Patients with advanced non-small-cell lung cancer achieved a significant increase in survival time when tumor treating fields (TTF) therapy was added to their chemotherapy. In a single-arm, phase II study, physicians delivered TTF therapy, using the NovoTTF-100L from Novocure, to 42 patients with stage IIIb-IV metastatic NSCLC who had failed prior treatments. Patients in the study received TTF therapy for 12 hours a day in combination with pemetrexed (Alimta) every three weeks until disease progression. TTF therapy slows and reverses tumor cell proliferation by inhibiting mitosis. Patients treated with TTF plus pemetrexed had a median overall survival time of 13.8 months compared with 8.3 months reported for pemetrexed alone. The one-year survival rate for the combination was 57% vs 30% reported for pemetrexed alone (ESMO 2010 abstract 371PD).