Cervical cancer is considered an almost 100% preventable tumor. Worldwide, the average age of cervical cancer patients is 55 years, but the average age of patients in China is 45 years, 10 years earlier and 13 years earlier than in China in the last century. There are young patients who have cervical cancer at the age of 17. Among them, the increase of female sexual partners and earlier time of sexual intercourse are the main reasons.
I. Expert opinion on cervical cancer.
1.Younger cervical cancer: more sexual partners, the body can’t clear many kinds of HPV virus; I don’t pay attention to cleanliness and hygiene and body resistance decline are also one of the reasons for the development. Smoking can cause the body’s resistance to decline.
There are many types of HPV viruses, and if women have fixed sexual partners, the types of HPV viruses they are exposed to are relatively fixed. Under this condition, if one’s body is good and immune, the body can get rid of HPV virus within a year. But if there are many sexual partners and the body has many different types of HP
The type of HPV virus infection in Chinese is different from foreign countries. 70% of foreign patients are infected with HPV16 and HPV18, and the vaccine is also for that type, but HPV33, HPV31 and HPV58 in China have the risk of causing disease.
At present, physical examination is still the only way to detect cervical cancer early. There is a long process of cervical cancer, from HPV infection causing cervical lesion to becoming cancer, there is an average of 6-8 years, if detected early, the treatment is simple not to become cancer.
About HPV infection
1. HPV infection is a necessary factor for the occurrence of cervical intraepithelial neoplasia and cervical cancer.
HPV infection is closely related to cervical neoplasm, and HPV16 was first discovered in 1983. High-risk HPV infection can lead to cervical precancer and cervical cancer, as well as vaginal cancer, most vulvar cancers, anal cancer and oral cancer, mainly HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, 82, etc. 70% of cervical cancer can be attributed to HPV16 and HPV18 infection. It is now believed that women without persistent HPV infection have little risk of cervical cancer, and laboratory studies and epidemiological evidence confirm this view.
2. Incidence of HPV infection
HPV infection is a common sexually transmitted infection with a population prevalence of 10%. Seventy to 80 percent of women will have at least one HPV infection in their lifetime. The highest prevalence occurs in young women, up to 20-25%, with infection rates decreasing after age 30. The infection rate is high in young women after first intercourse, leading to severe neoplasia in the second half of their 20s, to the point where cervical cancer occurs in their 40s. At the same time, the rate of persistent high-risk HPV infection increases. the risk of HPV infection is a gradual and cumulative process. Among women who are not infected with HPV, about 3% of women will be infected with HPV every month.
3. The starting age for routine HPV screening
Among women aged 15-19 years, the cumulative HPV infection rate exceeds 40% (3 years after initial intercourse.) HPV testing among women younger than 30 years generally represents a new infection, while a larger proportion of HPV testing values among women older than 30 years will be for persistent infection. Therefore, routine HPV nucleic acid screening should not be geared toward women under 30 years of age. Younger women will have multiple recurrent cycles of HPV infection, and such infections are often associated with only minor cytologic changes. Women in this age group tend to self-clear their viral infections and restore cytologic changes to normal. Testing for transient HPV infections is not meaningful and can cause unnecessary anxiety in women. Conversely, detection of oncogenic HPV types in older women is indicative of pathology.
4. Clearance time of HPV infection
HPV is a sexually transmitted disease, and HPV infection of the genital tract is very common in women who have recently been sexually active (75%), while the number of sexual contacts is positively correlated with the risk of genital warts. The vast majority of HPV infections are transient, with spontaneous healing occurring within 1 year after a new infection. Only a minority of HPV infections remain latent and reactivate years or decades later. Most HPV infections have only subclinical symptoms. HPV is acquired through direct skin-to-skin contact, sexual intercourse is not necessary, multiple types of infection can occur simultaneously, and re-infection with the same type can occur despite previous infection with a particular type. It takes about 3 weeks from HPV infection to release of the virus, but it can take weeks to months between HPV infection and the onset of injury, during which there is essentially no inflammatory response, and there may be immune escape early in the viral infection. 80% of infections are self-clearing, and the time to clearance is largely determined by the type, taking 5-6 months for low-risk types and 8-14 months for high-risk types. (Persistent infection studies are reviewed every 6 months.) The median value for HPV self-clearance is six months, one year, or two years, with more than 90% of gender-specific HPV clearing in less than two years. HPV16 infection persists longer, with five consecutive years of infection having a 40% risk for CIN3 formation. Persistent HPV infection is a molecular marker for the progression of CIN2 as well as CIN3.
