A family history of breast cancer does not necessarily mean that women who have the disease are more likely to die from it.
Investigators reviewed 28,649 Swedish women diagnosed with breast cancer from 1991 to 2019.
Overall, 5081 patients (17.7%) had at least one female first-degree relative previously diagnosed with breast cancer.
After adjusting for demographics, tumor characteristics, and treatments, a family history of breast cancer was associated with a lower risk of breast cancer-specific death in the full cohort (hazard ratio [HR], 0.78) and in ER-negative women (HR, 0.57) within 5 years of diagnosis, after which point the association was no longer significant.
The lower risk of death among women with a family history could mean that these women are more motivated and likely to get screened, potentially catching tumors earlier, and may be more likely to adhere to treatment recommendations.
However, having a family history of early onset breast cancer (before the age of 40) was associated with a higher risk of breast cancer-specific death (HR, 1.41).
Although the findings are reassuring for many women with breast cancer, "genetic testing of newly diagnosed patients with early onset family history may provide useful information to aid treatment and future research," the researchers concluded.
The study was led by Yuqi Zhang, PhD, of the Karolinska Institutet, Stockholm, Sweden, and published June 13, 2023, in JAMA Network Open.
The main analysis did not include tumor characteristics only available within the last 20 years, including ERBB2 status.
Relatively wide confidence intervals make the association between a family history of early onset breast cancer and higher risk of breast cancer death somewhat uncertain.
The work was funded by the Swedish Cancer Society and others.
The investigators report no relevant financial relationships.
M. Alexander Otto is a physician assistant with a master’s degree in medical science and a journalism degree from Newhouse. He is an award-winning medical journalist who worked for several major news outlets before joining Medscape. Alex is also an MIT Knight Science Journalism fellow. Email: email@example.com
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Cite this: Breast Cancer Family History Linked to Better BC Survival - Medscape - Jun 21, 2023.