Do the Benefits of Cervical Screening Extend to Rare Cancer Types?

Although squamous cell carcinoma and adenocarcinoma comprise most cervical cancers, uncommon types (including adenosquamous cell [ASC], glassy cell, and clear cell cancers) originating from glandular tissue often present at advanced stages with poor prognosis. As these types are so infrequent, they may be excluded from analysis; thus, it remains unclear whether their risk is reduced by cervical cancer screening. In a population-based study, investigators in Sweden reviewed >4500 cervical cancer cases from 2002 through 2011 and identified 164 cases of ASC and 174 cases of other rare types. Among tumor samples available for testing, 70% were positive for high-risk human papillomavirus (HPV).

Compared with untested women, those who underwent cy…