Pemetrexed-induced radiation recall dermatitis of the breast

Pemetrexed (Alimta™) is a frequently used multi-targeted antifolate drug for the treatment of inoperable and metastatic non-squamous cell lung cancer and mesothelioma, administered as a single-agent or in combination with platinum analogs. In some patients, radiotherapy to any part of the body precedes administration of pemetrexed. This drug has been associated with hematological toxicity and cutaneous side-effects. Most skin toxicities are benign, mainly presenting as a diffuse rash and occurring shortly after treatment. In the present case report we present a rare cutaneous side-effect namely radiation recall dermatitis. A grade 2 dermatitis strongly mimicking mastitis of the breast was observed in a patient treated with a second cycle of single-agent pemetrexed, used as maintenance treatment post-induction chemotherapy with cisplatin and pemetrexed for newly-diagnosed non-squamous cell lung cancer. Fifteen years earlier, the patient had undergone irradiation of the whole breast after breast-conserving surgery. In previously published cases, there were initial symptoms of pain, dysesthesia or burning sensation in the previously-irradiated skin area after the initial pemetrexed administration in the absence of visible cutaneous signs. Although this was not the case for our patient, such symptoms should alert physicians to subsequent potentially more severe clinical dermatitis if the drug is continued. Prevention studies are required to overcome this rare but potentially severe side-effect.