149-AP-00
EMBARGOED UNTIL 2 P.M. PST WED., NOV. 1, 2000
STOMACH CANCER BEHAVES DIFFERENTLY IN ASIANS COMPARED WITH NON-ASIANS; MAY EXPLAIN HIGHER ASIAN SURVIVAL RATES
Study Suggests That Biology of Cancer May Vary Among Races
Irvine, Calif. - Asian-American stomach cancer patients have tumors with biological traits that differ from tumors in non-Asians, which may explain why they have better survival rates from stomach cancer than non-Asians, according to a UC Irvine College of Medicine study.
The findings may be the first to link differences in tumor biology to survival rates among ethnic groups and provide insight into why certain tumors affect some populations more - and more severely - than others. The findings appear in the November issue of Cancer.
Hoda Anton-Culver, professor of epidemiology, and Dr. Charles Theuer, assistant professor of surgery, led a team that examined records from 3,770 Asian and non-Asian stomach cancer patients in Southern California. They found that the survival rates of Asians with stomach cancer were far higher than any other ethnic group. They also found that tumors in Asians did not invade normal tissues as aggressively as tumors in non-Asians.
"The differences in cancer rates between Asians and non-Asians have been attributed in the past to varying diet, diagnostic methods and more radical surgical techniques by Asian doctors," Anton-Culver said. "But we found that Asian-Americans with the same stage of disease who received the same health care as non-Asians still exhibited superior survival rates. The variation indicates that diagnosis, screening and treatment will have to accommodate biological differences in the way cancer attacks certain ethnic groups."
Supporting the UCI findings that the tumor cells were biologically different between Asians and non-Asians, previous studies had found that tumors in Japanese patients had higher levels of a chemical marker called "antimetastasis factor nm23," which discourages metastasis. In contrast, studies noted British patients had been found to have higher levels of a growth cell receptor that encouraged cancerous cell proliferation.
"We think some of these contrasts result from differences in the biology of tumors among different races," Theuer said. "There is growing evidence of significant biological differences in the tumors between Asians and non-Asians. We now need to find out why this occurs; this knowledge may help us find ways to more quickly and effectively treat stomach and other cancers among all ethnic groups."
The team is looking at how the biology of cancer cells can create this protective effect in certain populations and how genes and other molecules in the cell control the behavior of cancer cells.
Anton-Culver and Theuer colleagues in this study included Tom Kurosaki, Argyrios Ziogas and Dr. John Butler, all of UCI. A grant from the National Cancer Institute and a gift from the V Foundation in Cary, N.C., supported the research.
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Contact:Andrew Porterfield(949) 824-3969[email protected]
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