Women with and without family history of breast cancer are equally likely to develop the disease, according to a new study.

The research was presented Tuesday at the annual meeting of the Radiological Society of North America (RSNA).

"In the 40 - 49 age group, we found a significant rate of breast cancer and similar rates of invasive disease in women with and without family history," said Dr. Stamatia V. Destounis, a radiologist and managing partner of breast imaging and cancer diagnostic center Elizabeth Wende Breast Care, "Additionally, we found the lymph node metastatic rate was similar."

In the study, Destounis performed a retrospective review aimed at identifying the number and type of cancers diagnosed among women between the ages of 40 and 49, who underwent screening mammography at Elizabeth Wende Breast care from 2000 to 2009.

The results were alarmingly similar for both groups.

It was found that of the 373 patients who were diagnosed with breast cancer as a result of screening, 39 percent of the group had a family history of breast cancer, 61 percent of the group had no family history of the disease.

In the family history group, 63 percent of the patients had an invasive disease, and in the no family history group, 64 percent of the patients had an invasive disease.

It was also found that the respective lymph node metastatic rates between the two groups were also very similar, with 31 percent in the family history group and 29 percent in the no family history group.

In 2009, the U.S. Preventative Services Task Force (USPSTF) issued a revised version of their previous breast cancer screening guidelines. Contrary to the old guidelines, the new guidelines recommended against a routine annual mammography screening for women in their 40s, noting that their old guidelines were based on “weak” evidence.

The USPSTF also states that, “The current evidence is insufficient to assess the balance of benefits and harms of the service,” and that because of lacking, conflicting and poor evidence, the balance of the benefits and the harms of a recommended annual mammography screening for women between the ages of 40 and 49 cannot be determined.

The new guidelines spurred a controversy among physicians, advocacy groups and in the media. Many groups such as the American Cancer Society and the American College of Obstetricians and Gynecologists are still following the old USPSTF guidelines, and recommend yearly screenings for women who are aged 40 or older.

"We believe this study demonstrates the importance of mammography screening for women in this age group, which is in opposition to the recommendations issued by the task force," said Destounis.