Pelvic Radiation Recommended for Early Endometrial Cancer

Researchers at the University of Kentucky (UKY; Lexington, USA), Memorial Sloan-Kettering Cancer Center (MSKCC; New York, NY, USA), and other institutions conducted a phase III trial involving 601 women (mean age 63) with stage I endometrioid histology and high intermediate risk to determine if vaginal cuff brachytherapy and chemotherapy (VCB/C) could increase recurrence-free survival, compared to pelvic external beam radiation therapy (PXRT). Secondary objectives included comparisons of overall survival (OS), patterns of failure, and frequency/severity of adverse events.

In all, 301 patients were assigned to PXRT and 300 to VCB/C; 74% had stage I disease, and 89% underwent lymphadenectomy. The results revealed that acute toxicity was more common and more severe with VCB/C, with grade 3 or higher adverse events reported in 32 patients on the PXRT arm, compared to 187 patients on the VCB/C arm. With a median follow-up of 53 months, the 36 month OS was 91% for PXRT, versus 88% for VCB/C. While no significant differences were noted between the two arms in terms of vaginal or distant failure, pelvic or para-aortic nodal recurrences were significantly more common in the VCB/C arm. The study was presented at the 59th annual meeting of the American Society for Radiation Oncology (ASTRO), held during September 2017 in San Diego (CA, USA).

“Previous Gynecology Oncology Group trials confirmed that pelvic radiation is an effective, safe, and tolerable option to manage early-stage endometrial cancer,” said lead author Professor Marcus Randall, MD, of UKY. “The current trial confirms that this standard treatment is preferable to the experimental approach of vaginal cuff brachytherapy followed by chemotherapy, in terms of tumor control in the nodal regions and also in terms of acute toxicity. This finding holds true even for patients at a higher risk of recurrence.”

Endometrial cancer begins in endometrium, a layer of cells that form the lining of the uterus. It is often detected at an early stage since it frequently produces abnormal vaginal bleeding. Risk factors include hormonal imbalance (estrogen versus progesterone); irregular ovulation patterns; early menstruation; never having been pregnant; old age; obesity; tamoxifen hormone therapy for breast cancer; and hereditary nonpolyposis colorectal cancer (HNPCC), a syndrome that increases the risk of colon cancer and other cancers, including endometrial cancer. If discovered early enough, a hysterectomy often cures endometrial cancer.

Related Links:
University of Kentucky
Memorial Sloan-Kettering Cancer Center