Park Hyojung
Departments of Radiation Oncology, Dankook University Hospital, Dankook University College of Medicine, Cheonan 46115, South Korea.
World J Gastrointest Oncol. 2021 Apr 15;13(4):252-264. doi: 10.4251/wjgo.v13.i4.252.
Distant relapse is the leading cause of cancer-related death in locally advanced rectal cancer. Neoadjuvant chemoradiation (NACRT) followed by surgery inevitably delays delivery of systemic treatment. Some patients show early distant metastasis before systemic treatment.
To identify the most effective treatments. We investigated prognostic factors for distant metastasis, especially early distant metastasis, using the standard treatment paradigm to identify the most effective treatments according to recurrence risk.
From January 2015 through December 2019, rectal cancer patients who underwent NACRT for having clinical T 3-4 or clinical N 1-2 disease according to the 8 American Joint Committee on Cancer staging system were included. Radiotherapy was delivered to the whole pelvis with concomitant chemotherapy. Patients received surgery 6-8 wk after completion of NACRT. Adjuvant chemotherapy was administered at the physician's discretion.
A total of 127 patients received NACRT. Ninety-three patients (73.2%) underwent surgery. The R0 resection rate was 89.2% in all patients. Pathologic tumor and node downstaging rates were 41.9% and 76.3%. Half the patients ( = 69) received adjuvant chemotherapy after surgery. The 3-year distant metastasis-free survival (DMFS) and overall survival (OS) rates were 81.7% and 83.5%. On univariate analyses, poorly differentiated tumors, > 5 cm, involvement of mesorectal fascia (MRF), or presence of extramural involvement (EMVI) were associated with worse DMFS and OS. Five patients showed distant metastasis at their first evaluation after NACRT. Patients with early distant metastasis were more likely to have poorly differentiated tumor ( = 0.025), tumors with involved MRF ( = 0.002), and EMVI ( = 0.012) than those who did not.
EMVI, the involvement of MRF, and poor histologic grade were associated with early distant metastasis. In order to control distant metastasis and improve treatment outcome, selective use of neoadjuvant treatment according to individualized risk factors is necessary. Future studies are required to determine effective treatment strategies for patients at high risk for distant metastasis.
远处复发是局部晚期直肠癌患者癌症相关死亡的主要原因。新辅助放化疗（NACRT）后行手术不可避免地会延迟全身治疗的实施。一些患者在全身治疗前就出现了早期远处转移。
为确定最有效的治疗方法。我们采用标准治疗模式，研究远处转移尤其是早期远处转移的预后因素，以根据复发风险确定最有效的治疗方法。
纳入2015年1月至2019年12月期间，根据美国癌症联合委员会第8版分期系统，因临床T3 - 4期或临床N1 - 2期疾病接受NACRT的直肠癌患者。放疗采用全盆腔照射并同步化疗。患者在完成NACRT后6 - 8周接受手术。辅助化疗由医生酌情给予。
共有127例患者接受了NACRT。93例患者（73.2%）接受了手术。所有患者的R0切除率为89.2%。病理肿瘤降期率和淋巴结降期率分别为41.9%和76.3%。一半患者（n = 69）术后接受了辅助化疗。3年无远处转移生存率（DMFS）和总生存率（OS）分别为81.7%和83.5%。单因素分析显示，低分化肿瘤、肿瘤直径>5 cm、直肠系膜筋膜（MRF）受累或存在壁外侵犯（EMVI）与较差的DMFS和OS相关。5例患者在NACRT后的首次评估时出现远处转移。与未发生早期远处转移的患者相比，发生早期远处转移的患者更可能具有低分化肿瘤（P = 0.025）、MRF受累的肿瘤（P = 0.002）和EMVI（P = 0.012）。
EMVI、MRF受累和组织学分级差与早期远处转移相关。为了控制远处转移并改善治疗效果，有必要根据个体风险因素选择性地使用新辅助治疗。未来需要开展研究以确定远处转移高危患者的有效治疗策略。
