Researchers warn in a study just published on bmj.com that many women with ovarian cancer can go undiagnosed for months because their symptoms are not always being investigated without delay.

Three key symptoms associated with ovarian cancer are identified in the study. They should help clinicians decide whether to investigate further. However, one of these symptoms is not included in current guidance for urgent investigation.

Accounting for 4 percent of all cancers in women, ovarian cancer has the worst prognosis of all gynecological cancers. In the past, ovarian cancer was thought to have few symptoms and was often dubbed the “silent killer”. But recent studies have shown that symptoms are frequent and that their early identification has the potential to improve prognosis.

Researchers at the University of Bristol set about classifying the key symptoms that could indicate ovarian cancer in women presenting to primary care. They also estimated the positive predictive value for each symptom which is the probability that a woman with a particular symptom actually has ovarian cancer.

The study involved 212 women aged over 40 with a diagnosis of primary ovarian cancer. It also included 1,060 healthy controls from 39 general practices in Devon, England.

Seven symptoms were associated with ovarian cancer:
• abdominal distension
• urinary frequency
• abdominal pain
• postmenopausal bleeding
• loss of appetite
• rectal bleeding
• abdominal bloating

Some women presenting with the first three of these symptoms waited at least six months before the diagnosis was made.

All symptoms had positive predictive values below 1 percent, except for abdominal distension, which had a positive predictive value of 2.5 percent. The authors explain that this means that it carries the highest risk and warrants rapid investigation. Yet persistent abdominal distension is not included in present guidance for urgent investigation. If it were, some women could have their diagnosis speeded up by many months.

The authors mention that the fact that symptoms are common and often reported is encouraging. This means there is some possibility of identifying early ovarian cancer by using symptoms. “This study provides an evidence base for selection of patients for investigation, both for clinicians and for developers of guidelines”, they write in conclusion.

In an associated note Dr Robin Fox writes that there is now increasing evidence that ovarian cancer is not a “silent killer” but one that presents with vague symptoms that have a low positive predictive value for cancer.

He writes that this study adds to the evidence base derived from primary care of red flag symptoms for several cancers, and is essential as the majority of patients in the United Kingdom present at first to primary rather than secondary care.

In an accompanying editorial, Joan Austoker from the University of Oxford adds that “the diagnosis of ovarian cancer will continue to be a challenge for primary care doctors.”

She argues that there is a need for further research to improve our knowledge of the predictive value of different symptoms in ovarian cancer. For now, she says it is important for both women and primary care doctors that ovarian cancer is no longer regarded as a silent killer.

“Risk of ovarian cancer in women with symptoms in primary care: population based case-control study”
William Hamilton, consultant senior lecturer, Tim J Peters, professor, Clare Bankhead, university research lecturer, Deborah Sharp, professor
BMJ 2009; 339:b2998

“Commentary: Diagnosing ovarian cancer – more problems than answers”
Robin Fox, honorary general practice research associate
doi=10.1136/bmj.b3233

“Diagnosis of ovarian cancer in primary care”
Joan Austoker, Director
doi=10.1136/bmj.b3286
bmj.com

Written by Stephanie Brunner (B.A.)