Ductal carcinoma in situ, the most common type of non-invasive breast cancer, is diagnosed in about 60,000 Americans a year, or about 1 out of every 5 new breast cancer cases.
DCIS is called non-invasive because it hasn’t spread beyond the milk duct into any normal surrounding breast tissue. It isn’t life threatening, but having this form of cancer can increase your risk of developing an invasive breast cancer later.
If you have had DCIS, you’re at higher risk for the cancer coming back or for developing a new breast cancer than a person who has never had breast cancer. Most recurrences happen within five to 10 years after your initial diagnosis, but the chances of a recurrence are less than 30 percent.
DCIS typically has no symptoms, though a small number of people may feel a lump in the breast or discharge coming out of the nipple. Most cases of DCIS, about 80 percent, are found by mammogram, according to the National Cancer Institute.
A DCIS diagnosis is treated in one of four ways:
• Lumpectomy followed by radiation: This is the most common treatment for DCIS. Lumpectomy is sometimes called breast-conserving treatment because most of the breast is saved, though you may be left with a dent or bulge near the incision site. Women who opt for this treatment reduce their risk of recurrence to about 15 percent.
• Mastectomy: Mastectomy, or removal of the entire breast, is recommended in some cases, usually if the DCIS covers a large area or is in multiple areas of the breast.
• Lumpectomy alone: Removing the DCIS alone may be an option if your risk of recurrence is very low. In this case, adding radiation may offer minimal benefit. Women who have a lumpectomy alone to treat DCIS have a 25 percent to 30 percent chance of a recurrence at some point in the future.
• Hormonal therapy after surgery: This therapy, which blocks or lowers the amount of estrogen in the body, is used if the DCIS tests positive for hormone receptors. Adding hormonal therapy after surgery reduces the risk of recurrence. You will need to make sure to talk to your doctor about having your DCIS tested for hormone receptors because not all hospitals automatically do this.
If breast cancer does recur after earlier treatment, the recurrence is non-invasive (DCIS again) about 50 percent of the time and invasive—meaning it has spread beyond the milk duct into surrounding breast tissue–the other 50 percent of the time.
If you think you’re hearing more about DCIS now than you used to, you’re right. The number of diagnoses has been increasing. Experts point to two reasons why:
- People are living longer. And as we grow older, our risk of breast cancer increases.
- More people are getting mammograms, and the quality of them has improved. Better screening catches more cancers early.
