the genetic "language" of breast epithelial and stromal cells being deciphered!

[Lani]

stromal cells are the cells surrounding the tumor cells. Researchers have been able to pinpoint the chromosomes where the changes occur which are associated with increased tumor grade, others associated with regional lymph node metastasis...and they even found a chromosome 14 change which was associated with Progesterone receptor status!

Genomic Alterations in Tumor Stroma May Help Explain Diversity of Breast Cancer

NEW YORK (Reuters Health) May 15 - Genomic alterations are known to occur in the epithelium and stroma of breast cancers, and now new research suggests that these changes, primarily those in the stroma, actually affect the clinicopathologic features of the malignancy.

"These results support a model in which genetic changes in both stromal and epithelial compartments occur during tumorigenesis, and progression is codetermined by local interaction between these cell populations within the primary tumor," senior author Dr. Charis Eng, from the Cleveland Clinic, and colleagues note.

The findings are based on a comparison of clinical features and genomic alterations in 220 invasive breast cancer specimens. In particular, Dr. Eng's team was looking for a loss of heterozygosity/allelic imbalance with 386 microsatellite markers.

The investigators report their findings in the Journal of the American Medical Association for May 16.

Genomic alterations on chromosome 11 in the stroma were significantly associated with tumor grade, whereas alterations on chromosomes 1, 2, 5, 18, 20, and 22 were linked to regional lymph node metastases (p < 0.05 for all).

Also, the researchers found that genomic changes on chromosome 14 in the epithelium were tied to the progesterone-receptor status.

"Our data suggest that clinical tumor progression, reflected in the measured clinicopathologic features, may be more influenced by locally acquired changes in the stromal environment than carcinoma cell genotype per se," the authors state.

"Stromal genetic changes that contribute to clinically relevant outcomes can be mapped to particular chromosomal loci, including 2 markers on chromosome 11 that correlate with tumor grade and 9 markers on 6 chromosomes associated with regional lymph node metastasis."

JAMA 2007;279:2103-2111.