The breast: tissue changes and cancer risk.

Long-standing confusion about the premalignant significance of benign changes in breast tissue is being resolved. The majority of patients whose breast biopsy sample does not show invasive carcinoma is not at a significantly-increased risk of developing a breast malignancy. Tissue markers that indicate a risk for invasive carcinoma include atypical hyperplasia and carcinoma-in-situ but only a minority of patients with these changes ever develops invasive carcinoma. The implications for patient management are discussed.