Benefits of preventive radiation therapy to the head in stage III-N2 non-small cell lung cancer

The authors evaluated the benefits of preventive radiation therapy in patients with non-small cell lung cancer (NSCLC) who have high risk of developing brain metastases (spreading of cancer from the lungs to the brain).

NSCLC is the most common type of lung cancer, accounting for 85% of all lung cancers. In patients with stage III-N2 NSCLC the cancer has spread from the lungs to the nearby lymph nodes (tiny, bean-shaped organs that help fight infections) in the chest. Treatment of stage III-N2 NSCLC remains a challenge. A combination of therapies (surgery, radiation and chemotherapy) has become the standard treatment, but the risk of patients developing brain metastases is high.

Prophylactic cranial irradiation (PCI) is preventive radiation therapy to the head. PCI kills cancer cells that may have already spread to the brain but are not seen yet by scans. Previous studies showed that PCI lowered the occurrence of brain metastasis in locally advanced NSCLC (cancer that has grown outside the lungs but has not yet spread to distant parts of the body). However, no study has analyzed the effect of PCI on NSCLC patients with high risk of brain metastasis.

The authors evaluated the effect of PCI on overall survival and occurrence of brain metastases in NSCLC patients with high risk of brain metastases.

156 patients with stage III-N2 NSCLC with high risk of brain metastases were included in the study. All patients had previously undergone surgery to remove the tumors and had been treated with combination chemotherapy. None of the patients had relapse (return) of cancer at the beginning of the study. Patients were randomly assigned to receive either PCI (81 patients) or observation (75 patients). 

The average disease-free survival (survival without any sign or symptom of the cancer) was 28.5 months in the PCI group compared to 21.2 months in the observation group. There was a 72% reduced risk of developing brain metastasis in the PCI group. The average overall survival was 31.2 months in the PCI group and 27.4 months in the control group. PCI was well tolerated with mild adverse events including headache, nausea, vomiting and fatigue. 1% of patients had severe headaches and 2% of patients had severe fatigue. 

The authors concluded that PCI prolonged the disease-free survival and lowered the occurrences of brain metastases in stage III-N2 NSCLC patients with a high risk of brain metastases.

Talk to your doctor about whether you are at risk of brain metastasis and if PCI is an appropriate option for you.