D2.64 - Incidence and trends of Carboplatin Allergy in Gynecological Malignancy Patients at a single tertiary hospital in Hong Kong

Chemotherapy-related allergies are frequently underdiagnosed in Hong Kong due to scarce drug allergy services. We examined Carboplatin allergy incidence among gynaecological malignancy patients at our institution.

We studied patients with gynaecological malignancies receiving Carboplatin-based chemotherapy from January 2021 to December 2023 at a single-centre tertiary hospital in Hong Kong. Cases not completing the initial chemotherapy course were excluded. Clinical data such as age, sex, diagnosis, treatment response, adverse events, and concurrent drug allergies were retrospectively collected and analysed.

Of 183 patients completing the first chemotherapy course, 83% (151/183) achieved complete response. Up to 45% (68/151) experienced primary disease relapse, with 81% (55/68) receiving Carboplatin-based chemotherapy, and 38% (21/55) achieving complete response. Among these responders, 48% (10/21) relapsed again, all receiving Carboplatin-based chemotherapy. Overall, 19% (34/183) presented with a drug reaction, with 60% (20/34) being allergic. Immediate-type hypersensitivity reactions to Carboplatin increased with each cycle, from 1% (2/183) in the first cycle to 60% (6/10) in the third. The median number of Carboplatin doses before a reaction was 13.5 (range: 6–43). Concurrent drug allergy labels were present in 15% (28/183) of patients, with antibiotics (11/28, 39%), IV iodinated contrast (8/28, 29%), and NSAIDs (4/28, 14%) being the most common.

High relapse rates in gynaecological malignancies require effective chemotherapy. Our cohort reveals increasing immediate-type hypersensitivity reactions to Carboplatin with repeated treatments, consistent with prior studies. Collaboration between oncologists and allergists is crucial to establish safe desensitization protocols, improving treatment outcomes for this patient population.