More than 80 percent of women feel unsafe by the new guidelines which say routine breast cancer screening for women younger than 50 is not mandatory.

Instead of recommending yearly mammograms in all women age 40 and above, the U.S. Preventive Services Task Force (USPSTF) told women should not regularly get screened until they reach 50, and those between 50 and 74 should only have mammograms every two years.

But at the same time USPSTF didn't say no women younger than 50 should be screened either. They left the decision up to the individual to decide and to consult with their doctors.

On the other hand, so many women are over-concerned and overestimate the risk of developing breast cancer, however.

Dr. Autumn Davidson and her colleagues handed out questionnaires to 247 women in their 40s who came to the hospital for an annual exam.

On average, they considered U.S. Women's lifetime risk of getting the disease at 37 percent.

Indeed, they have been exposed to consistent and high profile media campaigns, endorsed by medicine and variety of interest groups, that have indoctrinated them into the concepts that mammograms lead to early detection and early detection saves lives, the researchers wrote in the American Journal of Obstetrics and Gynecology.

However, in reality about 1 in 8 women in the United States (12%) will develop invasive breast cancer over the course of her lifetime.

But, it is also true that for women in the U.S., breast cancer death rates are higher than those for any other cancer, besides lung cancer.

Elizabeth Thompson, president of advocacy group Susan G. Komen for the Cure, said her group is concerned that the new recommendations would stop women in their 40s from taking screening. The group recommends women in their 40s should have an annual mammogram each year if they are of average risk.

However, mammograms are very expensive and invasive occasionally, and often give a false positive, causing unnecessary worries to women that gets screening annually.

In 2010, an estimated 207,090 new cases of invasive breast cancer were expected to be diagnosed in women in the U.S., along with 54,010 new cases of non-invasive (in situ) breast cancer.