Abstract
INTRODUCTION: The association between the risk of latent tuberculosis infection (LTBI) reactivation and immune checkpoint inhibitor (ICI) administration has been reported. CASE PRESENTATION: A man in his seventies underwent robot-assisted laparoscopic radical cystectomy with ileal conduit diversion for muscle-invasive bladder cancer. Three years postoperatively, CT revealed metastases to the para-aortic lymph nodes and rectum. Four cycles of gemcitabine and carboplatin were administered, with CT showing a partial response (PR). Avelumab maintenance therapy was initiated following radiotherapy for the rectal metastasis. Prior to avelumab administration, LTBI was diagnosed based on a positive interferon-gamma release assay (IGRA). Isoniazid was administered concurrently with avelumab for 6 months. No active tuberculosis developed, and PR was maintained. CONCLUSION: IGRA screening is advisable prior to ICI initiation. Prompt and appropriate management is warranted in patients with LTBI.