome was only examined in 2 of the 7 studies they used. The women treated with the progesterone IUD did have significantly fewer hysterectomies than those who took the progesterone pills.
In conclusion, this meta-analysis of seven prior randomized trials provides strong evidence that women with endometrial hyperplasia without atypia should be offered progesterone IUDs as a potential treatment option and not just offered progestin pills.