Fertility treatment was not linked to a higher overall risk of invasive cancer in women, a large Australian study has found.

The study, published today in JAMA Network Open, analysed health records of more than 417,000 women and found some specific cancers were slightly more common, while others were less common.

The researchers said the findings need to be interpreted with caution, and in the context of the many factors that influence cancer risk.

Adrian Walker, joint lead author from UNSW’s Centre for Big Data Research in Health, said the overall findings were reassuring, with women who receive fertility treatment not having a higher total incidence of cancer than other women.

“Women who’ve had assisted fertility should continue to participate in routine cancer screening programs they’re eligible for,” he said.

“And they should discuss their cancer risk with their doctor, to understand how else they can reduce their risk.”

The study analysed national health and cancer records from 417,984 Australian women who underwent medically assisted reproduction between 1991 and 2018.

This included IVF, intrauterine insemination and treatment with the fertility drug clomiphene. Cancer outcomes were examined over an average of 10 years.

The researchers compared how often cancer occurred in these women with how often it occurred in Australian women of the same age and in the same calendar years.

While the overall cancer rate was not higher, some specific cancers were slightly more common in women who had fertility treatment, while others were less common.

Uterine and ovarian cancer were slightly more common, as was melanoma. A non-invasive form of breast cancer was also more common in women who had IVF, but invasive breast cancer was not increased.

At the same time, some cancers, including cervical and lung cancer, were less common.

“It is very normal for a specific group of people to have a slightly different cancer profile from the general population,” Walker said.

“But as we see here, that doesn’t mean that their overall risk is increased.”

Claire Vajdic, professor at UNSW’s Kirby Institute and study lead, said the findings need to be interpreted carefully.

“This study focused on comparing rates of cancer in different populations, not whether fertility treatments themselves cause cancer.

“As such, we must consider the pre-existing risks of cancer in these populations when interpreting the findings.

“Women with infertility who are having or have had treatment, like all women, should ensure that they have regular check-ups, and seek further evaluation if they have concerns about unusual symptoms.”

Of the cancers that occurred at a higher rate than in the general population, uterine cancer was between 23 per cent and 83 per cent more common, depending on the type of fertility treatment.

Ovarian cancer was around 18 per cent to 23 per cent more common in women who had IVF or related treatments, while melanoma was about 7 per cent to 15 per cent more common.

On the other hand, some cancers were less common. Cervical cancer rates were about 40 per cent lower than in the general population, and lung cancer rates were about 30 per cent lower.

However, when the researchers looked at the actual number of additional cases, the difference was small. Across the cancers that were more common, the largest increase amounted to three to seven extra cases per 100,000 women per year.

So even where a relative increase was observed, the overall chance of developing cancer remained low.

Very few medical treatments are without risk, but the elevated cancer incidence here is low,” Vajdic said.

The researchers said there could be many reasons why certain cancers were more common in women who had fertility treatment.

“Women who need fertility treatment may differ from other women in ways that affect cancer risk,” Vajdic said.

Certain underlying causes of infertility, such as endometriosis and polycystic ovary syndrome, are known to increase the risk of uterine and ovarian cancers.

The researchers showed Australian women who underwent fertility treatment were more likely to live in major cities and be socioeconomically advantaged.

Although not examined in this study, women having fertility treatment are also more likely to have fair skin and be less likely to smoke. Additionally, before starting fertility treatment, doctors must check that women are up to date with any recommended routine cancer screening.

All these factors will contribute to the cancer patterns observed in this study, including reduced lung cancer rates and reduced cervical cancer rates.

“What this study does is describe cancer patterns we’re seeing at a population level,” Walker said.

“It doesn’t tell us the risk of receiving treatment, or the risk for individual women who undergo treatment.”

Because many women in the study were still relatively young at the end of follow-up, the researchers said longer follow-up would provide additional insights.

“Continued cancer awareness is important as this population ages,” Vajdic said.

The researchers concluded that cancer risk after fertility treatment was not higher overall, and that further research to better understand differences in incidence for individual cancers will help women and their doctors make informed decisions.

Lifestyle factors are linked to more than a quarter of healthy years lost to breast cancer worldwide, according to the largest study of its kind.

The research analysed data from population-based cancer registries across more than 200 countries between 1990 and 2023 to examine how lifestyle affects the global burden of breast cancer.

The study, published in Lancet Oncology, also used the data to forecast trends in breast cancer cases up to 2050.

It found high red meat consumption had the largest impact, linked to nearly 11 per cent of healthy life lost to the disease.

