Reaction-diffusion pre-patterning and its potential role in tumour invasion

The growth of a solid tumour proceeds through two distinct phases: the avascular phase and the vascular phase. It is during the latter that the insidious process of invasion of surrounding tissues can and does take place. Once vascularized the tumours grow rapidly as exophytic masses. In certain types of cancer, e.g. carcinoma arising within an organ, this process typically consists of columns of cells projecting from the central mass of cells and extending into the surrounding tissue area. The local spread of these carcinoma often assume an irregular jagged shape. Experimental results have demonstrated that tumour cells secrete both growth-activating and growth-inhibiting chemicals. Using this knowledge a pre-pattern theory of cancer cell invasion is proposed. The theoretical results are compared with experimental and clinical results regarding the heterogeneity of cancer cells within multicell spheroids and the well-known invasion characteristics of carcinoma.