Therapeutic options carried out after hypersensitivity reactions to chemotherapy: the value of skin tests.

Introduction: Hypersensitivity reactions (HSRs) to chemotherapy agents constitute a real challenge for cancer treatment. Skin tests (STs) can help risk-stratify patients after initial HSRs and identify cross-reactions between chemotherapeutic agents.

Objective: This study aimed to assess the value of STs in an integrative cancer centre to address the treatment of patients with suspicion of HSRs to platinum salts (carboplatin, oxaliplatin, cisplatin), and taxanes (paclitaxel, docetaxel).

Methods: This single-centre, retrospective study was conducted on data collected from hospital medical records between August 2018 and December 2023. STs (prick tests and intradermal tests) were performed according to the recommendations of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology. The concordance between the allergist's recommendations and the therapeutic strategies implemented in clinical practice following ST results was evaluated.

Results: Among the 105 patients included (76 females, 29 males), the positive ST rate was 61%. In total, 71% of the reactions to platinum salts (n=82) were identified as allergies versus 26% for taxane reactions (n=23). We found a cross-reactivity of 34.5% for platinum salts and 66.7% for taxanes. The allergist's recommendations were carried out in practice for a total of 56 patients (53%). For 47 patients (45%), a clinical reason justified not following the allergist's recommendations and discontinuing treatment.

Conclusion: This study confirms the relevance of STs to help oncologists guide treatment strategies after a presumed allergy. As part of the allergological work-up, STs help prevent unnecessary changes to chemotherapy lines in patients with unproven allergies and facilitate the identification of alternative treatments following HSRs. In practice in our centre, allergists' propositions are carried out as much as possible to guide the re-exposure strategy in patient care.