The population benefit of radiotherapy for cervical cancer: local control and survival estimates for optimally utilized radiotherapy and chemoradiation.

Abstract

Population benefits of radiotherapy if evidence-based guidelines were routinely followed across the entire population are largely unknown. The aim of this study was to investigate population-based benefits for cervical cancer. Overall survival (OS) and local control (LC) benefits were investigated. XRT benefit was defined as the absolute benefit of radiotherapy, over no treatment, for radical indications and defined as the benefit of adjuvant radiation over surgery alone for adjuvant indications. The concurrent chemoradiation (CRT) benefit was the incremental benefit of CRT over XRT. Australian population benefits were modeled using decision trees. Citation databases were systematically queried. Meta-analysis was performed if multiple sources of the same evidence level existed. Robustness of the model assumptions was tested through sensitivity analysis. 53% of all cervix patients had adjuvant or curative radiotherapy indications. 96% were for CRT. The estimated 5-year absolute benefits of optimally utilized radiotherapy alone were: LC: 31% (95% Confidence Interval 29%, 34%), OS: 17% (15%, 18%). These were over and above the contribution of other modalities to outcomes. The incremental 5-year absolute benefits of CRT were: LC 4% (2%, 5%), OS 3% (1%, 5%). In sensitivity analysis, the model was robust. Optimally utilized radiotherapy provides substantial population OS and LC benefits for cervical cancer. Chemoradiation provides a modest population benefit over XRT. The population-based model was robust.