University of Texas M. D. Anderson Cancer Center researchers have identified a gene that may provide a new breast cancer prognostic marker.
In the study, Ann Killary from the university and colleagues used a genetic technique termed 'suppression subtractive hybridization' to identify a new gene that is located on Chromosome 1 in a region where loss of heterozygosity (a specific type of genetic alteration) regularly occurs.
They called the gene ductal epithelium-associated RING Chromosome 1, or DEAR1.
Further analysis of a series of 14 samples showed that DEAR1 protein expression was reduced or lost in 71 percent of ductal carcinomas in situ (abnormalities that can develop into breast cancer).
Sequence analysis of 55 primary breast tumours obtained from The University of Texas M. D. Anderson Cancer tumor bank also showed that 13 percent contained genetic alterations in DEAR1.
Also, the researchers found that DEAR1 expression was frequently lost in women with early-onset breast cancer and the loss of DEAR1 expression correlated with a strong family history of breast cancer and with a breast cancer subtype that has a poor outcome.
At 5-year follow-up of a cohort of 123 pre-menopausal women with onset of breast cancer between the ages of 25 and 49 years, DEAR1-positive expression correlated significantly with a 95 percent local recurrence-free survival.
Although laboratory experiments may not necessarily reflect what happens in people, the researchers said that these findings "indicate that DEAR1 expression is an independent predictor of local recurrence in early-onset breast cancers and suggest that DEAR1-negative staining on immunohistochemistry could be an important marker to stratify early-onset breast cancer patients for increased vigilance in follow-up and adjuvant therapy."
The study research has been published in this week's PLoS Medicine.