The value of expression of EGFR, telomerase and topoisomerase II alpha in malignant effusion smears before and after chemotherapy

Purpose: To evaluate the significance of expression of epidermal growth factor receptor (EGFR), telomerase and topoisomerase II alpha (topo II alpha) in cells of malignant effusions of patients under chemotherapy. Methods: We studied the expression of EGFR, telomerase and topo II alpha in malignant effusion smears of 95 cancer patients before and after chemotherapy Immunocytochemical and in situ hybridization techniques were applied. Results: Positive expression before chemotherapy of telomerase, topo II alpha and EGFR was found in 64.2, 63.2 and 69.5% of the cases, respectively; the expression of these markers following chemotherapy was 43.6, 28.2 and 53.8%, respectively. The stronger prognostic factor affecting survival before chemotherapy was telomerase (p=0.0002), whereas after chemotherapy the strongest factor was EGFR (p<0.0001). A positivity for all three markers following chemotherapy was associated with shorter survival compared with positivity for only 1 or 2 markers (p<0.0001) or with a negative expression. Conclusion: It seems that expression of EGFR, telomerase and topo II alpha in malignant effusion smears is adversely affecting prognosis and survival.