October is Breast Cancer Awareness Month

join with aacr to find better ways to prevent and treat breast cancer

October is Breast Cancer Awareness Month. It’s a time for reflection on trends in breast cancer research, prevention, and treatment. According to the National Cancer Institute, approximately 321,910 women in the United States are estimated to be diagnosed with breast cancer in 2026. Furthermore, about 42,140 are expected to die of the disease. 

Breast cancer is the most common type of non-skin cancer in women in the United States. Notably, it accounts for about 30% of all new cancer cases in women. It is second only to lung cancer as a cause of cancer death in American women. In the United States, about one in eight women—about 13%—will develop breast cancer in their lifetime.

Breast cancer can develop in different parts of the breast. Cancers that arise in the milk ducts are called ductal carcinomas and represent the majority of breast cancer cases. Cancers that form in the breast lobules are known as lobular carcinomas and are more likely than ductal carcinomas to be present in both breasts. Another type of breast cancer, known as inflammatory breast cancer, can cause the breast to look swollen and appear pink, reddish purple, or bruised.

Risk factors

Like most cancers, the risk of breast cancer increases with age. Additional risk factors include exposure of breast tissue to estrogen made by the body; presence of dense breast tissue; early onset of menstruation; late onset of menopause; older age at first birth or having never given birth; the use of hormones for symptoms of menopause; drinking alcohol; obesity; and not getting enough exercise.

Hereditary breast cancer makes up 5% to 10% of all breast cancer diagnoses. Women who have mutations in the BRCA1 and/or BRCA2 genes have a higher level of risk.

Breast cancer in men

Men can also get breast cancer. An estimated 2,800 men were expected to be diagnosed with breast cancer in 2025, and about 510 were estimated to die of the disease. Radiation exposure, high levels of estrogen, inherited BRCA gene mutations, and a family history of breast cancer can increase a man’s risk of the disease.

Breast Cancer Survivor Stories

At age 29, Carolyn Searles tested positive for the BRCA1 mutation and decided to undergo a prophylactic double mastectomy at age 31. Five years later, at age 36 and while pregnant with her second child, she was diagnosed with stage 2B triple-negative breast cancer. Read her story in the AACR Cancer Progress Report 2026. 

Melanie R. Stewart is a nurse and citizen of the Chickahominy Tribe living in a rural community in Virginia. When a routine mammogram revealed she had breast cancer in February 2022, she opted for a lumpectomy (surgery to remove cancer or other abnormal tissue from the breast), followed by brachytherapy, which delivers radiation by placing small radioactive sources in or next to the tumor. Her decision was shaped by geography since brachytherapy can be completed in just a few days and the closet cancer center to her is 40 miles away. Read her story in the AACR Cancer Disparities Progress Report 2026.

The San Antonio Breast Cancer Symposium

The annual San Antonio Breast Cancer Symposium (SABCS®) is cosponsored by the AACR and UT Health San Antonio’s Mays Cancer Center. SABCS® is a major contributor to breast cancer research and breast cancer awareness. This year, an international audience of basic scientists, physician-scientists, clinical investigators, breast care providers, and patient advocates will gather from December 8-11 at the Henry B. González Convention Center. Topics include advances in breast cancer prevention and treatment, applications of AI in drug development, factors contributing to disparities in care, and more.

AACR’s official blog, Cancer Research Catalyst, wrote about some of the exciting developments that came out of SABCS 2025. These include:

more about breast cancer

  • Genetic testing can identify inherited gene mutations that increase a patient’s risk of breast cancer. Read more in AACR’s magazine Cancer Today.
  • A clinical trial found that first-line treatment with an antibody-drug conjugate improved outcomes for certain patients with triple-negative breast cancer. The trial results led to the therapeutic’s approval by the U.S. Food and Drug Administration. Read more in Cancer Today.
  • A meta-analysis found that among breast cancer patients treated with tamoxifen, those with certain genetic variants may have worse outcomes than those without these variants. Learn more in Cancer Today.
  • Studies have found that binge drinking may be associated with higher rates of certain breast cancers in individuals under 40. Read the details in this post on Cancer Research Catalyst.

Supporting Research through Grants and Fellowships

The AACR and its partners provide grants to scientists to support their investigations of various aspects of breast cancer. The following grants were awarded in 2026: 

  • AACR awarded an AACR Trailblazer Research Grant for Early-stage Investigators to Ana Luísa Correia, PhD, from the Champalimaud Foundation, for her research on the neuro-immune regulation of metastatic breast cancer dormancy. 
  • The Breast Cancer Research Foundation and AACR awarded career development grants to three recipients: Hung V.T. Nguyen, PhD, of Dartmouth College, to study multivalent polymer conjugates for metastatic triple-negative breast cancer therapy; Veena Padmanaban, PhD, of Johns Hopkins University, to study tumor-instructed neuronal programs that drive breast cancer metastasis; and Marina N. Sharifi, MD, PhD, of University of Wisconsin, Madison, to study liquid biopsy biomarkers of endocrine resistance in metastatic invasive lobular carcinoma (ILC). 
  • The Breast Cancer Research Foundation and AACR awarded the NextGen Grant for Transformative Cancer Research in Honor of Nancy E. Davidson, MD, to Qiwei Wang, PhD, of University of Virginia, for research on harnessing the antitumor immunity in triple-negative breast cancer.  
  • The Breast Cancer Research Foundation, Lobular Breast Cancer Alliance, and AACR awarded a career development grant to Lounes Djerroudi, MD, PhD, of Institut Curie, to study leveraging AI for ILC histobiological classification, prognostic modeling, and target discovery; and a fellowship to Stephen Connor Purdy, PhD, of University of Pittsburgh, to study how E-cadherin loss reprograms the endoplasmic reticulum to remodel the membrane proteome in ILC.
  • AACR and the Lobular Breast Cancer Alliance awarded grants and fellowships to Carla R. Zeballos Torrez, MD, PhD, of University of Pennsylvania, to study a multimodal AI approach for detecting ILC and lymph node involvement; and Karmella A. Haynes, PhD, of Emory University, to study epigenetic mechanisms modulated by adipocyte signaling to promote ILC. 
  • AACR and Think Forward Foundation granted a career development award to Qian Zhu, PhD, of Baylor College of Medicine, to study how spatial OMIC profiling and modeling reveals targetable drivers of ER-positive breast cancer bone metastasis. 

for more information

Please see our page on breast cancer for more information on prevention, screening, and treatment. This page also has information on breast cancer treatment during pregnancy.