IDC - Invasive Ductal Carcinoma - Invasive Ductal Carci...

IDC - Invasive Ductal Carcinoma

IDC - Invasive Ductal Carcinoma

Invasive ductal carcinoma (IDC), sometimes called infiltrating ductal carcinoma, is the most common type of breast cancer. About 80% of all breast cancers are invasive ductal carcinomas.

Invasive means that the cancer has “invaded” or spread to the surrounding breast tissues. Ductal means that the cancer began in the milk ducts, which are the “pipes” that carry milk from the milk-producing lobules to the nipple. Carcinoma refers to any cancer that begins in the skin or other tissues that cover internal organs — such as breast tissue. All together, “invasive ductal carcinoma” refers to cancer that has broken through the wall of the milk duct and begun to invade the tissues of the breast. Over time, invasive ductal carcinoma can spread to the lymph nodes and possibly to other areas of the body.

According to the American Cancer Society, more than 180,000 women in the United States find out they have invasive breast cancer each year. Most of them are diagnosed with invasive ductal carcinoma.

Although invasive ductal carcinoma can affect women at any age, it is more common as women grow older. According to the American Cancer Society, about two-thirds of women are 55 or older when they are diagnosed with an invasive breast cancer. Invasive ductal carcinoma also affects men.

Signs and Symptoms of IDC

At first, invasive ductal carcinoma may not cause any symptoms. Often, an abnormal area turns up on a screening mammogram (x-ray of the breast), which leads to further testing.

In some cases, the first sign of invasive ductal carcinoma is a new lump or mass in the breast that you or your doctor can feel. According to the American Cancer Society, any of the following unusual changes in the breast can be a first sign of breast cancer, including invasive ductal carcinoma:

swelling of all or part of the breast
skin irritation or dimpling
breast pain
nipple pain or the nipple turning inward
redness, scaliness, or thickening of the nipple or breast skin
a nipple discharge other than breast milk
a lump in the underarm area

Diagnosis of IDC

Tests for Diagnosing IDC

Diagnosing invasive ductal carcinoma usually involves a combination of procedures, including a physical examination and imaging tests.

Physical examination of the breasts: Your doctor may be able to feel a small lump in the breast during a physical examination. He or she also will feel the lymph nodes under the armpit and above the collarbone to see if there is any swelling or other unusual changes.
Mammography: Invasive ductal carcinoma is usually found by mammography, a test that obtains x-ray images of the breast. Mammograms are used to screen apparently healthy women for early signs of breast cancer. One key feature of an invasive breast cancer is spiculated margins, which means that on the mammography film, the doctor sees an abnormality with finger-like projections coming out of it. These projections show the “invasion” of the cancer into other tissues.

If a screening mammogram highlights an area of concern, additional mammograms often will be done to gather more information about that area. Mammography will be performed on both breasts.
Ultrasound bounces sound waves off of the breast to obtain additional images of the tissue. Ultrasound is sometimes used in addition to mammography.
Breast MRI: MRI, or magnetic resonance imaging, uses magnetic fields, radio waves, and a computer to obtain images of tissues inside the body. In certain cases, a doctor may use breast MRI to gather more information about a suspicious area within the breast.
Biopsy: If you do have a suspicious mammogram or other imaging test result, your doctor will probably want you to have a biopsy. A biopsy involves taking out some or all of the abnormal-looking tissue for examination by a pathologist (a doctor trained to diagnose cancer from biopsy samples) under a microscope.

When possible, your doctor will usually use one of the quicker, less invasive approaches to biopsy:
Fine needle aspiration biopsy involves inserting a very small, hollow needle into the breast. A sample of cells is removed and examined under the microscope. This method leaves no scars.
Core needle biopsy inserts a larger needle into the breast to remove several cylinder-shaped samples of tissue from the area that looks suspicious. In order to get the core needle through the skin, the surgeon must make a tiny incision. This leaves a very tiny scar that is barely visible after a few weeks.

In cases where the doctor cannot feel the lump, he or she may need to use ultrasound or mammograms to guide the needle to the right location. You may hear this referred to as stereotactic needle biopsy or ultrasound-guided biopsy.

If a needle biopsy is not able to remove cells or tissue, or it does not give definite results (inconclusive), a more involved biopsy may be necessary. These biopsies are more like regular surgery than needle biopsies:
Incisional biopsy removes a small piece of tissue for examination.
Excisional biopsy attempts to remove the entire suspicious lump of tissue from the breast.

