Comparison of Treatment Outcomes between Adenocarcinoma/Adenosquamous Carcinoma and Squamous Cell Carcinoma of Early-Stage Cervical Cancer with Adjuvant Concurrent Chemoradiotherapy

Abstract

The relative and absolute frequency of adenocarcinoma/adenosquamous carcinoma (AC/ASC) of cervix has increased. Because of lack of prospective studies, there remains conflicting results about therapeutic response and prognostic differences between AC/ASC and squamous cell carcinoma (SCC). Pelvic radiotherapy (RT) combined with concurrent chemotherapy(CCRT) is the standard adjuvant treatment for cervical cancer, regardless of the histological subtype. However, there is little information regarding the impact of adeno- and adenosquamous histology in early-stage cervical cancer treated with adjuvant CCRT Our study aimed to compare survival outcomes of AC/ASC and SCC cervical cancer treated with adjuvant intensity-modulated radiotherapy (IMRT) and concurrent paclitaxel-cisplatin (TP) chemotherapy. Medical records of cervical cancer patients treated with adjuvant CCRT in our institute from August 2009 to April 2018 were retrospectively studied. Patients received IMRT in a total dose of 50-50.4 Gy in 25-28 fractions. Integrated boost (SIB) or late course accelerated boost (LCAB) with external beam radiotherapy (EBRT) to the vaginal cuff was added for patients with high risk factors. All patients received 3-4 cycles of TP chemotherapy. Two cycles of which were administered as the regimen of concurrent chemotherapy in escalating-dose. The treatment outcomes of patients with AC/ASC and SCC were compared with a multivariate Cox regression model and log-rank method before and after propensity score matching (1:3). After matching, a total of 284 patients with early-stage cervical cancer was selected, 71 patients in AC/ASC group and 213 patients in SCC group. The median follow-up was 37.8 months. When treated with IMRT and concurrent TP chemotherapy, the patients with AC/ASC of the cervix exhibited a similar overall survival (OS) (p=0.376) and disease-free-survival (DFS) (p = 0.243) compared the patients with SCC. The 3-year OS in the SCC group and AC/ASC group were 97.2% and 92.5%, and the 3-year DFS were 94% and 85.7%, respectively. Survival in patients of both histologic subtypes were: 3-year OS 96.3% and 3-year DFS 91.1%. Recurrences occurred in 11 patients and relapse patterns did not differ significantly between AC and SCC in the entire cohort. Adverse events to treatment were similar across histologies. AC/ASC of the cervix are associated with similar DFS and OS compared to SCC of the cervix when treated with IMRT and concurrent TP chemotherapy.