Correlation of cyclin D1 MRNA levels with clinico-pathological parameters and clinical outcome in human breast carcinomas

Abstract

In order to evaluate the prognostic significance of cyclin D1 mRNA expression in mammary neoplasia, its levels were measured in 97 breast cancers by reverse transcription-polymerase chain reaction (PCR) using fluorescent primer and standard RNA along with estrogen receptor (ER). The median value of cyclin D1 mRNA was 1.60 amol/microg RNA (range, 0.01 to 5.63 amol/microg RNA). ER mRNA was detectable in 70 breast cancer samples (72.2%) and cyclin D1 mRNA levels were significantly higher in ER mRNA-positive than in ER mRNA-negative tumors (p = 0.009). Furthermore, cyclin D1 mRNA levels were significantly (p = 0.001) lower in patients who experienced a recurrence during the follow-up period (mean of 40.8 months, median of 39 months) compared with those with no evidence of recurrent disease (mean of 49.2 months, median of 48 months), and in those who died from disease (mean follow-up period of 30.5 months, median of 26 months) than in the survivors (mean of 50.5 months and median of 48 months) (p = 0.005). Setting the median value (= 1.60 amol/microg RNA) as the cutoff point, expression was significantly associated with relapse-free survival (p = 0.002). Similarly, a significant correlation was observed between the cyclin D1 mRNA level and overall survival (p = 0.015). The expression was found to be an independent factor for predicting relapse-free survival using multivariate analysis.