Women with two types of early breast cancer may be at higher risk of progressing to advanced disease than previously thought.

A new study suggests that women diagnosed with early-stage lobular carcinoma in situ (LCIS) and women diagnosed with ductal carcinoma in situ (DCIS) who are under 50 years old, black, or Hispanic are at increased risk of developing advanced-stage breast cancer tumors that may spread to other parts of the body.

LCIS and DCIS are two types of early-generation cancer cells that have not yet spread beyond the breast. Researchers say the diagnosis of these types of early breast cancers has increased sevenfold since 1980, largely due to more frequent breast cancer screening and breast biopsies.

Current recommendations call for these types of localized breast cancer to be treated differently.

For example, surgery is recommended for DCIS because it is considered a precursor to more advanced types of breast cancer. LCIS is usually considered to be a nonsurgical disease, based on research studies done from 1974 to 1991.

But the results of this study suggest that more aggressive treatments and follow-up care may be needed.

Precursor to Advanced Disease

The study, published in the journal Cancer, included analysis of follow-up information on more than 37,000 women diagnosed with DCIS and about 4,500 women with LCIS.

Researchers found that women with LCIS tumors were more than five times as likely to develop an advanced type of breast cancer known as invasive lobular carcinoma (ILC) than women with DCIS, although they were slightly less likely to develop invasive ductal carcinoma (IDC).

They say the results suggest that LCIS may be a precursor to ILC rather than just a risk factor.

Among women with DCIS, those who were under 50 years old, as well as Hispanic and black women, were at higher risk of developing advanced, invasive disease that spread to other areas than older and white women.

Researchers say these findings may potentially change the way early breast cancer is treated as well as lead to new follow-up strategies for women with early breast cancer.

By Jennifer Warner, reviewed by Louise Chang, MD

SOURCES: Li, C. Cancer, May 15, 2006; vol 106. News release, John Wiley & Sons Inc.