Cervical screening in Western Kazakhstan: Liquid-based cytology 'Cell Scan' versus azur-eosin staining

Objective To assess the effectiveness of the current cervical cancer screening tools in Western Kazakhstan. Methods Smears taken through (i) conventional cytology using azur-eosin staining and (ii) liquid-based cytology (LBC) ‘Cell Scan’ in the general female population and in women first diagnosed with cervical cancer were collected throughout the region. ROC-analysis with curve construction and weighted Cohen's κ calculation were applied. A total of 494 cytological pairs were collected, including 94 sets with histology findings. Results The conventional (azur-eosin staining) technique contained 0.2% non-informative material and LBC ‘Cell Scan’ had 5.9%. Area under the curve was 0.95 for the conventional technique and 0.92 for ‘Cell Scan’ (p > 0.05). The conventional smears showed κ 0.62, sensitivity 90.4% at specificity 90.0% for CIN2+, while LBC ‘Cell Scan’ smears showed κ 0.47, sensitivity 83.3% at specificity 92.5%. Conclusions In this analysis it was not possible to prove that the LBC ‘Cell Scan’ technique was superior to its predecessor, azur-eosin staining. These findings highlight the need to modify the current screening programme according to updated international scientific evidence on effective screening design, such as the use of HPV DNA testing with Pap smear triage in women aged 30 or older. Further research, and a Health Technology Assessment, are necessary if we wish to establish a national standardized screening programme using the available technology appropriately.

Objective To assess the effectiveness of the current cervical cancer screening tools in Western Kazakhstan. Methods Smears taken through (i) conventional cytology using azur-eosin staining and (ii) liquid-based cytology (LBC) 'Cell Scan' in the general female population and in women first diagnosed with cervical cancer were collected throughout the region. ROC-analysis with curve construction and weighted Cohen's kappa calculation were applied. A total of 494 cytological pairs were collected, including 94 sets with histology findings. Results The conventional (azur-eosin staining) technique contained 0.2% non-informative material and LBC 'Cell Scan' had 5.9%. Area under the curve was 0.95 for the conventional technique and 0.92 for 'Cell Scan' (p > 0.05). The conventional smears showed kappa 0.62, sensitivity 90.4% at specificity 90.0% for CIN2+, while LBC 'Cell Scan' smears showed kappa 0.47, sensitivity 83.3% at specificity 92.5%. Conclusions In this analysis it was not possible to prove that the LBC 'Cell Scan' technique was superior to its predecessor, azur-eosin staining. These findings highlight the need to modify the current screening programme according to updated international scientific evidence on effective screening design, such as the use of HPV DNA testing with Pap smear triage in women aged 30 or older. Further research, and a Health Technology Assessment, are necessary if we wish to establish a national standardized screening programme using the available technology appropriately.