Knowing Your Normal. Knowing Your Risk.
Reviewed Dr Jo Mackson
Published June 2026
Reading time About 10 minutes
Where the basics run out.
Breast health is one of the rare areas in women’s health where the basics are well known: mammograms from a certain age, know your breasts, see your GP if anything changes. Women haven’t been dismissed here. The problem is that the basics only get you so far, and the harder questions come next. What does dense breasts on my report actually mean? Do I need supplementary screening? What is my actual risk? This is where the answers stop being one-size-fits-all.
Knowing Your Normal: Breast Awareness.
Breast awareness is knowing your own breasts well enough to notice when something changes. The simplest way is a monthly habit: on the first of each month, give them a feel (Feel Them On The First, as we like to remember it). You are not looking for cancer, you are learning your normal. There is no perfect technique. If something feels new or different, come and see us.
First, a piece of geography: breast tissue extends well beyond the visible breast, into the underarm and up toward the collarbones, and most women miss those areas without realising.
Most changes you notice will be benign. Cysts, lumpiness that comes and goes with your cycle, tenderness before a period, and mild asymmetry are all common and rarely sinister. The rule of thumb is simple: if something is new, persistent, or different from your normal, please come and see us. Specifically:
- •A new lump or thickening that does not go away with your cycle
- •Skin changes: dimpling, puckering, redness, or texture changes (some describe it as orange peel)
- •Nipple changes: a new inversion, discharge (especially blood-stained or from a single duct), or persistent crusting and scaling
- •Persistent pain in one specific area, particularly if it does not vary with your cycle
- •Swelling, lumps, or skin changes in the armpit
None of these automatically mean cancer. They mean a conversation, and usually some imaging.
Breast cancer is overwhelmingly diagnosed in cisgender women, but anyone with breast tissue can develop it: trans men, non-binary people assigned female at birth, and cisgender men (under 1% of cases, but real). Trans men who have had top surgery still have residual tissue and remain at some risk. The same principles apply, though screening pathways may need to be individualised.
Understanding Your Risk.
Breast cancer is the most common cancer in Australian women. Around 1 in 7 will develop it in their lifetime, and the risk increases with age.
The first thing most women reach for is family history. It matters. But around 90% of breast cancers happen in women with no family history at all. That is why population screening exists for everyone, and why breast awareness matters at every age, whatever your family history.
Some factors you cannot change: age (this is the biggest risk factor, though still about a third of cases are diagnosed in women under 55), a close and recurring family history, known genetic mutations, i.e. BRCA1 or BRCA2 mutations, previous breast cancer or certain abnormal biopsy findings, dense breast tissue, and lifetime hormonal exposure. A few you can: alcohol, which has no safe lower limit for breast cancer; weight after menopause, when fat tissue becomes the body’s main source of oestrogen; and physical activity, the most strongly evidenced protective factor. The Deep Dive puts the full numbers against each.
What matters most is that these factors do not just add up, they multiply. Picture two women with the same strong family history. One drinks daily, carries extra weight after menopause, and rarely exercises, so her risks build on top of each other. The other keeps her alcohol low, stays active, and holds a healthy weight, so her actual lifetime risk comes down, even though her family history has not changed. You cannot change your family history, but you can change what sits around it.
Hormonal exposure is on the list because oestrogen and progesterone make breast tissue grow and turn over with each cycle, and more turnover over a lifetime means more chances for a cell to copy itself imperfectly. The numbers are smaller than most women have been led to believe: the absolute increase from the pill or MHT is around 4 extra cases per 1,000 women over 5 years, and modern body-identical MHT carries a more favourable profile than older synthetic formulations. The full discussion sits in our MHT Deep Dive and our Menopause Deep Dive.
So What Is My Actual Risk?
This is where personalised risk assessment comes in. It takes your individual factors (age, family history, reproductive history, breast density if known, and lifestyle) and estimates your risk over the next 10 years and across your lifetime, so you can see where you sit against the often-quoted 1 in 7 average.
The tool we recommend most for SWW patients is iPrevent, an Australian tool developed by Cancer Australia and the Peter MacCallum Cancer Centre. It is free, takes about 20 minutes, and you can do it from home before your consult. It shows you two things at once: your personalised risk, and how the modifiable factors shift it for you specifically. Once we know your number, we use it to shape your screening plan.
Screening: What It Catches, What It Misses.
