How elephants beat cancer

Abstract

Elephants have significantly reduced their risk of cancer by duplicating an important gene called TP53.

Keywords: African elephant; Asian elephant; aardvark; armadillo; cell biology; evolutionary biology; genomics; hyrax.

Figure 1.. Large-bodied animals have much lower rates of cancer than models predict.

Based on data on number of cell divisions and mutation rate, a model estimates that larger animals with larger colons should have a much higher risk developing colon cancer by age 70 (dashed line). This predicts a probability of less than 1% for humans, which matches reported incidence statistics in the UK (Cancer Research UK). However, although the model estimates much higher probabilities for large-bodied animals such African elephants and blue whales, cancer risk is actually much lower in elephants than in humans. Sulak et al. suggest that elephants have evolved to have this significantly reduced risk of cancer by replicating the tumor suppressor gene TP53. Whales appear to have evolved other solutions, which remain unknown. This model and figure are adapted from Caulin and Maley (2011).