| NCI Studies Examine Racial Disparity in Survival
Among Patients With Endometrial Cancer |
the National Cancer Institute (NCI), part of the National Institutes
of Health, report findings that suggest a biological disparity for
endometrial cancer exists between Caucasians and African Americans.
The research was done in conjunction with Walter Reed Army Medical
Center and other institutions. Two separate studies, one examining
patient outcome in four endometrial cancer clinical trials1, and
the other looking at gene expression patterns in endometrial tumors2,
provide evidence that biological factors can contribute to the significant
racial disparity in survival rates for this cancer. Both studies
will be presented at the Society of Gynecologic Oncologists (SGO)
2005 Annual Meeting on Women’s Cancer, March 19-23, 2005,
in Miami, Fla., and will be published later this year.
It is estimated that in 2005 there will be approximately 40,000
new cases of cancer of the endometrium, or lining of the uterus,
and about 7,000 endometrial cancer-related deaths. While the rate
for new cancers in African-American women is lower than for Caucasians,
African-American women have a greater mortality rate from endometrial
cancer than Caucasians; an NCI 1989-1994 review reported that 5-year
survival for endometrial cancer was 86 percent in Caucasians but
only 54 percent in African Americans.
“The etiology underlying this disparity is multi-fold,”
said LTC Larry Maxwell, M.D., of Walter Reed’s Department
of Obstetrics and Gynecology and NCI, an author of both studies.
“It can include cultural differences in dealing with medical
illness and unequal access to the proper care and therapy, but could
also arise from a difference in biology which may result in more
aggressive tumors in some populations.”
Maxwell and his group sought to uncover the role of biology by
examining survival outcome in a setting that should provide equal
treatment to all patients: a clinical trial. The researchers studied
data from four trials performed by the Gynecologic Oncology Group
(GOG), an NCI-funded cooperative group that coordinates most of
the large therapeutic gynecologic cancer studies in the United States.
The survival rates for 168 African-American patients and 997 Caucasian
patients with Stage III, Stage IV or recurrent endometrial cancer
were compared. The analysis showed that African-American women with
endometrial cancer have a 25 percent greater chance of dying than
Caucasian women with the same diagnosis, and the overall median
survival for African-American patients was 10.6 months compared
to 12.2 months for Caucasians.
In the second study, the investigators evaluated global gene expression
among endometrial cancer patients to determine any specific differences
that may account for a biological disparity. Tumors from 18 African-American
patients and 27 Caucasian patients were matched and compared according
to stage, tumor grade, and cell type. In the initial analysis, Maxwell
and his group could not identify expression profiles unique to each
race. However, when they excluded early-stage cancers and focused
only on advanced stage cancers, they observed expression profiles
that did cluster according to race; 325 total transcripts had different
expression levels in African Americans and Caucasians.
“Both of these studies suggest that underlying molecular
differences may partially explain the disparity in survival outcome
for endometrial cancer for these two groups,” said Maxwell.
He added that the studies do not imply that African Americans and
Caucasians are genetically different, but rather that multiple factors
including environment and culture may result in a difference in
gene expression. “Further research is needed to determine
how these differences can be used to help identify better therapies
for high-risk minority groups.”
”Though this study looks at one particular cancer in terms
of racial disparities, we hope that it may shed light on our broader
work in this area,” said Harold Freeman, M.D., Director of
The NCI Center to Reduce Cancer Health Disparities
For more information about cancer, visit the NCI Web site at http://www.cancer.gov
or call NCI's Cancer Information Service at 1-800-4 CANCER (1-800-422-6237).
1. “Racial disparity among patients with advanced/recurrent
endometrial adenocarcinomas: a Gynecologic Oncology Group (GOG)
study.” G. Larry Maxwell, Chunquio Tian, John I. Risinger,
Carol Brown, Wendy Brewster.
2. “Racial disparity in global gene expression among patients
with advanced endometrial adenocarcinoma.” G. Larry Maxwell,
G.V.R. Chandramouli, Lou Dainty, Tracy Litzi, Michael A. Bidus,
Andrew Berchuck, Carl J. Barrett, John I. Risinger