Adjuvant chemotherapy administered concurrently with and after radiotherapy does not prolong 5-year overall survival (OS) among patients with high-risk endometrial cancer, according to a study published in The Lancet Oncology.
The standard of therapy for women with high-risk endometrial cancer is pelvic external beam radiotherapy, but there is a lack of evidence supporting that this treatment improves survival. Previous studies have suggested that chemoradiotherapy may be more effective in prolonging survival outcomes compared with radiotherapy or chemotherapy alone.
For the open-label PORTEC-3 phase 3 study, researchers randomly assigned 686 women with high-risk endometrial cancer to receive radiation treatments of 48.6 Gy in 1.8-Gy fractions given 5 days a week alone, or plus cisplatin during radiotherapy followed by 4 cycles of carboplatin and paclitaxel. Of the initial 686 women who enrolled in the study, 660 were eligible for the final analysis.
After a median follow-up of 60.2 months, patients in the chemoradiotherapy arm had a 5-year OS rate of 81.8% vs 76.7% among patients in the radiotherapy alone group (P =.011), and failed to demonstrate a statistically significant improvement.
The 5-year failure-free survival was 75.5% and 68.6% among patients treated with chemoradiotherapy compared with radiotherapy alone, respectively (P =.022).
Patients treated with chemoradiotherapy had a significantly higher rate of adverse events vs radiotherapy alone (60% vs 12%; P <.0001). Patients treated with chemoradiotherapy experienced significantly prolonged grade 2 or worse neuropathy after 1 year compared with radiotherapy alone.
Five-year failure-free survival, but not 5-year OS, is improved by chemoradiotherapy. The authors concluded that “women with high-risk endometrial cancer should be individually counselled about this combined treatment. Continued follow-up is needed to evaluate long-term survival.”
de Boer SM, Powell ME, Mileshkin L, et al. Adjuvant chemoradiotherapy versus radiotherapy alone for women with high-risk endometrial cancer (PORTEC-3): final results of an international, open-label, multicentre, randomised phase 3 trial [published online February 12, 2018]. Lancet Oncol. doi: 10.1016/S1470-2045(18)30079-2