麻豆传媒

NEW YORK -- Women with recurrent endometrial cancer do not benefit from receiving weekly cisplatin chemotherapy on top of standard radiation, according to findings from a randomized trial.

Among patients getting cisplatin-based chemotherapy concurrent with radiation, 57.3% were alive and progression-free compared with 68% of patients who got definitive radiation alone -- a relative 50% worse outcome for the chemotherapy group over the study's median 5 years of follow-up, though this difference was not statistically significant (P=0.8).

There were no differences in overall survival (OS) between the two cohorts, with 75.6% and 78.6% alive at data cutoff, respectively, according to data presented by Ann Klopp, MD, PhD, of the University of Texas MD Anderson Cancer Center in Houston, at the International Gynecologic Cancer Society (IGCS) annual meeting.

"The addition of concurrent chemotherapy does not improve outcomes for patients treated with definitive radiation for recurrent endometrial cancer," Klopp said. She added that these results are applicable to patients with low-grade tumors and vaginal apex occurrences, as that population made up the majority of trial participants.

This was the first prospective trial demonstrating durable, long-term survival with radiation treatment among patients with recurrent endometrial cancer, Klopp added, stating that this research demonstrates the value of randomized trials for less common presentations.

Radiation therapy alone remains the standard of care for pelvic-only, vaginal cuff endometrial cancer recurrences, concluded IGCS session discussant for the study Carol Aghajanian, MD, of Memorial Sloan Kettering Cancer Center in New York City.

The large proportion of low-grade illnesses included in this trial may have been evidence of selection bias, if those with high-grade cancer were encouraged to undergo chemotherapy instead of randomization, she suggested. Or it could just be that recurrent endometrial cancer in the pelvis is more often low grade, she added.

Further studies are needed, Aghajanian argued, because 32% of patients who received radiation therapy alone still had recurrences.

The pelvis is a common site of recurrence for endometrial cancer, Klopp said. Previous studies have shown that definitive-dose radiation therapy can be curative for patients with isolated recurrences, with between 50-70% of patients surviving at 5 years after treatment for their recurrent illness, she added.

In the , the investigators evaluated whether the addition of concurrent chemotherapy in patients with endometrial cancer recurrence improved rates of progression-free survival. The trial accrued 165 participants between February 2009 and August 2020 who had recurrent endometrial cancer limited to the pelvis.

Patients received radiation therapy to the whole pelvis with 3D or intensity-modulated radiation therapy techniques, followed by low dose-rate or high dose-rate interstitial or intracavity brachytherapy. Participants in the intervention group received 40 mg of cisplatin-based chemotherapy each week.

The mean age of trial participants was around 65, and the majority were white. Approximately 81% of trial participants had grade I or II endometrial cancer, and 86% of the recurrences were vaginal.

Klopp acknowledged that this trial had a slow accrual, noting that patients may have been offered concurrent chemotherapy outside of the protocol by clinicians thinking that there was a benefit. The trial protocol also changed during the study, which may have impacted accrual.

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