What are the risk factors for penile cancer?
Phimosis and smegma
Uncircumcised men with certain conditions may be at higher risk for penile cancer.
Phimosis
In men who are not circumcised, the foreskin can sometimes become tight and difficult to retract. This condition is known as phimosis. Penile cancer is more common in men with phimosis. The reason for this is not clear. Phimosis can often be prevented by retracting the foreskin when washing the penis.
Smegma
Sometimes secretions can build up underneath the intact foreskin. If the area under the foreskin isn’t cleaned well, these secretions build up enough to become something called smegma. Smegma is a thick, sometimes smelly substance found under the foreskin. It is made up of oily secretions from the skin, along with dead skin cells and bacteria. It is more common in men with phimosis, but can occur in anyone with a foreskin, if the foreskin is not regularly retracted to clean the head of the penis.
Some older studies have suggested a link between smegma and penile cancer, and in the past some experts were concerned that smegma may also contain compounds that can cause cancer. Most experts now believe that smegma itself probably doesn’t cause penile cancer, but it can irritate and inflame the penis, which may increase the risk of cancer. It may also make it harder to see very early cancers. Men can prevent smegma from building up simply by washing the penis with the foreskin retracted.
Human papilloma virus infection
Human papilloma virus (HPV) is a group of more than 100 related viruses. They are called papilloma viruses because some of them cause a type of growth called a papilloma. Papillomas are not cancers, and are more commonly called warts. Different HPV types cause different types of warts in various parts of the body. Some types cause common warts on the hands and feet. Other types tend to cause warts on the lips or tongue.
Buried penis
Buried penis was described in the early 20th century as a penis of normal size that lacks an appropriate sheath of skin and is located beneath the integument of the abdomen, thigh, or scrotum. This condition is more common in children, usually presenting in neonates or obese prepubertal boys; however, it can also be seen in adults and has been observed in both circumcised and uncircumcised individuals. Marginal cases may not be diagnosed until adulthood, when increased fat deposition accentuates the problem.
Several classification systems of buried penis have been proposed, although none has been universally adopted in the literature. Maizels et al (1986) differentiated among the terms concealed (before circumcision), trapped (cicatricial [scarred] after circumcision), and buried (associated with adolescence and obesity).
In most congenital pediatric cases, the buried penis is self-limited. In untreated adults, however, the condition tends to worsen as the abdominal pannus continues to grow.
Certain HPV types can infect the outer female and male genital organs and the anal area, causing raised, bumpy warts. These warts may barely be visible or they may be several inches across. The medical term for genital warts is condyloma acuminatum. Two types of HPV, HPV 6 and HPV 11, cause most cases of genital warts. These 2 types are seldom linked to cancer, and so are called low-risk types of HPV. However, other HPV types have been linked with cancers and are known as high-risk types of HPV. These include HPV 16, HPV 18, HPV 31, as well as others. Infection with a high-risk HPV may produce no visible signs until pre-cancerous changes or cancer develops.
HPV infection is found in about half of all penile cancers. Researchers believe that infection with HPV is an important risk factor for penile cancer. HPV infection is also linked to many other cancers, including cancers of the cervix, vagina, and vulva in women and cancers of the anus in men and women. It is also a factor in some throat cancers (in men and women).
HPV is passed from one person to another during skin-to-skin contact with an infected area of the body. Although HPV can be spread during sex - including vaginal intercourse, anal intercourse, and oral sex - sex doesn’t have to occur for the infection to spread. All that is needed is skin-to-skin contact with an area of the body infected with HPV. Infection with HPV seems to be able to be spread from one part of the body to another,for example, infection may start in the penis and then spread to the anus. The only way to completely prevent anal and genital HPV infection is to never allow another person to have contact with those areas of the body.
HPV infection is common, and in most people the body is able to clear the infection on its own. In some, however, the infection does not go away and becomes chronic. Chronic infection, especially with high-risk HPV types, can eventually cause certain cancers, including penile cancer.