Obesity and cancer third most important risk factor for cancer in the United States, just behind tobacco and diet (see Figure). Obesity is the source of about 15% of all preventable cancers. In 2018, Chinese researchers performed a systematic review and comprehensive quantitative meta‐analysis of cohort studies reporting body mass index (BMI) and the risk of 23 cancer types, providing epidemiological evidence supporting the association between BMI and cancer risk. The strongest positive association between BMI and cancer risk was found among patients in North America. The mechanisms by which obesity may increase the risk of cancer are not well understood, but it
The Hallmarks of Cancer be able to avoid interaction with the body’s via a loss of interleukin-33 immune system. (See cancer immunology) The updated paper also identified two emerging characteristics. These are labeled as such since their acquisition leads to the development of the hypothesized "hallmarks" Cancer cells generally have severe chromosomal abnormalities which worsen as the disease progresses. HeLa cells, for example, are extremely prolific and have tetraploidy 12, trisomy 6, 8, and 17, and a modal chromosome number of 82 (rather than the normal diploid number of 46). Small genetic mutations are most likely what begin tumorigenesis, but once cells begin the