Prospective Study on Surface-enhanced Laser Desorption/Ionization Protein Fingerprinting for Diagnosing Gene Polymorphism Leading to Drug Resistance Drift: Sequential Therapy with a Platinum-based Regimen and Gefitinib for Non-small Cell Lung Cancer

Background and objective This study aims to observe the long-term effects of sequential therapy with a platinum-based regimen and gefitinib for non-small cell lung carcinoma (NSCLC) with failed chemotherapy under the guidance of surface-enhanced laser desorption/ionization (SELDI). Methods Nine NSCLC patients with failed chemotherapy and ≤15% abundance of M/Z: 8,693±50H+ were selected. The patients were administered with 250 mg of gefitinib (p.o., once a day). During the therapy, SELDI was applied every 2 months. If the M/Z: 8,693±50H+ abundance was >25%, chemotherapy was applied; if the abundance was ≤15%, gefitinib (p.o.) was applied. In between, we chose gefitinib according to the mass and tumor markers. On the base, we sequentially applied the drug and observed the total survival time. Results Follow-ups until December 2010 revealed that the median overall survival time of the nine patients was 27 months (10 months-66 months). Conclusion The treatment benefit ratio and benefit time of anti-NSCLC drugs can be improved by SELDI fingerprinting.