Abstract: In accordance with the apparatus and method of the present invention, a biopotential lesion sensor is placed directly over a lesion in a symptomatic breast and a reference sensor is located away from the symptomatic breast. A plurality of electropotential test measurements are taken during a test period with the lesion sensor and averaged to obtain a primary test potential. This primary test potential can be weighted to compensate for one or more biologic variables such as patient age, time in the patient menstrual cycle, and the time of day during which the measurement is taken. To provide noise enhancement of the primary test potential average measurement, the symptomatic breast is divided into four equal quadrants with one quadrant containing the lesion.