id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-017752-ofzm3x3a	nan	Theories of Carcinogenesis	2007		.txt	text/plain	12289	692	47	Others attributed the simplified enzyme patterns of cancerous cells to a regression of the tumor tissues to early embryonal stages of development. Viral DNA is frequently integrated into the cancer cells, but additional agents or factors may be involved at various stages of the progression to invasive carcinoma. The encounter with a family, in which many members developed breast or liver cancer, led Pierre Paul Broca to hypothesize, in 1866, that an inherited abnormality within the affected tissue caused the tumor development [Broca 1866 Theodor Boveri (1862 Boveri ( -1915 then proposed that defects in chromosomes lead to malignancy [Boveri 1914 ]. Any mutation of cancer associated genes can be handed on to following generations and predispose the affected cells to malignant transformation in the case of additional DNA damage. Further developments in tumor immunology have led to models of selection and evolution of cancer cells.	./cache/cord-017752-ofzm3x3a.txt	./txt/cord-017752-ofzm3x3a.txt