Most people don't associate breast cancer with men — but men have breast tissue, and men can and do develop breast cancer. Male breast cancer is rare, accounting for around 1% of all breast cancer diagnoses in Australia, but it is a real condition that is frequently under-recognised and diagnosed later than it should be, largely because men don't expect it to happen to them.

If you are a man who has noticed a lump or change in your chest, or a woman whose male relative has been affected by breast cancer, this page is for you. Early assessment leads to earlier diagnosis, and earlier diagnosis leads to better outcomes. At Breast & Surgical Oncology at The Poche Centre, we see and treat male breast cancer as part of our specialist practice.

Why Men Get Breast Cancer

All men are born with a small amount of breast tissue — glandular cells, ducts, and fatty tissue beneath the nipple and areola. Although far less than women, this tissue is enough for cancer to develop. Most male breast cancers begin in the milk ducts (invasive ductal carcinoma) and are almost exclusively hormone receptor-positive — driven by oestrogen — reflecting the same biology as the most common subtype of breast cancer in women.

Male breast cancer is most commonly diagnosed in men in their 60s and 70s, though it can occur at any age. Approximately 200 Australian men are diagnosed each year.

Risk Factors for Male Breast Cancer

While the exact cause of any individual breast cancer is rarely identifiable, several factors are known to increase a man's risk:

Inherited gene mutations — this is the single most important risk factor for male breast cancer. Men who carry a BRCA2 mutation have a lifetime breast cancer risk of approximately 6–8%, compared to around 0.1% in the general male population. BRCA1 mutations also carry an elevated risk, though lower than BRCA2. Other gene mutations including PALB2 and CHEK2 also increase risk. Any man diagnosed with breast cancer should be offered genetic counselling and testing, as a confirmed mutation has significant implications for other family members.

Family history — a family history of breast cancer, particularly in multiple relatives or at a young age, and especially in combination with ovarian cancer in female relatives, raises the likelihood of an inherited predisposition. Because male breast cancer is itself rare, a male relative diagnosed with breast cancer is a particularly meaningful signal of possible inherited risk in a family.

Age — risk increases with age, with the peak incidence in men occurring between 60 and 70 years.

High oestrogen levels — conditions or circumstances that raise oestrogen levels in men are associated with increased breast cancer risk. These include Klinefelter's syndrome (a chromosomal condition in which men carry an extra X chromosome and have naturally higher oestrogen levels), liver cirrhosis (which impairs the liver's ability to metabolise oestrogen), obesity (as fat tissue produces oestrogen), and oestrogen-containing medications.

Testicular conditions — undescended testes, orchitis (testicular inflammation), and orchiectomy (surgical removal of a testicle) are each associated with a modestly elevated risk, likely through their effects on hormone balance.

Radiation exposure — prior radiotherapy to the chest area, for example as treatment for Hodgkin's lymphoma, increases the risk of breast cancer in both men and women.

Gynecomastia vs. Breast Cancer — Understanding the Difference

One of the most common reasons men notice a change in their chest is gynecomastia — a benign enlargement of the male breast tissue. Gynecomastia is extremely common, affecting a significant proportion of men at some point in their lives, and is frequently triggered by hormonal changes during puberty, ageing, certain medications (including some blood pressure, prostate, and psychiatric drugs), anabolic steroid use, alcohol, and conditions affecting liver or kidney function.

Gynecomastia typically presents as a disc of rubbery, sometimes tender tissue felt symmetrically beneath the nipple in one or both breasts. It is not cancer and does not significantly increase cancer risk.

The challenge is that gynecomastia can feel similar to a breast lump, and distinguishing between the two without proper assessment can be difficult. Features that raise concern for cancer rather than gynecomastia include a lump that is hard, irregular, or fixed rather than rubbery and mobile; a lump that is off-centre rather than sitting directly under the nipple; nipple discharge (particularly bloodstained); skin dimpling or puckering; nipple retraction; and swelling or a lump in the armpit.

Any new, unexplained breast lump or change in a man should be assessed by a doctor promptly. The presence of gynecomastia does not mean a separate cancerous lump cannot also be present.

