Structural, antigenic, and biological characteristics of precancerous mastopathy.

A biologically significant relationship between precancerous mastopathy (PCM), in situ carcinoma (ISC), and invasive breast carcinoma is evidenced by the following: (a) PCM and ISC are commonly associated with each other and with invasive breast cancer; (b) Stage O PCM and ISC are both associated with an increased risk of subsequent breast cancer; (c) patients with Stage O PCM and ISC are more similar to invasive breast cancer patients than to patients with normotypic breast lesions in regard to family history of breast cancer and parity characteristics; (d) PCM and ISC resemble invasive breast cancers and differ from normotypic mammary epithelium in regard to epithelial cell-lymphoreticuloendothelial relationships; (e) PCM and, particularly, ISC are associated with distinctive immunogenic components; (f) prognostically significant immunogens of invasive breast cancer tissues are related to and antigenically similar to immunogenic components of associated ISC; (g) immunogenic cancers (ISC and invasive) from different patients are antigenically similar to one another; (h) immunogenic cancers (ISC and invasive) from different patients are antigenically similar to some component of murine mammary tumor virus.