Correlation of referring cytology and in-house cytology in detection of early cervical neoplasia

Objective:

Currently in Germany, an essential change of national cervical cancer screening program is undergoing by implementing an organized HPV- and Cytology based screening program. Suspicious results are recommended to be examined in specialized Colposcopy Units.

Aim of the following work is to analyze the correlation and precision of external documented Pap smear results within the cervical cancer detection to in-house Pap cytology results within a specific colposcopic assessment.

Materials and methods:

In this retrospective study, we analyzed clinical data of 2296 women visiting the Dysplasia Unit of the university hospital Erlangen from 2014 – 2017. All patients underwent Pap-smear (Munich II/III nomenclature), colposcopic examination and a colposcopically guided biopsy, if necessary.

Results were analyzed descriptively by Spearman's rank correlation and crosstabulation.

Results:

In 50.05% (1104 cases), external Pap and in-house Pap results were congruent. In 20.81% (459 cases), external Pap cytology results were lower than in-house Pap results. In 33.23% (733 cases), external Pap cytology results were higher than in-house Pap results.

Data in this case had a p-value of 0.001 using the Wilcoxon signed-rank test to compare a significant distinction between the two variables and is considered to be clinically significant. Spearman's rank correlation coefficient rho equals 0.633 (P < 0.001).

Conclusion:

The detection rate of cervical abnormalities differs significantly depending on being performed as a routine examination or within a triage for pathological findings.

Further investigation by comparing Pap results to final histology is necessary to objectify which procedure has the highest diagnostic accuracy.