(RxWiki News) Women who have a mutation in the BRCA1 and/or BRCA2 gene are at a much greater risk for developing breast cancer by age 70 than women who do not have the mutations. Should they continue to get mammograms as they age?
United States guidelines for screening women with these mutations advise annual MRIs and mammograms with no upper age limit. However, most international guidelines recommend annual breast exam, MRI and mammogram for women under the age of 50 who have the BRCA mutations, and give inconsistent advice for screening after that age.
A recent study examined the occurrence of breast cancer in women aged 60 and over with BRCA mutations and compared the results with how often a women had breast cancer screening.
The results of this study showed that twice as many breast cancers found on mammograms done every two years were at an advanced stage, compared to breast cancers found on annual mammograms. The researchers recommended that annual breast cancer screening should continue for women with BRCA gene mutations beyond age 60.
"Ask your doctor if you need regular breast cancer screenings."
This study was conducted by Madeleine M. Tilanus-Linthorst, MD, PhD, from the Department of Surgery at the Erasmus Medical Centre in Rotterdam, The Netherlands.
The researchers reviewed medical records and records of the National Breast Cancer Screening Program in The Netherlands. They collected data on women who had the BRCA1 or BRCA2 mutation and were at least 60 years old.
From the record review, Dr. Tilanus-Linthorst and team identified 548 women with mutations in the BRCA genes — 413 with a mutation in the BRCA1 gene, 133 with a mutation in the BRCA2 gene, and two women with a mutation in both genes. Of these women, 395 had one or both breasts and were included in the study.
The researchers obtained information on breast cancer screenings done on the women, types of screening (MRI or mammogram), frequency of screenings (done annually or every other year), findings of breast cancer, and types and stages of breast cancer.
The researchers classified tumors as “unfavorable” or “favorable” based on the cancer stage. Favorable tumors were defined as small with no evidence of cancer spread to nearby lymph nodes or to other organs. Unfavorable tumors had characteristics that did not fit into the favorable category; for example, they were larger or had spread to other organs.
A total of 113 breast cancers were diagnosed in the women, and slightly over half were first breast cancers.
Among the women who carried a BRCA mutation and were screened every other year, 53 percent of the tumors found were in an unfavorable stage, compared with 21 percent of the tumors found on annual screening. The results were similar whether the mutation was in the BRCA1 or BRCA2 gene.
In the group of women screened every other year, 40 percent of the breast cancers were found in the period of time between mammograms, compared with 20 percent in the group of women who had annual mammograms.
The authors cited several limitations of their study. First, they recognized that some women lived in countries where women with BRCA1 or BRCA2 mutations were given strategies to reduce their risk of developing cancer. Second, the women in this study with BRCA2 mutations were not screened as intensively for cancer as women with BRCA1 or both mutations.
The authors of this study also noted that they did not collect and analyze survival data and did not report on false-positive breast cancer screening results.
"An unacceptably high percentage of breast cancers (53 percent) were detected in unfavorable stage with biennial [every other year]," the authors wrote.
"While screening biennially is beneficial in the general population, our results suggest that continuation of annual screening is the advisable strategy for BRCA 1/2 mutation carrier [greater than or equal to] 60," they wrote.
This study was published in the May issue of the International Journal of Cancer.
Funding for the study was provided by grants from the Dutch Cancer Society, the Netherlands Organization of Scientific Research, the BBMRI and a Pink Ribbon grant.
The authors declared no conflicts of interest.