Does Pulmonary Fibrosis Increase the Risk of Pneumonitis Related to Anti–PD-1 Treatment?
Posted: Wednesday, December 19, 2018
In response to anti–PD-1 immunotherapy, patients with preexisting pulmonary fibrosis have a significantly higher risk of pneumonitis than those without fibrosis, according to a retrospective analysis published in Lung Cancer. Teppei Yamaguchi, MD, of the Aichi Cancer Center Hospital, Japan, and colleagues noted that further studies are necessary “to identify predictive factors of anti–PD-1–related pneumonitis in patients with fibrotic changes on computed tomography findings.”
The study focused on 123 patients at the Aichi Cancer Center Hospital who had a chest computed tomography (CT) scan in the 6 months before receiving treatment with anti–PD-1 antibodies (nivolumab or pembrolizumab). Two diagnostic radiologists examined the CT images and assigned patients a fibrosis score on a scale from 0 to 5 and an emphysema score on a scale from 0 to 4. Patients were excluded from the study if they had received chemotherapy between the CT scan and immunotherapy or if they had received thoracic radiotherapy to the primary lesion, mediastinum, spinal, or rib metastases.
Dr. Yamaguchi and colleagues found that a fibrosis score of 1 or more was a significant risk factor for pneumonitis, but the emphysema score did not seem to affect the risk. Of the 37 patients with a fibrosis score of 1 or more, 35% experienced pneumonitis associated with anti–PD-1 treatment. However, of the 86 patients with a fibrosis score of 0, 6% experienced pneumonitis.
The authors proposed that additional studies are needed to elucidate the relationship between fibrosis, which is often associated with a history of smoking, and changes to the lung during anti–PD-1 treatment.