HOT SPRINGS, VA. — Patients with ovarian cancer who have a hypersensitivity reaction to carboplatin can be successfully treated with cisplatin without a lengthy desensitization procedure, Dr. Megan Callahan said at the annual meeting of the South Atlantic Association of Obstetricians and Gynecologists.
She presented a review of 24 women with ovarian cancer who received cisplatin after an allergic reaction to carboplatin—the largest case series to date.
Carboplatin hypersensitivity is correlated with the number of treatment cycles experienced, said Dr. Callahan of the University of Virginia, Charlottesville. “The cumulative risk increases from 0.92% for less than five cycles to 6.5% for six cycles, and up to 19% for eight cycles,” she said. Her patients' reactions occurred at a median of 10 cycles. None of the reactions were life threatening.
All 24 patients were rechallenged with cisplatin in a subsequent treatment cycle. The drug was given at a standard infusion rate over 1.5 hours. None of the patients received desensitization with steroids or antihistamines.
Most (18) were able to tolerate the full number of cisplatin treatment cycles without a hypersensitivity reaction. Of the six who did react to cisplatin, only one did so in the first cycle. The rest were able to tolerate one to six cycles before having a reaction. All of the cisplatin reactions were managed conservatively on an outpatient basis, and none of the reactions were life threatening.
Dr. Callahan's 24 patients bring the total reported in the literature to 57. Among these patients, only seven had cisplatin reactions; one died. “This results in an 86% success rate for cisplatin rechallenge,” Dr. Callahan said.
Unfortunately, she added, she has been unable to identify any predisposing factors that might predict which patients would react to either drug. “We looked at past medical history, reported allergies, and concurrent medications, and we couldn't identify anything that would predispose them to a reaction.” Nor did the severity of the initial carboplatin reaction predict which patients would later experience a cisplatin reaction, she said.