奥沙利铂在局部进展期直肠癌术前同步放化疗中的应用进展

目前基于氟尿嘧啶及卡培他滨的术前同步放化疗是局部进展期直肠癌的标准治疗模式,但仍有较高的远处转移率,为进一步提高疗效,探索新的化疗药物越来越受到学界的重视.其中奥沙利铂因其在辅助化疗及姑息治疗中的效果卓越,受到越来越多学者的关注,并因此开展了一系列Ⅰ～Ⅲ期临床研究.绝大多数Ⅰ/Ⅱ期临床研究表明奥沙利铂具有很好的应用前景,不仅达到良好病理完全缓解(pCR)率及肿瘤降期率,且不良反应可耐受.但是,在Ⅲ期临床研究中,STAR-01、ACCORD-12、NSABP-R04、PETACC-6均为阴性结果,仅CAO/ARO/AIO-04是阳性结果,显示奥沙利铂组能够获得显著的总生存期(DFS)获益,故奥沙利铂能否应用于局部进展期直肠癌术前放化疗存在明显的争议.因此根据目前研究结果,在直肠癌术前新辅助放化疗中,仍然不推荐在5-Fu/卡培他滨基础上常规使用奥沙利铂.全文对奥沙利铂在局部进展期直肠癌术前同步放化疗中的应用进行了总结,希望为进一步的临床研究提供依据.     

局部晚期直肠癌术前与术后同步放化疗的疗效比较

[目的]比较术前同步放化疗与术后同步放化疗对局部晚期中低位直肠癌的临床疗效和不良反应。[方法]收集100例局部晚期中低位直肠癌患者,50例行术前同步放化疗,同期50例先行根治术再行术后同步放化疗,比较两组的保肛率、局部复发率和生存率以及不良反应。[结果]术前同步放化疗的保肛率明显高于术后同步放化疗组,而局部复发率明显低于术后同步放化疗组（P〈0.05）,3、5年生存率两组间没有差别（P〉0.05）。[结论]局部晚期中低位直肠癌术前同步放化疗可以提高保肛率,降低局部复发率,值得临床推广。     

PDCD4 as a Predictor of Sensitivity to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer Patients

Objective: The purpose of this study was to examine the role of programmed cell death 4 (PDCD4) expressionin predicting tumor response to neoadjuvant chemoradiotherapy and outcomes for patients with locally advancedrectal cancer. Methods: Clinicopathological factors and expression of PDCD4 were evaluated in 92 patientswith LARC treated with nCRT. After the completion of therapy, 4 cases achieved clinical complete response(cCR), and thus the remaining 88 patients underwent a standardized total mesorectal excision procedure.There were 38 patients (41.3%) with a good response (TRG 3-4) and 54 (58.7%) with a poor one (TRG 0-2).Results: Immunohistochemical staining analyses showed that patients with high expression of PDCD4 were moresensitive to nCRT than those with low PDCD4 expression (P=0.02). High PDCD4 expression before nCRT andgood response (TRG3-4) were significantly associated with improved 5-year disease-free survival and 5-yearoverall survival (P<0.05). Multivariate analysis demonstrated that the pretreatment PDCD4 expression was anindependent prognostic factor. Conclusion: Our study demonstrated that high expression of PDCD4 protein isa useful predictive factor for good tumor response to nCRT and good outcomes in patients with LARC.     

Circulating Lymphocytes as Predictors of Sensitivity to Preoperative Chemoradiotherapy in Rectal Cancer Cases

Objective: The objective of this study was to identify clinical predictive factors for tumor response afterneoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC). Methods: All factors wereevaluated in 88 patients with LARC treated with nCRT. After a long period of 4-8 weeks of chemoradiotherapy,3 patients achieved clinical complete response (cCR) and thus aggressive surgery was avoided, and the remaining85 patients underwent a curative-intent operation. The response to nCRT was evaluated by tumor regressiongrade (TRG) system. Results: There were 32 patients (36.4%) with good tumor regression (TRG 3-4) and 56(63.6%) with poor tumor regression (TRG 0-2). Lymphocyte counts and ratios were higher in good responsecases (P=0.01, 0.03, respectively) while neutrophil ratios and N/L ratios were higher in poor response cases(P=0.04, 0.02, respectively). High lymphocyte ratios before nCRT and good tumor regression (TRG3-4) weresignificantly associated with improved 5-year disease-free survival (P<0.05). Pretreatment nodal status wasalso significantly associated with 5-year disease-free survival and 5-year overall survival (P<0.05). Multivariateanalysis confirmed that the pretreatment lymphocyte ratio and lymph nodal status were independent prognosticfactors. Conclusion: Our study suggested that LARC patients with high lymphocyte ratios before nCRT wouldhave good tumor response and high 5-year DFS and OS.     

