Clear Cell Carcinoma (CCC) of the Cervix Is a Human Papillomavirus (HPV)-independent Tumor Associated With Poor Outcome: A Comprehensive Analysis of 58 Cases

Cervical clear cell carcinoma (CCC) is a rare human papillomavirus-independent adenocarcinoma. While recent studies have focused on gastric-type endocervical adenocarcinoma (GTA), little is known about CCC. A total of 58 (CCCs) were collected from 14 international institutions and retrospectively analyzed using univariable and multivariable methods and compared with 36 gastric-type adenocarcinomas and 173 human papillomavirus-associated (HPVA) endocervical adenocarcinoma (ECA) regarding overall survival (OS) and recurrence-free survival (RFS). Most cases were FIGO stage I (72.4%), with Silva C pattern of invasion (77.6%), and the majority were treated with radical surgery (84.5%) and adjuvant therapy (55.2%). Lymphovascular invasion was present in 31%, while lymph node metastasis was seen in 24.1%; 10.3% were associated with abdominopelvic metastases at the time of diagnosis; 32.8% had recurrences, and 19% died of disease. We did not find statistically significant differences in OS and RFS between CCC and GTA at 5 and 10 years (P=0.313 and 0.508, respectively), but there were significant differences in both OS and RFS between CCC and HPVA ECA (P=0.003 and 0.032, respectively). Also, OS and RFS in stage I clear cell and GTA were similar (P=0.632 and 0.692, respectively). Multivariate analysis showed that OS is influenced by the presence of recurrence (P=0.009), while RFS is influenced by the FIGO stage (P=0.025). Cervical CCC has poorer outcomes than HPVA ECA and similar outcomes to human papillomavirus-independent GTA. Oncologic treatment significantly influences RFS in univariate analysis but is not an independent prognostic factor in multivariate analysis suggesting that alternative therapies should be investigated.