Second Cancers After Breast Cancer

Women who’ve had breast cancer can still get other cancers, although most don’t get cancer again. Breast cancer survivors are at higher risk for getting another breast cancer, as well as some other types of cancer. Steps for staying as healthy as possible include eating right, getting regular exercise, staying away from tobacco, and getting recommended screening tests.

Breast cancer survivors can be affected by a number of health problems, but often a major concern is facing cancer again. Cancer that comes back after treatment is called a recurrence. But some cancer survivors develop a new, unrelated cancer later. This is called a second cancer.

Women who have had breast cancer can get any type of second cancer, but they have a higher risk for certain types of cancer, including:

  • A second breast cancer (This is different from the first cancer coming back.)
  • Salivary gland cancer
  • Esophagus cancer
  • Stomach cancer
  • Colon cancer
  • Uterine cancer
  • Ovarian cancer
  • Thyroid cancer
  • Soft tissue cancer (sarcoma)
  • Melanoma of the skin
  • Acute myeloid leukemia (AML)

The most common second cancer in survivors of breast cancer is another breast cancer. The new cancer can occur in the opposite breast, as well as in the same breast for women who were treated with breast-conserving surgery (such as a lumpectomy).

Cancers linked to genetic factors

For some second cancers, shared genetic risk factors may play a role. For example, women with mutations in one of the BRCA genes have an increased risk breast cancer, ovarian cancer, and some other cancers.

Cancers linked to radiation treatment

Lung cancer: The risk of lung cancer is not increased in all women who have had breast cancer, but it is higher in women who had radiation therapy as part of their treatment. The increased risk is first seen about 10 years after radiation and gets higher over time. The risk is even higher in women who smoke.

Sarcoma: Radiation therapy to the breast also increases the risk of sarcomas of blood vessels (angiosarcomas), bone (osteosarcomas), and other connective tissues in areas that were treated. This risk remains higher even 30 years after treatment.

Certain blood cancers: Breast radiation is linked to a higher risk of leukemia and myelodysplastic syndrome. Overall, though, this risk is low.

Cancers linked to chemotherapy

There is a small increased risk of developing leukemia and myelodysplastic syndrome after chemotherapy (chemo) for early breast cancer. The risk is higher if both chemo and radiation therapy are given.

Cancers linked to treatment with tamoxifen

Taking tamoxifen lowers the chance of hormone receptor-positive breast cancer coming back. It also lowers the risk of a second breast cancer. Tamoxifen does, however, increase the risk for uterine cancer (endometrial cancer and uterine sarcoma). Still, the overall risk of uterine cancer in most women taking tamoxifen is low, and studies have shown that the benefits of this drug in treating breast cancer are greater than the risk of a second cancer.

Follow-up after breast cancer treatment

After completing treatment for breast cancer, you should still see your doctor regularly to look for signs that the cancer has come back. If you have not had both breasts removed, you need annual mammograms to look for breast cancer (either a recurrence of the cancer or a new breast cancer). See Follow-up Care After Breast Cancer Treatment for more on the types of tests you might need after treatment.

You should also follow the American Cancer Society guidelines for the early detection of cancer, such as those for colorectal cancer and cervical cancer. Screening tests can often find these cancers early, when they are likely to be easier to treat. In some cases, the tests might even help prevent these cancers if pre-cancers are found and treated. For women who have had breast cancer, most experts do not recommend any additional testing to look for second cancers unless you have symptoms. 

Let your doctor know about any new symptoms or problems, because they could be caused by the breast cancer coming back or by a new disease or second cancer. 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 of getting a second cancer?

It’s not possible to prevent all cancers, but there are steps you can take to lower your risk and stay as healthy as possible. Getting the recommended early detection tests, as mentioned above, is one way to do this.

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

To help maintain good health, breast cancer survivors should also:

  • Get to and stay at a healthy weight
  • Keep physically active
  • Eat a healthy diet, with an emphasis on plant foods
  • Limit alcohol to no more than 1 drink per day

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

See our section on second cancers in adults for more information about causes of second cancers.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Bertelsen L, Mellemkjaer L, Christensen J, Rawal R, Olsen JH. Age-specific incidence of breast cancer in breast cancer survivors and their first-degree relatives. Epidemiology. 2009;20:175-180.

Boice JD Jr, Harvey EB, Blettner M, Stovall M, Flannery JT. Cancer in the contralateral breast after radiotherapy for breast cancer. N Engl J Med. 1992;326:781-785.

Brown LM, Chen BE, Pfeiffer RM, et al. Risk of second non-hematological malignancies among 376,825 breast cancer survivors. Breast Cancer Res Treat. 2007;106:439-451.

Curtis RE, Ron E, Hankey BF, Hoover RN. New Malignancies Following Breast Cancer. In: Curtis RE, Freedman DM, Ron E, Ries LAG, Hacker DG, Edwards BK, Tucker MA, Fraumeni JF Jr. (eds). New Malignancies Among Cancer Survivors: SEER Cancer Registries, 1973-2000. National Cancer Institute. NIH Publ. No. 05-5302. Bethesda, MD, 2006. Accessed at http://seer.cancer.gov/archive/publications/mpmono/MPMonograph_complete.pdf on June 1, 2016. 

Rock CL, Doyle C, Demark-Wahnefried W, et al. Nutrition and physical activity guidelines for cancer survivors. CA Cancer J Clin. 2012;62:243-274.

Smith RE, Bryant J, DeCillis A, Anderson S. Acute myeloid leukemia and myelodysplastic syndrome after doxorubicin-cyclophosphamide adjuvant therapy for operable breast cancer: The National Surgical Adjuvant Breast and Bowel Project Experience. J Clin Oncol. 2003;21:1195-1204.

Wolff AC, Blackford AL, Visvanathan K, et al. Risk of marrow neoplasms after adjuvant breast cancer therapy: The National Comprehensive Cancer Network experience. J Clin Oncol. 2015;33:340-348.

Last Medical Review: June 1, 2016 Last Revised: August 18, 2016

American Cancer Society medical information is copyrighted material. For reprint requests, please contact permissionrequest@cancer.org.