Cyclophosphamide exposure via sweat of patients receiving CHOP therapy

“Secondary exposure to anticancer drugs” refers to exposure to anticancer drugs after chemotherapy via the patient's urine and other excretions. The necessity of countermeasures against secondary exposure to anticancer drugs has been recently highlighted. Although anticancer drugs are also excreted through sweat, few studies have reported exposure to drug residues via this route. We investigated the amount of cyclophosphamide (CPA) excreted in the sweat of patients receiving CHOP therapy (cyclophosphamide, doxorubicin, vincristine, and prednisone). The study population included eight patients with malignant lymphoma who received CHOP therapy between May and December 2021. The amount of CPA in their underwear (namely, cotton short-sleeved shirts) worn from the start of the CHOP therapy until 24 h after the end of CPA administration was measured, using liquid chromatography-mass spectrometry (LC-MS/MS). CPA was detected in the underwear of all the patients, with levels ranging between 7.38 and 160.77 ng/cm2. No subjective changes were observed in the sweating status of any patients during the study period. These results suggested that patients’ sweat, as well as urine, is a potential route for exposure to anticancer drugs. Whether visibly contaminated or not, the clothing and linen worn directly by patients should be handled as a source of sweat-mediated exposure to anticancer drugs both in medical facilities and at home.