**Uterine Cervical Cancer Screening**

**Uterine Cervical Cancer Screening**

#### Doris Barboza and Esther Arbona Doris Barboza and Esther Arbona Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.72606

#### **Abstract**

Cervical cancer is the fourth most common cancer and the third cause of death among women worldwide. More than 85% of the cases occur in developing countries. In Latin America, cervical cancer is the most common cause of cancer deaths among women, primarily in young women with devastating social impact. It is mostly the consequence of lack of a health care infrastructure that allows cervical cancer screening suitable for detecting pre-malignant lesions. With the knowledge that human papillomavirus (HPV) infection is the main cause of cervical cancer, two major preventive interventions have emerged: HPV vaccination and screening, which involve the detection and treatment of cervical dysplasia and early-stage cervical cancer. HPV 16 and 18 cause up to 70% of all cervical cancer cases in Latin America and are covered in all available vaccines. Since tests for high-risk HPV types and HPV vaccines are expensive and they have not been included in immunization programs and given free of charge to eligible women in Venezuela and most less developed regions, screening campaigns with cytology and direct visualization of the cervix with VIN continue to be the major interventions that can prevent cervical cancer in these countries; they need to be implemented in a large scale.

DOI: 10.5772/intechopen.72606

**Keywords:** cervical cancer screening, human papillomavirus, HPV vaccine, PAP test, Papanicolaou, cytology, acetic acid, oncogenic HPV

#### **1. Introduction**

Cervical cancer is a public health problem in adult women in developing countries of South America, Central and Sub-Saharan Africa, meridional and Sub-oriental Asia [1]. It is the fourth most common cancer and the third cause of death among women worldwide [2]. Nine percent (529,800) of new cancer and 8% (275,100) of all cancer deaths in 2008 were caused by cervical cancer. More than 85% of the cases occur in developing countries. Twenty-seven percent (77,100) of all cervical cancer deaths occurred in India, the second most populous country in the world (**Figure 1**).

Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons

health, the principal importance is that cervical cancer mainly affects young women from low income households, with a devastating impact on them and their families with lot of orphans. Despite it being an easily preventable disease, prevention and screening of cervical cancer are not up to the mark in these regions. If prevention and screening programs do not improve, it is estimated that the annual cases will increase with estimation for 2025 of 126,000 new cases [3]. The highest incidence and mortality of cervical cancer in developing countries and other medically unattended areas is mostly the consequence of lack of a health care infrastructure that allows screening suitable for detecting pre-malignant lesions [4]. The most efficient and profitable screening techniques [5] are cytology-based screening (the Pap test) and HPV DNA screening. A clinical trial in one of India's rural areas with low income households found than 1 round of HPV DNA screening was related with a 50% reduction in probability of developing cervical cancer [6]. Screening programs fail because of substandard quality of pap-smear sampling techniques, methodology errors, limited geographical and population coverage with emphasis on high-

Uterine Cervical Cancer Screening

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http://dx.doi.org/10.5772/intechopen.72606

With the knowledge that HPV infection is the main cause of cervical cancer, two major interventions that can prevent cervical cancer have emerged: HPV vaccination and screening, which involves the detection and treatment of cervical dysplasia and early-stage cervical cancer.

All HPV vaccines currently available cover HPV 16 and 18 that cause up to 70% of all cervical cancer cases in Latin America [7]. Cervarix from GlaxoSmithKline is a bivalent vaccine that covers only HPV 16/18; Gardasil from Merck & Co is a quadrivalent vaccine that covers HPV 16/18 and HPV 6/11, which cause genital warts. Both vaccines prevent primary VPH infection, CNI2 and CNI3 related to HPV 16 and HPV 18, when 3 doses are completed. The 9-valent vaccine (Gardasil 9 from Merck & Co.) covers seven HPV types related to cervical cancer,

HPV vaccine is recommended for girls aged 9–26 years of age to prevent cancers of the cervix, vagina, and vulva related with HPV 16 or 18, or genital warts (HPV 6 or HPV 11), and lesions related with other HPV types, cervical adenocarcinoma in situ, vulvar or vaginal intraepithelial neoplasia [10]. In addition, women must be vaccinated before their first sexual activity, prior to exposure to HPV. HPV vaccination is also recommended for women with weakened immune systems (including people with HIV infection), given their higher risk of having HPV infection. By mid-2016, 65 countries had introduced HPV vaccines, mostly developing countries, but including an increasing number of middle and low-income countries. Unfortunately, HPV vaccines are expensive and they have not been included in immunization programs and given free of charge to eligible women in Venezuela and most less-developed regions. Thus, screening continues to be the major intervention that can prevent cervical cancer in these countries.

