Long-Term Survival in Ovarian Cancer May Be Better Than Expected in Some Patients
Combing data collected on thousands of California patients with ovarian cancer, University of California Davis researchers have determined that almost one-third of patients survived at least 10 years after diagnosis. The findings upend the notion that women diagnosed with cancer of the ovaries always have a poor chance of survival. In fact, the study not only confirmed earlier findings on characteristics associated with ovarian cancer survival—younger age, earlier stage, and lower-grade tumors at diagnosis—it also identified a surprising number of long-term survivors who did not meet those criteria. The findings of the study were published by Cress et al in Obstetrics & Gynecology.
“The perception that almost all women will die of this disease is not correct,” said Rosemary Cress, MPH, PhD. “This information will be helpful to physicians who first diagnose these patients and the obstetricians/gynecologists who take care of them after they receive treatment from specialists.”
Analysis Results
Dr. Cress, an epidemiologist and Associate Adjunct Professor in the University of California Davis Department of Public Health Sciences, used the California Cancer Registry to analyze data reported on all California residents diagnosed with epithelial ovarian cancer between 1994 and 2001.
Of the 11,541 patients in the registry database, 3,582 (31%) survived more than 10 years, Dr. Cress and her colleagues discovered. It was reportedly the first time that research has looked at 10-year trajectories for patients; most survival studies have looked only at 5-year survival or less.
As expected, the study found that the majority of long-term survivors were younger, had early-stage disease when they were diagnosed, and had tumors of a lower-risk tissue type. What struck the researchers was that of the 3,582 long-term survivors, 954 of them had been considered to be at high risk of dying from the disease, either because of their tumor stage, grade, or older age at diagnosis.
“This information is important for patient counseling,” said Gary Leiserowitz, MD, Professor of Gynecologic Oncology and Interim Chair of the University of California Davis Department of Obstetrics and Gynecology. “Many patients and physicians know that ovarian cancer is a dangerous cancer, but they don't realize that there is significant biological variability among patients. It's not a uniformly fatal prognosis.”
Possible Reasons for the Discrepancy
Dr. Leiserowitz says the next step in the research is to figure out why so many women who are given a poor prognosis eventually beat their odds. “For a disease that is so dangerous, why are so many surviving?” he asked.
Among the theories, said Dr. Leiserowitz, are that patients with ovarian cancer who carry mutations in the tumor suppressor genes BRCA1 and BRCA2 respond better to chemotherapy than those who do not. He also suggested that other biologic differences among patients with advanced ovarian cancer may affect individual outcomes. It is also possible that some patients receive more effective treatment than others, boosting their survival odds.
“This was an exploratory study to figure out who has survived,” Dr. Leiserowitz said. “We can now go back and look at tumor tissue to do a comparison between long- and short-term survivors to see if there is a genetic basis for that.”
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
