Microsatellite polymorphisms in the EGFR, NOTCH4 and E2F4 genes and their association with breast cancer risk

The sequences of many human genes that encode proteins involved in cancer contain polymorphic microsatellites. Variations in microsatellite length may constitute risk factors in several human diseases, a possibility that has been little explored in breast cancer. Among the genes that contain polymorphic microsatellites are EGFR, NOTCH4 and E2F4. The length of some of these microsatellites has been associated with breast cancer risk.

To determine whether the length of the microsatellites (CA)n in EGFR, (CTG)n in NOTCH4 and (AGC)n in E2F4 was associated with breast cancer risk, we genotyped these 3 microsatellites in 212 women with breast cancer and a control group of 308 women from the general population who did not have this disease.

The allelic distribution observed for the 3 microsatellites matched that found in other white populations, with the exception of some (AGC)n alleles in E2F4, which have not been described previously. The length of (CA)n in EGFR and (CTG)n in NOTCH4 was not associated with breast cancer (OR=0.99; 95% CI 0.59-1.37; p=0.619 and OR=1.08; 95% CI 0.71-1.65; p=0.725, respectively). Short alleles (<13 repeats) of (AGC)n in E2F4 were less frequent in women with cancer than in the control sample.