A retrospective review on extended carboplatin infusion and incidence of hypersensitivity reaction in gynecologic malignancies in a single institution.

Abstract

e17102 Background: Carboplatin has been the standard treatment for advanced gynecologic malignancies in the first line setting as well as treatment of relapsed disease. Carboplatin induced hypersensitivity reaction (HSR) is observed more frequently in a second line setting and symptoms can range from rash to life threatening symptoms such as anaphylaxis, which could preclude further treatment. A retrospective study by O’Cearbhaill showed HSR rate with extended infusion protocol to be 3.4%. However, two subsequent prospective studies by Lax and O’Cearbhaill did not find that extended infusion reduced the risk or severity of HSR. We reviewed the incidence of HSR with three hour extended-infusion carboplatin at our institution. Methods: Our practice at the Monter Cancer Center changed from standard 1 hour carboplatin retreatment infusion to extended-infusion in 2011. We reviewed charts of 162 patients from 2011 to present who received a three hour extended infusion of carboplatin. All patients received prophylactic H1 and H2 blockers along with steroids. HSR was determined in two ways: 1) Identifying patients who reported clinical symptoms of HSR. 2) Identifying which patients had received diphenhydramine, hydrocortisone and/or epinephrine as indicated for an infusion reaction. Results: 162 patients were identified: 83 with ovarian cancer, 44 with uterine cancer, and 16 with fallopian tube cancer, 10 with primary peritoneal cancer, and 9 with cervical/vulvar cancer. Most had relapsed disease and were previously treated for stage IV (35%), or stage III (47%) with platinum doublet chemotherapy at least six months prior. Only 1 out of 162 (0.6%) had a grade 1 reaction with hives and was treated with dexamethasone and diphenhydramine. She was previously treated with carboplatin 17 months prior. Her current HSR occurred during her fifth cycle of retreatment. She was not re challenged with the drug and elected not to undergo desensitization. Conclusions: Hypersensitivity reactions develop in about 12-33% of women retreated with carboplatin peaking at eight cycles (Lax et al.). The mechanism behind HSR is unclear but considered to be from repeated exposure to free platinum metal concentration. Incidence of HSR at our institution was lowest ever-reported at 0.6%, suggesting that our extended infusion protocol with the appropriate premedication is appropriate for carboplatin-retreat patients. Further prospective studies to evaluate this regimen is warranted.