This study aims to evaluate if a light based technique, called Transillumination Breast Spectroscopy (TIBS), can be used to construct a non-invasive breast cancer risk predictor which provides a better odds ratio than mammographic parenchymal density.

In a previous cross sectional study in a group of women without breast cancer and with varying degrees of parenchymal density patterns, a strong association was demonstrated between Transillumination Breast Spectroscopy (TIBS) and x-ray derived mammographic density. From this, we expect that TIBS should also provide a comparable odds ratio (4-6) as mammographic density for breast cancer risk shown in other independent epidemiological studies. It is possible that TIBS may provide complementary information and a higher odds ratio if compared to the incidence of breast cancer. In contrast to mammography derived parenchymal density pattern, no historical TIBS data is available for a retrospective analysis and hence a cross sectional study within a group of screened women is proposed. We hypothesize that TIBS provides physical information about the breast tissue which can be used to construct a breast cancer risk predictor with an odd ratio > 6.

Inclusion Criteria:

• Are in good health and capable of providing consent
• Are willing to come in to the Princess Margaret Hospital for a single visit to meet with a female research assistant

Exclusion Criteria:

• Have had breast augmentation or reduction
• Have a personal history of breast cancer
• Have had a previous bilateral fine needle aspiration or core biopsy
• Have a breast tattoo

Cases and controls recruited from the Breast Imaging Clinic at Princess Margaret Hospital or the Marvelle Koffler Centre at Mount Sinai Hospital (Toronto, Ontario, Canada)