Background: The associations between B-cell lymphoma 2 (BCL-2) and multi-drug resistance associated P-glycoprotein (MDR1) expressions and chemoradiotherapy outcome of patients with non-small cell lung cancer (NSCLC) were analysed.
Patients and methods: Thirty-two NSCLC patients were treated with paclitaxel-based chemoradiotherapy. The tumour expressions of BCL-2 and MDR1 were analysed by means of immunohistochemistry with regard to the clinical response and survival data.
Results: Partial remission and stable disease were achieved in 19 (59%) and 10 (31%) cases, respectively. Significant differences in progression-free survival were observed between responders and non-responders (13.7 vs. 6.0 months, p=0.028), and between patients with or without a gross tumour volume (GTV) shrinkage (GTV(>50) 13.7 vs. 6.0 months, p=0.009). Overexpression of BCL-2 and of MDR1 was observed in 6 (21.4%) cases each. Overexpression of both markers together was associated with poor response (GTV reduction: p=0.005; RECIST: p=0.023) and lower progression-free survival (overexpression of both, low expression of both, mixed: 3.1, 13.4, 4.1 months, respectively, p<0.001).
Conclusion: BCL-2 and MDR1 overexpression may predict the inefficacy of paclitaxel-based chemoradiotherapy.