As indicated in Fig 2C , the difference between malignant tissue and non-malignant paired tissue was highly significant ( p <0.0001), and the difference between malignant tissue and benign tumor tissue was significant ( p = 0.0115).
In the analysis of this larger group, the differences in mean values did not reach statistical significance, however ( p = 0.43), possibly due to the contribution of cellular factors independent of topo I, such as CPT uptake, intracellular CPT metabolism and distribution, and the cellular response to DNA damage, all of which can affect the outcome of CPT treatments [ 32 ].