Tobacco use, including secondhand smoke, accounted for 8 per cent, followed by high blood sugar (6 per cent), high body mass index, or BMI, a measure of body fat based on height and weight (4 per cent), high alcohol use and low physical activity (both 2 per cent).

In total, 28 per cent of the global breast cancer burden in 2023, equivalent to 6.8m years of healthy life lost to disability, illness and early death, was linked to six potentially modifiable risk factors.

Kayleigh Bhangdia, from the Institute for Health Metrics and Evaluation at the University of Washington and lead author of the study, said: “Breast cancer continues to take a profound toll on women’s lives and communities.

“While those in high-income countries typically benefit from screening and more timely diagnosis and comprehensive treatment strategies, the mounting burden of breast cancer is shifting to low- and lower middle-income countries where individuals often face later-stage diagnosis, more limited access to quality care and higher death rates that are threatening to eclipse progress in women’s health.”

New breast cancer cases in women are predicted to rise by about a third globally, from 2.3m in 2023 to more than 3.5m in 2050, according to the analysis by the Global Burden of Disease Study Breast Cancer Collaborators.

The findings suggest maintaining healthier lifestyles, including not smoking, doing sufficient physical activity, reducing red meat consumption and maintaining a healthy BMI, could help prevent more than a quarter of healthy years lost to illness and premature death due to breast cancer worldwide.

In the UK, about one in seven women will develop breast cancer during their lifetime.

The figures follow earlier research by Cancer Research UK which found that more than four in 10 UK cancer cases could be prevented through lifestyle changes.

The analysis also found that in 2023, three times as many new breast cancer cases were diagnosed in women aged 55 or older compared with women aged 20 to 54, with 161 cases per 100,000 women compared with 50.

However, rates of new cases among women aged 20 to 54 have risen by nearly a third, or 29 per cent, since 1990, while rates among older women have not changed substantially.

Claire Rowney, chief executive of Breast Cancer Now, said: “This new global study is a stark reminder that breast cancer is a disease that continues to take and rip apart far too many lives, not just here but around the world.

“We’re determined to realise our bold ambition that by 2050, everyone with breast cancer will live and live well, and we’re accelerating progress through building global collaborations with researchers and funders, as together we can go further, faster to ensure that every woman, no matter where she lives, can access early diagnosis, effective treatment and the support she needs.”

Sophie Brooks, health information manager at Cancer Research UK, added: “These figures are a sad reminder of the heavy toll breast cancer continues to take on women around the world.

“Prevention remains a key way to reduce rates, with a significant number of cases globally linked to preventable factors like smoking, overweight and obesity, and alcohol.”

The US Food and Drug Administration (FDA) has granted fast track status to a new drug combination for BRCA-mutated advanced breast cancer.

The designation covers ART6043, developed by Artios, used with the PARP inhibitor Lynparza, also known as olaparib.

It applies to adults with germline BRCA-mutated, HER2-negative locally advanced or metastatic breast cancer who have not previously been treated with a PARP inhibitor.

BRCA mutations are inherited genetic changes that increase the risk of breast cancer.

PARP inhibitors block cancer cells from repairing damaged DNA, but tumours with BRCA mutations often develop resistance when these drugs are used alone.

ART6043 is designed to address this resistance. The oral treatment inhibits DNA polymerase theta, or Polθ, an enzyme found in cancer cells but largely absent in healthy tissue.

By blocking Polθ, the drug targets a backup DNA repair process known as microhomology-mediated end joining, which cancer cells rely on when other repair pathways are disrupted.

The aim is to limit the tumour’s ability to repair itself and extend the effectiveness of PARP inhibitors.

The fast track decision was supported by data from an ongoing first-in-human phase 1/2a trial evaluating ART6043 in combination with Lynparza in patients with advanced solid tumours carrying mutations in DNA damage response pathways, including BRCA-mutated breast cancer.

Findings presented at the European Society for Medical Oncology Congress 2025 showed what the company described as expected pharmacokinetic and pharmacodynamic activity, as well as encouraging clinical signals.

Breast cancer is the second leading cause of cancer death among women in the US. Patients with BRCA mutations who develop resistance to PARP inhibitors often have limited treatment options.

The FDA fast track programme is intended to speed up the development and review of investigational medicines that may address serious or life-threatening conditions with unmet medical need.

The designation allows Artios to engage more frequently and earlier with the FDA to discuss the development pathway for ART6043.

Under the programme, the drug candidate may be eligible for priority review and accelerated approval if it meets the relevant clinical criteria.

HER2-negative breast cancer does not overproduce the HER2 protein, which drives tumour growth in some patients.

Locally advanced cancer has spread to nearby tissue but not distant parts of the body, while metastatic cancer has spread to other organs.