Low Breast Density in Mammography Worsens Breast Cancer Prognosis
Very low mammographic breast density worsens the prognosis of breast cancer, according to a recent study from the University of Eastern Finland. Disease free survivals as well as overall life expectancies were significantly shorter in women with very low-density breasts in comparison to women with high density breast tissue. The lower the breast tissue density, the less fibroglandular tissue there is compared to fat tissue.
In the future, these findings may prove significant for the assessment of breast cancer prognosis and treatment planning.
The study involved 270 breast cancer patients at Kuopio University Hospital, aged between 32 and 86 years. Breast tissue density was analyzed on the basis of mammographic images obtained at the time of diagnosis. The researchers determined the proportion of dense glandular tissue of the overall breast area. Breast tissue density was categorized as low when the proportion of glandular tissue was below 25%, and as very low when the proportion of glandular tissue was below 10%. The study was a six-year follow up focusing on the effects of breast tissue density and other mammographic features on breast cancer prognosis.
The results indicate that a very low breast tissue density is an independent poor prognostic factor of breast cancer, regardless of patients' age, menopausal status or body mass index. Out of the women with very low breast tissue density, 70.7% were alive at the end of the six-year follow-up, whereas out of women whose proportion of glandular tissue was higher than 10%, 87.7% were alive at the same time. Lower breast tissue density was also associated with more aggressive higher grade tumors.