Intratumor heterogeneity may foster tumor evolution, and is a key factor contributing to cancer therapeutic failure and drug resistance. The development of intratumor heterogeneity is analogous to a growing tree which develops an increasingly complex structure of twigs and branches. The ubiquitous mutations of a cancer present in every tumor subclone and region can be represented as trunk. The branches are different geographically separated regions of the tumor or subclones present within single biopsies that carry heterogeneous mutations that are not present in every tumor region. The phylogenetic tree shows different mutations as trunk (found in all regions), branch (at least two regions and not all regions), or leaf (identified in one region).Database Introduction
CancerTracer is a manually curated and integrated database aims to help researchers to decipher tumor heterogeneity at individual patient level. It contains two types of tumor heterogeneity data: 1) Intra-tumor or Intra-metastatic heterogeneity: the presence of multiple subclones within a primary tumor or a single metastatic lesion; 2) Inter-metastatic heterogeneity: the presence of different subclones in different metastatic lesions of the same patient. Somatic mutations and copy number alterations are available in CancerTracer, since both of them are principal factors drive heterogeneity in cancer. The structured heterogeneity data enables researchers to identify trunk mutations in different cancer types and investigate the molecular mechanisms underlying intratumor heterogeneity.