Premature adoption of adjuvant chemotherapy for locally advanced cervical carcinoma before the OUTBACK trial: cautionary tale on outcomes.

Abstract

The aim of this study was to investigate the use and outcomes of adjuvant chemotherapy for patients with locally advanced cervical carcinoma receiving definitive chemoradiation. The National Cancer Database was accessed, and patients diagnosed between 2004 and 2015 with International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IB2-IVA disease who underwent definitive chemoradiation were selected. Patients who received radio-sensitizing single agent chemotherapy and those who received adjuvant multi-agent chemotherapy were identified. Overall survival was evaluated following generation of Kaplan-Meier curves while a Cox model was constructed to control for confounders. A total of 9895 patients were identified; 1003 (10.1%) received multi-agent adjuvant chemotherapy. Patients who received adjuvant chemotherapy were less likely to receive brachytherapy (60.9% vs 68.4%, p<0.001). Rate of adjuvant chemotherapy was higher among patients with stage IVA (18.1%) and stage III (11.9%) disease compared with those with stage II (8.4%) and stage IB2 (7.2%) disease (p<0.001). After controlling for confounders, administration of adjuvant chemotherapy was not associated with a survival benefit (hazard ratio 1.09, 95% confidence interval 0.98 to 1.20). Following stratification by disease stage, there was no survival benefit of patients who received adjuvant chemotherapy compared with those who did not; stage IB (p=0.002; 5 year overall survival 59.2% vs 74.9% favoring chemoradiation alone), stage II (p=0.41; 5 year overall survival 63.8% vs 67.6%, respectively), stage III (p=0.52; 5 year overall survival 48% vs 47.8%, respectively), or stage IVA disease (p=0.27; 5 year overall survival 29.5% vs 34.3%, respectively). In the US, approximately 1 in 10 patients with locally advanced cervical carcinoma who underwent definitive chemoradiation also received adjuvant chemotherapy that was not associated with improvement in overall survival.