Cancer risk factors: a critical review

Abstract

The global burden of cancer cases has been estimated to rise from 14.1 million to 23.6 million between 2012 and 2030. Many genetic and environmental risk factors are likely to induce the incidence and mortality rate and hence, may further influence the frequency of cancer occurrence. The risk factors that contribute to the risk of developing cancer mainly comprise of genetic changes, family history, age, tobacco/smoking consumption, alcohol intake, air pollution, radiation, sunlight, obesity and poor diet. Often some vulnerable factors may not be avoided, but through the limitation of exposure to such causative agents, it may be possible to lower the risk of developing cancer to some extent. The most widely recognized cancers worldwide that includes lung, female breast, bowel, prostate accounts for 42% of all new cases. The cases were found to be higher in the low and medium human development index (HDI) countries than in high and very high human development index (HDI) countries. So far, very few studies have been conducted to identify the risk factors which might cause cancer. The purpose of this review article is to summarize and evaluate current literature on cancer risk factors as well as to point out gaps on the existing knowledge about cancer causing factors among people and recommend studies to be performed efficiently to discover any new risk factors involved.