Bystander effect and abscopal effect in recurrent thymic carcinoma treated with carbon-ion radiation therapy: A case report

Abstract

BACKGROUND Although the bystander effect and abscopal effect are familiar in medicine, they are relatively rare in clinical practice. Herein, we report the case of a patient who demonstrated an obvious bystander effect and abscopal effect response following carbon-ion irradiation for recurrent thymic carcinoma. CASE SUMMARY A 44-year-old female presented with shortness of breath. Eleven years prior, she was diagnosed with athymic tumor located in the anterosuperior mediastinum. She underwent extensive tumor resection, and the postoperative pathologic diagnosis was thymic carcinoma. She was administered 50 Gy/25 Fx of postoperative radiation. In 2019, she was diagnosed with a recurrence of thymic carcinoma, with multiple recurrent nodules and masses in the left thoracic chest and peritoneal cavity, the largest of which was in the diaphragm pleura proximal to the pericardium, with a size of 6.7 cm × 5.3 cm × 4.8 cm. She received carbon-ion radiotherapy. After carbon-ion radiotherapy treatment, the treated masses and the untreated masses were observed to have noticeably shrunk on the day of carbon-ion radiotherapy completion and on follow-up imaging. We followed the CARE Guidelines for consensus-based clinical case reporting guideline development and completed the CARE Checklist of information to report this case. CONCLUSION This report is the first of obvious abscopal and bystander effects following carbon-ion irradiation in a human patient, and further research is needed to better elucidate the mechanisms of bystander and abscopal effects.

Abscopal effect with unknown fever during radiotherapy: Two case reports

“…However, the number of reports of an abscopal effect in patients treated with a combination of radiotherapy and ICI has increased [7][8][9][10][11][12][13][14][15]. Only in one year of 2021, 21 case reports of abscopal effect promoted after radiotherapy were yielded [13,[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. This is thought to be due to T-cell activation by a damage signal from irradiated dying cells and upregulation of Programed death receptor-1 (PD-1) and programed cell death 1-Ligand 1 (PDL-1) [36,37], and an ICI disarms immune escape mechanisms, and this may increase the effects of the innate immune response activated by radiotherapy.…”

Understanding the Photodynamic Therapy Induced Bystander and Abscopal Effects: A Review

“…There were 46 case reports published between 1969 and 2014 regarding multiple different primary tumors, ranging from melanoma to cholangiocarcinoma and renal cell carcinoma, showing non-irradiated, distant responses, usually occurring two months after radiation. This effect is only well studied with respect to radiotherapy [83][84][85][86]. The abscopal effect in PDT was first noted in the 1990s when researchers noticed that, in animal models, treating a single tumor with PDT could cause distant tumors to regress [87].…”

Microwave ablation enhances the systemic immune response in patients with lung cancer

“…Irreversible electroporation induces abscopal effects by increasing the infiltration of specific T cells and enhancing specific immune memory ( 19 ). In addition, both radiotherapy ( 20 ) and heavy ion therapy ( 21 ) may modulate occurrence of immune-induced abscopal effects.…”