DCIS: Stage Zero Cancer – What Is It?

There is a debate on. When is a cancer a “cancer” and when is it a precursor to cancer? This is a very hot topic in the media now with some doctors and medical experts calling for a change in terminology for cancers like ductal carcinoma in situ (DCIS). They are suggesting that early or stage 0 cancers not be named cancers at all. Name them something else, something less scary, something that does not cause significant worry or possible over-treatment.

Ductal Carcinoma in Situ

We have previously discussed that cancer comes in different stages, or levels of progression. The stage of a cancer has a large effect on treatment and outcomes. Stage 0 cancer, otherwise know as DCIS or “ductal carcinoma in situ,” is a noninvasive form of breast cancer. In situ means “in place.”

In DCIS, abnormal cells reside only in the milk ducts of the breast and do not invade other nearby tissues. DCIS can be widespread throughout the breast or can be local or limited to a small portion of the breast. When widespread the outlook for the condition is less favorable. In DCIS cells have a change in shape, size and architecture from normal cells.

The farther away from normal the cells appear typically equates to a more aggressive form of DCIS, and the pathologist (a specialist doctor trained in diagnosing diseases from tissues) will grade the cancer based in part on these features. It has been shown on multiple occasions that untreated DCIS can become invasive, while other times little growth or change in cells occurs. Figuring out which cases will become invasive cancers and which will not is the problem at hand with no solution at present. So, while we can debate the renaming of DCIS, we really don’t have the means to tell which lesions might be left alone and which would benefit from early treatment and potential cure.

Lobular Carcinoma in Situ

This has a similar name, but this condition is not considered a cancer but rather a sign of an increased risk of breast cancer. In this condition, there are abnormal cells which have developed within the lobule of the breast – a different anatomic part of the breast tissue than the ducts. The abnormal cells in this condition remain “in place” in the breast lobule, not invading adjacent tissues. Cancerous cells arising from the breast lobule are not as common as cancers arising from the duct. If a diagnosis of lobular carcinoma in situ is made on biopsy, the patient will be at higher risk for breast cancer and may undergo additional screening, sometimes with breast MRI. Lobular carcinoma in situ can become invasive (invasive lobular carcinoma) which would require treatment.

Research dedicated to the important topic of the behavior and more importantly the management of in situ cancer is ongoing. We need methods to distinguish which lesions remain dormant and non-lethal from those that can spread.

For now, while it may seem prudent to debate the possibility of overdiagnosis of breast cancer and potential for over-treatment for women as a whole, it makes no sense to debate for you as an individual.

We simply do not have the means yet to say which lesions are safe to ignore.

Image credit: Breast Cancer Ductal Carcinoma in Situ by Don Bliss (Illustrator) via NCI Visuals Online Copyright Public Domain.

Originally published 9/4/13 on mammographykc.com.