Invasive breast cancer

Invasive breast cancer is the most common type of breast cancer. It was previously also known as invasive ductal carcinoma.

What is invasive breast cancer?

Invasive breast cancer means that the cancer cells have grown through the lining of the ducts into the surrounding breast tissue. 

Most invasive breast cancers have no special features and are classed as No Special Type (NST) or not otherwise specified (NOS). Between 70 and 80 out of 100 (between 70 and 80%) breast cancers are this type.

Special type means that when the doctor looks at the cancer cells under a microscope the cells have particular features. Breast cancers that are classed as special types include some rare types of breast cancer.

Ductal carcinoma in situ

Invasive breast cancer is different from ductal carcinoma in situ (DCIS). In invasive cancer, the cells have broken out of the duct and spread into the surrounding breast tissue. DCIS means that some cells have started to turn into cancer but these cells are all contained inside the ducts. 

Remember that if your doctor has told you that you have ductal carcinoma in situ (DCIS), you don't have invasive breast cancer.

Symptoms of invasive breast cancer

The symptoms listed here are more often caused by other medical conditions. But if you have any of them it is important to see your GP.

Symptoms of invasive breast cancer include:

• a new lump or thickening in your breast or armpit

• a change in size, shape or feel of your breast

• skin changes in the breast such as puckering, dimpling, a rash or redness of the skin

• fluid leaking from the nipple in a woman who isn’t pregnant or breastfeeding

• changes in the position of nipple

Diagnosing invasive breast cancer

Your GP may refer you to a breast clinic if you have any symptoms that could be due to invasive breast cancer. You may also be referred to a breast clinic for tests if your screening mammogram shows an abnormal area. 

You usually have a number of tests to check for breast cancer. This includes one or more of the following tests:

• a breast examination
• a mammogram  
• a breast ultrasound scan
• taking a sample of tissue from your breast called a biopsy 

It's important to know that most people who attend a breast clinic with symptoms do not have breast cancer. 

Treatment

Your doctor will take many different factors into account when deciding which treatment is best for you. This is why your treatment may be different from other people with invasive breast cancer. The factors include:

• the type of cells the cancer started in
• the size of the cancer and whether it has spread (the stage)
• how abnormal the cells look under the microscope (the grade)
• whether the cells have receptors for particular cancer drugs
• your general health
• whether you have had the menopause  

There are many different types of treatment that you can have. 

Drug treatments before surgery

You might have chemotherapy or hormone therapy before surgery. This is called neo adjuvant therapy.

The main aim of neo adjuvant therapy is to shrink the cancer before surgery.

Surgery

You might have breast conserving surgery or a mastectomy. 

Breast conserving surgery removes the cancer while leaving as much normal breast tissue as possible. A mastectomy is an operation to remove the whole breast.

If you have a mastectomy, you might be able to have a new breast made (breast reconstruction). This may be at the same time as the mastectomy or some time afterwards.

You may also have surgery to remove the lymph nodes  in your armpit. Your surgeon will let you know whether you need this. 

Other treatments

After surgery, you may have other treatments. These include:

• radiotherapy

• chemotherapy

• hormone therapy

• targeted cancer drugs

• drugs that strengthen the bones called bisphosphonates

Follow up

You have regular check ups and mammograms after treatment for invasive breast cancer. How often you have check ups depends on your individual situation.

Some hospitals have a system of follow ups where you don't have regular appointments. In this system, you might have regular phone calls with your breast specialist nurse. You can also contact them and arrange an appointment if you have any new symptoms or are worried about anything. This is called supported self management or patient initiated follow up (PIFU). 

You usually have a mammogram every year, for at least 5 years after treatment. 

It’s important to remember that you can contact your doctor or specialist nurse if you notice a new symptom or have questions. You can also speak to your GP.

Research and clinical trials

Invasive breast cancer is the most common type of breast cancer. So most breast cancer research is looking at this type.

Currently, researchers around the world are looking at:

• the causes and prevention of breast cancer

• screening and diagnosis

• new treatments

• ways to improve existing treatments

• ways to cope with breast cancer and its treatment

Go to Cancer Research UK’s clinical trials database if you are looking for a trial for breast cancer in the UK.

Coping with invasive breast cancer

Coping with invasive breast cancer can be difficult. There is help and support available to you and your family.