2/5/98
CONTACT: Kent Safford, (650) 723-6911; e-mail [email protected]
EMBARGOED FOR RELEASE at 10:30 a.m. U.S. Eastern Time on Wednesday, Feb. 11, to correspond with presentation at the annual meeting of the Society of Gynecologic Oncologists, held at the Walt Disney World Dolphin Resort in Orlando, Fla.
ENDOMETRIAL CANCER STUDY RAISES QUESTIONS ABOUT STANDARD TREATMENT
STANFORD -- Women facing surgery for endometrial cancer may want to think twice before embarking on a lengthy course of radiation treatments after the operation, a national study chaired by a Stanford researcher suggests.
The new findings show that routinely giving these patients full pelvic radiation therapy after surgery, as is now commonly done, may have limited benefit, particularly in light of the rigors and potentially serious complications of extended radiation treatment, said study chairman Dr. James Roberts, a professor of gynecology and obstetrics at Stanford University School of Medicine.
In the multi-center, prospective study, women who received standard radiation therapy after surgery for intermediate-stage endometrial cancer had a slightly lower rate of cancer recurrence after two years, but did not have a significant advantage in terms of their two-year survival rate.
"From a purely statistical standpoint, full pelvic radiation is better [than no radiation after the surgery], but if you factor in the costs and the alternative methods that are available, then it may not be that helpful," said Roberts, a gynecologic oncologist who practices at Stanford Hospital and Clinics, part of UCSF Stanford Health Care.
A less rigorous alternative in such cases is vaginal radiation, in which doctors deliver a smaller radiation dose directly into the vagina, he said.
"I would probably suggest that people who are in this [intermediate] category of risk look at just using vaginal radiation," Roberts said.
He is scheduled to present the new findings Wednesday, Feb. 11, at the annual meeting of the Society of Gynecologic Oncologists, held in Orlando, Fla.
Every year, some 36,000 women in the United States are diagnosed with cancer of the endometrium, the lining of the uterus. And every year, about 6,000 U.S. women die as a result of the disease.
The recent trial involved 428 women undergoing surgery for mid-stage endometrial cancer. Roughly half of the patients received full pelvic radiation after surgery, while the others received no radiation. The trial was conducted at more than 100 medical centers by investigators in the Gynecologic Oncologists Group, a national cooperative organization funded by the National Cancer Institute.
Two years after undergoing surgery, 96 percent of the women who had received radiation remained cancer-free, compared with 87 percent of those who did not receive radiation. This difference of 9 percentage points in cancer recurrence rates is statistically significant, Roberts said.
Survival rates, however, did not differ significantly between the two groups. At two years, the survival rate for women receiving radiation was 97 percent, compared with 95 percent in the no-radiation group, he said.
The researchers chose the two-year point for follow-up because this type of cancer, if it recurs at all, almost always turns up within two years, Roberts said.
Among patients from either treatment group who experienced a recurrence, the cancer was most likely to reappear in an area at the top of the vagina. Recurrences in this area struck three women in the radiation group and 13 women in the no-radiation group, Roberts said.
"You could probably eliminate that difference by giving people vaginal radiation instead, which is less expensive and has fewer complications," Roberts said.
Vaginal radiation therapy is delivered directly into the vagina in a single dose during an overnight hospital stay or in three outpatient visits over the course of a week. It rarely has any side effects, Roberts said.
Full pelvic radiation, in contrast, involves a larger dose delivered by an external beam to the entire pelvic region. Therapy usually consists of 28 treatments administered over the course of five weeks. Potential side effects include diarrhea, anemia, fatigue and bowel obstructions requiring surgical bypass. In rare instances, it can lead to death. One women in the recent study died as a result of radiation therapy, Roberts said.
"It can lead to serious problems in 2 to 4 percent of patients," he said. "You're talking about helping 9 percent of patients. So if you hurt 4 percent of them, your gain is not that great."
External radiation treatment is also more expensive, costing anywhere between $10,000 and $50,000, he noted.
Women with endometrial cancer, said Roberts, should carefully weigh the pros and cons of radiation therapy in close consultation with a physician who specializes in treating such cases. "Endometrial cancer is a complex disease with many factors that would require discussion between the patient and a gynecologic oncologist," he said.
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