October is Breast Cancer Awareness Month

join with the 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 316,950 women in the United States are estimated to be diagnosed with breast cancer in 2025. Furthermore, about 42,170 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 or late onset of menstruation; 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 certain genes, such as BRCA1 and BRCA2, can have a higher level of risk.

Breast cancer in men

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

One Person’s Story

Michelle Anderson-Benjamin, a mother of two in New York City, is a survivor of stage 4 triple-negative breast cancer. She founded the The Fearless Warrior Project to help others facing cancer prioritize their mental health, legacy, and self-worth. Read her story in the AACR Cancer Progress Report 2025.

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 9-12 at the Henry B. González Convention Center. Topics include breast cancer in young women, advances in treatment, risk prediction and prevention strategies, and rare tumor types.

The AACR’s official blog, Cancer Research Catalyst, wrote about some of the exciting developments that came out of SABCS 2024. These include:

more about breast cancer

  • Research advances have led to new treatment options for cases of HER2-low and HER2-ultralow breast cancers. Read more in the AACR’s magazine Cancer Today.
  • A clinical trial found that people with HER2-positive breast cancer who have signs of cancer after neoadjuvant treatment could benefit from a type of treatment called an antibody-drug conjugate. Read more in Cancer Today.
  • While breast cancer incidence among women 20 to 49 increased from 2000 to 2019, a new study found that the rate at which young women are dying from breast cancer declined dramatically between 2010 and 2020 in the United States. Learn more in Cancer Today.
  • Recent studies are redefining how much surgery is truly necessary for a number of different cancer types, including breast cancer. 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, including:

  • In 2025, the Breast Cancer Research Foundation and AACR awarded career development grants to María Teresita Branham, PhD, from the National Scientific And Technical Research Council (CONICET), for her research into using cellular reprogramming to tackle triple-negative breast cancer; Fernanda G. Kugeratski, PhD, from The University of Texas MD Anderson Cancer Center, who is working to define the role of LRRC17+ cancer-associated fibroblasts in the breast tumor microenvironment; Temidayo A. Fadelu, MD, MPH, from Dana-Farber Cancer Institute, who is working to mitigate stigma about breast cancer in Rwanda; and Mercedes Fuertes, PhD, from the Institute of Biology And Experimental Medicine (IByME – CONICET), who is researching monoclonal antibody-based immunotherapy against MICA in triple-negative breast cancer.
  • AACR-Lobular Breast Cancer Alliance-Deborah Mueller Foundation Fund Invasive Lobular Carcinoma Innovation and Discovery Grants were awarded to two recipients in 2024. One went to Julia M. Houthuijzen, PhD, of Netherlands Cancer Institute, for her study of “Ex vivo human ILC cultures for personalized treatment.” Carolina Reduzzi, PhD, Weill Cornell Medicine, received support for her study of “Comprehensive liquid biopsies to decipher lobular breast cancer metastasis.”
  • AACR’s Maximizing Opportunity for New Advancements in Research in Cancer (MONARCA) Grants for Latin America is supporting Maria Florencia Mercogliano, PhD, of Experimental Medicine and Biology Institute, Buenos Aires, Argentina. She is studying “Predictive biomarkers for HER2+ breast cancer using spatial transcriptomics.”
  • Min Yu, PhD, University of Maryland, Baltimore, received an AACR-Bristol Myers Squibb Midcareer Female Investigator Grant for her study of “Prolonged suppression of tumor intrinsic interferon signaling on metastasis.”
  • A 2024 grant from the AACR-Conquer Cancer®, the ASCO Foundation Young Investigator Award for Translational Cancer Research is helping Nolan Priedigkeit, MD, PhD, of Dana-Farber Cancer Institute, in his study of “Fusion RNAs as individualized therapeutic targets in advanced breast cancer.”
  • Two AACR-AstraZeneca Breast Cancer Fellowship for Endocrine Therapy Research grants were given in 2024. One went to Zachary E. Potter-Engelskirger, PhD, of Scripps Research, who is researching the mechanistic characterization of paralog-restricted, allosteric covalent CDK4 ligands. The other went to Alana A. Arnone, PhD, of Wake Forest University School of Medicine, who is looking into how endocrine-targeting therapies interact with short-chain fatty acids to reduce ER-positive breast cancer.
  • In 2024, Zhe Ying, PhD, from Icahn School of Medicine at Mount Sinai, received a Triple Negative Breast Cancer Research Foundation-AACR NextGen Grant for Transformative Cancer Research to help with his research on examining how basal-like breast cancer driver mutations initiate hormone independence.
  • In 2024, three researchers received grants as part of the Victoria’s Secret Global Fund for Women’s Cancers Career Development Award, in Partnership With Pelotonia and the AACR. Sangeetha Reddy, MD, MSci, of UT Southwestern Medical Center, is looking into dual-targeting myeloid cells and Tregs to enhance CD8 T cell immunity. Francesca S. Gazzaniga, PhD, of Massachusetts General Hospital, is working to uncover diet, microbiome, and immune interactions to treat breast cancer. Utthara Nayar, PhD, of Johns Hopkins University, is researching the mechanisms underlying allele bias of novel estrogen receptor mutation.

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.