Expression of P-glycoprotein, NUCLEAR FACTOR KAPPA B AND PROPORTION OF CANCER STEM CELLS ALDH1-POSITIVE as predictors KEMORESISTENSI
ABSTRACT: Introduction Locally advanced breast cancer is still a health problem, either in developed or developing countries. The role of neoadjuvant chemotherapy has been well known, but there was still nonoptimal response due to chemoresistance mechanism. Range of mechanisms involved in chemoresistance included overexpression of ATP binding cassette (ABC) transporter, apoptosis dysregulation, and possibly the excessive number of cancer stem cells. Chemoresistance process might involve more than one mechanism mentioned. Objective This study aimed to reveal the effect of P-glycoprotein, NF-κB, and ALDH1 expression simultaneously towards pathological response after administration of neoadjuvant chemotherapy FAC regiment, towards recurrence and survival, as well as if it correlates with other predictive/ prognostic factors. Material and methods This was a kohort study. Advanced local stage invasive ductal breast cancer patients were administered with neoadjuvant chemotherapy regiment FAC (Fluorouracil 500 mg/m2-Doxorubicin 50 mg/m2-Cyclophosphamide 500 mg/m2 on the first day of each three-week cycle) in 2008-2011. From incisional biopsy paraffin blocks, the histological grade, nuclear grade, lymphovascular invasion, expression of estrogen, progesterone, HER-2/neu, and KI-67 receptors were examined. Then further immunohistochemical examination for P-glycoprotein, NF-κB, and cancer stem cells ALDH1-positive intratumoral expressions were conducted. From mastectomy paraffin blocks, the pathologic response was also examined. Furthermore, they were followed until the outcome emerged, that is the recurrence and mortality rate until December 2012. Research description was presented in tables and graphics. Chi square method was used for bivariate analysis, and Kaplan-Meier (log rank test) method was used for survival analysis with a significance level of p <0.05. Binary Logistic Regression was used for multivariat analysis for pathological response, whereas for the recurrence and survival outcome, Proportional Hazards (Cox) Regression was used. Results It was suggested that from 131 locally advanced invasive ductal breast carcinoma patients, mainly in the premenopausal age / <50 years (55%), mostly came with primary status cT4 (55%), and the lymph nodes status cN1 (56.5%). Molecular subtypes of triple-negative was the most widely found (38.2%). After neoadjuvant chemotherapy regiment FAC, 87% of patients achieved clinical partial response (cPR) and whilst 88.5% achieved objective response (complete and partial response). Pathological complete response was achieved in 14.5% and major pathological response in 28.2 %. Only as much as 40.5% patients received adjuvant radiotherapy, and 43.5% received hormonal therapy. The most common recurrence location was local recurrence (25.9%), followed by lung (24.2%), and contralateral (13.8%). Variables significantly associated with pathological response was the expression of NF-κB (p = 0.02), while PGP and ALDH1 expression also have effect but it was insignificant (p = 0.15 and p = 0, 17). Other variables that significantly influence pathological response after neoadjuvant chemotherapy was lymphovascular invasion (p = 0.047) and Ki67 expression (p = 0,03). From the multivariate analysis, it was found that strong predictive factors of poor pathological response (no response and minor response) is positive Ki67 expression (RR 2.12; 95% CI 0.99 to 4.55), and premenopausal age (RR 1.87; 95% CI 0.87 to 3.99). The positive expression of PGP given RR = 1.67 (95% CI 0.75 to 3.72); expression of NF-κB positive given RR = 1.74 (95% CI 0.77 to 3.94), and positive ALDH1 expression given RR = 1.76 (95% CI 0.65 to 4.77). Variables significantly associated with the time of recurrence were NF-κB expression (p = 0.02), whereas ALDH1 expression took effect but it was insignificant (p = 0,19). PGP expression did not give effect to the time of recurrence (p = 0,86). Other variables that significantly influence the time of recurrence was lymphovascular invasion (p = 0,06), whereas histologic grade took effect but it was insignificant (p = 0,07). From the multivariate analysis, it was found that a strong predictor factor for recurrence was the expression of positive NF-κB (RR 2.00; 95% CI 0.95 to 4.12). Positive ALDH1 expression gives RR = 1.24 (95% CI 0.68 to 2.28). Variables significantly associated with survival were NF-κB expression (p = 0.04), whereas ALDH1 expression also had effect but it was insignificant (p = 0,25). PGP expression did not affect the time of recurrence (p = 0,84). Other variables that significantly affected the survival time was the lymphovascular invasion (p = 0.006), adjuvant hormonal therapy (p = 0.02), and recurrence (0.001). From the multivariate analysis, it was found that a strong predictor factor for the occurrence of death was recurrence (RR 2.77; 95% CI 1.24 – 6.18) and a positive lymphovascular invasion (RR 2.87; 95% CI 0.84 to 9.84). Whilet he expression of positive NF-κB given RR = 1.27 (95% CI 0.45 to 3.64). Variables significantly associated with PGP, NF-κB, and ALDH1 expression were age, lymphovascular invasion, molecular subtypes, and HER2 expression. Conclusion Expression of NF-κB significantly influenced pathological response, recurrence, and survival. Whereas ALDH1 expression offered no significant influence. Pgp expression apparently only affected pathological response although not significant. There was correlation between the expression of P-glycoprotein (PGP), Nuclear factor kappa B (NF-κB), and ALDH1 with age at diagnosed, lymphovascular invasion, molecular subtypes, and HER2 expression.
