A “catastrophic hypothesis” for pancreas cancer progression1 Francisco X Real  Gastroenterology  Volume 124, Issue 7, Pages 1958-1964 (June 2003) DOI: 10.1016/S0016-5085(03)00389-5

Figure 1 Hypothetical models of progression of PanIN lesions. (A) The most commonly depicted linear model has not been conclusively demonstrated. Alternative models (B and C) deserve further study in the context of the hypothesis discussed here. Panel B proposes that development of PanIN-1B lesions may occur without progression through a PanIN-1A stage. Panel C proposes that a direct progression from normal ductal epithelium to PanIN-2 may take place. These hypothetical models require further investigation. Gastroenterology 2003 124, 1958-1964DOI: (10.1016/S0016-5085(03)00389-5)

Figure 2 If a “catastrophe” takes place, when does it take place? It is conceivable that the catastrophe might take place after PanIN-3 (carcinoma in situ) develops (A). In the absence of precise information on the prevalence of PanIN and their temporal evolution, it is also conceivable that PanIN-2 lesions already display a highly aggressive behavior and might be “catastrophic” (B). The length of the arrows is meant to represent, in a nonquantitative manner, the rate of progression of each lesion; the thickness of arrows is depicted to represent the likelihood of progression to the next stage; the “explosion” icon is meant to correspond to the putative “catastrophe.” For the sake of simplicity, this figure is based on model A of Figure 1. These hypothetical models require further investigation. Gastroenterology 2003 124, 1958-1964DOI: (10.1016/S0016-5085(03)00389-5)