Abscopal effect and resistance reversion in nivolumab-treated non-small-cell lung cancer undergoing palliative radiotherapy: a case report

Abscopal effect has been mentioned for a long time, but only recently a deeper knowledge about underlying mechanisms supporting the interaction between immune system and radiation therapy became available. Furthermore, the introduction of immune-checkpoint inhibitors makes appealing the idea of combining them with radiotherapy (RT) to elicit abscopal effect and ideally revert an intrinsic or acquired resistance. Herein, we present the case of a non-small-cell lung cancer patient undergoing, during second line nivolumab, palliative RT on thoracic wall lesion, achieving a complete response in the metastatic adrenal site. This case report suggests that the abscopal effect exists in clinical practice of lung cancer care likely due to a synergism between immune-checkpoint and RT, even when administered with a palliative intent.Lay abstract Our case report highlights the possible value of adding palliative radiotherapy (RT) to immunotherapy treatment in clinical practice. This combination, which has extensively proved to be well tolerated, could guarantee patients with advanced lung cancer to obtain responses on metastatic lesions not directly treated with RT, based on the activation of the immune system induced by RT/immunotherapy. This finding could allow to improve the immunotherapy-derived benefit, while maintaining a good quality of life.