Your first mammogram could be life saving

When it comes to breast cancer, timing matters. A mammogram can pick up tiny changes in breast tissue long before a lump is felt, giving treatment the best possible chance of success. But research shows it’s not just having mammograms that matters it’s whether you go to your very first one.

Every year, around 3,500 New Zealanders – including 25 men - are diagnosed with breast cancer, and 650 lives are lost. These numbers are not just statistics; they are mums, sisters, wives, colleagues and friends. Just under half of breast cancer diagnoses are detected at regular screening mammograms - which provide the best chance of early diagnosis and cure. As of 2020, 70.8% of eligible women (aged 45-69) received free mammograms.

So why is having a mammogram so important?

A new Swedish study published in the British Medical Journal this year, followed more than 430,000 women invited to their first breast screening and tracked them for up to 25 years. The results were sobering. About a third of women didn’t turn up to their first appointment, and that decision echoed across decades. Those who skipped their first mammogram were far less likely to attend future screenings, more likely to be diagnosed with cancer at a late stage and faced a 40% higher risk of dying from breast cancer. The overall rate of cancer was similar across both groups, but the timing of diagnosis made the difference: late-stage diagnosis meant increased risk of cancer returning and lower survival.

The study shows a powerful solution. That first mammogram isn’t just a one-off health check; it sets a pattern. If you start attending, you’re more likely to keep going. If you don’t, non-attendance can become the default. And when breast cancer develops, the cost of that choice can be life-threatening.

So how do we make that first step easier? In New Zealand, many women face a mix of barriers: juggling work or childcare, worrying about pain or results, finding transport, or navigating clunky booking systems. For Māori and Pacific women, additional hurdles and experiences of cultural unsafety in healthcare play a role. These aren’t minor inconveniences. They are reasons why people delay, sometimes indefinitely.

This is why we are intrigued to see how BreastScreen Aotearoa’s new opt-out digital booking system, Te Puna, will affect first-time attendance in the years ahead. Instead of leaving women to arrange their own first appointment, the system books one automatically. Unless you cancel, the slot is yours.

This approach works because human behaviour is shaped by defaults. We’re much more likely to stick with an appointment that’s already made for us than to take the extra step of booking one ourselves. International evidence supports this. Opt-out strategies have boosted organ donor registration in Europe, vaccination rates in the United States, and cervical cancer screening in Australia. The message is simple: when health behaviours are made easier, participation rises. If Te Puna achieves this for breast screening, it could shift the long-term outcomes we see here in Aotearoa.

Behavioural science shows that default options are powerful. We tend to go along with them, not because we’re passive, but because they reduce friction. Booking a mammogram becomes less of a chore and more of a given. If Te Puna succeeds, more women could attend their first appointment, and if the Swedish research is any guide, that means more women will keep attending, more cancers diagnosed early, and more lives saved.

Of course, this approach isn’t perfect. Not everyone has reliable internet or feels comfortable managing digital appointments. And unless the system is designed with equity front and centre, it risks widening the very gaps it aims to close. For Te Puna to work, it must be flexible, culturally safe, and accessible for women who are often missed by mainstream health initiatives.

Still, the opportunity is enormous. If we can raise first-time attendance rates, we can change the trajectory of breast cancer outcomes in Aotearoa. The Swedish study shows that the first mammogram is more than a test. It’s a turning point. By making it easier to get there, Te Puna could become one of the more effective public health “nudges” we’ve seen.