Research Highlights Factors Influencing Secondary Breast Cancer Risk

Breast cancer is a tumor formed in the breast due to uncontrolled cell growth. It needs proper diagnosis and treatment as it can spread throughout the body if not treated on time. Even after proper treatment, there is a risk of the development of secondary primary breast cancer (SPBC). However, a recent study published in JAMA Oncology has revealed that breast cancer survivors aged 40 or younger who don’t have a specific genetic mutation don’t have the risk of the development of SPBC.  

This research involved 1297 women who had breast cancer before the age of 40. Six hundred eighty-five of these women had undergone either unilateral mastectomy or lumpectomy to treat breast cancer at 0 to 3 stages. These women were tracked for almost 10 years at Harvard T.H. Chan School of Public Health in Boston.  

When researchers observed and studied the collected data, they found that only 2.5% of these breast cancer survivors had developed SPBC. On the other hand, 2 out of the 17 women who had developed SPBC had it in the same breast where they had the lumpectomy. The average difference between the initial diagnosis of breast cancer and the occurrence of SPBC was 4 years.  

Researchers also conducted genetic testing on 577 women to understand the impact of genetic factors on the risk of developing SPBC. When they observed the results, they saw women who had a pathogenic variant were at a higher risk of developing SPBC compared to women who did not have it. The risk of developing SPBS was 2.2% for women who were carriers and 8.9% for women who were not.  

The researchers also found that the type of initial breast cancer diagnosis can influence the risk of SPBC. Women who were diagnosed with cancer with primary in situ had a higher risk of SPBC compared to those who were diagnosed with cancer with the invasive method.   

As this research reveals some factors like diagnosis methods can increase the risk of development of SPBC, it will be helpful for healthcare professionals to make effective strategies to treat women with breast cancer.   

Reference Link:  

Kristen D. Brantley et al, Second Primary Breast Cancer in Young Breast Cancer Survivors, JAMA Oncology (2024).   

DOI: 10.1001/jamaoncol.2024.0286