Human Papillomavirus (HPV): The Unseen Leading Cause of Cervical Cancer in Women.

By Olaitan Ayinde-Olayinka

A lot of women are scared of breast cancer, and justifiably so. As at 2005, it was the leading cause of death in mid-age women. Breast cancer can obviously and promptly be discovered by most women due to the intensive enlightenment crusades about it.

However, there is another type of cancer which has been discovered to be more dangerous and more widespread among women due to the annual number of women death due to it, but which is not easily discovered due to its location in a woman’s body. This is cervical cancer and its leading cause is a group of viruses called human papillomavirus (HPV).

HPV-induced cancer might be the most dangerous cancer of all in women due to its hidden nature.

HPV belong to the papillomaviruses (PVs), which comprise a group of small non-enveloped icosahedral DNA viruses that replicate in the nucleus of squamous epithelial cells, inducing benign lesions of the skin (warts), and mucous membranes (condylomas). Papillomavirus belongs to the family of viruses called Papilllomaviridae.

Human papillomavirus is the most common sexually transmitted disease in women worldwide and the leading cause of cervical cancer, which is the most common female genital tract cancer in females in large areas of the developing world where an estimated 80% of new cases arise. Studies in 22 countries, coordinated by the International Agency for Research on Cancer (IARC), identified HPV DNA in almost all (99.7%) cervical cancer cases

Genital HPVs can be divided into low risk type (rarely or never associated with cancer), and high risk type (often associated with cancer). High risk types are capable of infecting the genital skin, the vaginal epithelium, or the cervix. Persistent infections with high risk genital HPVs are the primary cause of cervical cancer, and almost all women with cervical cancer have at least one of these high risk types of HPV (types 16, 18, 31, 33,35, 39, 45, 51, 52, 56, 58, 59, 66 and 68) in the cells of their cervices.

Cervical cancer occurs when the cells in the cervix begin to grow and becomes progressively invasive. It is the second most common malignancy among women worldwide, with approximately 500,000 newly diagnosed cases each year and about 275,000 deaths annually. As at 2008, Nigeria has cervical cancer incidence of 14550 per 100000 persons, in which 9659 mortality was recorded.

Cancer of the cervix is the commonest cancer in the female genital tract and the leading cause of cancer mortality among women in developing countries. The incidence of cervical cancer in sub-Saharan Africa is among the highest worldwide, with age-standardised rates of 35.7 per 100 000 in Bamako, Mali, and 41.7 per 100 000 in Kyadondo, Uganda. The annual age-standardised incidence of cervical cancer in Ibadan in 1999 was 26.3 per 100 000.

The good news is that cervical cancer due to HPV infection is preventable through early detection, as the infection has a long progression rate before climaxing in cancer. Detection can be done through the Papanicoulaou (or Pap) smear test or the HPV DNA testing.

• Cervical cytology test: Known as the Pap smear test, cells are taken from the cervix through swabbing are fixed on a microscopic slide, and the cells are viewed by trained personnel for morphological changes and characteristics suggestive of cancer. Early stage of cancerous growth can thus be detected and treated appropriately before it becomes advanced.
• HPV DNA test: This is used to detect the presence of the viral DNA which is indicative of virus presence and infection. This test is done to know the subtype of HPV which is infecting the individual before any cell abnormalities become visible. This is very important in knowing the appropriate treatment to prescribe for an infected person.
• Visual Inspection: Visual inspection of the cervix with acetic acid (VIA) is an effective, inexpensive screening test that can be combined with simple treatment procedures for early cervical lesions, provided by trained health workers. 

We provide information on cervical cancer screening as well as consultation on the procedure, cost of tests and treatment/prevention methods. Stay safe.

Reference

Parkin et al., 1997; Walboomeret al., 1999; Parkin et al., 2002; Winer et al, 2003; Bosch et al., 1995; Munozet al., 2003; Parkin et al., 2005; GLOBOCAN, 2008; Parkin et al., 2002; Thomas et al., 2004.