INSUFFICIENT endometrial biopsy may be linked to a small but measurable increase in the risk of endometrial cancer, according to a nationwide Danish cohort study. The findings highlight the importance of careful follow-up when a biopsy does not contain enough tissue for a conclusive diagnosis.
Endometrial biopsies are routinely performed to investigate abnormal uterine bleeding and to detect early signs of endometrial cancer. However, in some cases, the sample obtained is too limited to determine whether abnormal or malignant cells are present. Researchers sought to understand whether this lack of diagnostic material was associated with a higher likelihood of cancer detection in subsequent years.
Cancer Outcomes Differ by Biopsy Sufficiency
Using data from the Danish Pathology Register, the team identified 80,761 women who had undergone endometrial biopsies between 2013 and 2017. Among them, 13,964 (17.3%) had an insufficient endometrial index biopsy, meaning the tissue sample was inadequate for analysis. Almost 44% of this group later underwent a repeat biopsy.
The unadjusted data showed a higher incidence of endometrial cancer – 2.6% in those with an insufficient biopsy versus 0.7% in those with normal results. When researchers adjusted for age, the risk was only slightly increased, suggesting that age is a significant factor influencing cancer risk.
“We found an increased risk of detecting endometrial cancer in individuals with an insufficient index biopsy compared to individuals with a normal index biopsy. After adjusting for age, the risk was only slightly increased,” the researchers reported.
Implications for Clinical Practice
Although the risk increase was modest, the findings suggest that biopsy insufficiency should prompt clinicians to consider follow-up testing, particularly in postmenopausal or higher-risk patients. Ensuring adequate tissue collection during the first procedure may help reduce diagnostic delays and improve outcomes.
Future research is needed to determine whether improved sampling methods or imaging-guided biopsies could further reduce the number of insufficient samples and ensure earlier cancer detection.
Reference
Vang C. et al. Risk of endometrial cancer after insufficient endometrial biopsy: a retrospective cohort study. Am J Obstet Gynecol. 2025;233(5):457.e1-e10.
