APC and ductal breast carcinoma in situ: It has been shown that APC gene hypermethylation can be detected in ductal carcinoma in situ, lobular carcinoma in situ, and invasive ductal and lobular tumours of all pathological grades and stages, which indicates that hypermethylation of APC can be a relatively early event in breast tumorigenesis (Dulaimi et al, 2004a).