Haq Muneeb Ul, Pritchard D Mark, Myint Arthur Sun, Javed Muhammad Ahsan, Duckworth Carrie A, Than Ngu Wah, Bonnett Laura J, Hughes David M
Institute of Systems, Molecular and Integrative Biology, The University of Liverpool, Liverpool, UK.
The Clatterbridge Cancer Centre NHS Foundation Trust, Liverpool, UK.
Cancer Med. 2025 Apr;14(7):e70697. doi: 10.1002/cam4.70697.
Currently, there are no clinically predictive models that can prognosticate the response of rectal cancers to Contact X-ray brachytherapy (CXB). This review aims to critically evaluate existing models that have attempted to predict the response of rectal cancer to external beam radiotherapy, with the objective of laying the foundation for the development of a CXB-specific prediction model.
A random-effects meta-analysis was employed to calculate pooled estimates of the discriminative ability of published models. Using the Prediction Model Risk Of Bias Assessment Tool (PROBAST), each model was evaluated for its risk of bias and applicability. Additionally, the frequency of commonly utilised predictive factors was documented.
Twelve papers discussed fifteen models based on pre-treatment factors. Models predicting response based on the Tumour regression grade (TRG) classified responders as patients who achieved a complete response or near complete response and achieved a pooled AUC of 0.82 (95% CI 0.74-0.89). Models that predicted pathologic complete response (pCR) had a pooled AUC of 0.76 (95% CI 0.71-0.82). The most utilised predictive parameters were age, tumour grade and T stage. However, these models were prone to significant risk of bias and had limited applicability to the general population.
Although the existing models were statistically robust, they lacked broad applicability. This was primarily due to a lack of external validation, which limits their clinical utility. A future CXB-specific model should prioritise dedicated data collection based on pre-calculated sample size and include the predictive factors identified in this review.
目前，尚无能够预测直肠癌对接触式X线近距离放射治疗（CXB）反应的临床预测模型。本综述旨在严格评估现有的试图预测直肠癌对外照射放疗反应的模型，以为开发特定于CXB的预测模型奠定基础。
采用随机效应荟萃分析来计算已发表模型鉴别能力的合并估计值。使用预测模型偏倚风险评估工具（PROBAST），对每个模型的偏倚风险和适用性进行评估。此外，记录常用预测因素的频率。
12篇论文讨论了基于治疗前因素的15个模型。基于肿瘤退缩分级（TRG）预测反应的模型将达到完全缓解或接近完全缓解的患者分类为反应者，合并AUC为0.82（95%CI 0.74 - 0.89）。预测病理完全缓解（pCR）的模型合并AUC为0.76（95%CI 0.71 - 0.82）。最常用的预测参数是年龄、肿瘤分级和T分期。然而，这些模型存在显著的偏倚风险，对一般人群的适用性有限。
尽管现有模型在统计学上具有稳健性，但它们缺乏广泛的适用性。这主要是由于缺乏外部验证，限制了它们的临床效用。未来特定于CXB的模型应优先根据预先计算的样本量进行专门的数据收集，并纳入本综述中确定的预测因素。
