Can more radiation help?

This study focused on the effectiveness of thoracic radiotherapy in treating extensive stage small-cell lung cancer.

Small-cell lung cancer (SCLC) is a fast growing cancer that has a tendency to spread to other parts of the body like the brain, liver and bone. Often, SCLC has already spread to the brain even if there are no symptoms. As a result, patients who respond well to chemotherapy are given radiation directed at the brain to make sure there is no cancer there. This is called prophylactic cranial irradiation. However, often despite these treatments, the cancer can persist within the chest. Further treatment must focus on this area and this can be achieved through thoracic (chest) radiotherapy, which aims radiation at the cancer cells to kill them.

This study evaluated a total of 498 patients who were diagnosed with SCLC and responded well to chemotherapy. These patients were then divided into two groups; one that received thoracic radiotherapy in addition to cranial irradiation (247) and the other that received cranial irradiation alone called the control group (248). The main focus of the study was to look at the survival of patients after 1 year. 

The study found that at the end of 1 year, the overall survival rate between the two groups was very similar; 33% in the thoracic radiotherapy group compared to 28% in the control group. However, when the study further analyzed the data at 2 years, it was found that the overall survival was 13% in the thoracic radiation group compared to 3% in the control group. Progression was 27% less likely for the thoracic radiation group compared to the control group. The authors found that the percentage of patients who were cancer-free at 6 months was much higher in the thoracic radiotherapy group (24%) compared to the control group (7%).