A new study looking at low dose radiation and immunotherapy is showing promising results for non-small cell lung cancer. Patients treated with the combination had higher progression free survival compared to patients who received immunotherapy alone. Research was completed at Weill Cornell Medicine, NewYork-Presbyterian as well as at Columbia University Vagelos College of Physicians and Surgeons. This gives hope to people struggling with NSCLC, which is the most common form of lung cancer in the United States. Chemotherapy is typically used alongside immunotherapy for the treatment of lung cancer. The study hypothesized that adding low dose radiation instead could increase options available to patients, especially in people who cannot tolerate chemotherapy.
A previous study led by NewYork-Presbyterian/Weill Cornell Medical Center had 60 patients with early-stage NSCLC. The phase 2 randomized clinical trial combined radiation and durvalumab, an immune checkpoint inhibitor. These types of drugs work by releasing checks and balances of the immune system to allow it to attack tumor cells. Using a low dose of radiation to enhance the immune response was a novel feature of the trial and made it unique compared to other trials.
Findings of the study were published in Lancet Oncology in 2021. Results showed that the combination treatment eradicated significantly more tumors than immunotherapy alone. The treatment was so effective that it invoked a “major pathological response,” with the death of more than 90 percent of the cells in the tumors that were surgically removed and analyzed during the study.
Researchers also wanted to see if the treatment combination improved patient survival. To do this, patients were followed for another two years. The extended study revealed that the combination treatment reduced the chance of cancer recurrence and extended progression-free survival. Six patients who only received immunotherapy died of cancer. The dual therapy group on the other hand had only one death from cancer while the rest died from causes unrelated to cancer recurrence.
Researchers also found that cancer free survival came alongside heightened immune activity. People who received immunotherapy and radiation had better responses and more T cells in their blood compared to those who did not receive a major pathology response. The activated T cells were associated with freedom from cancer recurrence. Researchers found that patients with major pathological responses had tissue-resident T cells in their blood, even before treatment began in some instances. This points to the immune system recognizing the cancer and initiating a response. This could mean that examining the T cell makeup of an individual could help determine if a patient would benefit from combination treatment.
The researchers will follow this study up with a trial to see how radiation compares to chemotherapy in improving immunotherapy. Radiation has proven to work, but now researchers want to find out how well it works compared to chemotherapy.
This research could one day benefit those with mesothelioma. Mesothelioma is a hard cancer to treat and in the case of pleural mesothelioma, right next to the lungs. Radiation alongside immunotherapy has not been tested on mesothelioma patients yet, but if it works well for NSCLC, one day the same treatment could be used to benefit mesothelioma patients.
