The first type is called ductal carcinoma in-situ, or DCIS, and that's where tumor cells grow from the wall of the ducts, into the lumen.

第一种被称为导管内原位癌（DCIS），指肿瘤细胞从导管壁向管腔内生长。

Breast cancer usually begins as an in-situ carcinoma, which can either be ductal carcinoma in-situ, or DCIS, which is localized to the ducts, or lobular carcinoma in-situ, or LCIS, which is localized within the lobules.

乳腺癌起初通常为原位癌，可以是导管内原位癌（DCIS）局限于导管内，或小叶原位癌（LCIS）局限于小叶。