Women with endometriosis or painful periods were four to five times more likely to receive an STI diagnosis, a large Japanese study found.

Endometriosis occurs when tissue similar to the lining of the womb grows outside the womb. Although not strictly a menstrual disorder, it can cause pain, irregular periods and infertility.

The study was led by researchers at the University of Yamanashi and funded by Rohto Pharmaceutical Co.

The analysis examined health insurance claims from more than 3.4m women aged 40 or younger who had at least one healthcare visit during 2023.

Around 260,000 women, or 7.5 per cent of those included, had been diagnosed with endometriosis, dysmenorrhoea or both.

Dysmenorrhoea is the medical term for painful periods or menstrual cramps.

Women with endometriosis, dysmenorrhoea or both were four to five times more likely to have a recorded diagnosis of a sexually transmitted infection, or STI, than women without the conditions.

Diagnoses were significantly more common across every category examined, including chlamydia, gonorrhoea, trichomoniasis, genital herpes and other STIs.

Chlamydia was recorded in 3.5 per cent of women with menstruation-related conditions, compared with 0.7 per cent of those without them.

This represented a fivefold increase and the largest difference in prevalence between the two groups.

Gonorrhoea was diagnosed in 0.9 per cent of women with the conditions, compared with 0.2 per cent of those without them, also representing an increase of about five times.

Trichomoniasis, genital herpes and other STIs were diagnosed four to five times more often in women with endometriosis, dysmenorrhoea or both.

Women with endometriosis had the highest STI diagnosis rates overall.

Almost five per cent had a recorded chlamydia diagnosis, making it the most common STI in this group and more than seven times as prevalent as among women without menstruation-related conditions.

Women with dysmenorrhoea also had higher diagnosis rates for every STI included in the analysis.

The study found little evidence that hormonal treatments, including low-dose oestrogen-progestin therapy, affected STI diagnosis rates.

Differences between women who used hormonal treatment and those who did not were generally less than one percentage point.

Researchers suggested several possible explanations for the association between menstruation-related conditions and STI diagnoses.

One likely explanation is that women with endometriosis and dysmenorrhoea attend healthcare appointments more often.

As many STIs cause only mild symptoms, women seeking care more frequently for these conditions may be more likely to have infections detected.

Biological and behavioural factors may also play a part.

Menstruation-related conditions, particularly endometriosis, are associated with inflammation, pain during sex and sexual dysfunction, which could influence contraceptive practices and susceptibility to infection.

However, the authors said these possible explanations “remain speculative.”

They cautioned that differences in healthcare-seeking behaviour make it difficult to determine whether women with menstruation-related conditions acquire more infections or are simply more likely to receive a diagnosis.

The authors concluded that the findings underline the importance of STI screening and reproductive health education for women with endometriosis or painful periods.

WID-easy, the only non-invasive triage test for endometrial cancer in routine use in a European public health system, has been cited in Germany’s highest-tier clinical guidance; a marker that non-invasive detection is reaching clinical maturity.

The vaginal-swab test designed to spare women unnecessary invasive procedures has been referenced in the updated German S3 Guideline on Endometrial Cancer, its maker Sola Diagnostics has announced.

The Austria-based women’s-health diagnostics company behind the WID-easy Test, said the test now features in the recommendations-supporting background text of the guideline’s latest version (v4.0, May 2026; AWMF 032-034OL), in Section 4.3.

The S3 designation is the highest evidence- and consensus-based tier in the German clinical guideline system, broadly comparable in standing to NICE guidance in the UK, and is widely drawn on in clinical practice, reimbursement and liability assessments.

In Section 4.3, the guideline cites four peer-reviewed validation studies of the WID-easy Test and credits it with a sensitivity of more than 95 per cent and a negative predictive value of at least 99.7 per cent.

It describes a fall in invasive workup from 19 to two dilatation-and-curettage (D&C) procedures per cancer detected when compared with transvaginal ultrasound alone, assuming a realistic 3.4 per cent cancer prevalence in women with postmenopausal bleeding, and states that the test has the potential to improve the diagnostic workup of women with peri- and post-menopausal bleeding by cutting the rate of invasive procedures.

A growing burden, an imperfect standard

Endometrial cancer is the most common gynaecological cancer in high-income countries, and its incidence is rising, driven by ageing populations and increasing obesity, making it one of the fastest-growing cancer burdens in women’s health.

A number of groups are now developing non-invasive tests for earlier detection. The current standard, transvaginal ultrasound, is an imperfect triage tool: it misses serous carcinomas and performs especially poorly in black women, a group with disproportionately high endometrial-cancer mortality.

