A critical early diagnosis of ovarian cancer may be delayed by four months or more in some women because doctors don't order the proper tests soon enough, researchers here reported.

Only about a quarter of women later diagnosed with ovarian cancer who had abdominal pain and swelling when first seen underwent pelvic imaging or CA125 serum testing in a timely manner, said Lloyd Smith, M.D., Ph.D., of the University of California at Davis here.

Instead, these women first received abdominal imaging or diagnostic gastrointestinal tests, which are less likely to establish the correct diagnosis, Dr. Smith and colleagues reported online today in the journal Cancer.

A delayed diagnosis of ovarian cancer is important because the disease can progress from early to advanced disease in as little as a year, the researchers said.

While acknowledging that symptoms such as abdominal pain and swelling are not specific for ovarian cancer, the researchers urged physicians to consider ovarian cancer in the differential diagnosis of women who present with these unexplained symptoms.