Ductal Carcinoma (Invasive and In Situ)

More than 250,000 American women will be diagnosed with breast cancer in 2008. More than half of these cases will be ductal carcinoma. Ductal carcinoma is a type of cancer that starts in the milk ducts of the breast.

There are two types of ductal carcinoma:

• Ductal carcinoma in situ, which is also referred to as intraductal carcinoma
• Invasive ductal carcinoma

What is ductal carcinoma in situ?

One out of every five new breast cancer diagnoses each year is ductal carcinoma in situ (DCIS). This is an uncontrolled growth of cells within the breast ducts. The phrase "in situ" means "in its original place." This cancer is noninvasive and has not yet made it to breast tissue outside of the ducts.

Ductal carcinoma in situ is the earliest stage at which breast cancer can be diagnosed. It's known as Stage 0 breast cancer. The prognosis for women diagnosed with this form is excellent. The vast majority of cases of ductal carcinoma in situ are curable.

Even though ductal carcinoma in situ is noninvasive, it is imperative that women with the disease receive medical treatment. Experts believe that one out of every three women with untreated DCIS will later develop invasive breast cancer.

How is ductal carcinoma in situ diagnosed?

Commonly, ductal carcinoma in situ does not cause the formation of a lump in the breast that can be felt upon examination. About 80% of cases are found by mammograms. Mammograms detect tiny bits of calcium that develop in dead cancer cells. As more and more cancer cells age and die, these calcifications grow. On the mammogram, they appear as a shadowy area.

If your mammogram suggests that you may have ductal carcinoma in situ, your doctor may recommend a biopsy. The purpose of the biopsy is to analyze the cells in the suspicious area for cancer and confirm the diagnosis. Biopsies for DCIS are typically done using needles to remove tissue samples from the breast.

After confirming that you have ductal carcinoma in situ, your doctor may recommend other tests. These tests may include an ultrasound or MRI of the breast to gather more information about your cancer. Based on the results of various tests, your doctor will be able to determine the size of your tumor and how much of your breast is involved in the cancer.

How is ductal carcinoma in situ treated?

No two patients are the same. Your doctor will customize your treatment plan for ductal carcinoma in situ based on your test results and medical history. Among other things, your doctor will consider:

• Tumor location
• Tumor size
• Aggressiveness of the cancer cells
• Family history of breast cancer

Most women with ductal carcinoma in situ do not have the breast removed with a mastectomy. Instead, they receive breast-conserving treatment.