Surprising as it may seem ,the number one risk factor for breast cancer seems to be Dense Breasts (FCBD) , ie breasts that are predominantly dense glandular tissue than fat.
After examining data from 18,000 women wt breast cancer and 184,000 women of the same ages without, it was determined that FCBD was the greatest risk factor for cancer, even more than risks of family history or having children later in life , almost twice the risk .
FCBD is seen in 60 % of younger women and 40% of post menopausal women but additionally FCBD makes the detection of Breast cancer harder to see on Mammograms.
There is not much women can do to reduce FCBD. Some reports have shown that a drug Tamoxefen can reduce FCBD , however logistically that would be difficult due to other side effects unless there is also concomitant high risk by family history. Gaining some weight to add fat to the breasts may be slightly protective however Obesity is in itself tied in as a separate risk factor.
5% of the breast cancer cases diagnosed in the USA can be tracked to genetic mutations and these women are more likely t have aggressive and hard to treat cancers .
It is recommended that women with FCBD consult their Doctors and consider an MRI type screenings beyond screening mammograms. I believe I could have benefited form early detection myself if we had indications the for MRIs for FCBD.