[Diagnosis and management of interstitial lung disease induced by antibody-drug conjugates in breast cancer: A French expert opinion paper]

Interstitial lung disease (ILD) has been reported with many cancer drugs including some recent antibody-drug conjugates (ADCs). The mechanisms of ILD induced by many chemotherapy drugs, other drug classes and ADCs used in cancer, including breast cancer, are not clearly elucidated. In the absence of specific clinical or radiological signs, the diagnosis of drug-induced ILD is often a diagnosis of exclusion. When present, the most frequent symptoms are respiratory signs (cough, dyspnea, chest pain) and general signs (fatigue, fever). Any suspicion of ILD should be evaluated by imaging and, if in doubt, the CT scan should be evaluated by a pulmonologist and a radiologist. A network of multidisciplinary experts for proactive early management of ILD is important, including oncologist, radiologist, pulmonologist, infectious disease specialist and nurses. Patient education is essential to report new or exacerbated lung symptoms and prevent high-grade ILD. Study drug is discontinued temporarily or permanently according to ILD severity and type of ADC. For asymptomatic cases (Grade 1), the efficacy of corticosteroids is not clearly established; for higher grades, the benefit/risk balance of long-term corticosteroid therapy should be considered for the dose and treatment duration. Hospitalization and oxygen supplementation are required for severe cases (Grades 3-4). For patient follow-up, the expertise of a pulmonologist is necessary with repeated chest scans, spirometry and DLCO. Preventing ADC-induced ILDs and evolution to high grade rests on a network of multidisciplinary experts for assessment of individual risk factors, early management, close follow-up and patient education.