RESUMEN
Medical information through media may influence physicians' prescriptions of medication. The Japan Broadcasting Corporation (NHK) aired on April and May 2005, a special program called 'Questioning Cancer Treatment in Japan', covering oxaliplatin. We investigated potential impact of this program on prescriptions, utilizing a post-marketing clinical trial monitoring of all patients receiving oxaliplatin. The post-marketing clinical trial reached the target sample size of 1200 by the 4th week of May, 44 weeks sooner than anticipated. The newly registered numbers of facilities and patients exhibited a bimodal peak in April and June. The viewer rating of NHK special was 8.3%, whereas three national newspapers and one weekly magazine took up the minor articles of oxaliplatin. In July 2007, 405 clinicians sent a written opinion to NHK, stating 'NHK special invites misperceptions and confusions to public.' NHK special might have had an impact on clinicians' prescriptions of oxaliplatin.