放疗联合希罗达治疗局部晚期直肠癌近期疗效

目的 观察放疗联合同步口服希罗达治疗局部晚期直肠癌的近期疗效和毒副反应.方法 选择局部晚期无手术指征或拒绝手术直肠癌和直肠癌术后局部复发患者50例,随机分为综合治疗组（23例,接受放疗联合希罗达）和单纯放疗组（27例,仅接受放疗）.结果 综合治疗组总有效率为87.0%,单纯放疗组为66.7%（P＜0.05）.综合治疗组放射性直肠炎发生率为26.1%,手足综合征为21.7%;单纯放疗组放射性直肠炎发生率为11.1%,对症治疗后均好转.结论 放疗联合希罗达治疗局部晚期直肠癌疗效确切、毒副反应较少,值得临床推广应用.     

Adding Three Cycles of CAPOX after Neoadjuvant Chemoradiotherapy Increases the Rates of Complete Response for Locally Advanced Rectal Cancer

Background and Objectives: the total neoadjuvant chemoradiotherapy (TNT) includes different strategies, but the most appropriate model remains uncertain. The purpose of this retrospectively study was to evaluate the safety and pathological response in the consolidation chemotherapy model. Methods: patients with cT3/T4 or TxN + M0 rectal cancer that were receiving neoadjuvant chemoradiotherapy (CRT) (50 Gy with oral capecitabine)/TNT (CRT followed by three cycles of CAPOX) during September 2017 to September 2019 in our department were included. All of the patients were recommended to receive radical surgery. Results: a total of 197 patients were included. Eighty-one patients received CRT, while one hundred and sixteen patients received TNT. Nine patients did not undergo surgery because of the distant metastases (one patient (1.2%) in CRT group, two patients (1.7%) in TNT group) or a refusal of resection (two patients in CRT group, four patients in TNT group). The pathological complete response (pCR) rate was 32.7% in TNT compared with 12.8% in CRT (p = 0.002). There was no statistically significant difference in grade 3 acute toxicities of neoadjuvant treatment and surgical complications between the two groups. Conclusions: the consolidation chemotherapy model is safe for patients with locally advanced rectal cancer and it has a high pCR rate. The long-term follow-up is necessary to be evaluated in a future prospective, randomized trial.     

Correlative Significance of Tumor Regression Grade and ypT Category in Patients Undergoing Preoperative Chemoradiotherapy for Locally Advanced Rectal Cancer

Background: In patients with locally advanced rectal cancer, the treatment response to preoperative chemoradiotherapy (PRCRT) varies, and the ypT stage may change as a result of tumor shrinkage. The purpose of this study was to evaluate the correlative significance and determine the prognostic value of tumor regression grade and ypT category staging systems.Materials and Methods: This retrospective observational study was conducted in a tertiary center. A total of 1240 patients with rectal cancer who underwent curative resection after PRCRT between January 2007 and December 2016 were consecutively included.Results: A significant association was found between the American Joint Committee on Cancer/College of American Pathology tumor regression grading system and ypT category, indicating a potential correlation between worse tumor regression grade and more advanced T stage (Cramer's V = 0.255, P < .001). The ypT stage and tumor regression grade were independent predictors of each other (P < .001). The good response group (tumor regression grades 0-1) had significantly higher 5-year disease-free survival (85.5% vs. 68.2%, P < .001) and overall survival (92.1% vs. 81.0%, P < .001) rates than the poor response group (tumor regression grades 2-3). However, the ypT and ypN categories were the most important independent prognostic factors for disease-free and overall survival.Conclusions: Tumor regression grade and ypT category were significantly correlated. Although tumor regression grade alone is not definitive, it is closely related to the ypT stage and impacts oncologic outcomes. These findings should be taken into consideration when stratifying the prognosis of patients undergoing PRCRT.     

