Pulmonary fibrosis induced by cyclophosphamide

Area of Science:

• Oncology
• Pulmonology
• Toxicology

Background:

• Cyclophosphamide is a widely used chemotherapy agent for various cancers, including breast cancer.
• While effective, cyclophosphamide carries a risk of pulmonary toxicity, including interstitial pneumonia and pulmonary fibrosis.
• The incidence of these adverse pulmonary effects is reported to be less than 1%.

Observation:

• A 52-year-old woman with breast cancer developed severe pulmonary fibrosis after four cycles of cyclophosphamide-containing chemotherapy.
• Pulmonary function tests indicated significant ventilatory restriction.
• Open lung biopsy confirmed pulmonary fibrosis, vascular sclerosis, and signs of pulmonary hypertension.

Findings:

• The clinical presentation of cyclophosphamide-induced pulmonary fibrosis includes progressive dyspnea and non-productive cough, potentially leading to severe respiratory insufficiency.
• Risk factors include concurrent use of other pulmonary toxic drugs, high cumulative doses, radiotherapy, and high-dose cyclophosphamide.
• Despite a low frequency, pulmonary fibrosis should be considered in patients with dyspnea and interstitial lung patterns during or after cyclophosphamide treatment.

Implications:

• Prompt diagnosis, often requiring open lung biopsy, is essential for managing cyclophosphamide-induced pulmonary fibrosis.
• Discontinuation of cyclophosphamide and initiation of corticosteroid therapy can lead to clinical recovery in about 50% of patients.
• Early intervention may allow for reversal of lung injury, highlighting the importance of vigilance for pulmonary toxicity in patients receiving cyclophosphamide.