Marker of Breast Cancer, Prostate Cancer Found in Tears

CANBERRA, Aug 08, 2000 (Reuters) - A marker protein in tears may indicate whether people have, or are likely to develop, breast cancer or prostate cancer, according to a serendipitous finding by a team of Australian scientists.

Mark Willcox, director of biological sciences at the Cooperative Research Centre for Eye Research and Technology, based at the University of New South Wales in Sydney, said that the discovery at the centre was made by scientists developing a new permanent-wear contact lens who were investigating why some people produce more tears than others.

The investigators found that tears of patients with breast or prostate cancer, or a family history of the cancer, contain the protein Lg.

"The possibilities are that people who have Lg in their tears are genetically disposed to those cancers, or that when they have or are developing those cancers, the protein increases in their tears," Willcox told Reuters.

Willcox said that the centre is now finalising clinical trials on 50 cancer patients to determine if the marker could be used as a diagnostic test for cancer or reveal a disposition to disease. He said that the next stage is to find a commercial backer and then conduct larger clinical trials. If the trials are found to be useful, a commercial testing kit could be on the market within 2 to 5 years.

"So far there have been few tests based on tears, and this would be certainly less invasive than looking at blood," he said.