[ad_1]
"Hundreds of women will be spared from cervical cancer each year when a new test will replace conventional screening," reports the Online Mail.
A study conducted in Canada found that an initial test of human papillomavirus (HPV), which causes almost all cases of cervical cancer, has found more lesions precancers than with conventional smears.
Smear tests look for changes in cervical cells, while HPV tests look for the presence of the virus.
At present, the NHS screening program for cervical cancer begins with a smear test. Women whose smear test results show possible changes to the limit of quality or cell limit will have the sample tested for HPV. Those with low grade and HPV changes will then be referred for further tests (colposcopy).
However, some areas of the NHS are testing a system where HPV testing is used first. If this is successful, the NHS can switch to the initial HPV test.
This study suggests that this change would lead to more cases of precancerous lesions than in the current system
Where does the story come from?
The research was conducted by physicians and scientists working on cervical cancer in Canada. screening program, including researchers from the University of British Columbia, the British Columbia Center for Disease Control, Lower Mainland Laboratories, British Columbia Cancer, and McGill University.
It was funded by the Canadian Institutes of Health Research and published in the Journal of the American Medical Association's open-access reading committee, so it is free to read online.
was accurate but did not explain that a possible risk of switching to the new system would be an increase in "false positive" results, where women with HPV, but no cancer changes, are referred to other investigations.
What kind of research was it?
This was a randomized controlled trial that examined the results of both screening systems over a 48-month period. This is usually the best way to compare tests and see what works best.
What did the research involve?
The researchers recruited 19,009 women for initial HPV testing or smear testing, about half of whom were randomly assigned to each group.
Women with negative HPV testing were recalled after 48 months for HPV and smear tests, while smear-negative women were recalled after 24 months for repeated smear and 48 months for both.
Women with positive HPV or smear tests had their samples immediately analyzed using the other test and then had colposcopy if the results showed both HPV and cell changes.
Smear tests were performed using liquid medium cytology (the standard method used in the NHS). The HPV test was performed by checking DNA samples. Women also completed questionnaires on the lifestyle and history of sexual health to ensure that differences in outcomes were not due to imbalances between the groups tested.
The women who participated in the study were 25 to 65 years old, had not had a Pap smear in the past 12 months, were not pregnant and did not have a Pap smear. had no history of cervical cancer or precancerous changes in the last 12 months. years.
The researchers compared the results of the first series of tests with results at the end of 48 months. They focused primarily on moderate or severe changes in cervical cells (pre-cancerous changes) that could lead to cervical cancer. The medical term for these types of changes is "cervical intraepithelial neoplasia grade 3 or greater" (CIN3 +).
What were the basic results?
In the first screening round at the beginning of the study, more cases of CIN3 + were found in women who had been tested for HPV (7 per 1000 women) than in women who had had smears (4 , 4 per 1,000 women).
However, 48 months after the start of the study, there were fewer cases of CIN3 + in women who had been tested for HPV than in smears, presumably because they had been found and treated during the first screening cycle
. the last 48-month screening was:
- 2.3 cases of CIN3 + per 1,000 women who initially underwent HPV testing (95% confidence interval [CI] 1.5 to 3.5)
- 5, 5 cases of CIN3 + per 1,000 women initially testing (95% CI 4.2 to 7.2)
Women who had a negative HPV test at the beginning of the study were significantly less likely to develop CIN3 + within 48 months as women who had a negative smear test at the beginning of the study.
The results showed:
- 1.4 cases of CIN3 + per 1000 women who had been tested negative for HPV (95% CI 0.8 to 2.4)
- 5.4 cases of CIN3 + per 1,000 women who had negative smears (95% CI 4.1 to 7.1)
More women were referred to colposcopy after HPV testing at the start of the study: 57 per 1000 women versus 30, 8 per 1000 after smear, but the opposite was true at 48 months.
Total references for colposcopy were similar between groups – 106.2 per 1,000 women for HPV testing and 101.5 per 1,000 women for smear testing. How did the researchers interpret the results?
The researchers said their findings show that "the primary HPV test detects cervical neoplasia earlier and more specifically than cytology," adding that he "detected significantly more cases of CIN3 + and CIN2 + round CIN3 + and CIN2 + rates significantly reduced 48 months later. "
They also cautioned that more work needs to be done to assess the economic consequences of changing the screening model.
Conclusion [19659008] Although the results of the study are encouraging and suggest that the HPV test may well serve as a primary test instead of cervical smears, we have no longer-term results to show if this really makes a difference, how many women have invasive cervical cancer or are dying of the disease.
So we do not know if the assertion of Mail Online that "of this Some women would be spared from cancer "is necessarily true.
However, we know that early detection of cervical cancer makes treatment easier. This can probably be welcome. What is not clear right now is if it could lead to more women needing further investigation, such as colposcopy.
Girls and young women are now offered HPV vaccination, but it will take some time before it prevents most cases of cervical cancer. Women should continue to participate in cervical cancer screening, whether they have been vaccinated or not.
To learn more about the current NHS cervical cancer screening program.
Source link
