Transilluinitiation breast spectroscopy (TIBS): a biomarker of breast tissue density

摘要

A primary goal of preventive oncology is the identification of women at increased risk for breast cancer who would benefit most from risk reducing interventions. An established physical risk assessment technique is the use of mammography to quantify the dense tissue content of the breast. Women with a majority of the breast occupied by dense tissue are at four to six times greater risk of breast cancer than women with the least density. The main drawback of mammography is that it requires exposure to ionising radiation and there are concerns regarding use in young women. Another potential physical risk assessment is Transillumination Breast Spectroscopy (TIBS). TIBS uses non-ionizing optical radiation to measure bulk tissue properties and thus is applicable to women of any age. This study examines the feasibility of using TIBS in vivo to detect mammographic density as an interim indicator of breast cancer risk. TIBS measurements were completed on 300 women with radiological normal mammograms. White light (625 to 1060 nm) was delivered to the breast tissue and transmitted light was detected on the opposite side of the breast. Principal component analysis was used to reduce the spectral data and generate individual 'risk' scores. Agreement between the obtained 'risk' scores and mammographic density was established using density cluster analysis, the Kappa statistic and logistic regression. The agreement between breast density assessed by mammography and by TIBS was statistically significant for all 'risk' scores. Logistic regression indicated a strong association between the TIBS scores and mammographic density. TIBS provides an alternative to x-ray derived mammographic density as a biomarker of breast density and hence cancer risk.