Delayed Paclitaxel-trastuzumab-induced interstitial pneumonitis in breast cancer

Pneumonitis is a rare but serious complication associated with paclitaxel and/or trastuzumab treatment. We report a 51-year-old female patient with locally advanced breast cancer who presented with shortness of breath, fever, dry cough and pulmonary infiltrates. She had been treated without complications for 10 weeks with paclitaxel (Taxol®) and trastuzumab (Herceptin®) as neoadjuvant therapy, with complete clinical and pathological response. Infections and cardiomyopathy were excluded as causes of her symptoms. Bronchoscopy and biopsy were performed and a diagnosis of drug-induced interstitial pneumonitis was made. After treatment with steroids, the patient showed a significant response in less than 24 h; she was discharged home without the need for oxygen less than 48 h after therapy initiation. Although no causative association could be found between either trastuzumab or paclitaxel and this patient's pulmonary syndrome, the potential for such toxicity should be considered, especially as paclitaxel/trastuzumab is a vey common combination therapy for breast cancer.