By age 75, half of all men develop an inguinal hernia, a condition where soft tissue pushes through a weak spot in the abdominal muscles. Surgery is currently the only treatment option, but it comes with a recurrence rate of 10 to 15%. A recent study by Northwestern Medicine offers hope for a non-surgical solution.
The study demonstrated that an anti-estrogen drug, already approved for breast cancer treatment, could reverse inguinal hernias in male mice. This approach restored normal anatomy without surgery. Human hernia tissue showed similar molecular markers as those found in the mouse model. In the United States alone, over a million inguinal hernia surgeries are performed annually under general anesthesia.
“This is a blockbuster publication about the first medical treatment of inguinal hernias,” said Dr. Serdar Bulun, senior author and chair of obstetrics and gynecology at Northwestern University Feinberg School of Medicine. “Our findings strongly suggest that men would also respond to this medication as the male mice did.”
The study identified estrogen receptor-alpha (ESR1) as a likely cause of these hernias. ESR1 triggers connective tissue cell growth and fibrous tissue buildup, leading to hernia development.
Published on February 4 in the Journal of Clinical Investigation, the research involved two experiments: one with modified male mouse models and another examining human tissue. In mice, scientists used fulvestrant to block ESR1 in connective tissue cells, preventing muscle damage and hernia formation. Fulvestrant helped shrink large hernias and restore healthy anatomy.
In humans, biopsies from both hernia sites and adjacent healthy muscle revealed biological markers matching those in mice. Estrogen and ESR1 were found to activate genes linked to excessive tissue scarring.
“We expect that estrogen/ESR1 is a promising molecular target for developing pharmaceutical treatments for inguinal hernia in men,” said Dr. Hong Zhao, corresponding author and research professor at Feinberg.
While inguinal hernias are less common in women (one woman for every 34 men), they recur in more than 10% of elderly male patients after surgical repair—affecting approximately 100,000 elderly men annually according to Bulun. Though typically not painful, complications can arise if bowel becomes strangulated by the hernia.
The study titled "Estrogen receptor alpha ablation reverses muscle fibrosis and inguinal hernias" was funded by NIH grants R01-DK121529 and R01-DK139052.