OVARIAN cancer is widely known as 'the silent killer'. Its symptoms are non-specific and frequently, they are similar to more common conditions such as bladder or digestive disorders. Because of this, doctors have been unable to diagnose ovarian cancer until its advanced stages. By then, it is more often than not, too late.

The key to survival - as to all cancers - is in early detection. But, unlike a number of other cancers - breast cancer, for example, or cervical cancer - it's not necessarily the patient's lack of diligent checks that ovarian cancer can't be detected early.

'When ovarian cancer presents itself, in 80 per cent of the cases, the cancer has already reached stage three or four,' says associate professor Mahesh Choolani, the non-executive chairman for Innovations Exchange Private Limited (INEX), a National University of Singapore spin-off company that focuses on women's health.
Early detection has proven to be a challenge so far.

Apart from a physical examination and an ultrasound, the current convention is a blood test to check the level of a blood protein, CA125. Elevated levels of CA125 tend to indicate the presence or recurrence of ovarian cancer.

However, at elevated levels, the cancer will already be in its advanced stages. Even worse, given that Asian women are highly susceptible to severe endometriosis and pelvic inflammatory diseases, which will also elevate CA125 levels, the blood test is even less accurate and effective.

When the cells in a woman's ovaries grow abnormally, the result is a malignant tumour in one or both ovaries. Ovarian cancer is most common in women nearing or going through menopause. Indicative symptoms of ovarian cancer include abdominal mass or bloating, lower back pain, loss of appetite or getting full quickly, changes in bladder habits, or fatigue.

According to the Singapore Cancer Registry Interim Report 2003-2007, ovarian cancer is the fifth most frequent cancer among Singapore women. Every year, more than 260 cases are diagnosed and close to 100 women lose their lives to ovarian cancer. According to statistics, the Singapore woman has a one in 69 chance of developing ovarian cancer.

All these challenges may now be countered with a new multi-biomarker test, OvPlex™, developed by HealthLinx Limited, an Australian company focusing on novel diagnostics.

INEX, working with HealthLinx, recently launched it in Singapore as a test for early detection of ovarian cancer. Singapore is the third country in the world, in addition to Australia and the UK, where OvPlex™ is available.

'OvPlex™ tests five substances in blood, one of which is CA125. It combines information of CA125 and four other markers mathematically into one value - which will be a better value than CA125 alone in representing the likelihood that a woman has ovarian cancer,' explains Gregory Rice, founding director of HealthLinx and professor in the Department of Medicine at Monash University.

To get to these markers, Heathlinx looked at a whole range of blood biomarkers that are known to be associated with cancer - by looking at previously studied markers and scientific literature.

Some of the markers show an obvious elevated level because of the presence of an ovarian tumour; most are associated with some form of infection or inflammation.

'Although some of them aren't specific for ovarian cancer, but when put into the mathematical model, they can actually make CA125 perform better,' he elaborates.

In a clinical trial that screened 362 women in Australia, Prof Rice explained that the test consistently showed, for example, markedly elevated levels of two markers other than CA125 in women with early stages of ovarian cancer.

However, it is not designed to be used as a population screening test. Unlike a Pap smear or a mammogram, the OvPlex™ test cannot be used in an asymptomatic or normal population yet to find out who's at risk for ovarian cancer.

Assoc Prof Choolani cautions against taking the test at the first sign of the symptoms - which could unfortunately be as generic to women as a bloated abdomen. Symptoms should persist for about one to two weeks before a test is considered. Medical advice should be sought before and after the test.

In Singapore, the OvPlex™ test is currently available at Quest Laboratories for $300, before GST. Test results will be available within 10-15 working days.

'We are working towards bringing the number of ovarian cases down. The first dive in the numbers will be through early detection, while researchers will continue working out the etiology and biology of ovarian cancer. Once we figure out ways to bring the numbers down, we can focus on prevention. There must be a way,' asserts Assoc Prof Choolani.

With late detection, the survival rate for ovarian cancer will be a bleak 30 per cent, or less. However, if it is detected earlier, at stage one or two, the patient's five-year survival rate increases dramatically to over 90 per cent.

This article was first published in The Business Times.