WEDNESDAY, March 2, 2016 (HealthDay News) -- Ovarian cancer isn't a single disease, but rather a number of different malignancies involving the ovaries, an expert U.S. panel says.
Evidence suggests that many ovarian cancers begin in other tissues, such as the fallopian tubes, and eventually spread to the ovaries. In other cases, cancers arise from cells not considered to be part of the ovaries, a report from the U.S. National Academies of Sciences, Engineering, and Medicine said. The report was mandated by Congress.
The authors noted there are "surprising gaps" in knowledge about ovarian cancer. They called for additional research to learn more about the causes and improve prevention, early detection, treatment and management of the disease.
"While progress has been made in ovarian cancer research over the past few decades, much remains to be learned," Jerome Strauss III, chair of the report committee, said in an academy news release. Strauss is also executive vice president for medical affairs and dean of Virginia Commonwealth University School of Medicine, in Richmond.
"The more that is understood about the basic biology of various types of ovarian cancers, such as where they originate in the body, the more rapidly we can move toward advances in prevention, screening, early detection, diagnosis, treatment and supportive care," he explained.
Each year, more than 21,000 women in the United States are diagnosed with ovarian cancer, the researchers said. And, more than 14,000 women die from the disease each year, they added. The five-year survival rate is less than 50 percent, the researchers noted.
Early ovarian cancer doesn't have any distinctive symptoms. There's also no effective screening test for ovarian cancer. About two-thirds of these patients are diagnosed in the late states of the disease, when the cancer has already spread to other parts of the body, the report authors said.
The report also found that the quality of care for ovarian cancer patients varied widely across the nation. Several groups have developed standard-of-care guidelines, but less than half of ovarian cancer patients receive that recommended care, the research revealed.
The report found two main predictors of a better outcome for women with ovarian cancer. One was being treated by a gynecologic oncologist. The other was receiving treatment at a hospital that handles a large number of such cases. However, many patients don't have access to such care, the report authors said.
To reduce disparities in care, they recommended that doctors and scientists look for ways to ensure consistent use of the current suggested standards of care.
The report also said that better methods of identifying women at high risk for ovarian cancer could improve prevention and early detection. For example, there are strong links between ovarian cancer and a family history of the disease, specific inherited genetic mutations such BRCA1 and BRCA2, and certain hereditary cancer syndromes, the authors noted.
The U.S. Office on Women's Health has more on ovarian cancer.