Excellent outcomes with radiation alone for localized recurrences of endometrial cancer

The addition of chemotherapy to radiation therapy for patients with localized recurrences of endometrial cancer does not improve survival outcomes and increases toxicity according to a prospective, randomized study published in the Journal of Clinical Oncology.¹

Although concurrent chemotherapy and radiation are widely used to treat other gynecologic cancers such as cervical cancer, the benefit of adding chemotherapy to radiation for patients with endometrial recurrences localized to the pelvis has not been evaluated.

This study was conducted to fill that gap. The study included 165 patients randomized 1:1 to receive radiation alone or a combination of cisplatin and radiation. Most patients had low-grade tumors with endometrioid histology (82%) with recurrences confined to the vagina with or without pelvic lymph node involvement (86%). All patients received initial external-beam radiation therapy to the whole pelvis (4500 cGy in 25 fractions), which was followed by a boost of either brachytherapy or external-beam therapy according to the extent of disease recurrence. Patients in the concurrent chemotherapy/radiation arm received cisplatin (40 mg/m²) once weekly for five cycles.

At a median follow-up of 62 months, no significant difference was seen in progression-free survival between the two treatment arms, as demonstrated by a hazard ratio of 1.25 (95% CI, 0.75–2.07). Patients treated with concurrent chemotherapy and radiation had a higher rate of grade 3 toxicity (57% vs. 31% with radiation alone).

At 3 years, 73% of patients treated with radiation alone were free from disease progression, whereas 62% of patients treated with concurrent chemotherapy and radiation were.

“Patients with localized recurrences of endometrial cancer can be treated with radiation alone, especially patients who have low-grade vaginal recurrences, which was the most common presentation for patients in the study,” says the lead author of the study, Ann Klopp, MD, PhD, professor of radiation oncology at The University of Texas MD Anderson Cancer Center.

She underscores that the high survival rate seen with radiation alone highlights the importance of detecting recurrences of endometrial cancer localized to the pelvis “and treating them curatively with radiation, including brachytherapy.”

Dr Klopp and her colleagues adopted principles of image-guided brachytherapy in cervical cancer to inform the use of brachytherapy in the study and noted that in the future, magnetic resonance imaging–guided adaptive brachytherapy, which has improved local control rates for recurrences in cervical cancer, also may improve them for recurrences in endometrial cancer.