WID-easy has been validated prospectively across multiple cohorts, including a dedicated cohort of black women in Ghana (Ken-Amoah et al., 2025).

Adopted in routine care

WID-easy is the only endometrial-cancer triage test in Europe with real-world adoption in a public health system. It is UKCA-marked and in use across NHS pilot sites in England and Scotland, and is delivered through commercial laboratory partners across the DACH region of Austria, Germany and Switzerland. Its UK pivotal study, EASY-CARE, is funded by a competitively awarded NIHR i4i grant.

The postmenopausal bleeding pathway has been singled out for change across three UK Government strategy documents published in 2026 — the National Cancer Plan for England (DHSC), the renewed Women’s Health Strategy for England (DHSC) and the National HealthTech Access Programme (NICE).

The NICE initiative names speeding up access to better tools for detecting endometrial cancer in women with unexplained bleeding as one of only four priority areas.

WID-easy is the only non-invasive endometrial-cancer triage test that is UKCA-marked and commercially available for NHS use today, with no competing molecular test yet on the market.

“Seeing WID-easy referenced in a guideline of this standing confirms that the science behind non-invasive endometrial cancer detection has reached clinical maturity,” said Prof Martin Widschwendter, founder and member of the scientific advisory board at Sola Diagnostics.

“Our goal has always been to spare women unnecessary invasive procedures without missing the cancers that matter — and to do so equitably, across all populations.”

The WID-easy Test detects and triages endometrial cancer from a vaginal swab using DNA methylation. It is built on the WID-qEC biomarker, exclusively licensed from University College London Business and complemented by Sola’s own patent portfolio. The same methylation platform underpins a pipeline of further tests in cervical, ovarian and breast cancer.

A vaccine trial will test whether an mRNA jab can help stop precancerous cells developing into bowel and ovarian cancer in people with Lynch syndrome.

The first stage is due to launch this summer and will assess whether the jab can train the immune system to recognise and eliminate precancerous cells before cancer develops.

Around 175,000 people in England have Lynch syndrome, but only five per cent, or around 10,000 people, know they have it.

The inherited condition increases the risk of developing bowel cancer by 80 per cent and is linked to around 1,100 bowel cancer cases each year.

Lynch syndrome is also linked to a far higher risk of bowel, womb and ovarian cancer, alongside other types including stomach, pancreatic, kidney and skin cancer.

While the syndrome does not directly cause cancer, the genetic changes can lead to more abnormal cells developing, which then multiply and increase the risk of cancers such as bowel, prostate and endometrial cancer.

It is caused by an alteration in a mismatch repair gene. Carriers do not have any symptoms.

The new Intercept-Lynch trial is part of a scientific collaboration between the University of Oxford and Moderna, while Cancer Research UK has backed the vaccine’s development.

Once patients receive the new mRNA-4194 jab, experts will analyse their immune responses, assess the best dose and check whether the jab is safe.

The second phase of the study will include multiple centres across the UK, including Oxford, and is expected to begin in 2027.

The aim of the trial is to train the immune system with a vaccine to recognise abnormalities and stop them developing into cancer.

Professor David Church, Cancer Research UK senior cancer research fellow in the University of Oxford’s centre for human genetics and lead investigator of the trial, said: “People with Lynch syndrome are at risk of cancers over their entire lives.

“So, it’s very common, for instance, a woman to have a first cancer of her womb, and then some years later have a bowel cancer, or vice versa.

“The targets we’ve chosen for the vaccine were chosen based on their sharedness across multiple cancer types in Lynch syndrome, so we think they should provide broad protection, if the vaccine works.”

In people with Lynch syndrome, mutations can build up, making the cells containing them more likely to turn into cancerous cells.

However, those mutations can be made visible to the immune system and, with enough stimulation, the immune system can attack the abnormal cells and stop cancer from forming.

Professor Church said the mRNA jab acts as “an instruction manual” for the body to attack precancerous cells.

He added that, as with many vaccines, patients may need a booster jab at some stage.

On whether similar approaches could help prevent cancers not caused by Lynch syndrome, Professor Church said: “In terms of proof of principle that we can train the immune system to recognise these cancer-associated alterations and enhance the immune response against them to prevent these pre-cancers or prevent the progression of pre-cancer to cancer, that proof of principle should give us insights that are generalisable.”

David Berman, chief development officer at Moderna, said: “By applying mRNA technology earlier in the patient journey, we aim to harness the immune system when it can have the greatest impact.

“We are proud to bring this innovation to the UK, building on our long-standing collaboration with leading UK institutions to advance mRNA research and development.”