Safely and feasibly investigating chemotherapy allergies
Published online: January 6, 2020
Improved diagnosis and care of patients with cancer has resulted in better patient survival and longer treatment. Patients are thus exposed more frequently and for longer periods of time to chemotherapy. This situation increases the risk of hypersensitivity reactions (HSRs) to chemotherapy and constitutes a challenge to cancer treatment. With limited therapeutic options, being able to accurately and safely identify allergy is crucial to manage cancer patients. Allergy to platinum salts (PS) and taxanes (TX) is among the most frequent side-effects of chemotherapy.
When a drug allergy is suspected, the evaluation method is based on skin tests (ST) and if needed graded challenges (GC). It provides a diagnosis of an allergy to a suspected drug and indicate possible treatment options with alternative drugs of the same class.
A recent study, published in The Journal of Allergy and Clinical Immunology: In Practice by Pradelli and colleagues, aimed to estimate the performance and safety of ST and GC in 119 patients enrolled with suspected HSRs to chemotherapy. ST were performed for PS and/or TX, drugs of the same pharmacological class and other agents (latex or co-treatments). For patients with negative ST, a GC was performed by the cancer teams trained in allergy management.
ST results were positive for more than half of the whole cohort (58%): 63% for PS, 33% for TX and 4.2% for other agents. These tests were also able to detect cross-reactivity between chemotherapy from the same class of drug (50% for TX and 30% for PS). For patients with negative ST, an intravenous graded challenge was performed to assess the negative predictive values (NPV) of ST. NPV were excellent: 100% for TX and 92% for PS if ST were done within a minimal delay of 14 days after the reaction.
Allergy evaluation for PS and TX hypersensitivity should be reliably integrated into the therapeutic management of patients. It can reliably and safely identify cases of allergy and even suggest a safe alternative treatment. However, this process requires close interaction between allergy and oncology teams and training in anaphylaxis management.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.