Printed: Ž. Gudlevičienė , Z. Stukonienė. “Risk factors for cervical cancer”. Health, 2004, 7, 29-30.
Živilė Gudlevičienė, Zofija Stukonienė. Institute of Oncology, Vilnius University
Cervical cancer is becoming more common in our country, according to scientific epidemiological studies, after the leading breast cancer, especially among women aged 20-30. In 2002, 468 women with cervical cancer were registered in Lithuania, of whom only one in four had an initial stage of the disease.
Cervical cancer never occurs suddenly and in healthy tissues. This requires a long period of untreated various diseases, not months, but years. During this period, there are reactive dysplastic changes in the epithelial tissue of the outer part of the cervix and its mouth, which are noticed by doctors in time, and the woman may not develop cancer.
A woman must take care of her own health, which, according to the World Health Organization, depends on as much as 50-60% of her lifestyle (sex, diet, smoking, etc.). It is no coincidence that the priorities of the National Health Concept today are focused on health promotion and maintenance, disease prevention and the development of primary health care.
Therefore, knowing, understanding, and eliminating risk factors for cervical cancer can help a woman not develop the disease.
Various risk factors contribute to the development of cervical cancer. One of the most important risk factors is the human papilloma virus. However, viral infections alone are not enough, most other risk factors are affected – environmental influences, a woman’s hormonal condition, smoking, etc.
The risk of cervical cancer has been shown to increase with the increase in the number of sexual partners due to the increased risk of HPV infection (1).
The risk of cervical cancer increases if sex begins at a young age . According to many authors, the earlier a woman starts having sex, the more sexual partners she agrees with, the more often she may be infected with various infections, sexually transmitted diseases, including HPV (2). Proper sexual hygiene is also important for the prevention of this disease.
Analysis of the effects of oral contraceptives (OK) on the development of cervical lesions suggests that long-term use is a risk factor for cervical cancer. The risk of developing cervical cancer increases if a woman takes OK for a long time and changes her sexual partners frequently. Some authors have shown a protective effect of oral contraceptives for the development of cervical cancer. However, when OK use was associated with other risk factors such as sexual behavior, these data were statistically unreliable. The International Agency for Research on Cancer has published data from multicentre studies that show that women who are infected with HPV and have taken OK have an increased risk of developing cervical cancer. However, the increase in risk is associated with the duration of OK use: OK use for less than five years is not associated with cancer risk, but if OK is used for a longer period, this risk increases up to 5 times, especially if OK is used for more than 10 years (1, 2) .
According to many studies, barrier contraceptives can reduce the risk of cervical dysplasia and cancer by preventing the spread of sexually transmitted infections to the cervix. They also contain a variety of spermicides with antiviral activity. In this way, the protective mechanism of various contraceptive pastes and gels containing antiviral substances is also explained (2).
There is an association between the number of births and the risk of developing invasive cervical cancer, as pathological lesions of the cervix develop at the site where the cervix was damaged during labor. HPV-infected women who have had seven or more pregnancies are four times more likely to develop cervical cancer than HPV-infected and unborn women. An increased risk of cervical cancer is also associated with abortions (1,2).
Women’s smoking relatively increases the risk of squamous cell carcinoma. This risk is associated with long and intense smoking and with tobacco smoke in the environment. It has been found that when cigarettes are smoked, tobacco metabolites enter the cervical mucosa and can directly affect the mucosa. HPV-infected women who have ever tried to smoke are twice as likely to develop cervical cancer. The results of various studies summarized by the International Agency for Research on Cancer suggest that smoking acts as an independent risk factor for cervical cancer. Smoking often begins in adolescence and the process often takes several years, and thus women who have been infected with HPV already have a significant “experience” of smoking. After cessation of smoking, the lesions found in women in the cervix often disappear (1).
Studies of the effects of various trace elements on the risk of cervical cancer have shown that high levels of carotene, vitamins C, E and folate in the diet are associated with a reduction in the risk of cervical cancer. An inverse correlation was found between b carotene levels and cervical cancer. Low levels of carotene in food or serum levels increase the risk of cervical cancer and also support the presence of HPV infection in the body. Data on the association between vitamin E intake and the risk of cervical cancer are highly conflicting. Vitamin E stimulates cellular immunity, but it also supports the presence of HPV infection in the body. Folates play a key role in the DNA methylation process. Their small number facilitates the integration of HPV into the genome of the cell. Folate consumption should play a protective role in the development of cervical cancer. However, the results of the performed studies show that the use of folates for the chemoprophylaxis of cervical cancer has no protective effect. No association was found between dietary vitamin A levels and serum retinol levels and the risk of cervical cancer. Vitamin A and its derivatives are thought to inhibit HPV-associated cervical proliferation.
Women who have not undergone a prophylactic cytological test for PAP have a multiple-fold increased risk of developing cervical cancer compared to women who have ever undergone such a test (4). These tests detect precancerous lesions of the cervix at an early stage, which, if detected and cured in time, prevent the cancer from developing.
Older women (over 60 years of age) have an increased risk of developing cervical cancer because they are less likely to see a doctor and have fewer medical check-ups.
The influence of socioeconomic conditions on the development of cervical cancer has also been demonstrated. It was found that women from lower social strata suffer 3 times more often than those belonging to higher social strata. The low level of education of women is also considered a risk factor. According to some authors, less educated women start having sex earlier and give birth more (3, 4).
Some national minorities are at increased risk of developing cervical cancer, which is related to their historical socio-economic conditions and related risk factors (2,3).
The link between cervical cancer and other infectious agents is also being sought. If women who are infected with HPV are tested for antibodies to Herpes simplex type 2 virus or Clamydia trachomatis , they have an increased risk of developing cervical cancer. However, there is insufficient scientific evidence in this regard.
Elucidation of cervical cancer risk factors is important in the development of primary cervical cancer prevention, which includes reducing the risk of these factors, proper nutrition, vitamin and micronutrient intake, sex education, improving socio-economic conditions, and more. measures.
1. Castellsagué X, Mu?oz N. Cofactors in Human Papillomavirus Carcinogenesis – Role of Parity, Oral Contraceptives and Tobacco Smoking. J Natl Cancer Inst,2003,31,20-28.
2. Bayo S., Bosch F.X., de Sanjose S., Munoz N., Combita A.L.,Coursaget P., Diaz M, Dolo A., van den Brule A.J., Meijer C.J. Risk factors of invasive cervical cancer in Mali. – Int. J. Epidemiol, 2002, Vol.31, N1, p. 202-209.
3. Moreno V, Bosch FX, Mu?oz N, Meijer CJ, Shah KV, Walboomers JM, et al. Effect of oral contraceptives on risk of cervical cancer in women with human papillomavirus infection: the IARC multicentric case-control study. Lancet 2002; 359:1085-92.
4. Ferrera A., Velema J.P., Figueroa M., Bulnes R., Toro L.A., Claros J.M., de Barahona O., Melchers W.J.G. Co-factors related to the causal relationship between human papillomavirus and invasive cervical cancer in Honduras. – Int. J. Epidemiol., 2000, Vol.29, p. 817-825.