Cervical cancer vaccine has limited protection for sexually experienced women
Preferred cancer prevention measure for “mature” women: regular HPV + cervical cytology screening
Cervical cancer is the second most common malignancy among women worldwide. In recent years, it has become popular for many high-income women to get the HPV vaccine in Hong Kong and Macau to prevent cervical cancer. However, gynecologists point out that the protective effect of the vaccine is overestimated and that one may not be able to rest easy after getting the vaccine. Many women who are more aware of self-protection are already sexually active and past the optimal age for HPV vaccination.
Current vaccines do not cover all high-risk subtypes
The main “culprit” of cervical cancer is the human papillomavirus (HPV). The squamous cells on the surface of the cervix and the cervical mucus work together to protect against HPV, and most women are able to clear the virus from their bodies after infection. “However, less than 10 percent of women are unable to get rid of the virus, resulting in a persistent infection.” In this way, HPV then integrates with the DNA of the squamous cells of the cervix, causing the squamous cells to become diseased.
The primary route of transmission of HPV is sexual. During sex, there is more or less minor damage to the mucosa, and as long as one partner carries HPV, the virus can easily invade the mucosa of the reproductive tract of the other partner. Therefore, all women who have had sexual experience have the chance to be infected. The more sexual partners you have, the greater the probability of infection. Statistics show that 80% of women have been infected with HPV in their lifetime.
There are nearly 100 subtypes of HPV, 15 of which are associated with cervical cancer. High-risk subtypes include HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, etc., with 16 and 18 being the most common. Vaccines administered abroad mainly target these two subtypes.
”Foreign vaccines are divided into bivalent and quadrivalent, with the former covering two subtypes of HPV 16 and 18 and the latter covering four subtypes of HPV 16, 18, 6 and 11.” The existing vaccines are mainly developed based on the high-risk subtypes commonly found abroad, which are different from the virus subtypes prevalent in China. Other common high-risk subtypes in China include 58 and 31. If you have received the cervical cancer vaccine and encounter other high-risk subtypes, there is still a possibility of repeated infection.
Vaccination before the “first time” works best
The cervical cancer vaccine is not cheap and requires three injections of several thousand dollars each. As a result, most women who get vaccinated outside of China are high-income earners, most of whom are already sexually active. “Once you have had sexual experience, it means that you may have been exposed to HPV or even infected. The protection is not as good if you get the vaccine again.” The best time to get the cervical cancer vaccine is before a woman has her first sexual encounter, and it’s best to get the universal vaccination when a woman is young, like the hepatitis B vaccine. It is understood that a significant percentage of people who receive the HPV vaccine abroad are girls who are about to enter puberty or are in their prime.
Despite these limitations, the vaccine is still a positive preventive tool to reduce the risk of infection. However, from the perspective of cervical cancer prevention, “mature girls” do not necessarily need to hug the vaccine as a “tree” to prevent cervical cancer.
”The virus can be latent in the cells for several years after infection with HPV, and can resume its activity once the body’s immunity is reduced.” He said that from the latent infection period to the HPV-related tumor stage, especially the development of cervical cancer, there is a period of about 10 years in between, and there will be cervical epithelial atypical hyperplasia (in pathology called “cervical intraepithelial neoplasia”) and other precancerous warnings, enough to take precautions to protect themselves from the hands of cancer.
A positive HPV test does not necessarily mean a progression to cancer
For mature women, a more economical and reliable way to prevent cancer is to have regular gynecological checkups, including HPV test and cervical cytology screening, among which the result of HPV test is the most important for patients’ hearts.
The news that the gynecological examination results showed positive for HPV made 32-year-old Ms. Xu very worried: “Do I have to prepare to fight against cancer right away?” This kind of thinking is somewhat common among patients. In fact, positive does not mean the degree of cervical cancer progression.
Whether HPV-positive women can progress to precancerous lesions and cancers such as cervical intraepithelial high grade lesions is highly related to which subtype they belong to. Studies have shown that women who present with low-grade cervical lesions who are positive for HPV infection of high-risk types have a greater risk of cervical lesion progression than women with low-risk HPV infection or who are HPV negative. In addition, the DNA load level of HPV and the time of first HPV infection are also significant for the progression of cervical lesions.
Six categories of high-risk women should have regular gynecological examinations
The best combination of TCT (liquid-based thin-layer cytology) plus HPV testing is currently the best screening protocol. The combination of cervical cytology and HPV testing can detect the vast majority of high and low grade lesions. The cost of these two tests at a tertiary care hospital is about $500 or so, which is a lot less for women to have to buy a few bottles of skin care products or a few pieces of clothing to understand their health risks.
The TCT and HPV tests require specimens to be collected during the gynecological examination, and a special small brush is used to brush a number of cells on the cervix, which takes only a few minutes and is painless and non-invasive. There is no need to do any preparation before the test, just avoid menstruation. If the test is negative for HPV, cervical cytology can be done once or twice a year. If both tests are positive, the risk of “upgrading” to cervical cancer is much higher and colposcopy is required.
Six categories of women with high-risk factors should pay particular attention to regular gynecological checkups.
1. Early sexual life;
2. Women who have given birth early or multiple times;
3, women who have multiple sexual partners, or whose spouses have multiple sexual partners;
4, male partners with long foreskin or suffering from genital herpes and other sexually transmitted diseases;
5.Cervical lesions, such as cervicitis, cervical precancerous lesions, etc.;
6.Family history of cervical cancer, endometrial cancer, vaginal cancer or vulvar cancer.
Once abnormal vaginal bleeding occurs, especially after sexual intercourse, cervical screening should be performed immediately.