Early predictor of breast cancer aggressiveness

Physicians may be able to make early decisions on the best treatment for breast cancer, thanks to research published in Breast Cancer Research today. A gene involved in the adhesion of cells is less active in breast tumors with a poor prognosis than those that are less aggressive, researchers found.Measuring the activity of the ALCAM gene in primary breast tumors could give physicians advanced warning about the likely clinical outcome of the disease. This should help them decide whether to prescribe a more aggressive treatment regimen, such as chemotherapy, much earlier in the diagnostic process.

Dr Judy King and colleagues, from University of South Alabama and University of Wales College of Medicine, 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. To do this they counted the number of mRNA transcripts of the ALCAM gene in the different samples.

The researchers found that the ALCAM gene was significantly less active in higher-grade tumors compared to 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,” write the researchers.

They continue: “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.” They suggest that quantitative 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.

As ALCAM is involved in keeping cells together in a clump, the researchers hypothesize that reduced expression of the gene might allow the tumor cells to separate from one another. This would allow cells to enter the circulation and promote the formation of secondary tumors, which makes the cancer harder to treat.