A CASE OF LOMUSTINE-INDUCED PNEUMONITIS

ABSTRACT

SESSION TITLE Drug-Induced Lung Injury and Disease SESSION TYPE Rapid Fire Case Reports PRESENTED ON 10/18/2022 0135 pm - 0235 pm INTRODUCTION: Lomustine, a nitrosurea, inhibits DNA, RNA, and protein synthesis by carbamylation and alkylation, leading to cytotoxic effects 1, 3. Its concentration is high in the central nervous system (CNS) and therefore is commonly used for the management of CNS tumors including recurrent glioblastoma. While known side effects include pancytopenia, few pulmonary toxicities have been reported. This case is a rare example of lomustine induced pneumonitis. CASE PRESENTATION A 54-year-old female with a history of glioblastoma, treated with a combination of surgical resection, radiation therapy, and temozolomide followed by stereotactic surgery and bevacizumab after disease recurrence, developed progressive dyspnea after initiating lomustine. She had received one dose of lomustine 90 mg/m2 two months prior to developing dyspnea upon exertion. At baseline, she was an active individual who played sports. A chest computed tomography (CT) scan preformed ten months prior was without any parenchymal abnormalities, and pulmonary function tests (PFTs) two months prior were normal with an adjusted DLCO of 15.4 mL/mmHg/min (88%). Repeat chest CT revealed diffuse ground glass opacities, and repeat PFTs showed a moderately impaired adjusted DLCO of 10.4 mL/mmHg/min (60%). Other lab evaluation, CBC, BNP, troponin, and COVID PCR, were negative. After receiving six weeks of steroids, there was resolution of CT findings, improvement of DLCO, and relief from symptoms. DISCUSSION: More common adverse effects of lomustine are GI discomfort and pancytopenia. It is less widely documented to cause pulmonary toxicity compared to its chemical relative carmustine 1, 3. This is perhaps due to decreased alkylation ability and penetration into the lung tissue by lomustine7. There have been few case reports revealing pneumonitis and pulmonary fibrosis. Lomustine induced pneumonitis induces acute parenchymal changes of the lung demonstrated by characteristic symptoms and imaging/biopsies abnormalities after initiation of a drug. 2 Findings include breathlessness, dyspnea upon exertion, cough, hypoxia, crackles upon lung auscultation. PFT's may show a restrictive pattern with decreased FEV1/FVC ratio and DLCO. Imaging may reveal diffuse groundglass opacities, traction bronchiectasis, interlobular septal thickening, and honeycombing. Bronchoscopy with lavage would rule out infection. Management involves discontinuation of culprit medication, immunosuppression, and supportive therapies to alleviate respiratory discomfort. Lack of treatment may produce complications of acute respiratory distress syndrome and fibrosis. CONCLUSIONS: Lomustine is an essential treatment drug for recurrent CNS tumors. Toxicities such as pneumonitis have been rarely demonstrated. Timely recognition of pneumonitis features is key to treat this complication, improve quality of life, and prevent permanent lung compromise. Reference #1 Dent RG. Fatal pulmonary toxic effects of lomustine. British medical journal. 1982;DOI10.1136/thx.37.8.627 Reference #2 Skeoch S, Weatherley N, Swift AJ, Oldroyd A, Johns C, Hayton, C, et al. Drug-Induced Interstitial Lung Disease A Systemic Review. Journal of Clinical Medicine. 2018;doi 10.3390/jcm7100356 Reference #3 Weiss RB, Issell BF. The nitrosureas carmustine and lomustine. Cancer treatment reviews. 1982;https//doi.org/10.1016/S0305-7372(82)80043-1 DISCLOSURES No relevant relationships by Sukhdeep Kaur No relevant relationships by Chelsea Kennedy-Snodgrass No relevant relationships by Sarun Thomas