Intensified Total Neoadjuvant Therapy in Patients With Locally Advanced Rectal Cancer: A Phase II Trial

AimsWe assessed the efficacy and safety of total neoadjuvant therapy, including targeted agent plus FOLFOXIRI (5-fluorouracil, leucovorin, oxaliplatin and irinotecan) induction chemotherapy followed by intensified chemoradiotherapy (CRT) and surgical resection, in patients with locally advanced rectal cancer.Materials and methodsThis was a single-arm, single-centre phase II trial. Eligible patients had non-metastatic locally advanced rectal adenocarcinoma. Based on Ras-BRAF status, patients were treated with bevacizumab (mutated Ras-BRAF) or panitumumab/cetuximab (wild-type Ras-BRAF) plus FOLFOXIRI regimen followed by oxaliplatin–5-fluorouracil-based CRT and surgery. The primary end point was pathological complete response rate. Secondary end points were toxicity, compliance, tumour downstaging, complete resection, surgical complications, local and distant failures and overall survival. The sample size was planned to expect an absolute 20% improvement in pathological complete response rate over historical literature data with an α error of 0.05 and a power of 80%.ResultsBetween October 2015 and September 2019, 28 patients (median age 66 years) were enrolled. All patients had regional lymph node involvement at diagnosis. FOLFOXIRI plus bevacizumab was administered in 11 mutated Ras-BRAF patients, whereas the 17 wild-type Ras-BRAF patients received FOLFOXIRI plus panitumumab/cetuximab. Overall, total neoadjuvant therapy was well tolerated and 26 patients (92.9%) completed the programmed strategy. A complete response was achieved in nine cases (32.1%) and a nearly pathological complete response (ypT1 ypN0) in two patients (7.2%). There was no evidence of febrile neutropenia and no grade 4 adverse events were recorded. Radical resection was achieved in all cases.ConclusionFOLFOXIRI plus targeted agent-based induction chemotherapy and intensified CRT before surgery showed promising clinical activity and was well tolerated in locally advanced rectal cancer patients. This phase II trial provides a strong rationale for phase III studies.     

Prognostic Significance of Two Dimensional AgNOR Evaluation in Local Advanced Rectal Cancer Treated with Chemoradiotherapy

The prognostic significance of AgNOR proteins in stage II-III rectal cancers treated with chemoradiotherapy was evaluated. Silver staining was applied to the 3μm sections of parafin blocked tissues from 30 rectal cancer patients who received 5-FU based chemoradiotherapy from May 2003 to June 2006. The microscopic displays of the cells were transferred into the computer via a video camera. AgNOR area (nucleolus organizer region area) and nucleus area values were determined as a nucleolus organizer regions area/total nucleus area (NORa/ TNa). The mean NORa/TNa value was found to be 9.02±3.68. The overall survival and disease free survival in the high NORa/TNa (>9.02) patients were 52.2 months and 39.4 months respectively, as compared to 100.7 months and 98.4 months in the low NORa/TNa (<9.02) cases. (p<0.001 and p<0.001 respectively). In addition, the prognosis in the high NORa/TNa patients was worse than low NORa/TNa patients (p<0.05). In terms of overall survival and disease-free survival, a statistically significant negative correlation was found with the value of NORa/TNa in the correlations tests. Cox regression analyses demostrated that overall survival and disease-free survival were associated with lymph node status (negative or positive) and the NORa/TNa value. We suggest that two-dimensional AgNOR evaluation may be a safe and usable parameter for prognosis and an indicator of cell proliferation instead of AgNOR dots.     

VMAT应用于局部晚期直肠癌术前同步放化疗的剂量学研究

[目的]比较局部晚期直肠癌术前静态调强放疗(IMRT)与动态容积调强放疗(VMAT)计划的剂量学差异.[方法]应用Pinnacle 9.0治疗计划系统分别对10例术前同步放化疗的直肠癌患者行IMRT和VMAT放疗计划设计,比较两种放疗技术的靶区剂量分布特点以及小肠、膀胱、双侧股骨头等危及器官的受照射剂量及体积.[结果]10例患者的靶区中位体积为2321.25cm3(2021.19cm3～2741.65cm3).IMRT和VMAT计划均能满足计划设计要求.VMAT与IMRT计划靶区的Dmax、Dmin、Dmean、V95％、V100％和V105％均无统计学差异,适形指数(CI)和均匀指数(HI)亦均无统计学差异(P=0.522,P=0.452).VMAT计划对小肠的保护较好,VMAT计划中小肠受量的Dmax、Dmean、V40及V50较IMRT计划均有明显下降(P=0.014,0.044,0.018和0.043).两组计划中膀胱及双侧股骨头受量的指标Dmax、Dmean、V50均未见统计学差异.VMAT计划的平均加速器跳数(MU)为507.220,IMRT计划为528.060(P=0.003).IMRT计划平均治疗时间390s,VMAT计划为157s (P＜0.001).[结论]VMAT计划具有降低总MU,缩短治疗时间及减少小肠受照射剂量的优势,但仍需要多中心、大样本的临床研究进一步证实.     

