CHAPTER 6 Secondary prevention of cervical cancer

Epidemiology of cervical cancer with special focus on India

Cervical cancer is on the declining trend in India according to the population-based registries; yet it continues to be a major public health problem for women in India. Multifactorial causation, potential for prevention, and the sheer threat it poses make cervical cancer an important disease for in-depth studies, as has been attempted by this paper. This paper attempts to review the available knowledge regarding the epidemiology and pattern of cervical cancer; types of HPV (human papilloma virus) prevalent among cervical cancer patients and among women in general, high-risk groups such as commercial sex workers, and HIV (human immunodeficiency virus)-positive women; and the role of the national program on cancer in control efforts. The peak age of incidence of cervical cancer is 55-59 years, and a considerable proportion of women report in the late stages of disease. Specific types of oncogenic HPV-16, 18 have been identified in patients with cervical cancer. Other epidemiological risk factors are early age at marriage, multiple sexual partners, multiple pregnancies, poor genital hygiene, malnutrition, use of oral contraceptives, and lack of awareness. A multipronged approach is necessary which can target areas of high prevalence identified by registries with a combination of behavior change communication exercises and routine early screening with VIA. Sensitizing the people of the area, including menfolk, is necessary to increase uptake levels. Vaccination against types 16 and 18 can also be undertaken after taking into confidence all stakeholders, including the parents of adolescent girls. Preventing and treating cervical cancer and reducing the burden are possible by targeting resources to the areas with high prevalence.

PPV of an HSIL cervical cytology result in China's largest CAP-certified laboratory

INTRODUCTION

Cervical cancer remains a major health problem in China, where no uniform national standards for cervical cytology quality control exist. This study extends previously reported findings on cervical cytology performance in China's largest independent laboratory to have achieved accreditation under the international Laboratory Accreditation Program of the College of American Pathologists.

MATERIALS AND METHODS

A retrospective study identified high-grade squamous intraepithelial lesion (HSIL) cervical cytology reports between 2007 and 2013 from the Cytology Laboratory, Guangzhou Kingmed Diagnostics. Four liquid-based cytology (LBC) preparations were used in 73% of cases and conventional Papanicolaou tests (CPT) in 27%. Follow-up histopathologic diagnoses after HSIL reports were identified in the laboratory database. The positive predictive value for laboratory HSIL cytology results was determined for follow-up histopathologic diagnoses of cervical intraepithelial neoplasia 2 or worse (CIN2+), a recognized international quality control monitor.

RESULTS

Of 1,804,108 cervical cytology reports, 11,929 HSIL reports (0.66%) were identified. The LBC HSIL rate was 0.79%, which was higher than the CPT HSIL rate of 0.33% (P < 0.001). Follow-up CIN2+ histopathologic diagnoses within 6 months after HSIL were identified in 1994 of 2414 patients (82.6%), including 1860 of 2246 LBC HSIL (82.8%) and 134 of 168 CPT HSIL (79.8%). Cervical cancers were diagnosed on follow-up in 244 of 2414 HSIL cases (10.1%).

CONCLUSIONS

The positive predictive value of HSIL cervical cytology results for follow-up histopathologic CIN2+ was within currently recognized benchmark ranges for cytology laboratories. The high rate of cervical cancer diagnoses likely reflects the largely unscreened population. The College of American Pathologists Laboratory Accreditation Program provided quality standards not otherwise available in many international settings.

Optimal positive cutoff points for careHPV testing of clinician- and self-collected specimens in primary cervical cancer screening: an analysis from rural China

careHPV, a lower-cost DNA test for human papillomavirus (HPV), is being considered for cervical cancer screening in low- and middle-income countries. However, not a single large-scaled study exists to investigate the optimal positive cutoff point of careHPV test. We pooled data for 9,785 women participating in two individual studies conducted from 2007 to 2011 in rural China. Woman underwent multiple screening tests, including careHPV on clinician-collected specimens (careHPV-C) and self-collected specimens (careHPV-S), and Hybrid Capture 2 on clinician-collected specimens (HC2-C) as a reference standard. The primary endpoint was cervical intraepithelial neoplasia grade 3 or more severe (CIN3+) (n = 127), and secondary endpoint was CIN2+ (n = 213). The area under the curves (AUCs) for HC2-C and careHPV-C were similar (0.954 versus 0.948, P = 0.166), and better than careHPV-S (0.878; P < 0.001 versus both). The optimal positive cutoff points for HC2-C, careHPV-C, and careHPV-S were 1.40, 1.74, and 0.85, respectively. At the same cutoff point, careHPV-C was not significantly less sensitive and more specific for CIN3+ than HC2-C, and careHPV-S was significantly less sensitive for CIN3+ than careHPV-C and HC2-C. Raising the cutoff point of careHPV-C from 1.0 to 2.0 could result in nonsignificantly lower sensitivity but significantly higher specificity. Similar results were observed using CIN2+ endpoint. careHPV using either clinician- or self-collected specimens performed well in detecting cervical precancer and cancer. We found that the optimal cutoff points of careHPV were 2.0 on clinician-collected specimens and 1.0 on self-collected specimens.