Recognising the carcinogenic nature of cytostatic drugs in order to improve occupational risk prevention

Many workers exposed

Cytostatic active ingredients are mainly used to treat cancer in human and veterinary medicine, in various healthcare institutions, not just in hospital: medical care at home, hospices, nursing homes, veterinary clinics, etc. In hospitals, their use is not limited to oncology units; they can also be used in rheumatology, immunology, dermatology and gynaecology. According to the 2017 SUMER survey (PDF), nearly 92,000 employees are exposed to these substances: from manufacturing through to handling, and including transport, waste management, cleaning, etc.

The mechanisms of action of cytostatics mean that they may be carcinogenic to healthy cells. Paradoxically then, these drugs for treating cancer patients may expose the healthcare workers handling them to substances that are themselves carcinogenic.

Due to strong suspicions about the carcinogenic nature of cytostatics and their routine use in the workplace, therefore, the Directorate General for Labour asked ANSES to investigate this topic in 2017.

Taking the exposure circumstances into account to prevent risks in the workplace

After an initial study (PDF) published in 2018, and drawing on existing European or international assessments, ANSES now proposes that work involving exposure to 18 active ingredients of cancer drugs be included in the French ministerial order establishing the list of carcinogenic substances, mixtures and processes as defined by the French Labour Code.

"Cytostatic drugs currently fall outside the European regulatory framework for classification and labelling. Unlike products used in an industrial environment, the European regulation does not require users to be warned of the hazardous nature of drugs via specific labelling. By proposing to include work involving exposure to these 18 substances in the French ministerial order, we are helping to shape the regulatory framework to ensure better protection of exposed workers", emphasises Henri Bastos, Scientific Director for Occupational Health at ANSES.

To achieve this, ANSES recommends taking into account the circumstances of exposure to these 18 substances, rather than the occupations exposed:

• exposure during drug manufacture, packaging, preparation, transport and handling;
• exposure when implementing protocols involving one or more of the identified substances;
• exposure through contamination of the working environment or via management of waste and excreta.

"To define effective prevention solutions, we need to look at the entire exposure chain, from drug preparation and administration through to contamination of staff by patient excreta (sweat, vomit) or the treatment of linen or waste," continues Henri Bastos.

Raising awareness among exposed workers 

In the case of cytostatics, substitution of these substances would be difficult because of their therapeutic benefit to patients.

To control the existing risks as much as possible, ANSES recommends that employers:

• identify and assess the carcinogenic risk to exposed staff;
• raise awareness and train workers potentially exposed to this risk (e.g. techniques for removing potentially contaminated gloves);
• set up exposure monitoring for these workers.

Although ANSES's expert appraisal focused on the carcinogenic nature of cytostatics, the Agency points out that these active ingredients can also have effects on reproduction and development, which need to be taken into account in the prevention of occupational risks.

Improve knowledge

ANSES also recommends more generally improving knowledge on the carcinogenic risk associated with exposure to these drugs through:

• an extension of this debate to other drugs than just cancer treatments;
• a possible classification of the active ingredients through the CLP Regulation, which would, in the case of carcinogenic, mutagenic and reprotoxic (CMR) substances, ensure automatic implementation of prevention, protection or medical monitoring measures for exposed staff;
• the provision of improved and harmonised information on genotoxicity and carcinogenicity in the summary of product characteristics.