Early Uterine Cancer: Radiation Helps
After Hysterectomy, Radiation Raises Stage I Endometrial Cancer Survival
Jan. 24, 2006 -- Radiation therapy raises the odds of surviving endometrial cancer, a new study shows.
Uterine cancer usually starts in the lining of the uterus, called the endometrium. It's easiest to cure when caught early: before the cancer breaks through the uterus and into surrounding tissues. This is stage I endometrial cancer.
Surgery to remove the uterus (hysterectomy) and the ovaries (oophorectomy) usually results in a cure for those with stage I. But patients are more likely to die in the five years after surgery if they had what's known as stage IC endometrial cancer. That's when the cancer has already spread deep into the muscular wall of the uterus.
Now researchers find strong evidence that radiation therapy improves survival in patients with stage IC endometrial cancer.
"Radiation therapy was significantly associated with improved overall survival and relative survival," write Christopher M. Lee, MD, of the University of Utah Medical Center, and colleagues.
Their report appears in the Jan. 25 issue of The Journal of the American Medical Association.
High-Grade Cancers Included
Doctors have several ways of predicting how dangerous endometrial cancer is. One is the stage of the cancer. Early stage cancer -- stage I -- hasn't spread beyond the uterus. There are three basic kinds of stage I endometrial cancer:
- In stage IA, the cancer is almost completely confined to the uterus lining.
- In stage IB, the cancer hasn't penetrated more than halfway through the muscle of the uterine wall.
- In stage IC, the cancer has penetrated more than half way through the muscle of the uterine wall.
In each of these categories, doctors consider the cancer better or worse depending on its grade -- that is, on what the tumor cells look like under the microscope. In grade 1, the cells look a lot like normal cells. That's good. In grade 4, the cells lump together in a primitive mass. That's bad.
Lee's team looked at the medical records of more than 21,000 women with endometrial cancer. The cancers ranged from stage IA to IC, and from grade 1 to grade 4.
They found that radiation therapy after surgery significantly improved survival for women with stage IC endometrial cancer at grades 1, 3, and 4. It probably helped women with grade 2 cancers, too, but there were so few women with this diagnosis that it was hard to tell.
Radiation therapy boosted survival for women at all ages. But the exact benefit differed with age.
For women younger than 56:
- For stage IC/grade 1 disease, 5-year overall survival improved from 88% to 98%.
- For stage IC/grade 1 disease, 10-year overall survival improved from 69% to 92%.
- For stage IC/grade 3-4 disease, 5-year overall survival improved from 77% to 86%.
- For stage IC/grade 3-4 disease, 10-year overall survival improved from 77% to 86% (the same as 5-year survival).