Decreased expression of a gene involved in cell adhesion helps to identify breast cancers that are more aggressive, giving physicians more information at diagnosis to decide upon individual treatment plan, according to an article in the July-August issue of Breast Cancer Research.

Dr Judy King and her American colleagues compared the expression of the gene for the Activated Leukocyte Cell Adhesion Molecule (ALCAM) in normal breast tissue and tissue samples from primary breast tumors. The researchers found that the ALCAM gene was significantly less active in higher-grade tumors compared with lower-grade tumors, and in tumors with a worse prognosis compared to those with a better prognosis.

“Tumors from patients who died of breast cancer had significantly lower levels of ALCAM transcripts than those with primary tumors but no metastatic disease or local recurrence,” wrote the researchers.

They continued, “The data clearly suggest that decreased ALCAM expression in the primary tumor is of clinical significance in breast cancer, and that reduced expression indicates a more aggressive phenotype and poor prognosis.”

The authors suggest that quantitative polymerase chain reaction (PCR) to measure the number of ALCAM transcripts in a tissue sample from a primary breast tumor could be used to identify these more aggressive tumors at an early stage of the diagnostic process.

The researchers hypothesize that under-expression of ALCAM may underlie the increased ability of certain malignant cells to break from the primary tumor mass and cause metastatic disease.