Distinct clinical and prognostic features of cervical adenosquamous carcinoma: a nationwide registry-based and...

We aimed to clarify the clinical and prognostic characteristics of cervical adenosquamous carcinoma (ASC) by comparing it with both adenocarcinoma (AC) and squamous cell carcinoma (SCC).

Using the Japanese nationwide cervical cancer registry, we identified 37,556 patients with SCC, usual-type AC, or ASC who initiated treatment between 2015 and 2020. Propensity score matching (PSM) was conducted to balance baseline characteristics across histologic subtypes, including age, International Federation of Gynecology and Obstetrics (FIGO) stage, and initial treatment modality. Stage-stratified analyses were performed to compare lymph node metastasis (LNM) patterns and prognosis between subtypes.

The age distribution of ASC largely overlapped with that of AC and was younger than SCC (median 47, 48, and 53 years, respectively). In contrast, the frequency of LNM in ASC resembled that of SCC; both ASC and SCC generally had higher LNM than AC. Initial treatment strategies were similar between ASC and AC, whereas chemoradiotherapy was more frequently selected for SCC in FIGO IB-IIIC1. After PSM, overall survival was worse for ASC versus SCC (hazard ratio [HR]=1.32; 95% confidence interval [CI]=1.08-1.60) but comparable between ASC and AC (HR=0.93; 95% CI=0.77-1.11). Stage-stratified analyses showed consistently poorer outcomes for ASC versus SCC, particularly in IB1, IIIC1-T1, IIIC1-T2, and IIIC2. In contrast, ASC versus AC revealed bidirectional patterns: ASC tended to fare worse in IB1, IB2, IIIC1-T1, and IIIC2, whereas AC tended to fare worse in IIB and IIIC1-T2.

ASC displayed an LNM profile more closely resembling that of SCC and showed stage-dependent survival distinct from AC.