Interstitial pneumonitis associated with leuprorelin acetate for a prostate cancer: A case report

Androgen deprivation therapy remains the essential treatment for disseminated prostate cancer. Interstitial pneumonitis following this therapy has been documented for just a few cases. However, reported cases frequently describe the onset of symptoms after recent administration (days or a few weeks) of both GnRH analogues and androgen antagonists, which makes the precise individual impact of each treatment difficult to estimate.

This report presents a case of a 94-year-old patient with interstitial pneumonitis whose onset started three months after the first dose of leuprorelin and bicalutamide for a metastatic prostate cancer.

Once other possible diagnosis were ruled out, empiric corticosteroid treatment was initiated within 48 h of the admission. A spectacular clinical and radiological improvement was observed after 3 doses of steroids, enabling the patient to recover his basal respiratory situation. We considered that the most probable cause was toxic interstitial pneumonitis induced by leuprorelin.

To our knowledge, it describes the longest interval between last administration of antiandrogen therapy and the development of pneumonitis. This fact may support a direct relation with leuprorelin, whose serum levels remain high for months because of its long-acting depot formulation.