Benign breast disease is known to increase the chances of subsequent breast cancer. According to Spanish researchers, the way benign breast disease is detected may be an indication of how likely it is to become cancerous. The findings from the team led by Xavier Castells, MD, PhD, Head of the Epidemiology Department at the Hospital del Mar Medical Research Institute in Barcelona, were presented at the 12th European Breast Cancer Conference (Abstract 15).
Benign breast disease detected on the first occasion a woman undergoes breast screening is classified as “prevalent” benign breast disease, whereas cases detected on subsequent visits are classified as “incident” benign breast disease.
Xavier Castells, MD, PhD
Marta Román, PhD
Marta Román, PhD, a senior researcher in the epidemiology department at the Hospital del Mar Medical Research Institute, told attendees of the conference, “Our results show that women with a benign breast disease diagnosed from the second screening onward have a significantly higher subsequent risk of breast cancer than those with benign breast disease diagnosed on their first mammographic screening.”
Analysis Results
The researchers analyzed data from 629,087 women who underwent 2,327,384 screening mammograms between 1995 and 2015, and they followed them until 2017. They found that women diagnosed with incident benign breast disease had a 2.67-fold increased chance of developing breast cancer than women with no benign breast disease, whereas women with prevalent benign breast disease had a 1.87-fold increased risk.
They also classified the benign breast diseases as nonproliferative or proliferative, depending on whether the breast tissue showed an increase in the growth of certain cells, such as the ductal cells found in ductal hyperplasia. They found that women with proliferative benign breast disease had a 3.28-fold increased chance of breast cancer compared to women with no breast disease, while women with nonproliferative benign breast disease had a 1.96-fold increased risk.
Dr. Román said, “We found the highest risk of breast cancer in women with incident, proliferative benign breast disease. They had a nearly fourfold increased risk of breast cancer compared to women with no benign breast disease.”
Women with an incident, nonproliferative benign breast disease had a 2.39-fold increased chance of subsequently developing breast cancer compared to women with no benign breast disease; women with prevalent, proliferative benign breast disease had a 2.85-fold increased risk; and women with prevalent, nonproliferative benign breast disease had a 1.63-fold increased risk.
Study Implications
The researchers hope that their findings will be useful in designing personalized breast cancer screening strategies in order to improve the effectiveness of breast cancer screening.
“The likelihood that a woman will benefit from screening mammography depends on her risk for developing clinically significant breast cancer in her lifetime,” said Dr. Román. “Taking individual risk factors beyond age into account should enable the classification of women into groups at varying risk of breast cancer. Personalized risk-based screening going beyond the current ‘one size fits all’ recommendation may increase the effectiveness of breast cancer screening. Including information from benign breast disease, in addition to other factors, to develop risk-based screening approaches can help with the prediction of whether a woman would develop breast cancer in a defined period.”
“Different screening strategies can be considered for each woman based on her personal risk of breast cancer: by modifying the screening interval, which could be annual, or every 2 or 3 years, the method of screening—for instance, mammogram, ultrasound, or magnetic resonance imaging—or the age range in which the woman is invited for screening participation,” she concluded.
Dr. Román and her colleagues believe these findings will help clinicians understand the different risks associated with benign breast disease and improve the accuracy of breast cancer risk predictions.
Disclosure: For full disclosures of the study authors, visit cm.eortc.org.
