Two Senate Democrats are pressing the U.S. Food and Drug Administration (FDA) for tougher action against power morcellators over uterine cancer concerns.

Sens. Kirsten Gillibrand and Elizabeth Warren sent a letter to the FDA, stating that the agency needs to do more to protect women from the risk of aggravating uterine cancer associated with power morcellators.

Power morcellators are a surgical tool used in laparoscopic surgery. In laparoscopic surgery, like “robotic hysterectomies,” surgeons use specialized implements to perform the bulk of the surgery inside the patient’s body.

This allows doctors to perform surgery without cutting through as much healthy tissue. This can reduce recovery times and improve survival rates for surgeries. However, some surgical techniques, like robotic hysterectomy, require surgeons to remove tissues and organs larger than the small incisions used in laparoscopic surgery.

In cases like this, power morcellators are used to cut organs like the uterus into smaller pieces for removal. However, it is strongly suspected that power morcellators can cause serious complications.

One of the main reasons for hysterectomies and related procedures seek to remove a type of benign tumor called a uterine fibroid. However, according to FDA estimates, about 1 in 350 uterine fibroids contain cancer cells, specifically uterine sarcomas. Cancers like these uterine sarcomas are most dangerous and most difficult to treat when they spread.

It is strongly suspected that power morcellators can spread these cells when they shred uterine tissue for removal during laparoscopic hysterectomies. This means that some women may discover they have aggressive uterine cancer shortly after laparoscopic hysterectomies or related procedures.

The senators’ letter references earlier actions by the FDA, including a safety notice from April advising against using power morcellators on the uterus. However, the senators said that the FDA has not done enough.

Despite the FDA stopping short of a full recall of all power morcellators, medical giant Johnson & Johnson, the market leader for power morcellators, has undertaken a voluntary recall.

While the senators’ letter acknowledges the FDA’s earlier efforts, they demand faster action and greater transparency on the matter.