Résumé
There is striking variation in the incidence of cancer in human organs. Malignant tumors are common in the colon and breast but rare in the heart and small bowel. The uterus frequently develops benign fibroid tumors but uterine cancers are relatively rare. The organ-specific difference in cancer prevalence has been explained primarily by the relative roles of intrinsic and extrinsic risk factors. In this opinion article, we propose also considering organs as distinct but connected ecosystems whose different vulnerabilities to malignant transformation may be partially explained by how essential each organ is for survival through the age of reproduction. We present and discuss some of the basic concepts and assumptions of this perspective on evolutionary medicine.