[Pap smear for mass screening: Results of an African experiment]

Systematic screening for cervical cancer in Dakar region: prevalence and correlation with biological and socio-demographic parameters

Background

Cervical cancer is a major public health problem. In 2018, globally 569,847 cervical cancer were diagnosed and 311,000 deaths were projected due to this preventable disease. Worldwide, therefore, the cervical cancer disease ranks as the fourth most frequently diagnosed cancer and the fourth leading cause of cancer death in women in 2018.

The high rate of dysplasia in Senegal and the absence of well-organized screening programs informed this study, which aims to determine the prevalence of cervical dysplasia and its relationship to biological and socio-demographic characteristics.

Methods

This study is based on 1000 conventional smears collected during routine cervical cancer screening at the Gaspard Camara Health Center and the Histology - Embryology and Cytogenetics Laboratory of the Cheikh Anta DIOP University in Dakar. The smears were read according to the Bethesda and Richart systems. However, all data were returned to the Bethesda system using the correspondence table between the different classifications of squamous cell lesions of the cervix. Some of the patients with abnormal smears had colposcopy and if necessary a biopsy. Other patients with low-grade lesions were recommended to have their smears resumed in 6 months or 1 year later.

Results

Cytological analysis was performed for 1000 patients aged 16 to 82 years (mean age = 41 ± 11.16). Among these, 176 patients had abnormal smears, 23 had Atypical Squamous Cells of Undetermined Significance (ASCUS), 143 had a low-grade lesion, 9 had a high-grade lesion and 1 had carcinoma. Among the remaining 822 patients, cytological analysis revealed no suspected malignant lesions, but 623 among them had dystrophy and 2 were unsatisfactory. Among patients with abnormal smears, 104 patients (23 ASCUS + 71 low grade + 9 high grade + 1 carcinoma) had performed colposcopy, 40 of whom had normal colposcopy and 64 had abnormalities. Sixty-four (64) biopsies were performed. Four (4) were not satisfactory. However, for 26/60 biopsies, the histology was normal, 21/60 had a low grade, 11 displayed a high grade and only 2 had carcinoma. Among the 176 patients with abnormal smears, 72 low-grade patients had undergone cytological examination 6 months to 1 year later to determine the persistence, regression or progression of low-grade dysplasia. During follow-up, persistence was observed in 25% (n = 18) of cases, progression to High-grade squamous intraepithelial lesion (HSIL) was detected in 2.78% (n = 2), while 72.22% (n = 52) of the patients experienced regression.

Conclusion

In this study, the prevalence of abnormal smear was 17.60% for cytology. Meanwhile, the Colposcopy and histology confirmed just 3.40%. These results underline the interest and need for a review of the discrepancies observed between pathologists.