The estimated amount of cancer cases attributed to specific risk factors Risk Factors Cases(% Diet 35 Tobacco use 25~30 Hereditary factors 5~10 Occupational exposures 5 Radiation 2 Viruses 15 Miscellaneous 16~23 OffitK. 1998 Abeloff's Clinical Oncology, 2008Risk Factors Cases (%) Diet 35 Tobacco use 25~30 Hereditary factors 5~10 Occupational exposures 5 Radiation 1~2 Viruses 15 Miscellaneous 16~23 The estimated amount of cancer cases attributed to specific risk factors Offit K, 1998 Abeloff‘s Clinical Oncology, 2008