Effect of Organized Cervical Cancer Screening Programs on Incidence and Mortality: A Systematic Review and Meta-analysis.

Abstract

The aim of this study was to assess the impact of organized screening programs on incidence and mortality rates of cervical cancer in women. A systematic review of the relevant literature was performed in accordance with the PRISMA 2020 protocol by searching PubMed, Scopus and Web of Science. Endnote20 and Rayyan Systematic Review Screening Software were used for duplicate removal and then, independent evaluation was done by two reviewers. The quality of studies was assessed using the Newcastle Ottawa scale. A random-effects meta-analysis was performed in order to compute the pooled effect size, with Hartung-Knapp adjustment for random effects model. DerSimonian-Laird estimator for Tau², Mantel-Haenszel estimator used in calculation of Q and Tau², and calculation of I² based on Q were used to assess and quantify heterogeneity between studies. Inverse variance method was also used. The results of the meta-analysis show that women who were regularly screened in an organized cervical cancer screening program were statistically significantly less likely to develop (OR = 0.40, 95% CI 0.29-0.55) or die (OR = 0.31, 95% CI 0.16 to 0.58) from cervical cancer. Significant heterogeneity among the case-control studies evaluating the incidence of cervical cancer has been detected (Tau² = 0.1034; χ² = 245.42; df = 12, p < 0.0001; I² = 95.1%). Moderate to high heterogeneity among the case-control studies evaluating the mortality has been detected (Tau² = 0.1161; χ² = 20.12; df = 3, p < 0.0002; I² = 85.1%). The results of tests for assessing asymmetry (Egger's and Begg's test, p < 0.05), indicates the absence of publication biases. The results of our meta-analysis show that women who participate in organized screening programs are significantly less likely to develop and die from cervical cancer, especially if they are screened regularly. Women who irregularly participated in an organized cervical cancer screening program have almost equal risk for cervical cancer compared to women who did not participate in an organized cervical cancer screening program. Women with irregular participation in an organized cervical cancer screening program have a cervical cancer risk that is nearly comparable to the risk among non-participants.