Morais Marina, Pinto Diogo Melo, Machado José Carlos, Carneiro Silvestre
Surgery Department, Hospital Pedro Hispano, Matosinhos, Portugal; Surgery Department, Faculty of Medicine, University of Porto, Porto, Portugal.
Surgery Department, Hospital Pedro Hispano, Matosinhos, Portugal.
Eur J Surg Oncol. 2022 Jan;48(1):218-227. doi: 10.1016/j.ejso.2021.08.034. Epub 2021 Sep 3.
The management of locally advanced rectal cancer (LARC) requires a multidisciplinary approach, with an increasing interest for non-operative strategies. Liquid biopsy for obtaining circulating tumor DNA (ctDNA) can provide information on neoadjuvant chemoradiotherapy (nCRT) pathological response and cancer-specific prognosis, and therefore might be a promising guide for these treatments.
A systematic review of the studies available in literature has been performed to assess the role of ctDNA as a predictive and prognostic biomarker in LARC patients.
We retrieved 21 publications, of which 17 full-text articles and 4 abstracts. Results have been labelled into two groups: predictive and prognostic. Data about the usefulness of liquid biopsy in this setting is still inconclusive. However, baseline higher levels of longer fragments of cell-free DNA and integrity index, tumor-specific mutations and certain methylated genes could predict non-responders. Also, undetectable baseline ctDNA and decrease of common rectal cancer mutations throughout treatment (dynamic monitoring) were predictive factors of pathological complete response. The continuous detection of ctDNA in different timepoints of treatment (minimal residual disease) was consistently associated with worse prognosis.
ctDNA is a promising biomarker that could assist predicting treatment response to nCRT and prognosis in patients with LARC. The ideal methods and timings for the liquid biopsy still have to be defined.
局部晚期直肠癌（LARC）的管理需要多学科方法，人们对非手术策略的兴趣日益增加。通过液体活检获取循环肿瘤DNA（ctDNA）可以提供有关新辅助放化疗（nCRT）病理反应和癌症特异性预后的信息，因此可能是这些治疗的一个有前景的指导指标。
对文献中可用的研究进行了系统评价，以评估ctDNA作为LARC患者预测和预后生物标志物的作用。
我们检索到21篇出版物，其中17篇全文文章和4篇摘要。结果分为两组：预测性和预后性。关于液体活检在这种情况下的有用性的数据仍然没有定论。然而，基线时游离DNA较长片段的水平较高、完整性指数、肿瘤特异性突变和某些甲基化基因可以预测无反应者。此外，基线ctDNA检测不到以及整个治疗过程中常见直肠癌突变的减少（动态监测）是病理完全缓解的预测因素。在治疗的不同时间点持续检测ctDNA（最小残留疾病）与较差的预后始终相关。
ctDNA是一种有前景的生物标志物，可以帮助预测LARC患者对nCRT的治疗反应和预后。液体活检的理想方法和时机仍有待确定。
