Phase I/II study of concomitant irradiation and carboplatin for locally advanced carcinoma of the uterine cervix: an interim report.

The outcome of women treated with either definitive irradiation alone or in combination with cisplatin-based chemotherapy for locally advanced (>IIb) squamous cell carcinoma of the cervix has been disappointing. To improve upon our reported results with irradiation alone, a trial using irradiation plus carboplatin chemotherapy was designed for these patients. Twenty-seven women with unresectable squamous cell carcinoma of the uterine cervix were referred to our institution between July 1991 and September 1994. Seven of these patients were enrolled in a phase I/II protocol combining concurrent irradiation and carboplatin chemotherapy. Megavoltage irradiation was used to deliver 45-50.4 Gy to the pelvis (and paraaortic chain when nodes were involved) through a multiple-field technique followed by the application of Fletcher-Suit-Delclos tandem and ovoids to boost the point A dose to 85 Gy. Chemotherapy consisted of intravenous carboplatin (60 mg/m2) administered in conjunction with irradiation to a total dose of 300 mg/m2. The enrolled patients consisted of six women with stage IIIb disease and one with stage IIa with concomitant paraaortic adenopathy. All seven patients enrolled in the study completed the planned course of treatment and tolerated the treatment without severe acute morbidities. No dose modifications were required for the radiation therapy regimen. For one patient, a dose of carboplatin was withheld to allow recovery from thrombocytopenia. The overall response rate was 100% (four complete response, three partial response). The combination of concurrent irradiation (pelvic or pelvic + paraaortic fields) and carboplatin chemotherapy can be safely administered to patients with locally advanced squamous cell carcinoma of the cervix. The treatment is well tolerated and is associated with a high rate of response. Longer follow-up will be necessary to assess the durability of response. In the meantime, we have elected to escalate the dose of carboplatin (90 mg/m2) in the hope of increasing the rate of complete response without incurring unacceptable toxicity.