Lymph Node Ratio is an Independent Prognostic Factor in Node Positive Rectal Cancer Patients Treated with Preoperative Chemoradiotherapy Followed by Curative Resection

Background: The lymph node ratio (LNR) has been shown to be an important prognostic factor for colorectal cancer. However, studies focusing on the prognostic impact of LNR in rectal cancer patients who received neoadjuvant chemoradiotherapy (CRT) followed by curative resection have been limited. The aim of this study was to investigate LNR in rectal cancer patients who received neoadjuvant chemoradiotherapy (CRT) followed by curative resection. Materials and Methods: A total of 131 consecutive rectal cancer patients who underwentneoadjuvant CRT and total mesorectal excision were included in this study. Patients were divided into two groups according to the LNR (≤0.2 [n=86], >0.2 [n=45]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS). Results: The median number of retrieved and metastatic lymph node (LN) was 14 (range 1-48) and 2 (range 1-10), respectively. The median LNR was 0.154 (range 0.04-1.0). In multivariate analysis, LNR was shown to be an independent prognostic factor for both overall survival (hazard ratio[HR]=3.778; 95% confidence interval [CI] 1.741-8.198; p=0.001) and disease-free survival (HR=3.637; 95%CI 1.838-7.195; p<0.001). Increased LNR was significantly associated with worse OS and DFS in patients with <12 harvested LNs, and as well as in those ≥12 harvested LNs (p<0.05). In addition, LNR had a prognostic impact on both OS and DFS in patients with N1 staging (p<0.001). Conclusions: LNR is an independent prognostic factor in ypN-positive rectal cancer patients, both in patients with <12 harvested LNs, and as well as in those≥12 harvested LNs. LNR provides better prognostic value than pN staging. Therefore, it should be used as an additional prognostic indicator in ypN-positive rectal cancer patients.     

College of American Pathologists Tumor Regression Grading System for Long-Term Outcome in Patients with Locally Advanced Rectal Cancer

BackgroundThe National Comprehensive Cancer Network''s Rectal Cancer Guideline Panel recommends American Joint Committee of Cancer and College of American Pathologists (AJCC/CAP) tumor regression grading (TRG) system to evaluate pathologic response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer (LARC). Yet, the clinical significance of the AJCC/CAP TRG system has not been fully defined.Materials and MethodsThis was a multicenter, retrospectively recruited, and prospectively maintained cohort study. Patients with LARC from one institution formed the discovery set, and cases from external independent institutions formed a validation set to verify the findings from discovery set. Overall survival (OS), disease‐free survival (DFS), local recurrence‐free survival (LRFS), and distant metastasis‐free survival (DMFS) were assessed by Kaplan‐Meier analysis, log‐rank test, and Cox regression model.ResultsThe discovery set (940 cases) found, and the validation set (2,156 cases) further confirmed, that inferior AJCC/CAP TRG categories were closely /ccorrelated with unfavorable survival (OS, DFS, LRFS, and DMFS) and higher risk of disease progression (death, accumulative relapse, local recurrence, and distant metastasis) (all p < .05). Significantly, pairwise comparison revealed that any two of four TRG categories had the distinguished survival and risk of disease progression. After propensity score matching, AJCC/CAP TRG0 category (pathological complete response) patients treated with or without adjuvant chemotherapy displayed similar survival of OS, DFS, LRFS, and DMFS (all p > .05). For AJCC/CAP TRG1–3 cases, adjuvant chemotherapy treatment significantly improved 3‐year OS (90.2% vs. 84.6%, p < .001). Multivariate analysis demonstrated the AJCC/CAP TRG system was an independent prognostic surrogate.ConclusionAJCC/CAP TRG system, an accurate prognostic surrogate, appears ideal for further strategizing adjuvant chemotherapy for LARC.Implications for PracticeThe National Comprehensive Cancer Network recommends the American Joint Committee of Cancer and College of American Pathologists (AJCC/CAP) tumor regression grading (TRG) four‐category system to evaluate the pathologic response to neoadjuvant treatment for patients with locally advanced rectal cancer; however, the clinical significance of the AJCC/CAP TRG system has not yet been clearly addressed. This study found, for the first time, that any two of four AJCC/CAP TRG categories had the distinguished long‐term survival outcome. Importantly, adjuvant chemotherapy may improve the 3‐year overall survival for AJCC/CAP TRG1–3 category patients but not for AJCC/CAP TRG0 category patients. Thus, AJCC/CAP TRG system, an accurate surrogate of long‐term survival outcome, is useful in guiding adjuvant chemotherapy management for rectal cancer.     

