Several Genetic Markers Linked To Variability Among Breast Cancer Patients
Researchers have linked genetic markers on eight chromosomes in the tissue surrounding breast tumors to the grade of the cancer and the spread of the disease to the lymph nodes.
The findings may help explain why patients with similar appearing breast cancers respond differently to treatment and may establish a basis for more personalized treatment. The research led by Charis Eng, M.D., Ph.D., Chairman of the Genomic Medicine Institute at Cleveland Clinic, appears in the May 16 issue of the Journal of the American Medical Association.
Previous research had shown that a high degree of variability in the behavior of sporadic breast tumors and clinical outcomes was attributable to individual patient factors. The work of Dr. Eng and her colleagues indicates that genetic alterations within breast cancer tumors are likely the prime reason for the variability among patients. The variability often makes it difficult for physicians to identify the most appropriate treatment.
In their work, the researchers tested the hypothesis that genetic alterations in stroma, or tissue surrounding breast tumors, significantly altered tumor behavior, as reflected in clinicopathological features at the time of diagnosis. The researchers completed a cross-sectional analysis of DNA from the epithelium and stroma of 220 primary sporadic invasive breast cancer tumors to identify genetic alterations.
The researchers found eight significant genetic markers that correlated with variances in clinicopathological features. "It is rather remarkable that genetic alterations in seven chromosomal regions that predict for poor outcome, such as spread of tumor to the lymph glands and aggressive appearance of the tumor, reside in the stroma," said Dr. Eng. "Only one chromosomal region in the epithelium was associated with any clinicopathologic feature."
"These results support a model in which genetic changes in both stroma and epithelial compartments occur during (the formation of tumors) and progression is co-determined by local interaction between these cell populations within the primary tumor," the JAMA study reports.
The authors note that additional research is needed to independently validate the results of the study and understand their significance as it relates to routine clinical care.