A139: Prevalence and primary prevention of human papillomavirus infection in Tomsk city and Tomsk region

Abstract

Cervical cancer is one of the most common female malignancies with incidence of 19.7 per 100,000 population in Russia in 2011 (Davydov, Aksel et al., 2011). Over 6000 women in Russia die of cervical cancer annually. The cervical cancer incidence shows a tendency towards increasing rates among young women (Chissov, 2009). Tomsk region has been found to be the territory of increased cancer risk for cervical cancer. The age-standardized incidence rate is 1.87 times higher in Tomsk region than in Russia, being 20.40/0000 (Pisareva, Odintsova et al., 2012). The highest incidence of cervical cancer is observed in women aged 15–39 years (Churuksaeva, Kolomiets, Shpileva, 2012). The causal role of human papillomavirus infections in cervical cancer has been documented beyond reasonable doubt. Prevention of exposure to high risk HPV types by vaccination may prove to be the most efficient and logistically feasible preventive intervention for cervical cancer. Epidemiological studies conducted at the Tomsk Cancer Research Institute have shown that the median age of patients with cervical intraepithelial neoplasia and cervical cancer is 39.9 ± 8.5, and 89.5% of women are HPV-positive. Prevalence of high-grade squamous intraepithelial lesion (H-SIL) peaks between ages 25 years and 30 years. The predominant HPV type in screened women of Tomsk region as well as worldwide is HPV-16, reaching peak incidence in women aged 36–40 years (74%). In the older age group (from 51 to 60 years), HPV-18 is associated with 25% of cervical cancer cases. High prevalence of HPV-31 has been found in women under the age of 45 years with an incidence peak (17%) in the age group ⩽20 years. The geographical widespread data on HPV type-distribution are essential for estimating the impact of vaccines on cervical cancer and cervical screening programs. Immunization against HPV for young women aged between 9 and 26 years, with a predominant age cohort 11–13 years, was introduced in Tomsk region in 2010. The aim of the HPV immunization program is to protect females before they reach an age when the risk of HPV infection increases. A total of 627 girls were vaccinated, and 1653 doses of vaccines were injected. The three- dose schedule was given to 414 (66%) girls and 2-dose schedule to 198 (31.6%) girls. Vaccine safety assessment was carried out. Adverse effects were observed in 9.6% of cases and were mainly characterized by dizziness and pain at the injection site. Vaccination was well tolerated. When calculating socio-economic feasibility of the proposed technology , not only the economic damage caused by the high mortality of women from cervical cancer, but also the cost for treatment of precancerous cervical lesions were taken into account, as out of 25 women with undetected CINII-III, 10 will develop cervical cancer. There have been calculated the estimated damage from cervical cancer in the Tomsk region, which takes into account not only the cost of diagnosis and treatment of cervical pre-cancer, but also losses associated with temporary permanent disabilities (social benefits, including disability pension before the age of 55 years). Calculations show that the total economic damage caused by the management of patients with cervical cancer, can be from 20 to 40 mln. rubles per year. Thus, primary prevention of cervical cancer, taking into account the prevalence of HPV infection and economic impact of cervical cancer can be considered as an effective technology for public health that will allow preservation of not only reproductive but also employment potential of women of Tomsk region.