Age Distribution of Cancer: The Incidence Turnover at Old Age |
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Authors: | Francesco Pompei Richard Wilson |
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Affiliation: | 1. Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, Tel (fax): 617-923-9911, Email: fpompei@post.harvard.edu;2. Department of Physics, Harvard University, Cambridge, MA 02138, Tel (voice): 617-495-3387, Tel (fax): 617-495-0416;3. tel (voice 617-923-9900 x201, Email: wilson@huhepl.harvard.edu |
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Abstract: | In recent years data on cancer incidence in the USA, the Netherlands, and in Hong Kong indicate a flattening and perhaps a turnover at advanced age, but no model has been successful in fitting this data and thus providing clues to the underlying biology. In this work we assume these data are reliable and free from bias. We find that a Beta distribution fits SEER age-specific cancer incidence data for all adult cancers extremely well, and its interpretation as a model leads to the possibility that there is a beneficial cancer extinction process that becomes important at elevated age. Particularly evident from the data is the apparent remarkable uniformity of adult cancers peaking in incidence at about the same age, including cancers in other countries. Possible biological mechanisms include increasing apoptosis and cell senescence with age. Further, the model suggests that cancer is not inevitable at advanced age, but reaches a maximum cumulative probability of affliction with any cancer of about 70% for men and 53% for women in the US, and much smaller values for individual cancers. |
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Keywords: | cancer incidence age cancer model multistage clonal expansion. |
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