The cancer that won’t stop rising

Sunday, 19 October 2025

With cases soaring, and more younger women facing fertility-destroying hysterectomies, experts say the rise in womb cancer is a public health crisis. Nikki Macdonald investigates.

When her period pain escalated and bleeding dragged on, Sherina Shawe started wondering what was going on.

Sure, periods change as you age, but this was different. In June 2023, the Gore mum of three went to her GP, who gave her medication to slow the bleeding.

“It was kind of treating the symptoms more than investigating, which obviously got me a little concerned. But I trusted the system.”

By October that year, she was bleeding for 19 or 20 days straight.

“It was just horrendous.”

The 44-year-old got an ultrasound in Invercargill and was referred for a pelvic examination in March 2024. The top of the results letter read “risk of endometrial cancer”.

“Obviously I was very stressed about that.”

But no-one else seemed too concerned. Don’t worry, they told her, as she waited for an appointment with a gynaecologist. And waited. And waited. “Out of sheer desperation”, she emailed a scientist whose research paper she’d found online, who advocated to get her in.

By then it was March 2025. She had a specialist appointment and got a biopsy in May.

“Within a week or so, I was diagnosed with cancer. And after that, everything went absolutely amazing.

“It was really just the trying to get diagnosed and almost being brushed off by my doctor. Almost being treated like it’s nothing, don’t worry, it’s not a problem…I’d hate to know what would have happened if it was left any longer.”

Shawe isn’t here to bag the health system. She just wants to highlight the struggle to get a diagnosis of a cancer that’s ballooning in New Zealand.

Because the most common symptom is heavy bleeding, it’s easy to pick up in post-menopausal women, but can be overlooked in women who still have their periods.

“I felt like I wasn’t being heard…I just feel like it should be taken serious. And right now, I don’t think it is. It’s just like ‘Oh, don’t worry about it, it’s just your hormones. It’s normal, it’s natural.’ When you know your own body, and it wasn’t natural.”

The tsunami hitting New Zealand and the Pacific

While most cancer rates are static or declining, endometrial cancer is rising steeply.

The number of cases has increased 59% in a decade. But it’s not just the numbers that have doctors reaching for words like “exploding”, “catastrophic” and “crisis”.

It’s also the fact that a disease that mostly hit older people is now afflicting women who’ve yet to have children. That matters not only because young people getting cancer is upsetting, but because the gold standard treatment is a fertility-destroying hysterectomy.

“We're all really concerned about the changing landscape of it,” says Otago University lecturer and researcher, Claire Henry. “Cancers normally occur in older people, but with endometrial cancer, it's really starting to show in young women. We see women as young as 25 with endometrial cancer - that's terrible.”

It’s particularly hitting Pacific women who, with one of the highest endometrial cancer rates in the world, are five times more likely than European Kiwis to get the disease.

Tongan gynaecological oncologist Michael Burling, who trained in New Zealand but now works in Sydney, says endometrial cancer is overtaking cervical cancer in the islands.

“It’s a tsunami that is hitting the Pacific and New Zealand…Travelling through the Pacific, it’s the one cancer that is just increasing catastrophically.”

What’s the story?

Also called womb or uterine cancer, endometrial cancer is cancer of the lining of the uterus - the endometrium.

It’s usually caught and treated quickly in older women, because it announces itself with heavy or abnormal bleeding, which is an obvious red flag if you’re post-menopause.

But for younger women like Shawe, who still have regular periods, it can be dismissed - both by women and their doctors - as just heavy bleeding. Even when they’re wearing nappies or towels to stem the flow.

Add in scarce access to diagnostic tests, and cases that could have been caught and treated as early, pre-cancer lesions are instead being picked up late, after they've progressed to cancer.

“There’s been issues with getting those gynaecology appointments and women getting help and care for abnormal bleeding, and getting triaged in the right way, which is concerning,” Henry says. “We know the healthcare system is very, very stretched.

“Some people do receive good care, but it does come through that, quite often, these symptoms are not really investigated timely enough.”

And while early cancers can be managed by gynaecologists, late stage or complex disease needs specialist input from gynae-oncologists, who are in short supply.

Auckland University Head of Pacific Health, Karaponi Okesene-Gafa, has been worrying about rising endometrial cancer for years and is a co-investigator in a research project looking at the pre-diagnosis experiences of Māori and Pacific women.

While GPs told the study that women have a low awareness that heavy menstrual bleeding can be a red flag for endometrial cancer, some Pacific women detailed experiences similar to Shawe’s, Okesene-Gafa says.

“These are women with very abnormal periods. They were aware it wasn’t normal, but when they went to their GPs, they had to have recurrent appointments to actually get their voice across. And sometimes they feel like they haven’t been heard.”

Some women thought cervical screening also tested for endometrial cancer, Okesene-Gafa says.

“There’s a general lack of knowledge around the population.”

Especially for older Pacific women, there’s still taboo, stigma and shyness around vaginal examinations, she says. So improving diagnosis in that population would require an effort similar to cervical screening - education, more culturally-acceptable testing in more approachable, community settings.

“With cervical screening, once the women were comfortable, the messaging was appropriate, then women just came. Cervical screening rates went up, the rates of cervical cancer went down. I think’s it’s going to have to be the same approach.”

Health NZ says work is underway to improve early diagnosis of endometrial cancer, through the development of national guidelines for abnormal uterine bleeding, which are due to be published soon.

Obesity, estrogen and the endometrium

While obesity generally increases the risk of cancer, the link is much stronger with endometrial cancer.

