Published Mar 8, 2016

Cynthia Cree  


Cancer as one of the leading causes of death has been a major concern for medical practitioners and researchers for many years, not just because of the diagnosis and treatment, but understanding the roles of intrinsic and extrinsic factors on its genesis. Some of the recent discoveries about cancer are the roles of xenobiotics and some internally produced biological molecules in forming tumors when brought in contact with living tissue. The discovery of the roles of intrinsic and extrinsic factors in mutagenesis has since been extensively examined with various experiments and data collected from neoplasm with the various carcinogens. The detailed studies of cancer genesis have proved that extrinsic factors, such as chemicals and radiation at different wavelengths, and some biological molecules play critical roles in mutagenesis. The main purpose of this review is to weigh the effects of the various factors (intrinsic and extrinsic) on cancer genesis.



Cancer, Risk Factor, Pathogenesis, Mortality

1. Song M, Giovannucci EL. Cancer risk: Many factors contribute. Science 2015; 347:728-729.

2. Alexandrov LB, Stratton MR. Mutational signatures: The patterns of somatic mutations hidden in cancer genomes. Curr Opin Genet Dev 2014; 24:52-60.

3. Tomasetti C, Vogelstein B. Variation in cancer risk among tissues can be explained by the number of stem cell divisions. Science 2015; 347:78-81.

4. Lathrop AEC, Loeb L. Sex hormone in cancer. J Cancer Res 1916; 1:1.

5. Andervont HB, Lorenz E. US Public Health Service. Pub Health Rep 1937; 52:637.

6. Sall RD, Shear MJ, Leiter J, Perrault A. Studies in carcinogenesis. XII. effect of the basic fraction of creosote oil on the production of tumors in mice by chemical carcinogens. J Natl Cancer Inst 1941; 1:45-55.

7. Ashford NA, Bauman P, Brown HS, Clapp RW, Finkel AM, Gee D, Hattis DB, Martuzzi M, Sasco AJ, Sass JB. Cancer risk: Role of environment. Science 2015; 347:727.

8. Cramer W, Stowell RE. On the quantitative evaluation of experimental skin carcinogenesis by methylcholanthrene the factors of dosage, time, spacing of applications, and the multiplicity of the carcinogenic response. Cancer Res 1943; 3:668-681.

9. Kamangar F, Chow WH, Abnet C, Dawsey S. Environmental causes of esophageal cancer. Gastroenterol Clin N Am 2009; 38:27-57.

10. Blot WJ, McLaughlin JK, Winn DM, Austin DF, Greenberg RS, Preston-Martin S, Bernstein L, Schoenberg JB, Stemhagen A, Fraumeni JF Jr. Smoking and drinking in relation to oral and pharyngeal cancer. Cancer Res 1988; 48:3282-3287.

11. Parkin DM, Mesher D, Sasieni P. Cancers attributable to solar (ultraviolet) radiation exposure in the UK in 2010. Br J Cancer 2011; 105:S66-S69.

12. Johnson IT, Lund EK. Review article: Nutrition, obesity and colorectal cancer. Aliment Pharmacol Ther 2007; 26:161-181.

13. Tomasetti C, Vogelstein B, Parmigiani G. Half or more of the somatic mutations in cancers of self-renewing tissues originate prior to tumor initiation. Proc Natl Acad Sci USA 2013;110:1999-2004.

14. Gray J, Evans N, Taylor B, Rizzo J, Walker M. State of the evidence: The connection between breast cancer and the environment. Int J Occup Environ Health 2009; 15:43-78.
How to Cite
Cree, C. (2016). Cancer: Intrinsic Versus Extrinsic Factors on Its Genesis. Science Insights, 2016(2), 1–6. https://doi.org/10.15354/si.16.re120