Symptoms of Breast Cancer in Men

Because men have very little breast tissue, cancers often present at a relatively small size and may be very close to the nipple or areola. This means symptoms tend to be noticed more readily — but they are also more likely to be dismissed or delayed. The most common signs of breast cancer in men include:

• A painless lump or area of thickening beneath the nipple or areola — the most common presenting sign
• Nipple retraction — a nipple that has turned inward or changed position
• Nipple discharge — any discharge from the male nipple warrants assessment, particularly if it is bloodstained or spontaneous
• Skin changes over the chest — redness, dimpling, puckering, or scaling of the skin overlying the breast area
• Paget's disease — a scaly, eczema-like rash affecting the nipple or areola, which in men as in women can indicate an underlying cancer
• Swelling or a lump under the arm — enlargement of the axillary lymph nodes may indicate spread

Men are significantly more likely than women to delay seeking assessment for a breast change — often because they simply don't consider breast cancer a possibility. If you have noticed any of these changes, please see your GP promptly. There is no benefit to waiting.

How Is Breast Cancer in Men Diagnosed?

The diagnostic pathway for male breast cancer follows the same triple assessment approach used for women — clinical examination, imaging, and biopsy — though with some practical differences.

Clinical examination — your specialist will take a detailed history and perform a thorough examination of the chest, nipple, and axillary lymph nodes.

Imaging — a mammogram can be performed in men and provides useful diagnostic information, though male breast tissue is thinner and imaging is technically different from a female mammogram. Ultrasound is frequently used alongside mammography and is particularly helpful for characterising the nature of a lump and guiding biopsy.

Core biopsy — a small sample of tissue is taken under ultrasound guidance under local anaesthetic and sent for pathological analysis. The biopsy confirms whether cancer is present and, crucially, determines receptor status — almost all male breast cancers are oestrogen receptor-positive, which has direct implications for treatment.

If breast cancer is confirmed, staging investigations (CT scan, bone scan) will be arranged to determine whether the disease has spread beyond the breast and lymph nodes.

How Is Breast Cancer in Men Treated?

Treatment for male breast cancer follows similar principles to treatment for women, though some important differences apply given the anatomy and the predominantly hormone receptor-positive nature of male breast cancers.

Surgery is typically the primary treatment. Because men have relatively little breast tissue, the standard surgical approach is mastectomy — removal of all breast tissue on the affected side, including the nipple-areola complex. Breast-conserving surgery (lumpectomy) is less commonly performed in men but may be possible in selected cases. Sentinel lymph node biopsy is performed at the time of surgery to assess whether the axillary lymph nodes are involved.

Radiotherapy may be recommended after surgery to reduce the risk of local recurrence, particularly where the tumour was large, the lymph nodes were involved, or margins were close.

Hormonal (endocrine) therapy is the cornerstone of systemic treatment for male breast cancer, reflecting the near-universal hormone receptor positivity of these tumours. Tamoxifen is the standard agent and is typically prescribed for five to ten years. Aromatase inhibitors — which are the preferred endocrine therapy in postmenopausal women — are less effective in men unless combined with ovarian suppression equivalent (luteinising hormone-releasing hormone agonists), as men continue to produce oestrogen through the testes.

Chemotherapy may be recommended for more advanced or aggressive tumours, following the same general principles as in women.

Targeted therapy — where a tumour is HER2-positive (which is less common in men than in women), HER2-targeted agents such as trastuzumab may be incorporated into the treatment plan.

Genetic Implications of Male Breast Cancer

A diagnosis of breast cancer in a man has important implications beyond the individual patient. Male breast cancer is significantly associated with inherited gene mutations — particularly BRCA2 — and every man diagnosed with breast cancer should be offered referral for genetic counselling and testing.

If a BRCA2 or other pathogenic mutation is identified, this has direct relevance for the man's children (who each have a 50% chance of inheriting the mutation), his siblings, and other blood relatives. Female relatives who carry a BRCA2 mutation have a substantially elevated lifetime risk of breast and ovarian cancer and should be offered appropriate surveillance and risk management.

Genetic testing in this context is not just about the individual — it is a gift of information that can protect future generations of a family.

The Experience of Being a Man With Breast Cancer

A breast cancer diagnosis is challenging for anyone. For men, it carries an additional layer of complexity — a condition that most people associate exclusively with women, a lack of specific male-focused support resources, and sometimes a reluctance to seek help or talk openly about what they are going through.

We want to be direct: there is no shame in a man having breast cancer, and there is nothing unusual about seeking assessment for a breast concern. You are not alone, our practice has treated many men with breast cancer. Our team treats every patient — male or female — with the same expertise, respect, and sensitivity. If you have been diagnosed with breast cancer, or if you are a man who has noticed something concerning, we are here.

Male Breast Cancer Assessment in North Sydney

If you are a man with a breast concern, or a patient whose male relative has been diagnosed with breast cancer, our specialist team at The Poche Centre in North Sydney can provide prompt assessment, genetic counselling referral, and expert multidisciplinary treatment planning.

Urgent appointments are available when clinically needed.