How safe and effective is prophylactic cranial irradiation in patients with extensive stage small cell lung cancer?

This study evaluated the effectiveness and safety of prophylactic cranial irradiation (PCI) in patients with extensive stage (ES) small cell lung cancer (SCLC). The data indicated that PCI may decrease the occurrence of brain metastases in patients with ES-SCLC and improve 1-year survival time, without improving the overall survival rate.

SCLC is a type of lung cancer that is characterized by rapid cell multiplication and a higher risk of spread (metastases) from the lung to other areas of the body. Over 70% of these patients are diagnosed at ES. During ES-SCLC, the cancer has progressed beyond the lung region, extending to other areas of the body including the lymph nodes and brain. Patients with ES-SCLC typically receive 4 to 6 courses of cisplatin-containing chemotherapy, usually with short-term responses. Additionally, some first-line therapies cannot cross the blood-brain barrier (BBB; specialized, selective cells) to gain access to the brain.

PCI is a technique that has been successfully used to prevent the spread of highly aggressive but early cancers without brain involvement. Some studies have shown promising results for its application in limited-stage SCLC. However, the effectiveness of PCI in preventing the spread to the brain and increasing patient survival time remains unknown for patients with ES-SCLC.

This study involved 1,623 patients with ES-SCLC from 15 studies. Patients were assigned to a PCI group or a non-PCI group. 

Patients treated with PCI showed a significant decrease in the occurrence (by 43%) of brain metastases compared to non-PCI patients. PCI-treated patients had a 46% higher 1-year survival rate compared to those who did not receive PCI.

However, there were no significant improvements in 2, 3, 4, and 5-year survival rates between patients in the PCI and non-PCI groups.

More patients in the PCI group experienced fatigue, skin inflammation, loss of appetite, nausea, vomiting, discomfort, and a loss of mental function.

This study concluded that PCI may reduce the occurrence of brain metastases and improve 1-year survival in patients with ES-SCLC, however, there were no significant effects on overall survival.

This study included patients that received different chemotherapy treatments. Combined results from different trials were used to determine the effects of PCI treatment and did not include negative results which are less likely to be published.