Most of the risk factors for developing cervical cancer are associated with a compromised immune response that allows HPV infection, the etiologic agent of nearly all cases of cervical

risk women, and sub-optimal follow-up.

including HPV 16/18 and HPV 6/11 [8, 9].

cancer. These factors include the following.

**2. Risk factors**

**Figure 1.** Age-standardized cervical cancer: Incidence and mortality. Rates by world area. GLOBOCAN 2008.

In 2017, the American Cancer Society (Cancer Statistic Center) estimated that there will be 12,820 new cervical cancer patients and 4210 deaths. The incidence rate for cervical cancer from 2009 through 2017 is 7.6 per 100,000 women; the rate of death from 2010 through 2014 is 2.3 per 100,000 women. The incidence and death rates for cervical cancer in Latin America are still high; for example, in Venezuela, the annual average of new cervical cancer cases from 2010 through 2014 was 4019, with a standardized rate on 2014 of 24.88.

In developed countries, most patients are diagnosed in the early stage of the disease or with pre-malignant lesions susceptible to effective treatment. Nevertheless, with the current migratory movement of women, there is an upturn of advanced stage cervical cancer, especially among women who miss their routine gynecologic evaluation or belong to immigrant's groups without suitable medical assistance.

In Latin America, cervical cancer occupies the second position after breast cancer and is the most common cause of cancer deaths among women, primarily in young women. For public health, the principal importance is that cervical cancer mainly affects young women from low income households, with a devastating impact on them and their families with lot of orphans. Despite it being an easily preventable disease, prevention and screening of cervical cancer are not up to the mark in these regions. If prevention and screening programs do not improve, it is estimated that the annual cases will increase with estimation for 2025 of 126,000 new cases [3].

The highest incidence and mortality of cervical cancer in developing countries and other medically unattended areas is mostly the consequence of lack of a health care infrastructure that allows screening suitable for detecting pre-malignant lesions [4]. The most efficient and profitable screening techniques [5] are cytology-based screening (the Pap test) and HPV DNA screening. A clinical trial in one of India's rural areas with low income households found than 1 round of HPV DNA screening was related with a 50% reduction in probability of developing cervical cancer [6].

Screening programs fail because of substandard quality of pap-smear sampling techniques, methodology errors, limited geographical and population coverage with emphasis on highrisk women, and sub-optimal follow-up.

With the knowledge that HPV infection is the main cause of cervical cancer, two major interventions that can prevent cervical cancer have emerged: HPV vaccination and screening, which involves the detection and treatment of cervical dysplasia and early-stage cervical cancer.

All HPV vaccines currently available cover HPV 16 and 18 that cause up to 70% of all cervical cancer cases in Latin America [7]. Cervarix from GlaxoSmithKline is a bivalent vaccine that covers only HPV 16/18; Gardasil from Merck & Co is a quadrivalent vaccine that covers HPV 16/18 and HPV 6/11, which cause genital warts. Both vaccines prevent primary VPH infection, CNI2 and CNI3 related to HPV 16 and HPV 18, when 3 doses are completed. The 9-valent vaccine (Gardasil 9 from Merck & Co.) covers seven HPV types related to cervical cancer, including HPV 16/18 and HPV 6/11 [8, 9].

HPV vaccine is recommended for girls aged 9–26 years of age to prevent cancers of the cervix, vagina, and vulva related with HPV 16 or 18, or genital warts (HPV 6 or HPV 11), and lesions related with other HPV types, cervical adenocarcinoma in situ, vulvar or vaginal intraepithelial neoplasia [10]. In addition, women must be vaccinated before their first sexual activity, prior to exposure to HPV. HPV vaccination is also recommended for women with weakened immune systems (including people with HIV infection), given their higher risk of having HPV infection.

By mid-2016, 65 countries had introduced HPV vaccines, mostly developing countries, but including an increasing number of middle and low-income countries. Unfortunately, HPV vaccines are expensive and they have not been included in immunization programs and given free of charge to eligible women in Venezuela and most less-developed regions. Thus, screening continues to be the major intervention that can prevent cervical cancer in these countries.
