Breast Cancer Awareness: What Is DCIS?

9 min readOct 11, 2018

Cancer can begin anywhere in the body. Perhaps one of the most misunderstood forms of cancer is a specific type of breast cancer known as Ductal carcinoma in situ, or DCIS.

Ductal Carcinoma in Situ (DCIS) is a non-invasive or pre-invasive form of breast cancer that affects 60,000 women each year. DCIS is also referred to as intraductal (within the milk ducts) carcinoma, says the American Cancer Society. However, most women first learn about DCIS when they receive the shocking diagnosis.

A DCIS diagnosis can be confusing. You may feel alone after a DCIS diagnosis, but you’re not alone. This helpful information geared to help you make the most informed decisions about your breast health.

What is Ductal Carcinoma in Situ (DCIS)?

Your breasts are made up of lobules, ducts, and fibrous tissue and fat. Milk is produced in the lobules. The ducts are tiny tubes that carry milk from the lobules to the nipple. The fibrous tissue and fat give your breasts their shape and size and shape and hold the other tissues in place, reports the National Breast Cancer Foundation. If the tiny cells that line the walls of the breast ducts change and become abnormal, this can lead to DCIS.

Let’s break down what Ductal Carcinoma in Situ means. Ductal means that cancer has started in the milk ducts — the tubes that carry milk from the lobules to the opening of the nipple during breastfeeding. Carcinoma indicates any type of cancer that begins in the skin or other tissues — like breast tissue. The term in situ means “in place” because the abnormal cells have not spread past the milk ducts to nearby breast tissue. However, women with DCIS have an increased risk of developing invasive breast cancer later.

DCIS Symptoms

Ductal Carcinoma in Situ is considered a non-invasive form of breast cancer because it doesn’t spread outside of the breast and is not a life-threatening condition. DCIS does not typically produce symptoms. However, says Cancer Network, DCIS can often cause signs you can detect during your monthly breast self-exam. You may notice a lump in the breast, a thickening of the breast tissue, or a bloody discharge from the nipple.

Risk Factors

It is not clear the exact causes of the abnormal cell growth that causes Ductal Carcinoma in Situ. However, according to the Cancer Treatment Centers of America, certain DCIS risk factors may play a role like:

Over 55 years old
Past medical history of benign breast disease
A family history of breast cancer
No pregnancies or first pregnancy after age 30
Hormone Replacement Therapy
Genetic mutations that increase breast cancer risks, like the breast cancer genes BRCA1 and BRCA2

Diagnosing DCIS

Ductal Carcinoma in Situ can be found with or without invasive breast cancer. Any combination of the following medical procedures may be required to diagnose DCIS.

Physical examination. Your doctor may detect a small lump in the breast during a physical examination of your breasts, although a distinctive lump is not always present with DCIS.

Mammogram. DCIS may appear on a mammogram as small calcification clusters with asymmetrical shapes and sizes, reports the International Journal of Breast Cancer. If these microcalcifications are discovered, your radiologist will recommend additional breast imaging — like a diagnostic mammogram — to view both of your breasts at a higher magnification from more angles to conclude if these calcifications are a cause for concern. If your breast requires additional evaluation, then you may require an ultrasound or a breast biopsy.

Breast biopsy. During a fine needle aspiration (FNA) biopsy, a radiologist or surgeon uses a needle to remove breast tissue samples from the breast area in question. The tissue samples are sent to a lab where a pathologist will examine the tissue samples to conclude if the abnormal DCIS cells are present and, how aggressiveness of these cells.

Sentinel lymph node biopsy. A sentinel lymph node biopsy (SLNB) is a procedure is used to determine whether you have invasive breast cancer that has spread to the lymph nodes in the underarm area — known as axillary nodes. This biopsy removes one to five nodes for testing.

Types of DCIS

After a biopsy, the pathologist will examine the removed tissues for any atypical cells are present. If atypical cells are present, he or she will document the difference as compared to the cells to your healthy breast cells. According to Breastcancer.org, the array of possible DCIS growth findings include the following.

Normal cells. No abnormal cells present.
Ductal hyperplasia. Also known as overgrowth, means there are a lot of cells present.
Atypical ductal hyperplasia. This means that there are a lot of cells and they are starting to look abnormal or take on an atypical appearance.
Ductal carcinoma in situ (DCIS). There are a lot of cells, and they have the cancer features, but they contained to the inside of the breast duct. All DCIS is considered stage 0 breast cancer.
DCIS with microinvasion (DCIS-MI). There are a few cancer cells that have started to cause an interruption in the breast duct wall. This is stage I breast cancer.
Invasive ductal cancer (IDC). The cancer cells have migrated outside of the breast duct and have now evolved into a very common type of breast cancer — invasive ductal carcinoma (IDC). IDC can be detected and diagnosed from stage I to IV.

Grades of DCIS

There are three types or grades of Ductal Carcinoma in Situ. They can be divided into low, moderate, and high-grade DCIS. This grading is based on the appearance of the cells under the microscope. Recognizing the type and grade of DCIS can help you and your doctor choose the best treatment for you.

