Table 2a Primary tumour models
From: Guidelines for the welfare and use of animals in cancer research
Model type | Examples of models | Advantages | Disadvantages |
|---|---|---|---|
Chemically-induced tumours | Dimethyl hydrazine – gastric cancer (Watanabe et al, 1999) Azoxymethane – colon cancer (Hirose et al, 2004) Diethylnitrosamine – heptaocellular carcinoma (Ha et al, 2001) Dimethyl benzanthracene – breast cancer (Hawariah and Stanslas, 1998) N-acetylcysteine – squamous oesophageal carcinoma (Balansky et al, 2002) Dimethylbenzanthracene/ tetradecanoyl phorbol acetate (TPA) – skin cancer (Johansen et al, 2009) | Model the full spectrum of carcinogenic events Useful in chemoprevention studies | Low incidence and heterogeneous tumour development Safety aspects associated with use of carcinogens – may need to house animals in isolator Long time frame for tumour development Continuous monitoring not feasible Often highly immunogenic |
Radiation-induced tumours | Ultraviolet light (Ahsan et al, 2005; De Fabo, 2006; El-Abaseri and Hansen, 2007) | Models non-melanoma (using UVA) and melanoma (UVB) skin cancer Useful for prevention (e.g.. sunscreen) studies | Requires hairless mice |
Inflammation-induced tumours | Helicobacter pylori-induced gastric cancer in gerbils (Zheng et al, 2004) | Use of conventional rodents to facilitate the involvement of the full spectrum of immune mediators Models malignant progression and amenable for use of chemopreventive agents | Limited availability of models Long time frame and variability in tumour development |
Surgically-induced tumours | Oesophago-gastroduodenal anastomosis model of oesophageal carcinogenesis (Chen et al, 1999) | Can model malignant progression or metastatic spread | High level of skill required for initiation Incidence may not be 100% Accurate quantification can be difficult unless using real-time imaging |
Spontaneous tumours, sometimes with viral/genetic component | T138 mice and mammary carcinoma (Wood et al, 1992; Nordsmark et al, 1996) Cotton rats and neuroendocrine gastrointestinal tumours (Martinsen et al, 2003) Eker rat model of tuberous sclerosis (Kenerson et al, 2005) | Develop cancer without any intervention Conventional rodents, therefore fully immunocompetent | Limited tumour types and strains Variability in the time frame of tumour development |
