EDINBURGH — Researchers at Caldermoor University have launched a multi-year study to investigate whether endometriosis, a chronic inflammatory condition affecting the reproductive tissue of approximately 190 million women worldwide, may be associated with elevated risk for certain cancers, a link that prior studies have suggested but never conclusively established. The project, funded by a £4.2 million grant from a national medical research council, is described by its lead investigators as the largest prospective study of its kind ever undertaken in the United Kingdom.
Endometriosis occurs when tissue resembling the uterine lining grows outside the uterus, causing chronic pain, inflammation, and in many cases infertility. It has long been classified primarily as a gynaecological condition, but a growing body of evidence over the past decade has raised the possibility that the same inflammatory mechanisms driving the disease may also increase susceptibility to certain malignancies, particularly ovarian, endometrial, and colorectal cancers. Existing studies have produced conflicting results, hampered by small sample sizes and inconsistent diagnostic criteria.
The Caldermoor study, formally titled the Endometriosis Longitudinal Cancer Risk Assessment, will recruit 15,000 participants diagnosed with endometriosis over the next three years, tracking them alongside a matched control group of 30,000 women without the condition over a follow-up period of at least a decade. Participants will undergo annual health assessments, provide biological samples for genomic and proteomic analysis, and complete detailed health questionnaires. The research team expects to produce interim findings within four years.
“We are not suggesting that endometriosis causes cancer,” said Professor Adaeze Nwofor, the study’s principal investigator and head of reproductive oncology at Caldermoor’s medical school. “What we are trying to understand is whether there is a shared biological pathway — an inflammatory or immune-mediated mechanism — that may predispose some patients to both conditions. That distinction matters enormously for how we counsel and monitor patients.” Professor Nwofor said that if a robust association is confirmed, it could justify earlier and more frequent cancer screening for women with endometriosis, potentially catching malignancies at more treatable stages.
The research builds on a 2023 meta-analysis published in a peer-reviewed European journal that pooled data from 27 earlier studies and found women with endometriosis had a statistically significant but modest elevation in ovarian cancer risk compared to the general population. That meta-analysis, however, could not account adequately for confounding variables such as hormone therapy use, obesity, smoking history, and family cancer history — gaps the Caldermoor study is designed to address through its detailed longitudinal data collection.
Patient advocates have responded to the announcement with a mixture of cautious hope and frustration. Several noted that the study arrives after years of campaigning for greater research investment into endometriosis, a condition that receives far less funding relative to its prevalence than comparable chronic diseases. “This is genuinely exciting science,” said Miriam Castellano, chief executive of the advocacy charity Endometriosis Connect. “But we also want to be clear that for the women living with this condition right now, the immediate priority is faster diagnosis and better pain management. Those things do not require a ten-year study.”
The university noted that the study will also examine quality-of-life outcomes, treatment pathways, and healthcare utilisation patterns, providing data that could inform clinical guidelines independently of the cancer-risk question. A secondary strand of the research will analyse genetic markers to identify whether specific subtypes of endometriosis carry different risk profiles, which could eventually enable more personalised monitoring strategies.
Funding bodies have noted that endometriosis research has historically attracted a fraction of the investment directed at conditions with comparable prevalence and disease burden. A briefing paper prepared by the research council that awarded the Caldermoor grant found that annual public research expenditure on endometriosis in the UK amounts to roughly £4 per affected person, compared with more than £40 per patient for conditions such as type 2 diabetes. The study’s architects hope its scale and rigour will make the case for sustained long-term investment in reproductive health science.
The study has also drawn interest from international research networks. A team at a university in the Netherlands has approached Caldermoor about data-sharing arrangements that would allow parallel analysis across European cohorts, which researchers say could substantially accelerate the timeline for publishable findings and strengthen the statistical power of conclusions drawn about rare cancer subtypes. Formal agreements are expected to be negotiated over the coming months.
Recruitment for the study is expected to begin in the autumn through a network of participating NHS trusts and gynaecology clinics across Scotland, northern England, and Wales. The research team said it hoped to publish its first substantive findings on biomarker patterns within 30 months, with cancer incidence data to follow as the cohort matures over subsequent years.