Another Lesion: LCIS

Lobular carcinoma in situ, or LCIS, is considered a risk factor for invasive cancer. 

Lobular carcinoma in situ, or LCIS, sounds similar to its linguistic cousin DCIS (ductal carcinoma in situ). But its diagnosis is typically considered less worrisome.

Rather than being a precancerous lesion like DCIS, the lobular lesion is considered only a marker of elevated risk for invasive cancer down the road, according to the National Cancer Institute. Irene Wapnir, chief of breast surgery at Stanford School of Medicine in Stanford, Calif., explains that doctors approach LCIS as a high-risk lesion, unlike DCIS, which is regarded as a cancerous lesion that requires breast biopsy and then either lumpectomy with radiation or mastectomy.

[Read more about DCIS]

In some cases of LCIS, surgery might be recommended: for example, if the LCIS is scattered throughout the breast, Wapnir says. But for most women, taking the estrogen blockers tamoxifen or raloxifene is the recommended approach. In one large-scale prevention study, which included 830 women with a history of LCIS, use of tamoxifen reduced the risk of later developing an invasive cancer by more than half.