['The aim of this study was to determine whether receptor-dependent and receptor-independent retinoids sensitize cervical cancer cells to clinically relevant doses of concurrent radiation and cisplatin.', 'The clonogenic assay was performed on SiHa cervical carcinoma cultures treated with 5 microM 9-cis-retinoic acid (RA) or 3 microM 4-HPR for 3 days prior to and following concurrent treatment with 3 microM cisplatin and 2 Gy of Co(60) radiation.', 'Neither 9-cis-RA nor 4-HPR significantly decreased survival for radiation only or cisplatin only (t test: P < 0.05), but both significantly decreased survival of cultures receiving concurrent chemoradiation (t test: 9-cis-RA P = 0.045; 4-HPR P = 0.027).'] Do retinoids enhance cisplatin-based chemoradiation in cervical cancer cells in vitro?