A new way to analyse patterns of ultra-thin collagen fibres in breast tumour tissue samples — and to help tell if the cancer has spread — has been developed in the US.
The method, devised at Johns Hopkins University, uses advanced microscopes equipped with tissue-penetrating laser light.
In a statement, the Johns Hopkins researchers said 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 fibres, 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, researchers said 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,’ said study senior investigator Prof Kristine Glunde.
Women with denser tumour fibre patterns would likely stand a greater chance of needing lymph-node biopsy and removal and inspection of such tissue for malignant cells, said Glunde, an associate professor at the Johns Hopkins University School of Medicine Russell H Morgan Department of Radiology and the Sidney Kimmel Comprehensive Cancer Center.
Glunde added that complications from lymph-node biopsy and more invasive dissection include risk of infection, pain, severe swelling and leakage of lymph fluid around the armpit, as well as stiffening in the arm, which can be permanent.
Cancer imaging experts have known for more than a decade that the fibrous connective tissue located between cancer cells changes and bunches together as tumours grow and disease spreads, said study co-investigator Zaver Bhujwalla, a professor at Johns Hopkins and its Kimmel Cancer Center.
‘Until now, however, we had no proof in principle that such minute and progressive changes outside cancer cells, in the tumour micro-environment or extracellular matrix, could be measured and potentially used to better guide our staging and treatment decisions,’ said Bhujwalla, who also serves as director of the Johns Hopkins In Vivo Cellular and Molecular Imaging Center (ICMIC), where the latest imaging study was performed.