Invasive ductal carcinoma (IDC)

نظرة عامة

Invasive ductal carcinoma (IDC) is a kind of breast cancer. It causes a growth of cells in the tubes that can carry breast milk to the nipple. These tubes are called ducts.

Invasive ductal carcinoma is an invasive cancer, which means that the cancer cells have broken through the duct and grown into the surrounding breast tissue. The cells can spread to the lymph nodes and other parts of the body. This is different from ductal carcinoma in situ (DCIS). DCIS happens when cancer cells form inside a duct but haven't grown outside of it. DCIS is a noninvasive form of ductal carcinoma.

Invasive ductal carcinoma, also called infiltrating ductal carcinoma, is the most common type of breast cancer. Most breast cancers are invasive ductal carcinomas. The other main type of breast cancer is invasive lobular carcinoma. It forms in the milk-producing glands in the breast, called lobules.

Compared with the lobular type, invasive ductal carcinoma is more likely to cause a lump in the breast. It's also more likely to be detected on an imaging test, such as a mammogram.

There are many treatment options for invasive ductal carcinoma. Care is often tailored to your specific situation, and advances in treatment continue to expand those options. Many people who receive this diagnosis are cured. When a cure is not possible, treatments may help control the cancer and help you live longer.

Types

Breast cancers, including invasive ductal carcinomas, are often grouped into subtypes based on the results of tests on the cancer cells. Lab tests can show whether the cells use hormones or a protein called human epidermal growth factor receptor 2 (HER2) to help them grow. Whether the cancer uses one, both or none of these determines the type.

Hormone receptor positive

Hormone receptor (HR) positive invasive ductal carcinomas use the hormones estrogen and progesterone to help them grow. If testing finds the cancer cells have proteins called receptors for one or both hormones, the cancer is HR positive. HR-positive cancers tend to grow slowly and respond well to estrogen blocker therapy.

HER2 positive

HER2-positive invasive ductal carcinoma makes extra HER2 protein and uses it to help fuel the cancer growth. Healthy breast cells make some HER2, but the cancer cells can make a lot more. If tests detect extra HER2 in the cancer cells or extra copies of the genes that make HER2, the cancer is HER2 positive.

HER2-positive breast cancers tend to grow quickly. But there are many treatments that can target HER2.

HER2 negative

HER2-negative invasive ductal carcinoma doesn't make extra HER2. These cancers don't respond to treatment with medicines that target HER2.

Breast cancers that make a low level of HER2 are sometimes called HER2 low or HER2 ultralow. These cancers don't make enough HER2 to be considered HER2 positive, but they may respond to treatment with medicines that target HER2.

Triple positive

Triple-positive invasive ductal carcinoma has hormone receptors and makes extra HER2. These cancers respond to treatment with estrogen blocker therapy and to medicines that target HER2. Both approaches are often used to treat these cancers.

Triple negative

Triple-negative invasive ductal carcinoma doesn't have hormone receptors and doesn't make extra HER2. These cancers tend to grow quickly and are often diagnosed at a later stage. They don't respond to treatment with estrogen blocker therapy or medicines that target HER2. Triple-negative breast cancers respond to chemotherapy and may benefit from treatment with immunotherapy.

الأعراض

Invasive ductal carcinoma (IDC) doesn't always cause symptoms at first. Like other types of breast cancer, it may be found on a screening test, such as a mammogram, before it ever causes symptoms.

When they happen, invasive ductal carcinoma symptoms may include:

• A breast lump or thickened area of skin that feels different from the surrounding tissue.
• A nipple that looks flattened or turns inward.
• Changes in the color of the breast skin. In people with white skin, the breast skin may look pink or red. In people with brown and Black skin, the breast skin may look darker than the other skin on the chest or it may look red, purple or brown.
• Change in the size, shape or appearance of a breast.
• Changes to the skin over the breast, such as skin that looks dimpled or looks like an orange peel.
• Peeling, scaling, crusting or flaking of the skin on the breast.

Compared with other types of breast cancer, invasive ductal carcinoma is more likely to form a lump in the breast tissue. The other main type of breast cancer, invasive lobular carcinoma, often doesn't cause a lump you can feel.

When to see a doctor

If you find a lump or other change in your breast, make an appointment with a doctor or other healthcare professional. Don't wait for your next mammogram. Report any changes in your breasts even if a recent mammogram showed there was no breast cancer.

الأسباب

The exact cause of invasive ductal carcinoma (IDC) isn't known. Research has found a link between invasive ductal carcinoma and a family history of breast cancer, obesity and drinking alcohol. But it's not clear why some people who have all these risk factors don't get cancer and some people without any risk factors do. It's likely that invasive ductal carcinoma is caused by a complex mix of your genetic makeup and the world around you.

Invasive ductal carcinoma starts when something changes the DNA inside cells within a milk duct. A cell's DNA holds the instructions that tell a cell what to do. In healthy cells, the DNA gives instructions to multiply at a set rate. The instructions also tell the cells to die off at a set time. In cancer cells, the changes to the DNA alter the instructions for multiplying and dying. The result is that the cancer cells multiply faster than healthy cells. And they can keep living when healthy cells would die. This causes too many cells in the area.