BreastScreen Australia offers a free 2D mammogram every two years to women aged 40 to 74. Those aged 50 to 74 are actively invited and reminded; women aged 40 to 49 are eligible but not actively invited, so the responsibility for booking sits with you. This is part of why women in their 40s are screened less consistently than women over 50.
Our position is to recommend routine mammographic screening from age 40, earlier for women whose risk profile calls for it. Breast cancer in your 40s is not common, but it is not rare, and earlier screening reduces deaths in this group. Women with a strong family history, a known genetic mutation, or otherwise significantly elevated risk should usually start earlier, often after specialist input.
A mammogram is a low-dose X-ray of the breast. It comes in two forms: 2D, which BreastScreen uses, and 3D (tomosynthesis), which is better in dense breasts and worth choosing where you can. Mammography is the foundation of screening because it is the only test shown in large trials to reduce breast cancer deaths, not just diagnoses. But it is not perfect. It picks up around 75 to 85% of cancers in average-density breasts and about 60% in dense ones, so roughly 1 in 5 to 1 in 6 cancers will not show on a screening mammogram.
A normal mammogram means no cancer was visible on the imaging that day. It does not mean no cancer is present. This is why breast awareness still matters even when you screen on time.
Your hands know your breasts in a way no scan ever will. But a scan sees early changes, before even the best hands could. This is why one without the other will never be enough.
Dense Breasts: Why They Matter.
Breast density is one of the most useful things to understand about your own breasts, and one of the least understood. It is not how your breasts look or feel, and it has nothing to do with whether they are lumpy. The only way to know your density is from a mammogram report.
Breasts are made of glandular and fibrous tissue (which produces milk and holds the structure together) and fatty tissue. Density is the ratio between them. On a mammogram, glandular and fibrous tissue appears white and fat appears dark, which is why density can only be read off the imaging. It is reported on a four-point scale, BI-RADS A through D, from mostly fatty to extremely dense. Density is largely inherited and usually falls after menopause as glandular tissue gives way to fat, though some women stay dense well into their 70s.
Density matters for two reasons. First, it makes mammograms work less well: cancers appear white, the same colour as dense tissue, so finding a small cancer in dense breasts is like finding a snowflake on snow, where in fatty tissue it is more like a snowflake on a black coat. Second, density itself raises the risk of developing breast cancer, because dense breasts simply contain more of the tissue cancer arises from. The 10% of women with extremely dense breasts (BI-RADS D) have a 4 to 6 times higher risk than the 10% with mostly fatty breasts (BI-RADS A).
Density is the rare risk factor that does two things at once: it raises the chance of developing breast cancer, and it lowers the chance of catching it if it does.
If your last mammogram reported dense breasts, the next conversation is about supplementary screening: imaging or a blood test added to your mammogram to catch what it alone might miss. The options include ultrasound, contrast-enhanced mammography, breast MRI, and the BCAL Breastest Plus blood test. There are no Australian guidelines yet for routine supplementary screening in dense breasts, so the right choice depends on your density, your risk profile, and your family history. There is no flow chart to follow, instead it is an individual conversation, revisited every year or two to keep your screening matched to your risk.
Since 2025, BreastScreen NSW has begun reporting breast density on results, which matters: you cannot make informed decisions about your own screening if you do not know your density. Reporting is not yet uniform across Australia. If you have had a mammogram in NSW, your category should be on the report. If it is not, ask your GP about how to find out.
3 Steps to Breast Health.
Breast health is one of the areas where individual conversations matter most. A good plan comes down to three things: knowing your own risk (iPrevent is the best way to prepare), a screening plan matched to that risk and your density, and the lifestyle factors with the strongest evidence behind them, alcohol, weight, and physical activity.
If you have not had a breast health conversation in the last few years, you have dense breasts and are unsure what to do, or a family history of breast cancer that keeps you up at night, book in to see your GP. If you don’t have a GP, or you want a dedicated discussion, come and see us. This is the kind of conversation that benefits from time, the full picture, and looking at your breast health as a whole rather than a series of one-off decisions.
So there you have it, our Mini Guide on breast health. If it has left you hungry for more, the genetics, the MHT conversation, or a proper walk through the screening options, our Deep Dive is where to go next.
This Mini Guide is the taste test. The Deep Dive is the full degustation. It covers the full risk-factor breakdown with every number in context, the genetics conversation in detail, and the MHT and breast cancer question grounded in current evidence rather than 2002 headlines.
It is long, it is detailed, and it is the education on this topic we think every woman should have had years ago. We are not going to insist you read it. But if you ever find yourself wondering, the Deep Dive is here when you are. Read it here.