Impact of histological subtype on survival in patients with locally advanced cervical cancer that were treated with definitive radiotherapy: adenocarcinoma/adenosquamous carcinoma versus squamous cell carcinoma

Abstract

Objective: To compare the survival outcomes of patients with cervical squamous cell carcinoma (SCC) and adenocarcinoma/adenosquamous carcinoma (AC/ASC) among patients with locally advanced cervical cancer that were treated with definitive radiotherapy.

Methods: The baseline characteristics and outcome data of patients with locally advanced cervical cancer who were treated with definitive radiotherapy between November 1993 and February 2014 were collected and retrospectively reviewed. A Cox proportional hazards regression model was used to investigate the prognostic significance of AC/ASC histology.

Results: The patients with AC/ASC of the cervix exhibited significantly shorter overall survival (OS) (p=0.004) and progression-free survival (PFS) (p=0.002) than the patients with SCC of the cervix. Multivariate analysis showed that AC/ASC histology was an independent negative prognostic factor for PFS. Among the patients who displayed AC/ASC histology, larger tumor size, older age, and incomplete response to radiotherapy were found to be independent prognostic factors. PFS was inversely associated with the number of poor prognostic factors the patients exhibited (the estimated 1-year PFS rates; 100.0%, 77.8%, 42.8%, 0.0% for 0, 1, 2, 3 factors, respectively).

Conclusion: Locally advanced cervical cancer patients with AC/ASC histology experience significantly worse survival outcomes than those with SCC. Further clinical studies are warranted to develop a concurrent chemoradiotherapy (CCRT) protocol that is specifically tailored to locally advanced cervical AC/ASC.

Keywords: Adenocarcinoma; Carcinoma, Adenosquamous; Radiotherapy; Uterine Cervical Neoplasms.

Fig. 1

Clinical implications of AC/ASC histology in locally advanced cervical cancer patients. Kaplan-Meier estimates of survival according to the histological subtype. (A) PFS and OS (all patients). (B) PFS and OS (stage IIB–IIIA patients). (C) PFS and OS (stage IIIB–IVA patients). (D) PFFS and DMFS (all patients). AC, adenocarcinoma; ASC, adenosquamous carcinoma; DMFS, distant metastasis-free survival; OS, overall survival; PFFS, pelvic failure-free survival; PFS, progression-free survival; SCC, squamous cell carcinoma.

Fig. 2

Survival difference according to the poor prognostic factors possessed in AC/ASC patients. (A) Kaplan-Meier estimates of PFS. The PFS of the patients was inversely associated with the number of poor prognostic factors they possessed (p<0.001). The estimated 1-year PFS rates for those with 0, 1, 2, 3 factors were 100.0%, 77.8%, 42.8%, 0.0%, respectively. (B) Kaplan-Meier estimates of PFFS and DMFS. AC, adenocarcinoma; ASC, adenosquamous carcinoma; DMFS, distant metastasis-free survival; PFFS, pelvic failure-free survival; PFS, progression-free survival.