Statistical inference for tumor growth inhibition T/C ratio

J Biopharm Stat. 2010 Sep;20(5):954-64. doi: 10.1080/10543401003618983.


The tumor growth inhibition T/C ratio is commonly used to quantify treatment effects in drug screening tumor xenograft experiments. The T/C ratio is converted to an antitumor activity rating using an arbitrary cutoff point and often without any formal statistical inference. Here, we applied a nonparametric bootstrap method and a small sample likelihood ratio statistic to make a statistical inference of the T/C ratio, including both hypothesis testing and a confidence interval estimate. Furthermore, sample size and power are also discussed for statistical design of tumor xenograft experiments. Tumor xenograft data from an actual experiment were analyzed to illustrate the application.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Animals
  • Antibodies, Monoclonal / therapeutic use
  • Biostatistics / methods*
  • Confidence Intervals
  • Humans
  • Likelihood Functions
  • Mice
  • Neoplasms / pathology*
  • Neoplasms / therapy*
  • Sample Size
  • Statistics, Nonparametric
  • Treatment Outcome
  • Xenograft Model Antitumor Assays / methods*


  • Antibodies, Monoclonal