Can a blood test detect ovarian cancer early? What patients should know

When we think about cancer screening, a blood test seems like the simplest answer. A small sample, a laboratory report and, hopefully, an early warning. For ovarian cancer, that possibility is possible because the disease can be difficult to recognise in its early stages.

Ovarian Cancer is the third most diagnosed cancer among Indian women after breast and cervical cancer, and it remains a concern for women in the country. In the analysed ovarian cancer cases, 57.1 per cent were diagnosed in Stage III and 23.9 per cent at Stage IV.

The symptoms are often ordinary. The constant feeling of bloating, or an abdominal discomfort, change in urinary habits, or loss of appetite are often symptoms women choose to overlook thinking they may be due to indigestion or hormonal changes. However, symptoms these are the very symptoms that might point towards something more radical. This is exactly why a blood test is crucial.

IS CA-125 the answer?

To test for cancer, CA-125 has been a blood marker that doctors have prescribed for many years. However, a CA-125 rise in the body can have other reasons attached to it. More importantly, a woman with early ovarian cancer may not necessarily have a raised CA-125. Thus, a normal report might not always be the assurance that there’s no cancer in the body.

This brings us to the question that instead of one marker, can we look at a combination which might give us a clearer picture?

Looking beyond a single blood marker

That is where some of the newer research is particularly interesting. Scientists are studying proteins, fragments of DNA and other molecular changes that may be present in the blood as cancer develops. Some researchers are also examining whether changes in these markers over a period may be more informative than a single test result. Artificial Intelligence and Machine-Learning techniques are being explored as well, with the hope that they can recognise patterns that may be difficult to identify through conventional testing.

The idea is promising, but there is a significant gap between promising research finding and a test that can be offered routinely. A screening test in healthy women must meet very high standards, with cancer being able to be diagnosed earlier on.

What options do women have?

For a routine ovarian cancer screening test, CA-125 and ultrasound are the options women have, along with other routine blood tests. There is also a strong predisposition for ovarian cancer.

The family history of ovarian cancer in 2 or more first-degree relatives increases risk and is also associated with an early onset disease. A personal history of breast cancer prior to 40 or 50 years of age also increases the risk. Women with inherited gene mutation have the highest risk, such as BRCA1 or BRCA2.

Thus, they should consider genetic testing, and other risk-reducing options along with their blood work. A regular medical evaluation is mandatory.

Promising science, but evidence must lead the way. The research into blood-based detection gives us genuine reason for optimism. We are learning much more about the biological signals that cancer leaves behind, and technology is allowing researchers to study these signals in ways that were not possible before.

However, we cannot label every promising blood test as a breakthrough. The only breakthrough will be one where we will be able to detect ovarian cancer early, distinguish it from benign conditions, work across women of all groups and be able to save lives through early detections.

We may not be there yet. But the direction of research is encouraging, and in ovarian cancer, finding a dependable way to look for the disease before it becomes difficult to treat could make a profound difference.

(The writer is a Senior Consultant - Gynaec Oncology, HCG Cancer Hospital, KR Road, Bangalore)

ABOUT THE AUTHOR

Dr Abhilasha Narayan