Cervical cancer is a tumor that affects the lower portion of the uterus, called the neck or cervix. This cancer is highly prevalent in the female population. In the world, it ranks second in the “ranking” of female cancers, second only to breast cancer. In Brazil it is in third place, according to the National Cancer Institute in 2014, losing to breast, bowel (colon and rectum), with an incidence rate of 15 new cases per 100,000 women per year. Mortality can reach 5 cases per 100,000 per year.
Schematic representation of the female pelvis
It is a type of tumor that has a long history from its initial lesions to reach the cancer, about 10 to 20 years. If diagnosed early, mainly in the initial or pre-cancerous lesions (intraepithelial), it can be cured in 100% of cases. Already in the advanced stages where the tumor grew to regions beyond the cervix, the prognosis becomes reserved, at risk of suffering severe pain, bleeding, renal impairment, and even death.
The causative agent is the human papillomavirus (HPV). Woman gets this virus at the beginning of sexual life, often in adolescence, and due to immunological factors of women and the agent’s own aggression, the infection becomes persistent, causing precancerous lesions on the cervix. If the immune condition is bad and the type of aggressive HPV, or the recommended treatment is not applied, these lesions may progress to cancer.
HPV is a very common type of virus in the population. Most women will be exposed to this agent during their sex lives, but the infection is transient, where the organism itself has the capacity to eliminate viruses in a period ranging from six months to two years. Even if there is the development of an injury, the immune system itself can “cure” without any treatment. In about 10% of cases where immunity could not react to the presence of the virus can occur persistence of infection, progressing to more serious injuries. Here in this situation it is necessary to treat the injury, with the removal of the affected portion of the cervix.
There are over 150 HPV types, about 40 are inhabitants of the genital and 15 are more aggressive, called oncogenes (cancer). HPV not aggressive or not oncogenic, cause genital warts, or warts, which are benign lesions without risk of progression to cancer. The treatment of these warts can be through local drugs that destroy or stimulate immunity, or surgical removal.
Precancerous lesions caused by the cancer-causing virus in the cervix are called cervical intraepithelial neoplasia (CIN). These are divided into three levels: I, II and III. CIN I lesion is benign and usually does not require treatment because regresses spontaneously in most cases. CIN II, considered intermediate severity in adolescents has a benign behavior with high regression rates. In the older woman, usually from the age of 24 requires treatment which can be for destruction (cauterization or vaporization) or removed (excision). CIN III is the real precursor lesion of cancer and always requires treatment by excision. Cure rates are high, with low risk of recurrence.
In the cervical cancer occurs appearance of lesions with destruction or tumor formation, which has as a direct extension of the vagina, parametria (tissues around the neck), bladder and rectum.
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Risk factors for infection with human papillomavirus (HPV) and consequently for precancerous lesions and cancer are associated with sexual behavior, lifestyle, and some diseases. Among them are cited:
– Early sexual Home – Women who start very young sex life at increased risk of exposure to HPV, with several repeated infections. Also the teenager has youth cervix, which favors the penetration of the virus.
– Multiplicity of sexual partners – Risk of multiple infections by HPV and other infectious agents that may interfere with immune response to the virus presence.
– Smoking – Tobacco is absorbed through the lung and disseminated in the bloodstream and is eliminated in the cervical mucus. This causes damage to the tobacco cervical cell and has an effect of lowering local immunity, hindering the elimination of the virus.
– Immunosuppression – Diseases that interfere directly in the immune system such as HIV, hepatitis, diabetes, use of corticosteroids, transplanted organs, have bad behavior against the HPV infection. Even if injuries have adequad treatment, it is common to relapse with increased risk of progression to cancer and generally shorter.
– Malnutrition – The lack of foods rich in beta-carotene, found in yellow and green vegetables (papaya, carrot, cabbage, broccoli), interfere with immunity, leading to persistence of HPV infection.
– Use of hormonal contraception – has interference immunity when high doses of the hormones used for long periods, over 5 years.
– Low socioeconomic status – This factor is linked to lack of access to preventive examinations and the lack of medical assistance to forward cases of genital infections.
– Chlamydia trachomatis – sexually transmitted disease caused by bacteria and usually does not cause symptoms in most infected women. When is associated with HPV, it interferes with the elimination of viral infection, resulting in increased risk for cancer.