Ovarian cancer remains elusive to early diagnosis and successful treatment

A population-based study of all ovarian cancer cases diagnosed in Australia in 2005 found a crude five year survival rate of 35 per cent. 

Women with more advanced cancer, who were older or had certain cancer subtypes had a poorer prognosis.  Women with early stage cancer had the best prognosis but only 20 per cent of ovarian cancers are diagnosed at an early stage.

In the study published in the Medical Journal of Australia co-author UWA School of Women's and Infants' Health Professor Yee Leung and his colleagues "emphasised the need for primary and secondary prevention and better treatments for ovarian cancer to improve long-term outcomes".  They found that survival rates have not dramatically improved over the last 20 years.

The UK Collaborative Trial of Ovarian Cancer Screening has invested £30 million ($54 million AUD) into an ongoing study to determine if screening can save lives.  At present, Cancer Australia does not support population-based screening for ovarian cancer by pelvic examination, blood tests, ultrasounds or combinations of these.  The Prostate, Lung, Colorectal and Ovarian (PLCO) trial reported a 5 per cent false-positive test rate resulting in a 33 per cent surgical intervention rate.  Of those who had surgery, there was a 15 per cent major complication rate.

The histologic subtype, of ovarian cancer is also related to prognosis.  Molecular and genetic research has advanced the understanding of ovarian cancer to identify certain groups that may benefit from targeted therapy (eg PARP inhibitors for BRCA1 and BRCA2 mutation carriers, anti-angiogenesis agents for suboptimally debulked or recurrent ovarian cancer).  This would hopefully translate to increment increases in survival for women with advanced ovarian cancer.

The presence of co-morbidities (additional disorders), socio-economic status and residence were also associated with prognosis.  The Western Australian Gynaecologic Cancer Service is a centralised service involved in the care of more than 96 per cent of all new gynaecologic cancer diagnoses in the state and a core group of clinicians concentrate their expertise in providing multidisciplinary care.

"Of interest, there was a non-significant trend towards better survival in Western Australia compared to other states," Professor Leung said.

This population-based study confirmed that the majority of ovarian cancers cases were diagnosed at an advanced stage and associated with a poor prognosis.  Better screening tests to detect early stage ovarian cancer provides the greatest hope if emerging targeted therapies to individualise treatment does not translate into significant improvements in survival rates.