Grade I (low grade). Grade I or low-grade, the DCIS cells have a similar appearance to healthy breast cells. Grade I DCIS grows slowly and can increase a woman’s chance of developing invasive breast cancer five years or later following treatment, compared to women without DCIS.

Grade II (moderate grade) DCIS. Grade II or moderate-grade, the DCIS cells grow faster than normal breast cells and take on less of an appearance of healthy cells.

Grade III (high-grade) DCIS. Grade III or high-grade, the DCIS cells grow more rapidly and look distinctly different from healthy breast cells. Women diagnosed with high-grade DCIS display a higher risk of invasive cancer, at diagnosis or in the future. Women with this higher-grade of DCIS also have a higher chance of breast cancer recurrence within the first five years after treatment.

Treatment Goals for DCIS

The main goal of Ductal Carcinoma in Situ treatment is to treat and attempt to prevent the progression of invasive breast cancer. According to Breast Cancer Now, DCIS is a non-invasive form of cancer that if left untreated, it is estimated that nearly 50 percent of women with DCIS could spread beyond ducts into the adjacent breast tissue and develop an invasive form of breast cancer that can spread to other body parts. Consequently, you will receive regular screening mammograms screenings following your treatment.

Treatment Options

Since there is always a possibility that Ductal Carcinoma in Situ can progress to invasive breast cancer, nearly all cases are treated. DCIS treatment has a high rate of success, with most cases involving removing the tumor and preventing recurrence. Generally, says Harvard Health, the first step to treating DCIS is surgery — either mastectomy or lumpectomy — to remove abnormal breast tissue. In most women, treatment options for DCIS include:

Breast-Conserving Surgery (Lumpectomy)

In breast-conserving surgery (BCS) — also known as a lumpectomy — your surgeon will remove the tumor and a little bit of the normal breast tissue surrounding it. Removing the lymph node may not be required with BCS, but it can be performed if your doctor believes the DCIS could also include invasive cancer. The possibility that an area of the breast with DCIS includes invasive cancer increases with the size of the tumor and how quickly the cancer is spreading. Lymph nodes that are removed, is usually performed as a biopsy called a sentinel lymph node biopsy (SLNB).

Lumpectomy and Radiation Therapy

In the United States, most women with DCIS are treated with a lumpectomy followed by radiation therapy. Radiation therapy uses high-energy beams, likes X-rays or protons, to eliminate abnormal cancer cells. Radiation therapy following a lumpectomy helps to decrease the chance of breast cancer returning in the same breast, as DCIS or as invasive cancer. A lumpectomy without radiation therapy may be an option for women who had small, low-grade DCIS areas that were successfully removed.

Lumpectomy and Hormone Therapy

If the DCIS is hormone receptor-positive (estrogen receptor-positive/progesterone receptor-positive), it means the DCIS tumors have many hormone receptors. After a lumpectomy is performed, additional treatment with hormone medications can be utilized. Women who were treated with lumpectomy for estrogen receptor-positive DCIS may be advised to undergo hormone therapy for five years following initial treatment. Hormone therapy is an adjunct therapy used after surgery or radiation to decrease your chance of developing a recurrence of DCIS or future invasive breast cancer in either breast.

Hormone therapy works by blocking certain hormones from reaching cancer cells. However, hormone therapy is only effective against cancers that grow in response to hormones like hormone receptor-positive breast cancer. The two common hormone therapy medications are tamoxifen and an aromatase inhibitor. If you are hormone receptor-positive DCIS, talk with your doctor about the pros and cons of hormone therapy.

Mastectomy (Breast-Removing Surgery)

If DCIS has spread through the ducts, involving a large section of the breast, a total mastectomy will be performed. Women who undergo mastectomy have a good prognosis with low risks of DCIS recurrence or breast cancer development in the other breast. A mastectomy removes the entire breast and may be required if the DCIS area is large, if the breast has multiple DCIS areas, or if having a lumpectomy will not be able to remove the DCIS completely. Women who have a mastectomy are encouraged to have a sentinel node biopsy during the surgery to help prevent the need for an axillary dissection later.

Prognosis

With treatment, the prognosis for Ductal Carcinoma In Situ is excellent. Overall survival for women with DCIS is the same with mastectomy and lumpectomy, with or without radiation therapy, says the National Cancer Institute.

After DCIS treatment, there may be a slight risk of DCIS recurrence or invasive breast cancer. Currently, health care providers cannot predict which DCIS cases will progress to invasive breast cancer. With close follow-up after treatment, invasive breast cancer can be found and treated early and successfully.

If DCIS is identified alongside invasive breast cancer, the treatment plan and prognosis are determined by the type of invasive breast cancer, not DCIS.

Coping with Breast Cancer

Getting the news that you have Ductal Carcinoma in Situ can leave you feeling many mixed emotions. While DCIS is an early and treatable type of breast cancer, you may still experience anxiety and worry about your future, which is normal.

Remember, there are other women out there who can support you. You can find a friend and mentor who has been in the same situation as you and has gone through it all before with the National Breast Cancer Foundation, Inc. Choose your breast cancer support based on the criteria that matter to you. You are in control!