That’s because fat tissue increases the production of estrogen, which helps regulate the growth and shedding of the uterus lining. It also creates a cancer-friendly chronic inflammatory environment, Henry says.

“When we just have constant stimulation from estrogen, and nothing else to counteract that, it tells the lining to keep growing and keep growing.”

Inserting a Mirena contraceptive device can treat early cancer by countering the estrogen with the hormone progestogen, avoiding the need for a hysterectomy. But that’s not always an option for late-diagnosed cancers.

The link with obesity can also make cases harder to manage. A 2023 study of people treating endometrial cancer told heartbreaking stories of young women losing their ability to have children, dying because they refused a hysterectomy, or struggling to be treated because of their weight.

“‘I’ve got a very young woman at the moment…and she is dying,” one health professional told the study. “She couldn’t have radiotherapy, because she's too heavy to get on the machine and nobody wanted to operate on her really. Then she had an operation when she had a massive bleed…It's not just [that] size causes the endometrial cancer. It's that then also compromises treatment.’

Cancer Society medical director, Kate Gregory, says obesity is under-recognised as a cause of cancer.

“There’s very little public awareness of that. Also, as doctors, I don’t think we’re good at talking to patients about it, because we don’t want to make people feel uncomfortable, or as if they’re being blamed for what’s happening to them.

“And I think it’s a really big problem, and it’s getting more and more of a problem.”

But while increasing public awareness of obesity as a cancer cause would help, real change needs government action to make it harder for fast food outlets to flood low-income areas, and to make healthy food and exercise more available, Gregory says.

“It’s no good making people aware of that, if we’re not making changes to the environment around them…It is really complex, but we’ve got to do something, because, otherwise, these generations who are growing up, they’re just going to have an increased burden of cancer, because we haven’t done anything as a society.”

Okesene-Gafa says as well as better awareness and access to diagnosis and treatment, there needs to be greater focus on public health.

“Unfortunately there’s not a lot of funding around the prevention part of it, which I think is so critically important.”

College of Obstetricians and Gynaecologists president, Gillian Gibson, agrees.

“Endometrial cancer has just exploded in the last 10 years, particularly in the North Island…It’s basically a disease of obesity. Not only do we need a system to investigate and diagnose and treat women, we also need a prevention strategy…This is really a public health crisis.”

Could a microbe be the key?

We know your microbial signature - known as the microbiome - can influence everything from disease immunity to brain function. So could it also be implicated in endometrial cancer?

That’s what associate consultant at America’s Mayo Clinic, Marina Walther-Antonio, is trying to find out.

Her team identified 17 microbes often found in patients with endometrial cancer, but not in those without. But one stood out - Porphyromonas somerae (P somerae).

In the post-menopausal participants with obesity that they studied, if a woman had P somerae, there was an 86% chance she also had endometrial cancer.

A little-known microbe, P somerae had previously been found in deep tissue and bone infections in diabetic patients. But it has a cousin with form. Porphyromonas gingivalis causes gum bleeding, and is associated with gum-destroying periodontitis.

“We started to wonder, that maybe it was doing similar things in the uterus that Porphyromonas gingivalis is doing in the gums.”

At this stage, it’s still correlation rather than causation. But Walther-Antonio has found P somerae can invade calls like P gingivalis, and produces a compound that can disrupt the cellular signal.

It wouldn’t be the first time a microbe had been implicated in cancer. About 9 out of 10 people with stomach cancer carry the bacteria Helicobacter pylori. But like most things science, it’s more complicated than everyone who has H pylori (which is half the world at some point in their life) gets stomach cancer.

“It’s not just the microbe that’s going to give you cancer,” Walther-Antonio explains. “But it’s almost a necessary factor.”

When Walther-Antonio’s inbox pinged with an email from New Zealand, her interest was piqued. Health NZ director of health equity, Karen Bartholomew, had read her research and wondered if she knew that Pacific women had among the highest rates of endometrial cancer.

“I wasn’t aware of those numbers,” Walther-Antonio says. “It was quite shocking.”

So she agreed to help New Zealand set up its own microbiome research.

Health NZ failed to put up anyone for interview about the research, in the week given. However, public information says the $174,834 research aims to study 250 Kiwis to find out what proportion of women with and without endometrial cancer have P. somerae, and to understand what a healthy endometrial microbiome looks like for different sub-populations.

The study is currently recruiting participants in hospitals in Auckland, Wellington and Christchurch.

If having P somerae is a risk factor for getting (or having) endometrial cancer, that could help find new ways to test for it or treat it.

Unlike the often painful and invasive biopsy currently needed to confirm endometrial cancer, you can test for P somerae with an at-home vaginal swab and cheap PCR analysis, Walther-Antonio says.

It could also help early detection in the more aggressive type two cases, which don’t always show themselves with abnormal bleeding.

If P somerae is actually causing - or worsening - the cancer, it could be killed off with the most basic of treatments - antibiotics, Walther-Antonio says. However, that requires caution.

“If the microbe survives, it tends to become more invasive as a way to evade antibiotics, and so then it becomes even more difficult to treat.”

Okesene-Gafa says while better early detection tools could help in the future, action is needed now.

“It’s so critically important now for the Government to really speed up our response…I think we’ve got enough evidence, we’ve got enough data, we’ve got enough ‘how to’ guides and recommendations about what we should do. I think it’s just a matter of getting on and doing it now. Let’s go. Let’s do this.”