Again, if the doctor cannot feel the lump, he or she may need to use mammography or ultrasound to find the right spot. Your doctor also may use a procedure called needle wire localization. Guided by either mammography or ultrasound, the doctor inserts a small hollow needle through the breast skin into the abnormal area. A small wire is placed through the needle and into the area of concern. Then the needle is removed. The doctor can use the wire as a guide in finding the right spot for biopsy.
These surgical biopsies are done only to make the diagnosis. If invasive ductal carcinoma is diagnosed, more surgery is needed to ensure all of the cancer is removed along with “clear margins,” which means that a border of healthy tissue around the cancer is also removed. Usually this means having lumpectomy, or in some cases, mastectomy.

Screening and Testing

There's a whole world of testing that goes along with taking care of your breasts. Although medical tests can be nerve-wracking — especially when it comes to waiting for results — they are essential in keeping your breasts healthy and getting you proper care if you develop breast cancer.

In this section, you’ll learn about the different types of breast cancer tests, such as mammogram, breast MRI, and biopsy. You can also learn about getting your test results and keeping track of your medical records.

Tests for Staging IDC

Staging is the process used to figure out how far invasive ductal carcinoma may have spread from its original location. The stage of the cancer is based on three pieces of information:

the size of the tumor
whether the cancer has spread to any lymph nodes, and if so, how many
whether the cancer has spread to other parts of the body
Invasive ductal carcinoma is described on a scale from stage I (the earliest stage) through stage IV (the most advanced stage). (To read more about how breast cancer is staged, you can visit our Staging section.)

Based on a clinical exam and imaging studies, your doctor may have some sense as to whether the invasive ductal carcinoma cells have spread to the lymph nodes. However, your doctor will determine for sure whether any lymph nodes are involved at a later time by removing one or some of your lymph nodes for examination.

At this point, your doctor may look for clues as to whether invasive ductal carcinoma cells could have spread to other areas of the body. Your doctor may order certain blood tests, a test of your liver function, and a test for a substance in the blood called alkaline phosphatase, or ALP. ALP may be higher than usual in people who have cancer in the liver or the bones.

Based on these test results, a physical examination, and any symptoms you report, your doctor will decide whether or not additional tests are needed to check other areas of the body. In most cases, you can expect to have an x-ray of the chest to check the lungs. Beyond that, the need for additional testing is determined on a case-by-case basis. Tests that could be done include:

Bone scan: This takes pictures of the bones after you are given a small injection of radioactive substance.
CT (computerized tomography) scan, ultrasound, or MRI are used to create images of the abdomen and pelvis (the stomach area) or other areas of the body.
PET/CT scan: PET (positron emission tomography)/CT scan is a newer technology used to obtain images of the body’s cells as they work. Now or later on, this test may be used if your doctor suspects that the breast cancer has spread to other parts of the body. First, you’ll be injected with a substance made up of sugar and a small amount of radioactive material. The scan then “highlights” any cancer cells throughout the body as they absorb the radioactive substance. Whether PET/CT is better than other tests at staging the cancer is yet to be determined.
These tests are useful only if your doctor has reason to believe that the breast cancer could have spread to other parts of the body. The most common sites of spread for IDC are the bones, liver, lung, and/or brain.

Tests to Gather More Information About IDC
Additional tests will be done on the tumor tissue to gather more information about how the cancer is likely to behave and what treatments will be most effective. Examples include:

Grade: A pathologist examines the cancer cells under a microscope and determines how abnormal they appear and behave when compared with healthy breast cells. The lower the grade, the more closely the cancer cells resemble normal cells, the more slowly they grow, and the less likely they are to spread. There are three grades of invasive ductal carcinoma: low or grade 1; moderate or grade 2; and high or grade 3.

Grade 1 invasive ductal carcinoma cells, which are sometimes called “well-differentiated,” look and act somewhat like healthy breast cells. Grade 3 cells, also called “poorly differentiated,” are more abnormal in their behavior and appearance.
Surgical margins: When cancer cells are removed from the breast, the surgeon tries to take out the whole cancer with an extra area or “margin” of normal tissue around it. This is to be sure that all of the cancer is removed. The tissue around the very edge of what was removed is called the margin of resection. It is looked at very carefully to see if it is clear of cancer cells.

