MYTH No. 1: All Ductal Carcinoma In-Situ (DCIS) is the same.

DCIS is not all the same. Just like invasive cancer, there are different grades of DCIS. The grades are Grade 1or low grade DCIS; Grade 2 or intermediate grade DCIS; and Grade 3 or high grade DCIS. Also, DCIS can be either estrogen receptor and progesterone receptor positive or negative, meaning that some DCIS is sensitive to estrogen and/or progesterone and some DCIS is not.

MYTH No. 2: DCIS does not produce symptoms.

While most DCIS does not produce symptoms and is found by breast imaging only, some DCIS does produce symptoms. Symptoms may include nipple discharge, which can be either a clear discharge or a bloody discharge, typically from one duct. Other patients with DCIS will actually have a breast mass that can be felt.

MYTH No. 3: DCIS can always be detected by mammography.

While mammography does detect many cases of DCIS, some DCIS can not be found by mammography.

MYTH No. 4: Chemotherapy is used to treat DCIS.

DCIS is pre-invasive cancer and is not treated with chemotherapy. Chemotherapy is used for some patients with invasive breast cancer.

MYTH No. 5: Mastectomy is never required to treat DCIS.

Some cases of DCIS require a mastectomy because the breast contains a large area of DCIS that prevents breast conservation therapy.

MYTH No. 6: DCIS cannot be detected by breast ultrasound or MRI.

Although most cases of DCIS are detected with mammography,  some varieties of  DCIS can produce changes on  breast ultrasound and/or breast MRI.

MYTH No. 7: All DCIS becomes invasive breast cancer.

Not all DCIS goes on to become invasive breast cancer, in fact only about 30% of untreated DCIS would progress to invasive ductal cancer. This is one of the challenges in treating patients with DCIS because at present.  Doctors cannot accurately predict which patients with DCIS will go on to develop invasive breast cancer if left untreated, and which will not.  Doctors can predict that patients with high grade comedo carcinoma with necrosis, a special type of DCIS, are at high risk for developing invasive breast cancer. Other types of DCIS, especially low grade DCIS, will be at low risk for progressing to invasive breast cancer.

MYTH No. 8: All DCIS is hormone sensitive.

Not all DCIS is hormone sensitive. Some DCIS is estrogen and progesterone receptor negative (not sensitive to estrogen or progesterone). 

MYTH No. 9: Radiation Therapy is needed to treat all patients who choose breast conservation therapy for DCIS.

Not all patients with DCIS will require radiation therapy. Radiation oncologists make treatment recommendations based on the extent of the patient’s DCIS, as well as the grade and hormone sensitivity of the DCIS.  Radiation oncologists also factor in how well the DCIS was removed (were the margins of removal widely clear?), and they consider the patient’s age and overall health. And of course they consider the patient’s preferences after being fully informed of the arguments in favor and against radiation after surgery. 

MYTH No. 10: DCIS does not involve the nipple.

DCIS can involve the nipple, as the nipple areolar complex contains ductal structures which may be affected with DCIS.