The mammograms manquent-elles fewer breast cancers among women with a family history of breast cancer?
The mammograms appear to be missing a similar number of breast cancer among women with a family history of breast cancer. While mammograms detect the majority of invasive breast cancer, they lack some and this proportion is higher among young women than among older women regardless of family history.
If 100 women under the age of 50 without a family history with invasive breast cancer have a mammogram for the first time, cancer will appear on mammograms in about 70% of these women. The remaining 30 women will have a normal mammogram. These data are similar for women with a family history of breast cancer.
The mammograms found more cancer in women over 50 years since the breast density decreases. If 100 women over the age of 50 with invasive breast cancer have a mammogram for the first time, cancer will appear on mammograms in about 85% of these women. The remaining 15 women will have a normal mammogram. Again, these figures are similar for women with a family history of breast cancer.
So the proportion of cancers missed by mammography is largely influenced by the age of the woman. The mammograms miss the same proportion of cancer among women of similar age regardless of family history.
