New Findings on Pelvic Radiation

Endometrial cancer radiotherapy follow up study revealed some risks for younger women

/ Author:  / Reviewed by: Chris Galloway, M.D. Beth Bolt, RPh

(RxWiki News) Endometrial cancer develops in the lining of the uterus. It’s the most common gynecologic cancer in women, and thankfully has a very high survival rate. Recently, researchers looked at the long-term effects of two different types of radiation therapy used to treat the disease.

Endometrial cancer patients under the age of 60 who had both internal and external forms of radiation did not live as long as and had more secondary cancers than women who received only internal radiation, a new follow-up study found.

The researchers suggested that external radiation therapy be used with caution in young endometrial cancer patients.

"Ask about the long-term effects of all treatments you receive."

Mathias Onsrud, MD, a physician and researcher at the Norwegian Radium Hospital (NRH) led this study, which was a 20-year follow-up of an earlier NRH clinical trial.

A total of 568 women with early endometrial cancer who had undergone surgery to remove the diseased uterus were enrolled in the original study between 1968 and 1974.

Participants in this trial were randomly assigned to receive only vaginal brachytherapy (VBT), in which radioactive seeds are placed inside the woman’s body, or VBT plus external beam radiation therapy (EBRT), which involves high powered x-rays being beamed to the pelvis.

“Endometrial cancer has traditionally been treated with a combination of both EBRT and brachytherapy,” Alexis Harvey, MD, Medical Director of the NJ Region for 21st Century Oncology, told dailyRx News. “Many studies are being done to see if this is still the best management.”

After a median of 20.5 years of follow-up, the researchers learned there was no significant survival difference between the two groups.

The median survival for women in both groups was essentially the same — 20.5 years in the EBRT group and 20.48 years for women in the control group, who received only VBT.

The major differences were seen in participants who were younger than 60 at the time of their endometrial cancer diagnosis.

The younger women had a significantly (36 percent) higher death rate than women in the control group.

Secondary cancers were more common in the women who’d received EBRT, the researchers learned, with 30.5 percent of these women developing new cancers during the follow-up period, compared to 24.5 percent of the women who received only VBT.

Younger women under the age of 60 in the EBRT group had twice the risk of developing secondary cancers compared with the control group, with 39.7 percent in the EBRT and 25.6 percent of women in the control group being diagnosed with new cancers.

The risk of second cancers was not significantly different in women over the age of 60.

“In conclusion, there was no survival benefit after EBRT in early stage endometrial cancer. On the contrary, younger women experienced decreased survival, and the incidence of secondary cancers increased after long-term follow-up,” the authors reported.

21st Century Radiology's Dr. Harvey, who is a dailyRx Contributing Expert, said, “In this world of emerging technology, studies are always being done to see what type of treatment is enough, and what is too much when it comes to treating cancer. This study helps to confirm that there is a patient subset that does not require both forms of treatment, that the brachytherapy alone is sufficient. Curing cancer while using less radiation also leads to minimal morbidity and mortality as is proven here,” Dr. Harvey said.

Findings from this study were published in the November issue of the Journal of Clinical Oncology.

This research was supported by Mathias Onsrud. No conflicts of interest were disclosed.

Review Date: 
October 31, 2013
Last Updated:
January 2, 2014