Study finds inherited genetic factor may not extend ovarian cancer patient's survival.(Brief Article)

2002 JUN 13 - (NewsRx.com & NewsRx.net) -- A University of Iowa (UI) Health Care investigation has found that, contrary to some reports, women with inherited ovarian cancer may not have a better survival prognosis than women with ovarian cancer due to other mechanisms.

At least 10% of ovarian cancers are inherited, and many of these cases are due to women inheriting a BRCA1 gene that doesn't function properly. Some researchers have suggested that women with ovarian cancer who have a faulty BRCA1 gene are more likely to live longer than women who also have ovarian cancer but whose BRCA1 gene functions normally. Other investigators have suggested no such survival difference exists.

The UI study controlled for more outcome predictors than any of the previous studies and could not find a measurable difference in survival due to hereditary BRCA1 dysfunction. The findings are published in the May 2002 issue of Clinical Cancer Research.

"Our study could not validate previous conclusions that women with inherited ovarian cancer have a better overall prognosis than those who have sporadic or random ovarian cancer," said Richard Buller, MD, PhD, UI professor of obstetrics and gynecology and the study's principal investigator. "It still might be the case that hereditary ovarian cancer offers some increased survival over other ovarian cancers but we can't prove it with this study. Apparent survival differences are probably due to other factors."

Buller said the findings have implications for giving patients more accurate prognostic information. "Based on what we've learned, I can no longer tell women that having inherited ovarian cancer makes their prognosis better," he said. "The studies that would have allowed me to give that prognosis didn't have the appropriate controls that our study does."

Previous studies had shown an average 80% survival advantage for women who had hereditary BRCA1 gene dysfunction. Buller said the recent UI investigation included enough cases to have detected that 80% rate if it indeed existed. "Our next step will be to try to analyze more ovarian cancer cases. An even larger number of cases will increase our ability to detect a smaller difference in survival, such as 30%, if it exists," he said.

The UI study focused on 59 cases of ovarian cancer that showed BRCA1 dysfunction due to one of three causes - inheriting a defective gene; a gene mutation in the cancer but not inherited; or a loss of gene function in the cancer (known as gene silencing) - and 59 cases of ovarian cases in which the women's BRCA1 genes were not faulty. No previous study had controlled for the noninherited forms of BRCA1 dysfunction or for a mutated p53 gene (a tumor suppressor). All the cases had been diagnosed and/or treated at the Holden Comprehensive Cancer Center at the UI.