The cancer cells might form a growth, called a tumor, inside the milk duct. In invasive ductal carcinoma, the tumor grows beyond the duct and into the nearby breast tissue. The tumor can take over the local blood supply. Over time, cancer cells can break away and spread to other parts of the body. When cancer spreads, it's called metastatic cancer. Invasive ductal carcinoma most often spreads to the bones, lungs, liver and brain.

عوامل الخطورة

Risk factors for invasive ductal carcinoma are the same as the risk factors for breast cancer in general. Factors that may increase the risk of breast cancer include:

• A family history of breast cancer. If a parent, sibling or child had breast cancer, your risk of breast cancer is increased. The risk is higher if your family has a history of getting breast cancer at a young age. The risk also is higher if you have multiple family members with breast cancer. Still, most people diagnosed with breast cancer don't have a family history of the disease.
• A personal history of breast cancer. If you've had cancer in one breast, you have an increased risk of getting cancer in the other breast.
• A personal history of breast conditions. Certain breast conditions are markers for a higher risk of breast cancer. These conditions include lobular carcinoma in situ (LCIS) and atypical hyperplasia of the breast. If you've had a breast biopsy that found one of these conditions, you have an increased risk of breast cancer.
• Being female. Women are much more likely than men are to get breast cancer. However, everyone is born with some breast tissue, so anyone can get breast cancer, including men.
• Beginning your period at a younger age. Beginning your period before age 12 increases your risk of breast cancer.
• Beginning menopause at an older age. Beginning menopause after age 55 increases the risk of breast cancer.
• Dense breast tissue. Breast tissue is made up of fatty tissue and dense tissue. Fatty tissue is made of fat. Dense tissue is made of milk glands, milk ducts and fibrous tissue. If you have dense breasts, you have more dense tissue than fatty tissue in your breasts. Having dense breasts increases the risk of developing breast cancer and makes it harder to detect cancer on a mammogram. Talk with your healthcare team about other tests you might have in addition to mammograms to look for breast cancer.
• Drinking alcohol. Drinking alcohol increases the risk of breast cancer. There is no safe amount of alcohol when it comes to breast cancer. The more alcohol you drink, the greater your risk.
• Having never been pregnant. Having been pregnant one or more times lowers the risk of breast cancer. Never having been pregnant increases the risk.
• Having your first child at an older age. Giving birth to your first child after age 30 may increase the risk of breast cancer.
• Increasing age. The risk of breast cancer goes up as you get older.
• Inherited DNA changes that increase cancer risk. Certain DNA changes that increase the risk of breast cancer can be passed from parents to children. The most common changes are in genes called BRCA1 and BRCA2. These changes can greatly increase your risk of breast cancer and other cancers, but not everyone with these DNA changes gets cancer.
• Menopausal hormone therapy. Taking certain hormone therapy medicines to manage the symptoms of menopause may increase the risk of breast cancer. The risk is linked to hormone therapy medicines that combine estrogen and progesterone.
• Obesity. Obesity increases the risk of breast cancer.
• Radiation exposure. Radiation treatments to the chest as a child or young adult raises the risk of breast cancer.

الوقاية

You can take steps to help lower your risk of invasive ductal carcinoma (IDC) and other types of breast cancer.

Ask about breast cancer screening

Talk with your doctor or other healthcare professional about when to begin breast cancer screening. Ask about the benefits and risks of screening. Together, you can decide what breast cancer screening tests are right for you.

Become familiar with your breasts

Do occasional breast self-exams so that you know what your breasts typically feel like. If there is a new change, a lump or something not typical in your breasts, report it to a healthcare professional right away.

Breast awareness through self-exams can't prevent breast cancer. But it may help you to better understand the look and feel of your breasts. This might make it more likely that you'll notice if something changes.

Drink alcohol in moderation, if at all

If you choose to drink alcohol, limit how often you drink and keep the amount small. For overall health, drink one or fewer drinks a day. Do not drink every day. The less you drink, the better.

For breast cancer prevention, there is no safe amount of alcohol. So if you're concerned about your breast cancer risk, you may choose to not drink alcohol.

Exercise most days of the week

Aim for at least 30 minutes of exercise on most days of the week. If you haven't been active lately, ask a healthcare professional whether it's OK and start slowly.

Limit menopausal hormone therapy

Hormone therapy that uses a combination of estrogen and progesterone may increase the risk of breast cancer. Talk with a healthcare professional about the benefits and risks of hormone therapy.

Maintain a healthy weight

If your weight is healthy, work to maintain that weight. If you need to lose weight, ask a healthcare professional about healthy ways to lower your weight. In general, try to eat fewer calories and slowly increase how much you exercise.

Talk with a healthcare professional about your cancer risk

If you have a family history of breast cancer or think that you may have an increased risk of breast cancer, talk about it with your healthcare professional. Preventive medicines, surgery and more-frequent screening may be options for people with a high risk of breast cancer.