Men's Breast Cancer Awareness Week 2026: signs, risks, and the research gap

Every person is born with a small amount of breast tissue, and men are no exception. That tissue can develop cancer, yet breast cancer is so closely associated with women that many men do not consider it until a symptom has lingered. Men's Breast Cancer Awareness Week, observed during the third week of October, exists to close that gap in knowledge. In 2026, it runs from Sunday, October 18, through Saturday, October 24, within Breast Cancer Awareness Month. Its message is practical: men can get breast cancer, early changes deserve prompt attention, and men have long been underrepresented in breast cancer research.

What Men's Breast Cancer Awareness Week is and why it matters

Men's Breast Cancer Awareness Week grew out of advocacy by male survivors, their families, and the groups that formed around them. It is not a federal observance with a single fixed date. Instead, it has been recognized through state legislation and governors' proclamations. Massachusetts, for example, designated the third week of October as Male Breast Cancer Awareness Week in 2012. Most observers follow that third-week convention, although some national calendars list October 17 to 23 for 2026.

The reasoning behind the week appears in nearly every proclamation: the belief that breast cancer affects only women can delay diagnosis and treatment in men. A man who notices a firm spot under his nipple may dismiss it as a strained muscle or a sign of aging. Because routine breast screening is not recommended for men at average risk, noticing a change and acting on it is often how the disease is found early.

Breast cancer awareness has also shifted from symbols toward science, an emphasis shared by research-focused observances held earlier in the year. That shift matters for men, whose care still rests on a thin layer of male-specific evidence.

How common male breast cancer is and what types occur

Male breast cancer is rare. In the United States, about 1 in every 100 breast cancers is found in a man, which translates to a few thousand men diagnosed each year. Most are diagnosed in their 60s or later, although the disease can occur at younger ages, particularly in men with an inherited gene change.

The anatomy explains why the disease is possible. Men have a small amount of breast tissue behind the nipple and the areola (the darker ring of skin around the nipple). That tissue contains ducts, which are thin tubes that carry milk in women but stay underdeveloped in men. Men have few or none of the lobules, the small glands that produce milk. Cancer begins when cells in this tissue acquire DNA changes and grow out of control.

Most male breast cancers start in the ducts. The most common form is invasive ductal carcinoma, meaning cancer that began in a duct and has grown into the surrounding tissue. Ductal carcinoma in situ, or DCIS, describes abnormal cells that remain confined to the lining of the ducts. Cancers that begin in the lobules are very rare in men because men have so few lobules.

Men's tumors also tend to share a particular biology. Male breast cancer is almost always hormone receptor positive, which means the cancer cells carry proteins that allow hormones such as estrogen to fuel their growth. HER2-positive disease, driven by an excess of a growth-signal protein, is uncommon in men, and triple-negative breast cancer is rare. International research has also found that male tumors differ biologically from female tumors in ways still being studied.

Signs of breast cancer in men and how they differ from gynecomastia

The most common sign of breast cancer in men is a lump or thickening near the breast, usually painless and often located directly under the nipple or areola. Other signs include:

• A nipple that turns inward or changes shape or direction
• Discharge from the nipple, particularly if it is bloody
• Dimpling, puckering, or an orange-peel texture on the skin of the chest
• Redness, scaling, or flaking on the nipple or the surrounding skin
• A sore on the breast skin that does not heal
• Swollen lymph nodes under the arm or near the collarbone

Most of these changes turn out to have a non-cancerous cause, but each one deserves a prompt visit to a clinician. Several of them reflect changes beyond a lump that apply to breast cancer in anyone, regardless of sex.

The condition most often confused with male breast cancer is gynecomastia, a common and benign enlargement of breast gland tissue in males. It reflects an imbalance between estrogen and testosterone and can be linked to aging, certain medications, or liver and kidney conditions. Gynecomastia usually feels soft or rubbery, sits centered behind the nipple, often affects both sides, and may be tender. A cancerous lump is more likely to feel firm or hard, sit off-center on one side, and cause no pain. These patterns are general tendencies, not a diagnostic test, and only a clinical evaluation can tell the two apart.

Evaluation usually starts with an exam of the chest and armpit and questions about family history. Imaging comes next, typically a diagnostic mammogram (an X-ray of the breast done to investigate a symptom) and an ultrasound, which uses sound waves to show whether a lump is solid or filled with fluid. If imaging raises concern, a biopsy removes a small sample of tissue for a pathologist to examine. A biopsy is the only way to confirm cancer.

