"Currently, anyone with a breast cancer diagnosis fears the worst - that the cancer will spread and threaten their lives. A tissue test for metastatic risk could alleviate those worries, and prevent toxic and costly measures like radiation and chemotherapy," says senior author Joan G. Jones.
The investigators set out to build on previous research. Working in animal models, researchers had identified a link between blood-borne or systemic metastasis and a three-part association between invasive carcinoma cells, perivascular white blood cells (macrophages) and the endothelial cells that line vessel walls.
Jones and colleagues named the three cell types together TMEM (Tumour Microenvironment of Metastasis). In a case-control study, they performed a retrospective analysis of tissue samples from 30 patients with invasive ductal carcinoma of the breast who developed systemic, distant-organ metastases. These samples were compared to matched controls that had only localised disease.
They found that TMEM density was more than double in the group of patients who developed systemic metastases compared with the patients with only localised breast cancer. Offering further evidence in support of the TMEM concept, they found that in well-differentiated tumours, where the outcome is generally good, the TMEM count was low. Notably, TMEM density was associated with the development of distant-organ metastasis, independent of lymph node status and tumour grade.
"Traditionally, the likelihood of breast cancer metastasis is estimated based on tumour size, tumour differentiation - how similar or dissimilar the tumour is compared to normal breast tissue - and whether it has spread to the lymph nodes. While these are useful measures, TMEM density directly reflects the blood-borne mechanism of metastasis, and therefore may prove to be more specific and directly relevant," says Dr. Jones. The researchers say the next step will be to validate the findings in a larger sample group.
MEDICA.de; Source: NewYork-Presbyterian Hospital/Weill Cornell Medical Center