The modern rectal cancer treatment paradigm offers additional opportunities for organ preservation, most notably via total neoadjuvant therapy (TNT) and consideration for a watch-and-wait (WW) surveillance-only approach. A major barrier to widespread implementation of a WW approach to rectal cancer is the potential discordance between a clinical complete response (cCR) and a pathologic complete response (pCR). In the pre-TNT era, the identification of predictors of pCR after neoadjuvant therapy had been previously studied. However, the last meta-analysis to assess the summative evidence on this important treatment decision point predates the acceptance and dissemination of TNT strategies. The purpose of this systematic review was to assess preoperative predictors of pCR after TNT to guide the ideal selection criteria for WW in the current era. An exhaustive literature review was performed and the electronic databases Embase, Ovid, MEDLINE, PubMed, and Cochrane were comprehensively searched up to 27 June 2023. Search terms and their combinations included “rectal neoplasms”, “total neoadjuvant therapy”, and “pathologic complete response”. Only studies in English were included. Randomized clinical trials or prospective/retrospective cohort studies of patients with clinical stage 2 or 3 rectal adenocarcinoma who underwent at least 8 weeks of neoadjuvant chemotherapy in addition to chemoradiotherapy with pCR as a measured study outcome were included. In this systematic review, nine studies were reviewed for characteristics positively or negatively associated with pCR or tumor response after TNT. The results were qualitatively grouped into four categories: (1) biochemical factors; (2) clinical factors; (3) patient demographics; and (4) treatment sequence for TNT. The heterogeneity of studies precluded meta-analysis. The level of evidence was low to very low. There is minimal data to support any clinicopathologic factors that either have a negative or positive relationship to pCR and tumor response after TNT. Additional data from long-term trials using TNT is critical to better inform those considering WW approaches following a cCR.
现代直肠癌治疗模式为器官保留提供了更多可能性，其中最显著的是通过全程新辅助治疗（TNT）及考虑采用"观察等待"（WW）的单纯监测策略。然而，WW策略在直肠癌治疗中广泛实施的主要障碍在于临床完全缓解（cCR）与病理完全缓解（pCR）之间可能存在的不一致性。在TNT时代之前，新辅助治疗后pCR的预测因素已有相关研究。但此前评估这一重要治疗决策点汇总证据的最新荟萃分析，早于TNT策略被广泛接受和推广的时期。本系统综述旨在评估TNT后pCR的术前预测因素，以指导当前时代WW策略的理想选择标准。我们进行了详尽的文献检索，全面检索了截至2023年6月27日的Embase、Ovid、MEDLINE、PubMed和Cochrane电子数据库。检索词及其组合包括"直肠肿瘤"、"全程新辅助治疗"和"病理完全缓解"。仅纳入英文研究。纳入标准为：针对临床2期或3期直肠腺癌患者的随机临床试验或前瞻性/回顾性队列研究，这些患者除接受放化疗外，还接受了至少8周的新辅助化疗，并以pCR作为研究测量结果。本系统综述共纳入九项研究，分析了与TNT后pCR或肿瘤反应呈正相关或负相关的特征。结果定性归纳为四类：（1）生化因素；（2）临床因素；（3）患者人口统计学特征；（4）TNT治疗顺序。研究间的异质性使得无法进行荟萃分析。证据等级为低至极低。目前极少有数据支持任何临床病理因素与TNT后的pCR及肿瘤反应存在明确的正向或负向关系。从长期TNT试验中获得更多数据，对于更好地指导那些在cCR后考虑采用WW策略的临床决策至关重要。
肿瘤(癌症)患者之家