Does Paclitaxel Plus Carboplatin (TC) Substitute for Paclitaxel Plus Cisplatin (TP) in Cervical Cancer Without Prior Platinum Treatment? (SUBSET ANALYSIS OF JAPAN CLINICAL ONCOLOGY GROUP TRIAL (JCOG 0505))

ABSTRACT Objective TP is the standard regimen for advanced or recurrent cervical cancer. However, JCOG0505 presented statistically significant non-inferiority of TC to TP in terms of overall survival (OS), for stage IVB or recurrent cervical cancer in ASCO ‘12 annual meeting. By subset analyses of JCOG0505, we investigated whether the treatment effect of TP or TC is different among some specific subgroups including the one by prior platinum status. Methods Patients (Pts) with stage IVB or recurrent cervical cancer; not amenable to curative therapy; 0-1 prior platinum; no prior taxanes; were randomized with minimization method to either TP (T 135 mg/m2 24h d1 + P 50 mg/m2 2h d2) or TC (T 175 mg/m2 3h d1 + C AUC5 1h d1), both for maximum 6 cycles every 21 days. We estimated the hazard ratios and 95% confidence intervals in OS among subgroups (including prior platinum status) for the eligible patients, comparing TC and TP. Each hazard ratio (HR) was estimated by an unstratified Cox regression. Results Total 253 pts were enrolled. Median follow-up of all randomized patients is 17.4 months (mo). As was reported before, it was demonstrated that TC was not inferior to TP for OS (17.5 mo in TC and 18.3 mo in TP, HR 0.99 (non-inferiorityp = 0.032 with a non-inferiority margin 1.29)). Both arms were comparable with respect to toxicity except for grade 4 neutropenia (45% in TC vs. 75% in TP). In a subset analysis (n = 244), TP was superior to TC for OS in non-prior platinum group (n = 117) (13.0 mo in TC and 23.2 mo in TP, HR 1.57 (95% CI:1.06-2.32)). Contrary, TC tended to show better survival than TP for OS in prior platinum group (n = 127) (19.0 mo in TC and 16.3 mo in TP, HR 0.69 (95% CI:0.47-1.02)). Furthermore, TP tended to be superior to TC for OS in stage IVB (n = 51) (14.8 mo in TC and 25.4 mo in TP, HR 1.50 (95% CI:0.84-2.67)). Conclusion Non-inferiority of TC to TP was demonstrated in the whole population of JCOG0505. By the subset analyses, however, TP may be still the first choice for patients without prior cisplatin-based treatment such as those with primary stage IVB cervical cancer. Disclosure All authors have declared no conflicts of interest.