Profile of mRNA Expression of Ki-67 in Breast Cancer Patients Pre- and Post- Chemotherapy

Background: Proliferation is a distinct hallmarks of cancer. Ki-67 designated as a marker of proliferation in solid tumors. The proliferative activity of tumor demonstrated by expression of Ki-67 in breast cancer has been associated with a poor prognosis. Changes in the relative proportions of Ki-67 can be observed during chemotherapy and may correlated with clinical response in breast cancer. Purpose: Evaluate changes in mRNA expression of proliferation marker Ki-67 in breast cancer patients pre- and post-chemotherapy in relation with clinical response to chemotherapy. Method: This is a longitudinal study, 30 subjects breast cancer tissue samples pre- and post-chemotherapy using cyclophosphamide, adriamycin, 5FU regiment. We using qRT-PCR techniques to detect mRNA expression of Ki-67. Chemotherapy response is calculated using RECIST criteria. Results: Mean value of Ki-67 mRNA expression on breast cancer patients pre-chemotheraphy was 11.837±0.360. Mean value of Ki-67 mRNA expression on breast cancer patients post-chemotheraphy was 11.241±1.971. There was no significant correlation between expression of Ki-67 mRNA prechemotherapy with clinical response to chemotherapy, p = 0.862 ( p ≥0.05). There is a positive correlation between velocity of Ki-67 mRNA expression with clinical response with value of r = 0.378, this correlation was significant with p = 0.020 ( p <0.05). Conclusion: Chemotherapy cause decrease in mRNA expression of Ki-67. There is insignificant correlation between expression of mRNA Ki-67 baseline with chemotherapy response. Velocity of Ki-67 mRNA expression has significant correlation with clinical response to chemotherapy.