Current screening technology fails to reduce cervical cancer incidence in younger women

Cervical cancer, the most common cancer in younger women

Cervical cancer is the most common cancer in women under 35 years of age. Cervical cancer can be prevented by finding and treating early cellular changes in the neck of the womb (cervix). These changes could lead to cancer if left untreated.

Cytology is failing in younger women

The NORDCAN project includes incidence data on cervical cancer in the Nordic countries. As the graph below illustrates, since 1975-79 the incidence of cervical cancer has dropped dramatically for women 40 years or older. However, for women younger than 40 years, the incidence has not been reduced in the same time period. These results indicate that cytology as a screening test fails to prevent cervical cancer in younger women as efficient as in older women.

 Cervical cancer incidence over 5 year intervals in the Nordic countries since 1975. Based on data from the NORDCAN project.

Cervical cancer incidence over 5 year intervals in the Nordic countries since 1975. Based on data from the NORDCAN project.

Majority of cervical cancer cases occurs in women having only previous NILM cytology results

Among women attending an organized screening program, Norwegian statistics show that the majority of the cervical cancer cases occur in women having only previous NILM (Negative for Intraepithelial Lesion and Malignancy) cytology results. In the 4 year period 2008-2011 a total of 407 women developed cervical cancer among those attending the Norwegian cervical cancer screening program (age 25-69) and 54 % of these women (218 women) had only previous NILM cytology results (see CRN annual reports). This high level of screening failure indicates the need of an accurate quality control technology for women having NILM cytology results. 

Cytology quality control using PreTect SEE

Cytology needs assistance to identify younger women with a false negative cytology result in risk of having or developing cervical cancer. PreTect SEE is a molecular diagnostic test detecting oncogene activity (mRNA E6/E7) from HPV types 16, 18 and 45.

By using PreTect SEE on samples having NILM cytology results, only about 2 % of these women below 40 years of age will have a positive PreTect SEE test resulting in re-screening of the cytology smear. Re-screening the PreTect SEE positive cytology NILM samples will in a majority of cases reveal missed abnormal cells and thereby many false negative cytology results can be avoided. If no abnormal cells are found during re-screening, the smear sample may not include enough of the abnormal cells having oncogenic activity.

Having high accuracy, PreTect SEE is ideal as a quality control test for NILM cytology. 

An oral presentation including clinical test results was presented at Eurogin, 2015:

“The added value of rescreening cytology normal samples with positive HPV mRNA test for the detection of CIN2+ in primary screening”.
F. Skjeldestad