LOS ANGELES (KABC) -- If women aren't confused enough about whether to get yearly mammograms, a new report is generating more questions.Do yearly mammograms lead to more unnecessary testing or does it save lives? One local expert said it's a little bit of both.In Denmark, where the government offers breast cancer screening every other year to women over 50, researchers were able to compare the diagnosis rate and treatment in women who got regular mammograms versus those who didn't.The initial finding revealed one out of three women were treated for tumors that were better left alone."The women who were screened were possibly diagnosed with cancers that were not as aggressive and possibly they were over treated," said Dr. Yvonne Bohn, an OB/GYN with Providence St. John's Health Center.The study in the Annals of Internal Medicine also found women diagnosed with aggressive, larger cancers were not picked up at the time of screening.Bohn said taking family history and dense breast tissue into account helps doctors piece together a more accurate picture, but it's still difficult to know which tumors are deadly and which are not."As studies keep coming out that show these less invasive tumors aren't as dangerous as we once thought they were, we may be less radical in our treatment," she said.But Bohn believes many women who are told of a questionable lesion would find it hard to forgo treatment to simply watch and wait. However, she says combining other screening techniques with a mammogram helps give patients the answers they need."Women with dense breasts or high risk for breast cancer may get an ultrasound or an MRI," Bohn said.And in some cases genetic testing can also help guide women in their treatment decision.Bohn said this new study is not about encouraging or discouraging women from regular screening, but rather it's more about generating a discussion a patient should have with her doctor about the frequency of screening based on her individual risk.