A bipartisan bill that would require health insurers to cover additional breast screenings if a mammogram demonstrates dense breast tissue is advancing in the New Jersey Assembly.

The bill, sponsored by two Republicans and six Democrats, would require health insurance companies to cover ultrasound, MRI, 3-D mammography (tomosynthesis) and other supplemental breast screenings when a mammogram demonstrates a woman has dense breast tissue or her doctor deems it medically necessary due to other risk factors.

"A mammogram will detect only about 48 percent of tumors in women with dense breast tissue, meaning the rest will elude early detection," said one of the bill sponsors, Troy Singleton (D-Burlington), in a statement.

Like other bills passed in Connecticut, Texas, Virginia, California, New York and Hawaii in recent years, the New Jersey bill would also require mammography reports to contain information on breast density so that doctors will have to speak with women about the risks.

Connecticut and Illinois are the only states that require insurance coverage for supplemental screenings, specifically ultrasound and MRI. (Though a bill has been introduced, Illinois still does not have an "inform" law that requires doctors to talk to women about the risks of their dense breast tissue.)

Studies have shown that women with dense breast tissue — which often makes it hard for radiologists to see abnormalities on a mammogram — have a higher rate of breast cancer. However, a recent study from the Journal of the National Cancer Institute found breast density was not linked to increased cancer deaths. There is also debate in the medical community about what constitutes breast density in a woman, even though imaging equipment vendors have developed special qualitative software aimed at measuring breast density.

The bill was approved by the New Jersey Assembly Appropriations Committee and now awaits consideration by the full Assembly.