Survival After Induction Chemotherapy and Chemoradiation Versus Chemoradiation and Adjuvant Chemotherapy for Locally Advanced Rectal Cancer

BackgroundTotal neoadjuvant therapy (TNT) improves tumor response in locally advanced rectal cancer (LARC) patients compared to neoadjuvant chemoradiotherapy alone. The effect of TNT on patient survival has not been fully investigated.Materials and MethodsThis was a retrospective case series of patients with LARC at a comprehensive cancer center. Three hundred and eleven patients received chemoradiotherapy (chemoRT) as the sole neoadjuvant treatment and planned adjuvant chemotherapy, and 313 received TNT (induction fluorouracil and oxaliplatin-based chemotherapy followed by chemoradiotherapy in the neoadjuvant setting). These patients then underwent total mesorectal excision or were entered in a watch-and-wait protocol. The proportion of patients with complete response (CR) after neoadjuvant therapy (defined as pathological CR or clinical CR sustained for 2 years) was compared by the χ² test. Disease-free survival (DFS), local recurrence-free survival, distant metastasis-free survival, and overall survival were assessed by Kaplan-Meier analysis and log-rank test. Cox regression models were used to further evaluate DFS.ResultsThe rate of CR was 20% for chemoRT and 27% for TNT (P=.05). DFS, local recurrence-free survival, metastasis-free survival, and overall survival were no different. Disease-free survival was not associated with the type of neoadjuvant treatment (hazard ratio [HR] 1.3; 95% confidence interval [CI] 0.93-1.80; P = .12).ConclusionsAlthough TNT does not prolong survival than neoadjuvant chemoradiotherapy plus intended postoperative chemotherapy, the higher response rate associated with TNT may create opportunities to preserve the rectum in more patients with LARC.     

DWI在直肠癌术前同步放化疗疗效预测中的作用

 目的 探讨DWI在局部进展期直肠癌（LARC）术前同步放化疗疗效预测中的作用。方法 将经内镜活检病理证实的LARC患者44例纳入分析。将患者术后病理分期与治疗前临床分期作比较,分为T-降期组和T-未降期组,比较放化疗前后以及组间ADC值、组间ADC变化量（ΔADC）以及变化率（ADC%）之间的差异,并根据ROC曲线得出疗效预测的最佳临界ADC值。结果 44例患者中7例（15.9%）获得pCR。患者同步放化疗前后ADC值差异有统计学意义（P=0.000）。同步放化疗前T-降期组ADC值明显低于T-未降期组,差异有统计学意义（P=0.007）。同步放化疗后T-降期组ADC值明显高于T-未降期组,差异有统计学意义（P=0.005）。T-降期组同步放化疗后ΔADC及ADC%均高于T-未降期组,差异有统计学意义（Z=-5.53, P=0.000; P=-5.09, P=0.000）。取治疗前ADC值0.87×10^-3 mm²/s作为预测T分期是否降期的临界值,ROC曲线下面积为0.697（95%CI: 0.539~0.855）,预测疗效的敏感度为87.5%,特异性为55.0%。结论 通过对ADC的定量分析可早期预测直肠癌患者对术前同步放化疗的敏感度,对术前同步放化疗疗效的判断也有一定的价值。     

