Cancer selection

Lore & Background

The concept of cancer selection draws directly from Darwin's theory of natural selection, where selective pressures in the environment drive changes in populations over time. In cancer biology, the body of the organism is the environment, and changes—whether natural or from clinical therapies—apply selective pressures that drive adaptation in tumor cells. Cancer is viewed as an ancient pathology that emerged with multicellular organisms, leading to billions of years of co-evolution between hosts and cancers, with hosts developing cancer suppressors like cytotoxic lymphocytes and p53 genes.

Reader's Guide

Cancer selection is significant because it reframes cancer not merely as a disease but as an evolutionary process that shapes both tumor progression and host evolution. By viewing the host's body as an environment that applies selective pressures, this concept explains why cancer is so formidable: its genetic diversity allows it to adapt to treatments and immune responses. Moreover, the theory proposes that cancer itself acts as a selective force driving the evolution of animal hosts, potentially influencing the morphological and life-history diversity seen in animals today. This co-evolutionary perspective suggests that as animals evolved larger bodies and longer lifespans, they became more susceptible to cancer, which in turn selected for tumor-suppressing genes and other adaptations. Understanding cancer selection helps explain the difficulty of eradicating tumors and underscores the need for therapies that target the evolutionary dynamics of cancer cell populations.

Did You Know?

• Cancer selection is viewed through the lens of natural selection, with the animal host's body as the environment applying selective pressures on cancer cells.
• Tumor heterogeneity—genetic diversity within and between tumors—gives cancer a selective advantage over the host's immune system and clinical treatments.
• Cancer has been proposed as a selective force that has driven the evolution of animals, with hosts and cancers co-evolving over billions of years.
• Cancer cells are described as selfish, producing progeny with higher fitness that outcompete other clonal cells, to the detriment of the host.