Objectives: Carboplatin (C) is a standard treatment for gynecologic cancers, but its use in recurrence is associated with an increased risk of hypersensitivity reactions (HSR) in those previously treated with C. However, there is no way to predict those at risk for a C-HSR. We sought to evaluate whether the platinum-free interval (PFI) was predictive of incidence and severity of HSRs.
Methods: Patients treated with C between 1/99 and 12/2005 were identified through our chemotherapy database. Records were reviewed in those receiving multiple C regimens or with C HSR. Severity was defined as mild or severe based on symptoms.
Results: 126 patients were identified who had multiple C regimens. 63 (50%) experienced C HSRs of which 36 (29%) were severe. The incidence of C HSR was 25.8% for PFI < 12 months and 56.5% if > or = 12 months (p=0.0023). The incidence of a severe C HSR significantly increased with time as well: 6.5% PFI < 12 months, 23.9% PFI 12-24 months and 47% PFI > or = 24 months (p=0.0091). Of those receiving a 3rd regimen of C, 8/8 had a HSR and these were severe in seven (88%). Of note, 60 patients received > 8 (range 9-19) cycles with the first C regimen, and none of the patients reacted after cycle 8.
Conclusions: A duration of greater than 12 months between C regimens is associated with an increased risk of both any--and severe--HSR. Our data also suggests that upfront treatment with C beyond eight cycles is not associated with an increased risk of HSR.