Expression of C-myc and β-catenin and their correlation in triple negative breast cancer.

Background: The present study was planned to study the expression of C-myc and β-catenin in triple negative breast cancer (TNBC) tissue. Furthermore, their relations to clinical features of the tumor and the survival prognosis were also studied. Additionally, correlation was evaluated between the expression of C-myc and β-catenin to provide the theoretical basis for the targeted therapy of TNBC.

Methods: Sixty cases of patients diagnosed with TNBC for the first time were selected for the study. The immumo-histochemical staining was employed to detect the positive expression rates of C-myc and β-catenin in cancer tissues and normal mammary tissues 3 cm away from the carcinoma. Fluorescence in situ hybridization (FISH) was used to test the gene amplification of C-myc in order to analyze the relation between C-myc and the protein expression of β-catenin. Further, kept the median follow-up time to 25.0 months in order to compare the survival prognosis.

Results: The positive expression rates of C-myc and β-catenin in cancer tissues were significantly higher than those in precancerous normal tissues (P<0.05). Furthermore, the expression rates were related with the diameter of tumor, clinical staging, pathological grading and lymphatic metastasis (P<0.5). There were 33 cases that exhibited an increase in C-myc gene copy number and the gene amplification was observed to be 55% in total. On the other hand, patients with positive expression of C-myc and β-catenin protein exhibited a shortened disease-free survival without tumor with an increasing recurrence rate and lower survival rate (P<0.05).

Conclusions: The present study concludes that the positive expression of C-myc and β-catenin in TNBC tissue might be closely correlated with clinical features of cancer and the survival prognosis.