Who faces higher risk and why men are often diagnosed later

Several factors are linked to a higher chance of breast cancer in men:

• Older age, which is the strongest single factor
• Inherited changes in the BRCA2 gene, and to a lesser degree BRCA1, PALB2, and other genes that normally help repair damaged DNA
• A family history of breast cancer, especially in several close relatives
• Klinefelter syndrome, a genetic condition in which a male has an extra X chromosome, leading to higher estrogen and lower testosterone levels
• Past radiation therapy to the chest, such as treatment for lymphoma
• Conditions that raise estrogen levels, including obesity, liver cirrhosis, and certain hormone-based medications
• Conditions affecting the testicles, such as an undescended testicle or surgical removal of a testicle
• Heavy alcohol use, which may raise risk partly through its effects on the liver

Many men who develop breast cancer have no known risk factor other than age. For men who carry a BRCA mutation, current guidance generally recommends training in breast self-examination and a yearly clinical breast exam beginning around age 35. These men also face higher prostate and pancreatic cancer risk, so genetic counseling (a session with a trained professional who explains inherited risk and testing) can benefit the whole family.

Delayed diagnosis remains the central problem the awareness week addresses. Embarrassment, the assumption that breast cancer is a women's disease, and the absence of routine screening all contribute, so men are more likely than women to be diagnosed after the cancer has spread to nearby lymph nodes or beyond. Understanding how breast cancer stages work helps explain why this matters: outcomes are generally favorable when the disease is found while still confined to the breast. Large studies show that men have somewhat lower survival than women on average, a gap largely, though perhaps not entirely, explained by later diagnosis. The evidence does not support describing male breast cancer as inherently more aggressive.

Why men are missing from breast cancer research

For decades, most breast cancer clinical trials either excluded men or enrolled very few. In 2020, the FDA issued final guidance stating that men had historically been excluded from breast cancer drug trials because the disease is rare in men, and recommending that trial eligibility criteria allow men to take part. Analyses of large late-stage breast cancer trials have found that men made up only a fraction of one percent of participants, well below their share of people living with the disease.

The consequence is that much of the treatment men receive is based on studies conducted mostly in women. The overall approach is similar for both sexes:

• Surgery, where mastectomy (removal of the whole breast) is more common in men because they have less breast tissue
• Radiation therapy to destroy remaining cancer cells
• Chemotherapy when the risk of recurrence or the stage calls for it
• Hormone therapy, usually an estrogen-blocking pill taken for several years
• Targeted medications for specific tumor features or inherited gene changes

Some details differ in men. Certain estrogen-lowering medications used for women do not work well alone in men, because the testicles keep producing hormones the body converts into estrogen, so they are paired with a medication that reduces testosterone production. Hormone therapy can also cause hot flashes and sexual side effects in men. One of the few randomized studies designed only for men compared hormone therapy approaches, but it was small and did not measure long-term survival, which shows how limited male-specific evidence remains.

The picture is improving. More recent trials, particularly of newer targeted medications, have been more likely to allow men to enroll, and some approvals have extended treatments to men using a combination of trial data and real-world evidence. Eligibility still varies widely from one study to the next, and participation is always voluntary. For men considering research, taking a first step into clinical trials begins with understanding what participants are asked to do and what rights they keep.

Questions people ask about male breast cancer

Can men get breast cancer?

Yes. Men have breast tissue, and about 1 in every 100 breast cancers in the United States occurs in a man. Most cases are diagnosed in men in their 60s or older.

Is a lump under the nipple gynecomastia or cancer?

Gynecomastia is far more common and is not cancer, but the two can feel similar. A firm, one-sided lump, skin changes, or nipple discharge should be evaluated promptly by a clinician, who may order imaging and, if needed, a biopsy.

Should men do breast self-exams?

Routine self-exams are not formally recommended for men at average risk, but knowing how the chest normally looks and feels is useful. Men who carry a BRCA mutation are generally advised to learn self-examination and have yearly clinical breast exams starting around age 35.

Is breast cancer more dangerous for men?

On average, men have somewhat lower survival than women, largely because their cancers are found later. Detected early, outcomes are generally favorable, though individual outcomes cannot be predicted from averages.

Can men join breast cancer clinical trials?

Increasingly, yes. Federal guidance has encouraged sponsors since 2020 to allow men to enroll. Eligibility varies by study, so a conversation with an oncologist is the best starting point.

Turning a week of awareness into earlier checkups

Men's Breast Cancer Awareness Week asks for a small change in habit. A new lump, a nipple that turns inward, discharge, or a skin change on the chest is a reason to schedule an appointment rather than wait. Men with a strong family history of breast, ovarian, prostate, or pancreatic cancer, or a known BRCA mutation in the family, have good reason to ask about genetic counseling.

Research is the other half of the story. Treatment for men can only become more precise as more men are included in the studies that test it.

DecenTrialz is a clinical trial recruitment and pre-screening platform. A person shares some information about their health, an AI matching process identifies studies that may be relevant, and a registered nurse reviews that information before a referral is sent to a research site team. The research site team makes the final eligibility determination, handles informed consent, and manages enrollment. Men living with breast cancer who want to explore whether a study may fit their situation can begin there and discuss any potential match with their own care team.