350 / 1498
NCIC CTG ECOG HD.6 Trial
Small numbers and unusual events
• Unusual deaths correct from statistical point of view - misleading not
attributable to radiotherapy.
• No death of "other" causes in chemotherapy alone group or in STNI
favourable group. Imbalance misleading in favour of chemotherapy
alone group.
• Without these unusual events - negative study without a survival
difference but with a significantly better tumor control for the RT
group
• Imbalance due to an undersized and incompletely recruited study
with a small number of events.