Vaccination significantly reduces the risk of cervical cancer
Vaccination against human papillomavirus (HPV) offers young women good protection against the precursors of cervical cancer. This has now been shown by a large-scale meta-analysis by the Cochrane organization. According to this, women who were vaccinated between the ages of 15 and 26 would have a significantly lower risk of developing high-grade cervical intraepithelial neoplasia. The analysis further showed that there is no evidence of serious side effects from vaccination.
Researchers find no evidence of serious side effects
Cervical cancer (cervical cancer) is a malignant tumor that arises from altered tissue of the cervix (cervix). The biggest risk factor for this type of cancer is infection with the human papillomavirus (HPV). Since 2006 there has been a vaccination against the HP virus, which the Standing Vaccination Committee (STIKO) recommends as standard vaccination for all girls from nine to 14 years. A comprehensive data analysis has now shown that vaccination has been shown to protect young women from the precursors of cervical cancer and is safe against serious side effects, according to the Cochrane organization's report.
High-risk types 16 and 18 are the most dangerous
According to the German Cancer Research Center, more than 170 different types of HPV are currently known. Around 40 of these primarily affect the genital area and the anus (genital HPV types) and are mainly transmitted sexually. Some of the virus types lead to benign genital warts (e.g. HPV 6 and HPV 11), but others lead to tissue changes from which cancer can develop. These so-called high-risk types primarily include HPV 16 and HPV 18, which alone are responsible for around 70% of all cases of cervical cancer.
Researchers evaluate data from more than 73,000 women
For the meta-analysis, the Cochrane researchers evaluated the results of 26 randomized studies with a total of 73,428 women, which have been carried out worldwide over the past eight years. Most of the women in the studies were under 26 years of age, and three subjects between 25 and 45 years were examined.
Studies with the bivalent HPV 16 and 18 vaccine, the quadrival HPV 16/18 vaccine and two low-risk HPV types that cause genital warts were evaluated. The newer vaccine, which targets nine types of HPV, was not included in the review, the Cochrane organization said.
It has been shown that girls and young women who are vaccinated against these two high-risk viruses between the ages of 15 and 26 are well protected against the precursors of cervical cancer, the doctors report. Accordingly, two out of 10,000 women who had no HPV infection at the start of the studies in the study later developed pre-cancer stages despite the vaccination. In the control group, however, 164 subjects were affected.
Vaccination offers less protection in older women
The doctors were also able to show that the vaccination provided protection even if the young women had previously come into contact with pathogens. Regardless of whether or not they were infected with HPV, the experts found that only 157 out of 10,000 women had tissue changes that could develop into cancer in all participants. In the unvaccinated subjects in the control group, however, these changes were seen in 341 women. If the vaccination was carried out at a later age, the experts no longer offered good protection. This could be because older women were more likely to be exposed to HPV viruses.
Further long-term studies necessary
However, the researchers at the Cochrane organization point out that the studies considered did not run long enough to examine the development of cancer of the cervix. Because it can take years or decades for cervical cancer to develop from a tissue change. "Cervical cancer can develop many years after HPV infection and lesion formation," explains oncologist Jo Morrison of Musgrove Park Hospital in Somerset, UK. Accordingly, long-term follow-up studies are required to identify the effects of HPV vaccination on cervical cancer rates, the expert said.
“The vaccination aims to get the immune system to produce antibodies that can block subsequent natural HPV infection. These data show that immunization against HPV infection protects against cervical precancer, and it is very likely that this will reduce cervical cancer rates in the future. However, it cannot prevent all forms of cervical cancer and it is still important to screen regularly, even if you have been vaccinated, ”said Morrison.
More than 1,500 deaths a year
Cervical cancer is the fourth most common malignant tumor in women worldwide. According to the Association of German Tumor Centers, 528,000 initial diagnoses are made annually and approximately 266,000 deaths due to the disease are registered. In 2014, according to the RKI, more than 4,600 women in Germany contracted cervical cancer, and around 1,540 women currently die of it annually. 30 years ago, there were more than twice as many, according to the RKI. (No)