The pathologist also measures the distance between the cancer cells and the outer edge of the tissue. Margins around a cancer are described in three ways:
Negative: No cancer cells can be seen at the outer edge. Usually, no more surgery is needed.
Positive: Cancer cells come right out to the edge of the tissue. More surgery may be needed.
Close: Cancer cells are close to the edge of the tissue, but not right at the edge. More surgery may be needed.

What are called “negative” (or “clean”) margins can be different from hospital to hospital. In some places, doctors want at least 2 millimeters (mm) of normal tissue beyond the edge of the cancer. In other places, doctors may define a “clean margin” as less than 2 mm or more than 2 mm of healthy tissue. You may want to ask your doctor how your hospital defines clean margins.
Hormone receptor assay: This tissue test determines whether or not the breast cancer has receptors for the hormones estrogen and progesterone. A positive result means that estrogen or progesterone (or both) has the ability to fuel the cancer cells’ growth. If the cancer is hormone-receptor-positive, your doctor likely will recommend hormonal therapies that block the effects of estrogen or lower estrogen levels in the body. Examples include tamoxifen and aromatase inhibitors. If you are premenopausal, your doctor may discuss other options, such as using medications to shut down your ovaries temporarily, or even surgically removing them. The ovaries are the body’s main source of estrogen before menopause.
HER2-receptor status: Another test is done to find out whether the breast cancer cells make too much of a protein called HER2 (human epidermal growth factor receptor 2). If they do, then they also have too many HER2 receptors at the cell surface. With too many receptors, breast cancer cells pick up too many growth signals and start growing too much and too fast. One way to slow down or stop the growth of the cancer cells is to block the receptors so they don't pick up as many growth signals. That’s what the medication called Herceptin (chemical name: trastuzumab) does. About 1 out of 4 breast cancers are HER2-positive, which means they can be treated with Herceptin.

HER2-positive cancers also can be treated with Tykerb (chemical name: lapatinib), a medication that interferes with the activity of HER2 from inside the cell. Tykerb limits the amount of energy the breast cancer cells have to grow and multiply.
These tests are done on the tissue that is removed during biopsy, or, in the case of surgical margins, after the surgery to remove the cancer.

Treatment for IDC

The treatments for invasive ductal carcinoma fall into two broad categories:

Local Treatments for IDC: Surgery and Radiation Therapy
Local treatments treat the tumor and the surrounding areas, such as the chest and lymph nodes.

Systemic Treatments for IDC: Chemotherapy, Hormonal Therapy, Targeted Therapies
Systemic treatments travel throughout the body to destroy any cancer cells that may have left the original tumor and to help reduce the risk of the cancer coming back.

Follow-up Care for IDC

After treatment, you and your doctor will work together to come up with a schedule of follow-up visits and exams that is right for your situation. Your schedule may include the following tests and exams:

You’ll likely have a physical exam and medical history every 4 to 6 months for 5 years and then every year after that. If you are taking tamoxifen or other forms of hormonal therapy, you can consult with your doctor about treatment for any side effects you may experience.
If you had lumpectomy or breast-conserving surgery, you’ll arrange for a mammogram of the affected breast 6 months after radiation is completed, and then mammography on both breasts every year.
If you had mastectomy, you’ll schedule a mammogram of the remaining breast every year. If you are considered high-risk for developing another breast cancer, whether due to strong family history or a positive genetic test for BRCA1 or BRCA2 mutations, your doctor may recommend breast MRI in addition to yearly mammograms.
If you are taking tamoxifen, you’ll have a physical exam and medical history taken by a gynecologist every year, because this medication can increase the risk of cancer of the uterus. Any unusual symptoms, such as abnormal bleeding, should be reported immediately to your doctor. (If you have had a hysterectomy and no longer have a uterus, this recommendation does not apply to you.)
If your treatments have put you into menopause early or you have already gone through menopause naturally and are taking an aromatase inhibitor, you’ll need regular monitoring of your bone health with a bone density test. Having lower levels of estrogen in the body, which is a result of early menopause or taking an aromatase inhibitor, can impact bone health.
You may need to have additional tests or more frequent office visits, depending on your individual needs. Ask your doctor what he or she recommends.