Phase II Clinical Trial for Adjuvant Concurrent Chemoradiation Therapy in Post-operative Cervical Cancer Patients

Cervical carcinoma is one of the most common gynecologic cancers worldwide. The prognosis of cervical cancer is favorable, with around 80-90% 5-year survival rate in early stage disease. However, advanced disease carries a poor prognosis.

The standard postoperative treatment for patients with cervical cancer who had high-risk factors is chemoradiation. Based on the results of five randomized clinical trials, which consistently showed improved survival in patients treated with cisplatin-based CRT, the National Cancer Institute (NCI) of the United States announced that 'Strong consideration should be given to the incorporation of concurrent cisplatin-based chemotherapy with RT in women who require radiation therapy for treatment of cervical cancer' in 1999.

Although recently reported meta-analysis studies also demonstrated improved local control rates and survival with cisplatin-based chemotherapy concurrent to radiation therapy (RT), the optimal cisplatin dose and dosing schedule are still undetermined. Among the previous five randomized clinical trials, two trials performed by the Gynecologic Oncology Group (GOG) used weekly cisplatin 40 mg/m2 while the other three trials used tri-weekly cisplatin at a dosage range of 50 mg/m2 to 75 mg/m2 combined with 5-fluorouracil (5-FU).

Despite the diversity in cisplatin dose and dosing schedules, weekly cisplatin at a dose of 40 mg/m2 concurrent to RT is widely accepted as the standard regimen of CRT because of its convenience, equal effectiveness, and favorable toxicity in comparison to other 5-FU combined regimens.

However, as a result of the GOG 165 study, which was closed prematurely because an interim analysis found that patients in the 5-FU treatment group were not likely to achieve a better outcome, the role of 5-FU (previously popularly included in clinical trials) as a radiosensitizer became subject to debate. Furthermore, a clinical trial performed by the NCI in Canada comparing pelvic RT alone with weekly cisplatin 40 mg/m2 concurrent to RT failed to show improvement of progression free and 5-year survival. While the authors suggested several possible reasons for why their study failed to demonstrate a survival benefit with concurrent weekly cisplatin 40 mg/m2 chemotherapy, other investigators have tried to find another optimal dose and dosing schedule for cisplatin administration.