Women between the ages of 23 and 60 are regularly called in to submit cell samples. Participating in these check-ups has been shown to provide good protection against cervical cancer. But the test method is not entirely reliable. When a woman develops cervical cancer, the most common reason is that she did not take part in the check-up, but it happens that women who did participate nevertheless get cancer.
Researchers at the Sahlgrenska Academy have carried out a large-scale study comprising 13,484 women in the Göteborg area. Samples were taken at five different maternity clinics. The women were randomly selected to submit cell specimins using either the traditional method or a partially new method. With the new method, liquid-based cytology, the sampler mixes the cells in a fluid solution instead of smearing them on a glass slide. In the laboratory the solution is processed in a machine that produces a glass slide with a purer background that is easier to assess.
In the study, all cell changes found were examined in the same way, regardless of sample type. After the women had been examined using tissue biopsies taken by a gynecologist, between 40 and 60 percent more women with major changes were found in the group that had been sampled using liquid cell specimens. All changes of this degree of severity were then treated with a simple surgical procedure.
“If cell changes in a woman are missed, there are usually further chances of finding them, since these changes develop slowly. But the results of the study indicate that more cases of cancer can be prevented if we start using this more sensitive method,” says Björn Strander, a doctoral student at the Sahgrenska Academy who is in charge of preventing cervical cancer at the Oncology Center, Västra Götaland Healthcare Region in western Sweden.
The study also showed that fewer samples had to be thrown out as unassessable, but that the proportion of women who were asked to undergo further examination based on some deviation in their cell specimen rose from 3.5 percent to 4.5 percent of those submitting samples.
¬“Now that we have acquired experience with the method, we see many advantages for the laboratory. The samples are easier to assess, and work goes faster. The remaining fluid can be used for other lab analyses, such as virus testing, which can be a valuable complement in the diagnosis. What’s more, part of the diagnosis can be done automatically, a factor that will be important in the future,” says Walter Ryd, head of the Cytology Laboratory at the Sahlgrenska University Hospital and leader of the study.
The study is now being published on the Web page of the international scientific journal Cancer Cytopathology.
Journal: Cancer Cytopathology
Title of article: Liquid-based cytology versus conventional Papanicolaou smear in an organized screening program: a prospective randomized study
Authors: Björn Strander, Agneta Andersson-Ellström, Ian Milsom, Thomas Rådberg, Walter Ryd