Congratulations to AnnMarie Walton, assistant professor, and her entire team who have received an award for their Duke Cancer Control and Population Sciences Pilot Studies (CCPS) proposal entitled “Examining Occupational Exposure Risks and the Efficacy of Toilet Seat Covers and Routine Discharge Cleaning in Minimizing Antineoplastic Drug Contamination." This award is for a two-year period with a project start date of January 1, 2021.

Specific Aims

Antineoplastic drug (AD) exposure remains a significant concern for healthcare workers. Even at low levels, exposure to ADs can cause acute toxicities, reproductive problems, and an increased risk for cancer including abnormalities in chromosomes 5 & 7 which mirror therapy-related myelodysplastic syndrome (t-MDS) and therapy-related acute myeloid leukemia (t-AML). Our recent work on the inpatient bone marrow transplant unit at Duke University Hospital (DUH) showed the highest levels of AD contamination in patient rooms were on toilet seats, which supports concern about AD contaminated excreta as a source of exposure. Surprisingly, we also found the presence of drugs not administered to the patient occupying the room in 26% of the samples (n=9/34), suggesting the presence of residues leftover from a prior patient.(1) Though we did not examine cleaning methods in this prior work, we hypothesize that current handling and discharge cleaning practices need to be improved to sufficiently protect healthcare workers and minimize health and financial risks and burden. Furthermore, DUH is moving into compliance with a national pharmacopoeial standard called USP <800> issued on December 1, 2019 and designed to reduce risk of exposure to hazardous drugs but there is limited research exploring actionable ways to minimize healthcare workers’ exposure to ADs via excreta. Our proposed study will lead to actionable scientific and technical solutions toward reducing risk of exposure.

Recommendations exist to reduce risk of exposure for health care workers handling AD contaminated excreta but are inconsistently followed given the lack of evidence based findings to support an optimal approach. The Oncology Nursing Society (ONS) recommends use of plastic backed pads to minimize exposure to AD contaminated excreta when flushing but there are no data to support this recommendation, and they were used only 25% of the time in our prior study. As toilets were the most contaminated surfaces within the patient’s room, there is concern about aerosolization from flushing that could contaminate toilet seats and surrounding surfaces which healthcare workers may contact unknowingly. In this proposed study we aim to: 1. Test whether plastic backed pads over the toilet while flushing (experimental condition) are more efficacious than regular flushing (control condition) in minimizing AD contamination on toilet seats and on other bathroom surfaces, 2. Explore and test the efficacy of the current discharge cleaning method and agents to remove AD contamination from toilet seats and other bathroom surfaces.

We will conduct this study on DUH’s inpatient bone marrow transplant unit where staff have extensive contact with the AD contaminated excreta of patients and where it is standard care to measure patient output. We will utilize a cross-over design whereby the entire unit is randomly assigned to either the control or experimental condition for a two month period, followed by a one month washout period, and then assignment to the opposite condition. To maximize our analytic sampling we will repeat the cross-over approach a second time after another one month washout period. Rooms of patients who will receive cyclophosphamide or etoposide in the following 48 hours will be eligible for recruitment into this study. Three surfaces (toilet seat, wall beside toilet, and floor in front of toilet) in the patient bathroom will be swabbed at three time points; prior to chemotherapy administration, between 24-72 hours after administration, and after discharge cleaning. The swabbing solvent will be a combination of acetonitrile, methanol, and water and the swabbing will follow a standardized procedure for surfaces that approximate 200 cm2. All samples will be stored in the Pharmacokinetics and Investigational Chemotherapy Core Lab until analysis. Liquid chromatography/mass-spectrometry will be used to analyze the samples. Shimadzu 20A series HPLC and Applied Biosystems/SCIEX API 5500 QTrap MS/MS system will be used for quantitative analysis. Quantifiable detection of AD exposure and the development of ways to reduce exposure to ADs is an important cancer control strategy for healthcare workers as well as for the families of patients receiving these drugs.

The results of this study will provide preliminary data for a larger multi-centered study to examine the efficacy of current recommendations in handling and cleaning AD contaminated excreta. This timely study addresses a phenomenon of interest to numerous funding agencies and provides strategies for containment of hazardous drugs. It also supports DUH moving into compliance with USP <800>.