Laser-light testing of breast tumour fibre patterns shows when cancer spreads

Using advanced microscopes equipped with tissue-penetrating laser light, cancer imaging experts at Johns Hopkins have developed a promising new way to accurately analyse the distinctive patterns of ultra-thin collagen fibres in breast tumour tissue samples and to help tell if the cancer has spread.

The Johns Hopkins researchers say their criss-crossing optical images, made by shining a laser back and forth across a biopsied tissue sample a few millionths of a metre thick, can potentially be used with other tests to more accurately determine the need for lymph node biopsy and removal in women at risk of metastatic breast cancer.

In what is believed to be the first study to measure minute changes in tumour connective tissue fibers, researchers found that eight women whose cancers had spread beyond the breast through the body's lymphatic system had about 10 per cent more densely packed and radially spread-out collagenous structural proteins than six women whose cancers had not yet spread.

Collagen fibres in the non-metastasised tumours, also obtained during breast biopsy, were more diffuse and arranged in a transverse or horizontal pattern. All
14 women in the study had aggressive, malignant breast cancer.

In the new report, published in the Journal of Biomedical Optics' online edition on 1 November, researchers say that if these "proof of principle" findings hold up in testing now under way in hundreds more women with or without metastatic breast cancer, then their new optical imaging tool could simplify testing for spreading disease and help people avoid unnecessary lymph node surgery.

"Our new diagnostic technique has the potential to help reassure thousands of breast cancer patients that their cancers have not spread to other organs, and could help them avoid the risks and pain currently involved in direct inspections of lymph nodes for the presence of cancerous cells," says study senior investigator Kristine Glunde, Ph.D.