SAN DIEGO – Endometrial pathology findings at 3 months predicted response to levonorgestrel-releasing IUD treatment for complex atypical hyperplasia or grade 1 endometrial cancer at the MD Anderson Cancer Center in Houston.
Twenty-nine of 32 women (91%) who responded by 12 months showed stromal, glandular, or other endometrial changes indicating an effect at 3 months, vs. only 3 of 9 nonresponders (33%) (P less than .001). There were no differences in responders versus nonresponders in median age (47 vs. 56 years, P = .2) or body mass index (45 vs. 55 kg/m2, P = .16).
The finding addresses an “unmet need” for markers of response to levonorgestrel-releasing IUD therapy. “You can look at [early] pathology” and have an idea how patients will do, Dr. Shannon Westin, a study investigator who is with the department of gynecologic oncology at MD Anderson, said at the annual meeting of the Society of Gynecologic Oncology.
Twenty-seven of 29 women (93%) with complex atypical hyperplasia (CAH) responded completely to the IUD, meaning they had normal endometrium or hyperplasia without atypia at 12 months. The response rate for endometrial cancer was 67%; 7 of 12 women had a complete response, and an 8th was diagnosed at 12 months with CAH, indicating a partial response. The rest of the patients remained stable or progressed.
Endometrial biopsies were performed every 3 months; the team also did molecular testing on tumors from 20 patients. Baseline protein Ki67 – a marker of proliferation – was significantly higher in nonresponders. Expression of several estrogen-induced genes was higher in responders.
Patients opted for the IUD to retain fertility or because obesity or comorbidities precluded surgery. Exclusion criteria included prior treatment for CAH or endometrial cancer, evidence of extrauterine spread, or levonorgestrel IUD contraindications, such as uterine infection.
Adverse events – primarily irregular bleeding and cramping – were mild and tended to resolve by 12 months. Treatment had little effect on measures of social, mental, and physical function. About half of the patients were white, a third were Hispanic, and most of the remaining patients were black.
There was no external funding for the work. Dr. Westin is a consultant for AstraZeneca, Medivation, Roche, Ovation, and Vermillion, and reported receiving research funding from AstraZeneca, Critical Outcomes Technologies, and Novartis.