Lung cancer with diabetes mellitus and polymyalgia rheumatica during long?term nivolumab treatment: A case report

A 54-year-old man was referred to Kainan hospital (Yatomi, Japan) in June 2014 with a chief complaint of right hip pain. Computed tomography showed a pelvic tumor and a nodule in the right upper lobe of the lung. After transbronchial lung tumor biopsy and full-body screening, the patient was diagnosed with stage IV lung cancer. Epidermal growth factor receptor mutation and anaplastic lymphoma kinase fusion gene were not detected, and programmed cell death ligand 1 was negative. From July 2014, while undergoing radiotherapy to the right pelvic region, the patient also received combination therapy with carboplatin, paclitaxel and bevacizumab. The patient subsequently received pemetrexed monotherapy and docetaxel monotherapy, as well as radiotherapy, for right adrenal metastasis. From February 2019, the patient was administered nivolumab, which was effective, but 3 years and 3 months after the start of nivolumab treatment, he developed diabetes mellitus and insulin therapy was started. Then, 4 years and 5 months after the start of nivolumab, the patient developed polymyalgia rheumatica and was treated with prednisolone. The present study reports a rare case of diabetes mellitus and polymyalgia rheumatica in a patient with lung cancer who had received nivolumab treatment for more than 4 years.