Neoplasm Types and Prevalence

Maligant neoplasms (cancers) appear in humans at different ages, some appearing in very young children (neuroblastoma, Wilms’ tumors) and other in aged individuals (prostate carcinomas). Like humans, great apes have been reported to develop cancers of the blood (Leukemias) and of the mesenchymal tissues (Sarcomas). However, spontaneously occurring carcinomas (malignancies of epithelial cells of of the breast, stomach, colon, lung, ovary, prostate, cervix, uterus, pancreas etc.) that are very common in older human populations seem very rare in non-human primates.  The reasons for the apparent rarity of carcinomas in great apes are unknown.  Benign tumors of some of these organs have been reported, indicating that surveillance has been adequate. These carcinomas tend to occur in older ages in humans, and are also the ones most associated with various environmental factors, such as diet, reproductive activity, etc. Thus, it is possible that these carcinomas will begin to be reported in great apes as captive populations continue to age.