Skip Chemotherapy in Low-Grade Recurring Endometrial Cancer?
TOPLINE:
For women with pelvic recurrences of grade 1 or 2 endometrial cancer, adding cisplatin to definitive radiation treatment may result in more acute toxicities and no clinical benefit. These patients can skip chemotherapy and receive radiation alone.
METHODOLOGY:
- Chemotherapy is often added to curative radiation for locally recurrent, nonmetastatic endometrial cancer based on the assumption that it improves outcomes, but the approach has not been tested in a head-to-head trial that compares radiation to chemoradiation in this population.
- To fill the evidence gap, investigators in the GOG238 trial randomized 165 women (median age, 66 years; White and non-Hispanic, 89%) evenly to radiation alone — external beam followed by a boost with either brachytherapy or external beam — or radiation plus concurrent cisplatin 40 mg/m2 weekly.
- The majority of women had grade 1 or 2 endometrioid histology (82%) and recurrences confined to the vagina (86%).
- Researchers released results early after a planned interim analysis demonstrated lower rates of progression-free survival in the chemoradiation arm.
TAKEAWAY:
- At 3 years, 73% of patients treated with radiation alone vs 62% treated with chemoradiation were progression free.
- The researchers found no significant difference in progression-free survival between patients who received radiation alone and those who received chemoradiation. After a median follow-up of 62 months, median progression-free survival was not reached in the radiation alone group vs 73 months in the chemoradiation arm (estimated hazard ratio [HR], 1.25; 95% CI, 0.75-2.07).
- Median overall survival was 97 months with radiation alone vs 99.6 months with chemoradiation, a difference that was not statistically significant (stratified HR, 1.10; 95% CI, 0.57-2.12).
- Chemotherapy, however, increased constitutional symptoms and auditory, ocular, neurologic, vascular, and bone marrow toxicities.
IN PRACTICE:
The addition of chemotherapy to radiation for locally recurrent, nonmetastatic endometrial cancer “does not improve outcomes and predictably results in more toxicity,” the researchers concluded. “Patients with low-grade and vaginal recurrences who constituted the majority of those enrolled are best treated with radiation therapy alone.”
SOURCE:
The study, led by Ann H. Klopp, MD, PhD, of The University of Texas MD Anderson Cancer Center, Houston, was published in the Journal of Clinical Oncology.
LIMITATIONS:
Generalizability to larger, higher-risk recurrences was limited. Enrollment in the study was slower than expected. A bias in favor of adding chemotherapy may have resulted in preferential enrollment of lower-risk patients. Over the course of the trial, the protocol was adjusted multiple times as the practice of brachytherapy evolved but was mostly limited to vaginal brachytherapy using cylinders. Molecular subtype analysis was not performed.
DISCLOSURES:
The study was funded by the National Cancer Institute. Investigators reported consulting, honoraria, speakers’ fees, travel payments, research funding, and other ties to numerous companies, including AstraZeneca, Merck, and GlaxoSmithKline.
M. Alexander Otto is a physician assistant with a master’s degree in medical science and a journalism degree from Syracuse University. He is an award-winning medical journalist who worked for several major news outlets before joining Medscape Medical News. Email: [email protected]
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