Human papillomavirus in the context of Penis cancer

Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms of cancer include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in bowel movements. While these symptoms may indicate cancer, they can also have other causes. Over 100 types of cancers affect humans.

About 33% of deaths from cancer are caused by tobacco and alcohol consumption, obesity, lack of fruit and vegetables in diet and lack of exercise. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. Infection with specific viruses, bacteria, and parasites causes approximately 16–18% of cancers worldwide. These infectious agents include Helicobacter pylori, hepatitis B, hepatitis C, HPV, Epstein–Barr virus, Human T-lymphotropic virus 1, Kaposi's sarcoma-associated herpesvirus and Merkel cell polyomavirus. Human immunodeficiency virus (HIV) does not directly cause cancer, but it causes immune deficiency that can increase the risk of cancer from other infections, sometimes up to several thousandfold (in the case of Kaposi's sarcoma). Importantly, vaccination against the hepatitis B virus and the human papillomavirus have been shown to nearly eliminate the risk of cancers caused by these viruses in persons successfully vaccinated prior to infection.

Warts are non-cancerous viral growths usually occurring on the hands and feet but which can also affect other locations, such as the genitals or face. One or many warts may appear. They are distinguished from cancerous tumors as they are caused by a viral infection, such as a human papillomavirus, rather than a cancer growth.

Factors that increase the risk include the use of public showers and pools, working with meat, eczema, and a weak immune system. The virus is believed to infect the host through the entrance of a skin wound. A number of types exist, including plantar warts, "filiform warts", and genital warts. Genital warts are often sexually transmitted.

The Papanicolaou test (abbreviated as Pap test, also known as Pap smear (AE), cervical smear (BE), cervical screening (BE), or smear test (BE)) is a method of cervical screening used to detect potentially precancerous and cancerous processes in the cervix (opening of the uterus or womb) or, more rarely, anus (in both men and women). Abnormal findings are often followed up by more sensitive diagnostic procedures and, if warranted, interventions that aim to prevent progression to cervical cancer. The test was independently invented in the 1920s by the Greek physician Georgios Papanikolaou and named after him. A simplified version of the test was introduced by the Canadian obstetrician Anna Marion Hilliard in 1957.

A Pap smear is performed by opening the vagina with a speculum and collecting cells at the outer opening of the cervix at the transformation zone (where the outer squamous cervical cells meet the inner glandular endocervical cells), using an Ayre spatula or a cytobrush. The collected cells are examined under a microscope to look for abnormalities. The test aims to detect potentially precancerous changes (called cervical intraepithelial neoplasia (CIN) or cervical dysplasia; the squamous intraepithelial lesion system (SIL) is also used to describe abnormalities) caused by human papillomavirus, a sexually transmitted DNA virus. The test remains an effective, widely used method for early detection of precancer and cervical cancer. While the test may also detect infections and abnormalities in the endocervix and endometrium, it is not designed to do so.

Estimates place the worldwide risk of cancers from infectious causes at 16.1%. Viral infections are risk factors for cervical cancer, 80% of liver cancers, and 15–20% of the other cancers. This proportion varies in different regions of the world from a high of 32.7% in Sub-Saharan Africa to 3.3% in Australia and New Zealand.

A virus that can cause cancer is called an oncovirus or tumor virus. These include the human papillomavirus, which is associated with cervical carcinoma and nasopharyngeal carcinoma; Epstein-Barr virus, which is associated with a variety of Epstein-Barr virus-associated lymphoproliferative lymphomas; Kaposi's sarcoma herpesvirus, which is associated with Kaposi's sarcoma and primary effusion lymphoma; hepatitis B and hepatitis C viruses which are associated with hepatocellular carcinoma; and human T-cell leukemia virus-1 which is associated with adult T-cell leukemia/lymphoma. Bacterial infection may also increase the risk of cancer, as seen in Helicobacter pylori-induced stomach cancer. Parasitic infections strongly associated with cancer include Schistosoma haematobium (squamous cell carcinoma of the bladder) and the liver flukes, Opisthorchis viverrini and Clonorchis sinensis (cholangiocarcinoma).

Circumcision is a surgical procedure that removes the foreskin from the human penis. In the most common form of the operation, the foreskin is extended with forceps, then a circumcision device may be placed, after which the foreskin is excised. Topical or locally injected anesthesia is generally used to reduce pain and physiologic stress. Circumcision is generally electively performed, most commonly done as a form of preventive healthcare, as a religious obligation, or as a cultural practice. It is also an option for cases of phimosis, chronic urinary tract infections (UTIs), and other pathologies of the penis that do not resolve with other treatments. The procedure is contraindicated in cases of certain genital structure abnormalities or poor general health.

The procedure is associated with reduced rates of sexually transmitted infections and urinary tract infections. This includes reducing the incidence of cancer-causing forms of human papillomavirus (HPV) and reducing HIV transmission among heterosexual men in high-risk populations by up to 60%; its prophylactic efficacy against HIV transmission in the developed world or among men who have sex with men is debated. Neonatal circumcision decreases the risk of penile cancer. Complication rates increase significantly with age. Bleeding, infection, and the removal of either too much or too little foreskin are the most common acute complications, while meatal stenosis is the most common long-term. There are various cultural, social, legal, and ethical views on circumcision. Major medical organizations hold variant views on the strength of circumcision's prophylactic efficacy in developed countries. Some medical organizations take the position that it carries prophylactic health benefits which outweigh the risks, while other medical organizations generally hold the belief that in these situations its medical benefits are not sufficient to justify it.

Anal cancer is a cancer which arises from the anus, the distal opening of the gastrointestinal tract. Symptoms may include bleeding from the anus or a lump near the anus. Other symptoms may include pain, itchiness, or discharge from the anus. A change in bowel movements may also occur.

Risk factors include human papillomavirus (HPV), HIV/AIDS, receptive anal sex, smoking, and many sexual partners. Anal cancer is typically a squamous cell carcinoma. Other types include adenocarcinoma, small cell carcinoma, and melanoma. Diagnosis is suspected based on physical examination and confirmed by tissue biopsy.