Anyone who has had breast cancer in one breast has a slightly higher risk of developing a new primary breast cancer.

People who developed breast cancer because of inheriting an altered gene also have an increased risk of a new cancer.

A new breast cancer

A second primary diagnosis refers to a new cancer. It’s not the same as a recurrence, when the original breast cancer has returned.

A second primary breast cancer is also not the same as secondary breast cancer, when breast cancer cells have spread from the breast to other parts of the body.


A second primary breast cancer may happen in the same breast after breast-conserving surgery or, more commonly, in the other breast. When doctors carry out tests on the cancer, they can usually tell if it’s a new cancer or if the original cancer has come back.

A second primary diagnosis may be different from your first breast cancer. For example, your first breast cancer may have been oestrogen receptor positive but your new primary breast cancer could be oestrogen receptor negative.


Treatment for a new primary cancer will depend on the breast in which it is diagnosed.

If it’s in the same breast as your first cancer, and you previously had a wide local excision and radiotherapy, then a mastectomy is usually recommended. This is because it’s not usually possible to give radiotherapy to the same area twice. However, if another wide local excision is an appropriate option, your surgeon will discuss this with you.

If the new primary cancer is diagnosed in the other breast then, as with your first breast cancer, the type of surgery recommended will depend on the size and location of the cancer.

Treatment for the new breast cancer will be tailored to your individual situation. This will depend on features such as:

Outlook (prognosis)

The outlook (prognosis) for a new primary breast cancer will depend on the individual features of the new cancer, such as the grade and stage.

Having a new diagnosis of primary breast cancer is not in itself thought to affect the overall prognosis.

How you might feel

Having a new primary breast cancer can come as a shock. It might be hard to accept that you have to go through treatment all over again when you thought you had put that part of your life behind you. However, it may feel a little less frightening this time around as you know more about what to expect.

It’s important that you have a chance to ask any questions. Your cancer specialist is often the best person to ask as they can give you information that’s tailored to your individual situation. Your breast care nurse can also be a source of information and support.

You might find it helpful to contact other people who are experiencing something similar.

You can post and receive messages of support on our Forum

Our Someone Like Me service can put you in contact with someone who has been in a similar position to you.

Last reviewed: August 2016
Next planned review begins shortly

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