A risk factor is anything that may increase your chance of having a disease. Risk factors for a certain type of cancer might include smoking, diet, family history, or many other things. The exact cause of someone’s cancer may not be known. But risk factors can make it more likely for a person to have cancer.

Things you should know about risk factors for cancer:

• Risk factors can increase a person's risk, but they do not necessarily cause the disease.

• Some people with 1 or more risk factors never develop cancer. Other people can develop cancer and have no risk factors.

• Some risk factors are very well known. But there is ongoing research about risk factors for many types of cancer. 

Some risk factors, such as family history, may not be in your control. But others might be things you can change. Knowing the risk factors can help you make choices that might lower your risk. For example, smoking is a risk factor for penile cancer. You can protect yourself by quitting smoking.

Risk factors for penile cancer include:

• Age. The risk of penile cancer goes up with age. It occurs more often in men older than 50.

• Not being circumcised. Circumcision is surgery to remove part or all of the foreskin on the penis. This can be done at birth or later on in life. Researchers say that circumcision may protect against cancer of the penis by making it easier to keep the penis clean. This seems to lower cancer risk if done as a newborn. It does not lower the risk if done as an adult.

• Phimosis and smegma. A male who is uncircumcised may have foreskin on his penis that is difficult to retract or is constricted (phimosis). This condition can make it very difficult to clean the penis. This in turn can cause a buildup of dead cells and skin (smegma) under the foreskin and around the glans. The buildup can cause inflammation of the penis. This may increase the risk for penile cancer.  

• Human papilloma virus (HPV) infection. Certain types of HPV have been linked to penile cancer. HPV infection is fairly common. In fact, some research suggests that about half of all men have a genital HPV infection at any given time, but the body usually clears the infection.

• Smoking. Men who smoke are at higher risk for penile cancer than those who don't. Cancer-causing chemicals in tobacco smoke may harm the DNA in cells in the penis. This may lead to penile cancer.

• AIDS. Men who have AIDS may be at higher risk for penile cancer. This may be because AIDS causes a weakened immune system.

• Ultraviolet light treatment for psoriasis. Men who have had certain treatments for psoriasis may have a slightly higher risk for penile cancer. These treatments use psoralen medicine followed by ultraviolet A light therapy (PUVA). Men who are treated with PUVA now have their genitals covered during treatment.

Talk with your healthcare provider about your risk factors for penile cancer. No standard screening tests are available for penile cancer. There is also no definite way to prevent cancer of the penis. But several things may lower your risk:

• Practice safe sex. This will make it less likely for you to get HPV (or HIV, the virus that causes AIDS). It is not yet clear if the HPV vaccine can reduce the risk for penile cancer. 

• Don’t smoke.

• Follow good personal hygiene habits. If you have not been circumcised, retract the foreskin and clean under it regularly. 

• Routinely check for any skin changes on your penis. These changes might be warts, sores, ulcers, white patches, or blisters. If you notice any of these changes on the skin of your foreskin, glans, or shaft of your penis, tell your healthcare provider right away. Don't let embarrassment keep you from seeing your provider about these issues.