5, the occurrence of genital warts does not indicate infidelity between men and women.
In general, if a stable partner has genital HPV infection, the other partner will be infected or become immune to the infection. Condoms have been shown to provide only limited protection against the acquisition of genital warts and the progression of CIN2 and CIN3. Direct skin-to-skin contact is the most effective way to transmit HPV infection. The virus is not transmitted through blood and body fluids (e.g., semen) and primarily infects the mucous membranes and adjacent genital skin. One study confirmed that 60% of sexual partners with genital warts will further transmit genital warts to another partner. The most common mode of transmission among adults is sexual contact. The incubation period of genital HPV infection is extremely variable. Generally, genital warts become apparent after 3-6 months of HPV infection, however, some studies have shown incubation periods of several months or even decades. Longer incubation periods are common in patients with immunodeficiency or who have not had sex for many years, and such women may suddenly develop warts or cervical cell abnormalities.
6. Do I need to be tested for HPV after treatment for cervical CIN?
Numerous studies have shown that the use of high-risk HPV nucleic acid testing is necessary after non-surgical treatments such as local ablation or excision for CIN. HPV nucleic acid testing can predict treatment failure (specificity 75%).
7. Treatment of HPV-positive, cytology (TCT)-negative.
For ASC-US under 30 years of age, cytology is recommended every 6 months. for women over 30 years of age, repeated screening at 1-year intervals is an appropriate screening strategy. In sexually active adolescents and in women under 30 years of age, although the rate of high-risk HPV positivity is very high, the incidence of cervical invasive cancer is very low and therefore high-risk HPV testing is not necessary. HPV nucleic acid testing for ASC-US in postmenopausal women would be highly effective and would result in a relatively smaller number of women referring to colposcopy. For women over 35 years of age or with clinically suggestive endometrial neoplastic lesions, AGC (atypical glandular cells), diagnostic scraping is required to exclude endometrial lesions before it is meaningful.
C. How to perform cervical cancer screening properly?
The use of both liquid-based cytology (TCT) and HPV testing for cervical cancer screening is currently recommended due to the fact that the likelihood of individuals with both tests being negative progressing to high-grade cervical precancer as well as cervical cancer is almost zero.
1. Start and cut-off time.
When to start: Women over 20 years of age with a history of sexual intercourse.
When to terminate: 65 years old. Women with recent normal screening results (negative screening within the last 10 years) should stop screening at age 65; those with a history of CIN2 and above (CIN2+) should continue screening for at least 20 years after diagnosis.
Screening and follow-up after hysterectomy: Screening can be stopped for those who have had a hysterectomy and no history of CIN2+;
Those with a history of CIN2+ should continue to be screened after hysterectomy; those with preserved cervix should continue to be routinely screened after surgery.
2.How to properly perform cervical cancer screening?
Women should insist on 7 cervical cytology scrapings (TCT) and HPV tests in their lifetime after they start to have sex.
If the result of the first physical examination is negative, retest in a year.
If the re-test is negative, re-test after two years, and so on, increasing the interval of one year each time.
If the results of the last 7 tests are negative, you can leave the threat of cervical cancer forever. If the HPV test is positive, you need to pay high attention to it and follow the medical advice before treatment.
Women under 30 years old are routinely screened for TCT, suspicious lesions are added for HPV, and routine screening for HPV is not necessary.
Women over 30 years of age are recommended to be screened for both HPV and TCT if available.
HPV acquisition is age-related. In developed countries such as Europe and the United States, the peak rate of HPV positivity is around age 20, mainly related to the age of first sexual intercourse. The infection rate then declines, while at the same time the rate of persistent high-risk HPV infection increases, leading to severe neoplasia in the second half of the 20s, to the point where cervical cancer occurs around the age of 40.
The risk of HPV infection is a gradual and cumulative process. Among women who are not infected with HPV, approximately 3% of women become infected with HPV each month. among women aged 15-19 years, the cumulative HPV infection rate exceeds 40% (3 years after initial intercourse). an HPV test in women under 30 years of age generally represents a new infection, while a larger proportion of HPV test values in women over 30 years of age will be for persistent infection. Therefore, routine HPV nucleic acid screening should not be directed to women under 30 years of age.