An Asian multi-national, multi-institutional, retrospective study on image-guided brachytherapy in cervical adenocarcinoma and adenosquamous carcinoma.

Purpose: There are limited reports on outcomes of three-dimensional image-guided brachytherapy (3D-IGBT) for cervical adenocarcinoma in Asia. In a multi-institutional retrospective study, we assessed the clinical outcomes of three-dimensional image-guided brachytherapy for cervical adenocarcinoma or adenosquamous carcinoma (CA/CAC) in Asian countries.
Material and Methods: Patients who had undergone definitive radiation therapy/concurrent chemoradiotherapy for untreated cervical cancer between 2000 and 2016 were registered. Those who had undergone 3D-IGBT for histologically proven CA/CAC were included. Data on patients' characteristics and treatment were collected, including tumor reduction rate (defined as a percentage of reduction in tumor size before brachytherapy compared with that at diagnosis) and high-risk clinical target volume D ₉₀ . Overall survival (OS), local control (LC), and progression-free survival (PFS) rates were calculated using Kaplan-Meier method. Late toxicities were assessed using common terminology criteria for adverse events version 4.0.
Results: Anonymized data of 498 patients were collected. Of the 498 patients, 36 patients met inclusion criteria. The median follow-up period was 39 months. The 3-year OS, LC, and PFS rates were 68.4%, 68.5%, and 44.4%, respectively. After treatment, five patients had tumor re-growth without complete disappearance of the tumor. Two patients developed grade 3 vaginal toxicity or grade 4 rectal toxicity; none developed other severe late toxicities. A tumor reduction rate of > 26.3% was the only significant factor in multivariate analyses, and was associated with significantly better OS ( p = 0.018), LC ( p = 0.022), and PFS ( p = 0.013). There were no significant trends in local control or dose to high-risk clinical target volume D ₉₀ .
Conclusions: LC rate of CA/CAC was insufficient despite 3D-IGBT. Meanwhile, tumor reduction rate was associated with LC, OS, and PFS rates. Therefore, CA/CAC may require a different treatment strategy than that applied in cervical squamous cell carcinoma.
Competing Interests: Dr Okonogi reports grants and other (investigational drug supply) from AstraZeneca clinical trial, outside the submitted work. Dr Igaki reports grants and personal fees from HekaBio, grants from CICS, grants from Elekta KK, personal fees from AstraZeneca, personal fees from Itochu, personal fees from HIMEDIC, and personal fees from Varian, outside the submitted work. Dr Itami reports grants from Elekta KK, grants and personal fees from Itochu, personal fees from ViewRay, personal fees from Palette Science, personal fees from Alpha-TAU, and personal fees from HekaBio, outside the submitted work. This study received no financial support from any company; thus, there are no conflicts of interests to declare.
(Copyright © 2022 Termedia.)