Animal models of the cancer anorexia-cachexia syndrome.

BACKGROUND AND AIMS: Cancer cachexia, a complex wasting syndrome, is common in palliative medicine. Animal models expand our understanding of its mechanisms. A review of cancer cachexia and anorexia animal models will help investigators make an informed choice of the study model. RESULTS AND DISCUSSION: Cancer-anorexia cachexia animal models are numerous. No one is ideal. The choice should depend on the research question. To investigate cancer-anorexia cachexia independent of pro-inflammatory cytokine effects, the MAC16 ADK and XK1 are useful. MAC16 ADK helps study the host's tumor metabolic effects, independent of any anorexia or inflammation. XK1 is both anorectic and cachectic, but data about it is limited. All other models induce a host inflammatory response. The Walker 256 ADK and MCG 101 are best avoided due to excessive tumor growth. Since individual models do not address all aspects of the syndrome, use of a combination seems wise. Suggested combinations: MAC16-ADK (non-inflammatory and non-anorectic) with YAH-130 (inflammatory, anorectic, and cachectic), Lewis lung carcinoma (slow onset anorexia) or prostate adenocarcinoma (inflammatory, anorectic but not cachectic) with YAH-130.