Optimizing the Detection of Occult Cervical Cancer: A Prospective Multicentre Study in China

Early-stage cervical cancer is usually diagnosed by colposcopy-directed biopsy (CDB) and/or endocervical curettage (ECC), but some neglected lesions must be detected by conization because they are occult. This study aimed to explore the optimal method for detecting these "occult" cervical cancers.

A total of 1299 patients who were high-risk for early-stage cervical cancer from five centres in China were prospectively included. We evaluated the diagnostic performance of cytology, HPV testing, colposcopy and CDB&ECC for detecting "occult" cervical cancer and discussed the diagnostic importance of transformation zone (TZ) type, conization length and the proportion of cervical cone excision.

The diagnostic agreement between colposcopy impression and conization was 64.5% and 72.4% between CDB&ECC and conization. Forty-two patients were finally diagnosed with pathologic cancer, and the sensitivities of cytology, colposcopy, CDB&ECC were 4.8%, 7.1%, and 47.4%, respectively. Twenty cases were neglected by CDB&ECC but further diagnosed as cancer by conization, considered to be occult cervical cancer, accounting for 1.6%. Cytologic high-grade squamous intraepithelial lesion (HSIL)+, positive HPV, biopsy HSIL+ and cervical TZ type 3 were considered risk factors for developing HSIL+, while colposcopy impression HSIL+ was not. There was a significant difference between cancerous and HSIL patients in the proportion of cervical cone excision (P<0.001), which was recognized as a risk factor (P<0.001) for detecting cancer, while the length of cervical cone excision was not. The average proportion was 0.62, and the minimal effective proportion was 0.56.

Since the incidence of occult cervical cancer neglected by CDB&ECC, colposcopy and cytology was far beyond expectations, conization is necessary, especially in patients with TZ type 3, high-grade cytology and biopsy results. As the cervical length varies in patients, the proportion of cervical cone excision might be a better indicator for detecting occult cervical cancer.