Box 1 | Essential differences in cancer development between humans and rodents

From the following article:

Cancer in rodents: does it tell us about cancer in humans?

Vladimir N. Anisimov, Svetlana V. Ukraintseva & Anatoly I. Yashin

Nature Reviews Cancer 5, 807-819 (October 2005)


  • Tumour origin — commonly mesodermal sarcomas in mice compared with epithelial carcinomas in humans.
  • Carcinogenic risk factors — many rodent carcinogens are non-carcinogenic in humans and vice versa; some popular human medicines (for example, acetaminophen, chloramphenicol and metronidazole) are carcinogenic in rodents.
  • The spectrum of common spontaneous tumours — there are no rodent strains with a high incidence of spontaneous stomach, colon or bladder tumours that, by contrast, are common in humans.
  • The number of genetic events necessary to induce malignant transformation — fewer genetic events are required in rodents.
  • Spontaneous regression of tumours — occurs in infants but is rare in adult humans, whereas it is common in adult mice.
  • Excess weight — in humans, extreme obesity, as well as low weight, can increase the overall risk of cancer, whereas moderate excess weight might decrease this risk. In rodents, obesity and overfeeding were shown to increase cancer risk, whereas calorie restriction decreased it.