Second Cancers After Breast Cancer

Breast cancer survivors can be affected by a number of health problems. But one major concern for many survivors is facing cancer again.

If this happens, most often it is the breast cancer coming back after treatment. This is called a breast cancer recurrence. But some cancer survivors develop a new cancer later on. This is called a second cancer.

What is the risk of a second cancer?

Women who’ve had breast cancer can still develop other cancers. In fact, they are at higher risk for some types of cancer. Although the risk is increased, it’s still generally low overall.

Most breast cancer survivors do not get cancer again.

The most common second cancer in breast cancer survivors is another breast cancer. This is different from the first cancer coming back. If you were treated with breast-conserving surgery (lumpectomy), a new cancer can start in that breast. A new cancer can also develop in the opposite breast.

Breast cancer survivors might also be at higher-than-average risk for certain other cancers. This depends on the types of cancer treatment you received, genetic risk factors, and other factors. These cancers include:

• Salivary gland cancer
• Esophagus cancer
• Stomach cancer
• Colon cancer
• Uterine cancer
• Ovarian cancer
• Thyroid cancer
• Lung cancer
• Soft tissue cancer (sarcoma)
• Melanoma of the skin
• Acute myeloid leukemia (AML)
• Myelodysplastic syndrome (MDS)

Inherited BRCA mutations: Women with inherited mutations (changes) in one of the BRCA genes have an increased risk of breast cancer, ovarian cancer, and some other cancers.

Radiation therapy: Radiation therapy to the chest seems to increase the risk of lung cancer, especially in women who smoke. It also seems to increase the risk of sarcomas, which are cancers of connective tissues such as blood vessels and bones, as well as the risk of certain blood cancers, such as leukemia and myelodysplastic syndrome (MDS). However, the increase in risk is small, and the overall risk of these cancers is still low.

Certain chemotherapy medicines: Some chemo medicines can slightly increase the risk of developing leukemia and myelodysplastic syndrome (MDS).

Tamoxifen: Tamoxifen can increase the risk of uterine cancer (endometrial cancer and uterine sarcoma). But it also lowers the chance of hormone receptor-positive breast cancer coming back, as well as the risk of getting a second breast cancer. The overall risk of uterine cancer in most women taking tamoxifen is low, so the benefits of this medicine in treating breast cancer are higher than the small increase in risk of a second cancer.

Breast cancer survivors can get other types of cancer as well, even if they’re not at increased risk.

Follow-up and screening after breast cancer treatment

If you’ve finished treatment for breast cancer, you still need to see your healthcare team regularly. They will watch for signs of the cancer coming back and look for any late effects from cancer treatment.

Screening for breast cancer

If you haven’t had both breasts removed, you still need regular mammograms to look for a new breast cancer or a recurrence of the original cancer. For more about other tests you might need after treatment, see Living as a Breast Cancer Survivor.

Screening for other cancers

It’s important to follow the American Cancer Society guidelines for the early detection of other cancers, such as colorectal and cervical cancers.

Screening tests can often find these cancers early, when treatment is more likely to be successful. Some tests might even help prevent these cancers if precancers are found and treated.

Other than standard early detection screenings, most experts do not recommend any additional testing to look for second cancers in breast cancer survivors unless you have symptoms.

Watching for new symptoms

Let your healthcare team know about any new symptoms or problems. These could be caused by a new disease or second cancer, or by your breast cancer coming back. For example, abnormal menstrual bleeding, such as bleeding or spotting after menopause or between periods, can be a symptom of uterine cancer.

Can I lower my risk?

There is no sure way to prevent all cancers, but there are steps you can take to lower your risk of a second cancer and stay as healthy as possible.

It’s important to stay away from tobacco products. Smoking increases the risk of many cancers, including some of the second cancers that are more likely after breast cancer.

To help maintain good health, breast cancer survivors should also follow the ACS Guidelines on Diet and Physical Activity for Cancer Prevention:

• Get to and stay at a healthy weight.
• Keep physically active and limit the time you spend sitting or lying down.
• Follow a healthy eating pattern that includes plenty of fruits, vegetables, and whole grains, and limits or avoids red and processed meats, sugary drinks, and highly processed foods.
• It's best not to drink alcohol. Women who drink should have no more than 1 drink per day.

These steps may also lower the risk of some other health problems.

Learn more

See Second Cancers for more on the causes of second cancers.