Analysis of clinical trials in gynecologic cancer--timing and interpretation

When and how often a clinical trial is analyzed is as important as the use of appropriate methodology. Premature analysis may result in inaccurate estimation of tumor response and adverse effects as well as misrepresentation of survival. Moreover, bias may be introduced or the study may be abandoned entirely. Of parallel importance to the timing is the emphasis given to the analyses. If a randomized comparative trial of two regimens is conducted and a significant therapeutic effect is not discerned, the study is generally classified as a negative study. This view is oversimplified; the negative conclusion drawn must have a much more limited scope than is generally appreciated. Lastly, the pitfalls of interpreting time variable curves such as survival are of special note. Quite often the "tails" of the curves totally belie the true implications of the analysis.