同步放化疗致中晚期宫颈癌患者骨髓抑制发生的危险因素分析

目的 观察并分析中晚期宫颈癌患者同步放化疗后骨髓抑制的发生情况及其影响因素.方法 选取100例中晚期宫颈癌患者,对其采用15MV X线外放射治疗联合192Ir高剂量率腔内后装治疗,同步根据患者病情选用博来霉素+顺铂方案、顺铂单药、多西他赛+顺铂、紫杉醇+顺铂方案化疗,观察患者骨髓抑制的发生率.结果 中晚期宫颈癌患者同步放化疗后骨髓抑制发生率与其年龄、有无合并症、临床分期、分型均无相关性(P＞0.05),与放疗方式、化疗方案、治疗时间具有相关性(P＜0.05);骨髓抑制发生率与化疗周期数无相关性(P＞0.05);放疗方式、化疗方案、治疗时间均是中晚期宫颈癌发生骨髓抑制的独立危险因素(P＜0.05).结论 对中晚期宫颈癌患者采用同步放化疗,放疗方式、化疗方案、治疗时间均是骨髓抑制发生的独立危险因素.采用全盆+四野+腔内放疗,同步选择低毒性的化疗药物,进行较短时间的治疗,骨髓抑制的发生率较低.     

Neutrophil-to-Lymphocyte Ratio (NLR) as a Poor Predictive Biomarker for Pathological Response to Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer: A Prospective Study

Background: The literature is inconsistent for the role of neutrophil-to-lymphocyte ratio (NLR) obtained before neoadjuvant therapy (pre-NLR) in predicting pathological response to neoadjuvant chemoradiation (neoCRT) in patients with locally advanced rectal cancer (LARC). In the present cohort study, we explored the predictive role of pre-NLR in this setting. Methods: We prospectively included patients with LARC who were candidates for neoCRT at the Shohada-e-Hafte Tir Hospital (Tehran, Iran) between Mar 2018 and Feb 2020. The pre-NLR was obtained through a peripheral blood smear before CRT. We used the AJCC system for evaluating tumor regression grade (TRG). The TRGs were categorized into: response-group 1 (TRG 0-1 vs. 2-3), response-group 2 (TRG 0 vs. 1-3), and response-group 3 (TRG 0-2 vs. 3). We applied receiver operating characteristic (ROC) analysis to assess the predictive value of pre-NLR. Results: Of the 86 screened patients with rectal cancer, 30   patients who fulfilled the inclusion criteria were included in the study. In total, 63.3% were responsive, and 23.3% had complete pathologic response. Pre-NLR could not predict the pathologic response in response-group 1 (area under the ROC curve [AUC]: 0.45, 95%CI 0.23-0.66) and response-group 2 (AUC: 0.36, 95%CI 0.13-0.59). Nevertheless, it had a poor predictive value in response-group 3 (AUC: 0.55, CI%95 0.33-0.75) with an optimal NLR cutoff value of 2.94. Conclusions: Pre-NLR could not predict the pathological response to neoCRT in our cohort of patients with LARC.     

Carbohydrate Antigen 19-9 Levels Associated with Pathological Responses to Preoperative Chemoradiotherapy in Rectal Cancer

Purpose: To investigate whether pretreatment serum carbohydrate antigen 19-9 (CA 19-9) levels are associated with pathological responses to preoperative chemoradiotherapy (CRT) in patients with rectal cancer. Materials and Methods: In total, 260 patients with locally advanced rectal cancer (cT3-4NanyM0) whounderwent preoperative CRT and radical surgery were analyzed retrospectively. CRT consisted of 50.4 Gy pelvic radiotherapy and concurrent chemotherapy. Radical surgery was performed at a median of 7 weeks after CRT completion. Pathological CRT response criteria included downstaging (ypStage 0-I) and ypT0-1. A discrimination threshold of CA 19-9 level was determined using a receiver operating characteristics analysis. Results: The median CA 19-9 level was 8.0 (1.0-648.0) U/mL. Downstaging occurred in 94 (36.2%) patients andypT0-1 in 50 (19.2%). The calculated optimal threshold CA 19-9 level was 10.2 U/mL for downstaging and 9.0 U/mL for ypT0-1. On multivariate analysis, CA 19-9 (≤ 9.0 U/mL) was significantly associated with downstaging (odds ratio, 2.089; 95% confidence interval, 1.189-3.669; P=0.010) or ypT0-1 (OR, 2.207; 95%CI, 1.079-4.512; P=0.030), independent of clinical stage or carcinoembryonic antigen. Conclusions: This study firstly showed a significant association of pretreatment serum CA 19-9 levels with pathological CRT responses of rectal cancer. The CA 19-9 level is suggested to be valuable in predicting CRT responses of rectal cancer cases before treatment.