Better Survival with Microwave Treatment in Lung Cancer

Microwave ablation plus chemotherapy in advanced non-small cell lung cancer patients produced better survival than chemotherapy alone, as reported on 4 February 2020 in European Radiology by Zhigang Wei and colleagues.

What Is Microwave Ablation?

Microwave ablation is an interventional radiology technique in which high-frequency electromagnetic waves move water molecules within tissue, generating heat and destroying the tumor. Tumors in conductive tissues such as liver and soft tissue and relatively conductive tissues such as lung and bone can be destroyed using this method.

The development of microwave ablation has paralleled that of the microwave heaters used in our everyday kitchens. Waves generated through needles, or antennas, make tissue water molecules oscillate, and friction between these molecules produces temperatures of 80-100 degrees in tumor tissue. The heat kills cancerous tissue in an area approximately 3-4 cm in diameter around the needle. This area may increase or decrease somewhat depending on ablation duration and the type and number of needles. Microwave ablation delivers electromagnetic waves rather than electricity to tissue.

A Phase-III Clinical Trial Testing Microwave Ablation in Lung Cancer

Current treatment for advanced (stage 4, metastatic, inoperable) lung cancer can be summarized as: platinum-based doublet chemotherapy, targeted drugs for sensitizing mutations or new-generation immunotherapies. However, approaches meaningfully improving survival are needed for patients suitable only for chemotherapy.

Study Design

• A multicenter, randomized, controlled, open-label phase 3 clinical trial.
• The study enrolled patients with metastatic (stage 4) or inoperable (stage 3B) non-small cell lung cancer.
• Patients were divided into two groups: the experimental arm received microwave ablation followed by chemotherapy (148 patients), and the control arm received chemotherapy alone (145 patients).
• The median diameter of microwave-treated tumors was 3.6 cm (range 1 cm to 13 cm).
• The study was funded by the National Health and Family Planning Commission of the People's Republic of China.

Main Results

• Median progression-free survival was significantly better in the microwave group: 10.3 versus 4.9 months. Progression risk was reduced by %56.
• Median overall survival was significantly better in the microwave arm: compared with 12.4 months in the control arm, median overall survival had not yet been reached because more than half the microwave-arm patients remained alive. The risk of death was reduced by %62.
• Objective response rates were similar between groups.
• Complete tumor ablation, destruction, was achieved in % 89 of the microwave group. There was local progression in 27 patients.
• Overall adverse effect frequencies were similar between groups.
• In the microwave group, % 76 reported ablation-related adverse effects, of which% 20 were severe. There were no treatment-related deaths in either group.

Conclusion

In advanced non-small cell lung cancer, microwave ablation plus chemotherapy produced better survival than chemotherapy alone. Ablation also did not increase adverse effect frequency. Microwave ablation is therefore considered a meaningful and beneficial treatment option for patients with advanced lung cancer.