7.3 Risk factors

Table 7.2 Risk factors for prostate cancer, by direction of association and strength of evidence

Increases risk

Decreases risk

Convincing or probable

Family history of prostate cancer1,2

Foods containing lycopene8,9




Arsenic and arsenic compounds4


Cadmium and cadmium compounds4


Obesity (aggressive prostate cancer)5

Obesity (non-aggressive prostate cancer)5

Tobacco smoking6

Selenium or foods containing selenium9,10

Insulin-like growth factor-1 (IGF-1)7

Soya and soya food products11,12

Aspirin and other non-steroidal anti-inflammatory drugs13


1 One or more relative(s) with prostate cancer; 2 Bruner et al., 2003; 3 Zuccolo et al., 2008; 4 Straif et al., 2009; 5 Giovannucci and Michaud, 2007; 6 Huncharek et al., 2010; 7 Rowlands et al., 2009; 8 lycopene is a carotenoid found in tomatoes and tomato products, such as soup and puree; 9 World Cancer Research Fund / American Institute of Cancer Research, 2007; 10 Jiang et al., 2010; 11 Hwang et al., 2009; 12 Yan and Spitznagel, 2009; 13 Mahmud et al., 2010

The chances of a man developing prostate cancer are approximately doubled if he has a relative with the disease. Despite extensive study, relatively few other risk factors for prostate cancer have been firmly established (Table 7.2). Taller men appear to have higher risk, although height per se is unlikely to affect a man’s chances of developing the cancer: instead it probably points to relevant childhood exposures. One possibility is that the association operates through the insulin-like growth factor system, which plays a key role in cell proliferation, differentiation and apoptosis. Positive associations have been reported between prostate cancer and circulating levels of insulin-like growth factor 1.

There is limited evidence that exposure to arsenic and inorganic arsenic compounds (through occupational inhalation or ingestion in food or drinking water) and cadmium and cadmium compounds (via occupational use), are a cause of prostate cancer.

Some aspects of diet may influence risk. Higher intake of the carotenoid lycopene is associated with decreased risk in many studies. Risk may be reduced in men, especially those from Asian populations, who consume more tofu and soya food products. While observational studies suggest that higher intake of selenium or selenium-rich foods is also inversely associated with prostate cancer, two trials found no effect of selenium supplementation.

Obesity may be associated with reduced risk of non-aggressive prostate cancer but, since the opposite has been suggested for aggressive disease, the observations could be due to a detection bias relating to the ability to detect prostate cancer in obese men (Buschemeyer and Freedland, 2007). While current smoking per se does not appear to be associated with risk, risk may be elevated among smokers with higher levels of exposure. Meta-analyses suggest the possibility that regular use of aspirin and other non-steroidal anti-inflammatory drugs could be associated with reduced risk of prostate cancer overall, and of advanced cancers specifically, but there are inconsistencies and limitations in the evidence. 

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