Mammography and early breast cancer detection. Screening mammography has been shown to reduce breast cancer mortality. Both film-screen mammography and xeromammography are highly sensitive and specific. Mammography accreditation programs assure physicians and patients that a facility provides mammography of the highest quality, using the lowest possible radiation dose. Mammographic signs of early cancer include a small mass, calcifications, architectural distortion and a neodensity. Dense tissue may result in a false-negative examination even when a cancer is palpable, with adverse effects if biopsy is delayed. 