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(Drug information on 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).