What is disclosed is a system and method for breast cancer screening which determines whether hot spots, as seen in a thermal image of both breasts, can be classified as possibly malignant based on a measure of symmetry. A thermographic image of both breasts of a patient is received and analyzed to determine whether there exists, in each of a left breast and a right breast, a hot spot comprising a patch of pixels with an elevated temperature with respect to surrounding tissue. If a hot spot has been identified in each breast then a measure of symmetry comprising a ratio of an area of a smaller hot spot to an area of a larger hot spot is extracted from the thermographic image. The measure of symmetry is provided to a classifier system trained to classify an unclassified hot spot as malignant or non-malignant based on a measure of symmetry.