Quantitative Multi-gene Fluorescence In Situ Hybridization To Detect Cell Cycle Gene Copy Number Aberrations In Young Breast Cancer Patients

Objective:1. To discover cell cycle related gene copy number aberrations (CNAs) in young breast cancer patients and old breast cancer patients via QM-FISH (Quantitative Multi-gene Fluorescence In Situ Hybridization).2. To analyze the relationship between gene CNAs and the clinical pathological characteristics of young and old breast cancer patients.3. To evaluate the CNAs in the prognosis prediction and find out specific genes which related with the prognosis, and thus to provide the prognosis judgment and even the therapy target.Methods:1. This research selected196young female breast cancer patients (age<35) and227old female breast cancer patients (age>65) with definite pathological diagnosis by Tianjin Medical University Cancer Institute&Hospital from January2006to December2007. The excised tumor paraffin pathologic specimens and pathologic testing results were selected from the two groups. We employed QM-FISH to detect copy number aberrations of gene CCND1, gene Rb1, gene c-Myc and gene CHEK2, which were labeled with4fluoresceins:PromoFluor-415-aadUTP (Blue) PromoFluor-555-aadUTP (Orange)、PromoFluor-590-aadUTP (Red)、Green dUTP (Green), between young breast cancer patients and old breast cancer patients.2. The SPSS17.0statistic software and Graphpad6.0were applied to analyze the data. Comparisons of baseline characteristics between groups were made using chi-square tests for categorical variables. Kaplan-Meier Survival Analysis and the Cox proportional hazards model were applied to the Prognosis Survival Analysis. P-values less than0.05were considered statistically significant.Results:1. Young breast cancer patients always had bigger tumors (P=0.028) and were easier to have lymph node metastasis (P=0.009), as well as family history (P=0.026). The comparison among the molecular subtypes showed that there were more TNBC in young breast cancer patients than that in old breast cancer patients, the percentage were18.4%and10.6%, respectively.2. Gene copy number aberrations(CNAs) of Rb1, CHEK2and c-Myc were related with young age (P=0.000,0.000,0.000, respectively), however, the CNAs of CCND1was not related with young age(P=0.891). In the young breast cancer patients, the CNAs of Luminal A, Luminal B and TNBC subtype were related with young age (P=0.000,0.000,0.003), however, the CNAs were not related with young age in the Her-2overexpression subtype (P=0.142).3. Young breast cancer with gene CCND1amplification and gene Rbl deletion had a worse prognosis (P<0.001); old breast cancer patients with gene c-Myc amplification had a worse prognosis (P<0.001); however, both group with gene CHEK2deletion had a worse prognosis (P<0.001). In the Cox analysis, gene CHEK2, ER positive, Ki67, molecular subtypes, lymph node metastasis were the independent prognostic factors of5-DFS (P=0.014, HR=2.111,95%CI:1.166-3.822; P=0.024, HR=0.520,95%CI:0.295-0.918; P=0.044, HR=1.894,95%CI:1.018-3.524; P=0.039, HR=1.942,95%CI:1.003-4.931; P=0.000, HR=9.348,95%CI:3.625-24.106); Ki67, molecular subtypes and lymph node metastasis were the independent prognostic factors of5-OS (P=0.079, HR=2.069,95%CI:0.920-4.657; P=0.042, HR=1.975,95%CI:1.002-3.962; P=0.001, HR=26.294,95%CI:3.534-195.610).Conclusion:1. The tumor of young breast cancer patients not only had a higher degree of malignancy but aslo a higher frequency of metastasis and recurrence, which were related with the worse prognosis.2. The CNAs of Rbl, CHEK2and c-Myc happened more frequently in the young breast cancer patients. The CNAs of Luminal A, Luminal B and TNBC subtype were related with young age.3. These4cell cycle genes’(CCND1、Rb1、c-Myc、CHEK2) copy number aberrations provided a prognostic judgment for breast cancer patients.