Impact of tumour histology on survival in advanced cervical carcinoma: an NRG Oncology/Gynaecologic Oncology Group Study

BACKGROUND: Based primarily on studies concerning early-stage tumours (treated surgically), and locally advanced disease (treated with chemoradiation), the prognosis for women with adenocarcinoma (AC) or adenosquamous (AS) carcinoma has been reported to be poorer than those with squamous cell carcinoma (SCCA) of the cervix. It is unclear whether differences in prognosis also persist in the setting of recurrent or metastatic disease treated using chemotherapy doublets with or without bevacizumab. METHODS: Cases were pooled from three Gynaecologic Oncology Group randomised phase III trials of chemotherapy doublets. Pearson’s test was used to evaluate response rate (RR) of AC/AS vs SCCA, Kaplan–Meier method to estimate progression-free survival (PFS) and overall survival (OS), and Cox proportional hazards model to estimate the impact of histology on PFS and OS. RESULTS: Of 781 evaluable patients, 77% (N=599) had SCCA and 23% (N=182) AC/AS. There were no significant differences in RRs between histologic subgroups. The adjusted hazard ratio (HR) for death for SCCA vs AC/AS was 1.13 (95% CI 0.93, 1.38 P=0.23). When comparing SC/AS (N=661, 85%) to AC alone (N=120, 15%), the adjusted HR for death was 1.23 (95% CI 0.97, 1.57, P=0.09). CONCLUSIONS: AC/AS and SCCA have similar survival in recurrent or metastatic cervical carcinoma when treated with chemotherapy doublets.