ABSTRACT
PURPOSE: To investigate the prognostic relevance of disseminated tumor cells (DTCs) in bone marrow (BM) assessed by a multimarker mRNA panel consisting of TWIST1, cytokeratin 19 (CK19) and human mammaglobin A (hMAM) mRNA, in patients with early breast cancer. PATIENTS AND METHODS: TWIST1 (gene name: TWIST1), CK19 (gene name: KRT19), and hMAM (gene name: SCGB2A2) mRNA was quantitated in BM samples from 191 operable breast cancer patients by real-time reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Using the highest relative mRNA concentration of TWIST1 in the control population as a cut-off, 5 of the 191 breast cancer patients showed elevated TWIST1 mRNA levels in their BM by real-time RT-PCR. Two of these patients experienced a systemic relapse during a median follow-up of 98 months. Combining these results with previous hMAM and CK19 mRNA quantifications in the same BM samples, 12 (40%) of the 30 patients with BM positive for at least 1 marker (multimarker positive) experienced a systemic relapse as compared with 18 (11%) of the 161 patients with multimarker-negative BMs. The patients with multimarker-positive BM had significantly shorter systemic recurrence-free survival (P < .001, log-rank test), breast cancer-specific survival (P < .001), and overall survival (P = .03). The prognostic relevance of BM multimarker detection appeared to be independent of adjuvant treatment, although the difference was not statistically significant in the subgroup of patients who received adjuvant chemotherapy. Multivariate analysis demonstrated the BM multimarker panel status to be a strong independent predictor of clinical outcome. CONCLUSION: Our results demonstrated the prognostic relevance of BM DTCs assessed by a multimarker mRNA panel consisting of TWIST1, CK19, and hMAM in operable breast cancer patients.
Subject(s)
Biomarkers, Tumor/analysis , Bone Marrow/pathology , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Carcinoma, Lobular/pathology , RNA, Messenger/analysis , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/genetics , Bone Marrow/chemistry , Breast Neoplasms/genetics , Breast Neoplasms/mortality , Carcinoma, Ductal, Breast/genetics , Carcinoma, Ductal, Breast/mortality , Carcinoma, Lobular/genetics , Carcinoma, Lobular/mortality , Disease-Free Survival , Female , Gene Expression , Humans , Kaplan-Meier Estimate , Keratin-19/analysis , Keratin-19/genetics , Mammaglobin A , Middle Aged , Neoplasm Proteins/genetics , Nuclear Proteins/analysis , Nuclear Proteins/genetics , Prognosis , Proportional Hazards Models , Reverse Transcriptase Polymerase Chain Reaction , Twist-Related Protein 1/analysis , Twist-Related Protein 1/genetics , Uteroglobin/geneticsABSTRACT
PURPOSE: To study the prognostic significance of elevated cytokeratin 19 (CK19) mRNA levels in the bone marrow (BM) of operable breast cancer patients. PATIENTS AND METHODS: From 1998 to 2000, BM was collected from 195 consecutive breast cancer patients immediately prior to surgery and from 34 healthy volunteers. The patients received surgical and adjuvant treatment according to national guidelines at the time. We analyzed the level of CK19 mRNA in the BM samples from patients and normal controls using a real-time RT-PCR assay. The associations with known prognostic factors and the impact of pathological CK19 mRNA levels on patients' prognosis were investigated. RESULTS: Using the 99 percentile of the normal control group as a cut-off, 24 (12%) of the 195 patients and 1 (3%) of the 34 volunteers were diagnosed as CK19 mRNA positive. There was no correlation between CK19 BM status and the clinicopathological factors tested. During a median follow-up of 72 months, 7 (29%) of the 24 CK19 mRNA BM positive patients experienced systemic relapse compared to 20 (12%) of the 171 in the CK19 mRNA negative group. The patients with CK19 mRNA-positive BM had significantly shorter systemic recurrence-free survival (P=0.01) and overall recurrence-free survival (P=0.005). Multivariate Cox regression showed CK19 mRNA BM status to be an independent predictor of relapse. CONCLUSION: Detection of CK19 mRNA in the BM of breast cancer patients by real-time RT-PCR is an independent predictor of relapse-free survival in operable breast cancer patients.
