CON: Serum biomarker monitoring should not replace primary antifungal chemoprophylaxis in patients with acute leukaemia receiving systemic anti-cancer therapy.

Primary antifungal chemoprophylaxis (PAC) is the widespread strategy of choice for the prevention of invasive fungal disease in patients with acute leukaemia (AL). Twice-weekly monitoring of the serum biomarkers (SBM) galactomannan and 1,3-β-d-glucan has been proposed as an alternative prevention strategy to PAC for these patients. This paper outlines the arguments for why PAC should remain as the standard of care in AL, instead of switching to twice-weekly SBM. Arguments put forward in favour of PAC are the strength of evidence for its safety, cost-effectiveness and adaptability, and its adoption by multiple international guidelines as standard of care. The potential implications of PAC for drug interactions and antifungal resistance are also discussed. The drawbacks of twice-weekly SBM are appraised, including missed or delayed diagnoses, unnecessary investigations, deferral of systemic anti-cancer therapy and increased pressure on laboratory services.