Asymptomatic endometrial thickening
Postmenopausal women are increasingly being referred for asymptomatic endometrial thickening that is found incidentally during an unrelated evaluation, Dr. Shwayder said, noting that evidence to date on how to approach such cases is conflicting.
Although ACOG is working on a recommendation, none is currently available, he said.
However, a 2001 study comparing 123 asymptomatic patients with 90 symptomatic patients, all with an endometrial thickness of greater than 10 mm, found no prognostic advantage to screening versus waiting until bleeding occurred, he noted (Euro J Cancer. 2001;37:64-71).
Overall, 13% of the patients had cancer, 50% had polyps, and 17% had hyperplasia.
“But what they emphasized was ... the length [of time] the patients complained of abnormal uterine bleeding. If it was less than 8 weeks ... there was no statistical difference in outcome, but if it was over 8 weeks there was a statistically significant difference in the grade of disease – a prognostic advantage for those patients who were screened versus symptomatic.”
The overall 5-year disease-free survival was 86% for asymptomatic versus 77% for symptomatic patients; for those with bleeding for less than 8 weeks, it was 98% versus 83%, respectively. The differences were not statistically different. However, for those with bleeding for 8-16 weeks it was 90% versus 74%, and for those with bleeding for more than 16 weeks it was 69% versus 62%, respectively, and those differences were statistically significant.
The problem is that many patients put off coming in for a long time, which means they are in a category with a worse prognosis when they do come in, Dr. Shwayder said. That’s not to say everyone should be screened, but there is no prognostic advantage to screening asymptomatic patients versus symptomatic patients who had bleeding for less than 8 weeks.
“It’s a little clarification, but I think an important one,” he noted.
Another study of 1,607 patients with endometrial thickening, including 233 who were asymptomatic and 1,374 who were symptomatic, found a lower rate of deep invasion with stage 1 disease, but no difference in the rate of more advanced disease, and no association with a more favorable outcome between the groups. (Am J Obstet Gynecol. 2018;219[2]:183e1-6).
Additionally, a study of 42 asymptomatic patients, 95 symptomatic patients with bleeding for less than 3 months, and 83 symptomatic patients with bleeding for more than 3 months showed a nonsignificant trend toward poorer 5-year survival in patients with a longer history of bleeding prior to surgery (Arch Gynecol Obstet 2013;288:1361-4).
“So now the question becomes how thick is too thick [and whether there is] some threshold where we ought to be evaluating patients and some threshold where we’re not,” he said.
The risk of malignancy among symptomatic postmenopausal women with an endometrial thickness greater than 5 mm is 7.3%, and the risk is similar at 6.7% in asymptomatic patients with an endometrial thickness of 11 mm or greater, according to a 2004 study by Smith-Bindman et al. (Ultrasound Obstet Gynecol. 2004;24:558-65).
“So the thought process here is that if a patient is asymptomatic, but the endometrium is over 11 mm, maybe we ought to evaluate that patient, because her risk of cancer is equivalent to that of someone who presents with postmenopausal bleeding and has an endometrium greater than 5 mm,” he explained.
In fact, a practice guideline from the Society of Obstetricians and Gynecologists of Canada recommends that women with endometrial thickness over 11 mm and other risk factors for cancer – such as obesity, hypertension, or late menopause – should be referred to a gynecologist for investigation, Dr. Shwayder said, adding that he also considers increased vascularity, heterogeneity in the endometrium, and fluid seen on a scan as cause for further evaluation.
“But endometrial sampling without bleeding should not be routinely performed,” he said. “So don’t routinely [sample] but based on risk factors and ultrasound findings, you may want to consider evaluating these patients further.”
Dr. Shwayder is a consultant for GE Ultrasound.