The application of chimeric antigen receptor (CAR)-T cells in solid tumors is hindered due to the lack of specific tumor antigen and limited clinical efficacy. Our aim is to develop and validate novel CAR-T cell therapy against metastatic colorectal cancer (CRC). By analyzing the expression of B7-H3 in CRC tissue and cell lines using immunohistochemistry (IHC) and flow cytometry, respectively, we identified B7-H3 as a potential target in CRC. We thereby developed CAR-T cells targeting B7-H3 (B7-H3 CAR-T) and evaluated their anti-tumor activity in vitro and in vivo, using patient-derived organoids (PDOs) and xenograft (PDX) models to validate its translational potential. In our cohort of 170 CRC patients, B7-H3 was significantly upregulated in CRC tumors compared to paratumor tissue, as determined by IHC staining. When co-cultured with CRC cells or PDOs, B7-H3 CAR-T cells exhibited a dose-dependent cytotoxicity in vitro. Furthermore, B7-H3 CAR-T cells effectively controlled tumor growth and metastasis in vivo, significantly prolonging survival time for the tumor-burden mice through cytotoxic killing and potential immune regulatory effects, demonstrated in both CRC cell-based and PDX-based metastatic models. These findings underscore the potential efficacy of B7-H3 CAR-T cells for treating metastatic CRC and highlight its translational value.

Background Induction chemotherapy combined with neoadjuvant chemoradiotherapy has been recommended for patients with high-risk, locally advanced rectal cancer. However, the benefit of more intensive total neoadjuvant treatment (TNT) is unknown. This study aimed to assess the safety and efficacy of induction chemotherapy combined with chemoradiotherapy and consolidation chemotherapy for magnetic resonance imaging-stratified high-risk rectal cancer. Methods This was a single-center, single-arm, prospective Phase II trial in Peking University Cancer Hospital (Beijing, China). Patients received three cycles of induction oxaliplatin and capecitabine (CapeOX) followed by chemoradiotherapy and two cycles of consolidation CapeOX. The primary end point was adverse event rate and the second primary end points were 3-year disease-free survival rate, completion of TNT, and pathological downstaging rate. Results Between August 2017 and August 2018, 68 rectal cancer patients with at least one high risk factor (cT3c/3d/T4a/T4b, cN2, mesorectal fascia involvement, or extramural venous invasion involvement) were enrolled. The overall compliance of receiving the entire treatment was 88.2% (60/68). All 68 patients received induction chemotherapy, 65 received chemoradiotherapy, and 61 received consolidation chemotherapy. The Grade 3-4 adverse event rate was 30.8% (21/68). Nine patients achieved clinical complete response and then watch and wait. Five patients (7.4%) developed distant metastasis during TNT and received palliative chemotherapy. Fifty patients underwent surgical resection. The complete response rate was 27.9%. After a median follow-up of 49.2 months, the overall 3-year disease-free survival rate was 69.7%. Conclusions For patients with high-risk rectal cancer, this TNT regimen can achieve favorable survival and complete response rates but with high toxicity. However, it is necessary to pay attention to the possibility of distant metastasis during the long treatment period.

Background Few studies have evaluated the significance of sarcopenia in predicting the outcomes of patients with adenocarcinoma of the esophagogastric junction (AEG), especially those who received neoadjuvant chemoradiotherapy (NCRT). We aimed to identify the sarcopenic status and its impact on the outcomes of patients with locally advanced AEG who received NCRT followed by radical surgery or systemic therapy. Materials and methods Patients with T3-4N+M0 AEG with accessible abdominal computed tomography (CT) before and after NCRT were retrospectively analyzed. Body composition parameters, particularly the skeletal muscle index (SMI), were assessed using a CT-based method, and sarcopenia was defined using a predetermined SMI cutoff value. Survival analysis was conducted using the Kaplan–Meier method. A Cox proportional hazards regression model was used to identify independent prognostic factors. Receiver operating characteristic curve analysis was carried out, and the area under the curve (AUC) was calculated to test the prognostic accuracy of different factors. Results A total of 63 patients were enrolled, 65.1 and 79.4% of whom developed pre- and post-NCRT sarcopenia, respectively. Patients with pre-NCRT sarcopenia had lower radical surgery rates (70.7 vs . 95.5%, p = 0.047) than those without sarcopenia; however, sarcopenic status did not affect other short-term outcomes, including treatment-related toxicity and efficacy. Pre-NCRT sarcopenia was identified as an independent predictive factor for poor overall survival (OS) [adjusted hazard ratio (HR), 6.053; p = 0.002] and progression-free survival (PFS) (adjusted HR, 2.873; p = 0.031). Compared with nutritional indices such as the Nutritional Risk Screening 2002, weight loss during NCRT, and post-NCRT sarcopenia, pre-NCRT sarcopenia was regarded as the best predictive index for the 5-year OS (AUC = 0.735) and PFS rates (AUC = 0.770). Conclusion Pre-NCRT sarcopenia may be an independent predictive factor for OS and PFS rates in patients with locally advanced AEG receiving multimodal treatment.

Purpose Colorectal cancer is a common malignant tumor worldwide. In China, the ratio of rectal cancer to colon cancer in terms of incidence is close to 1: 1. Low rectal cancer accounts for more than half of all cases of rectal cancer. In recent years, the proportion of rectal cancer has trended downward, however the incidence of rectal cancer in younger adults is increasing. The CACA Guidelines for Holistic Integrative Management of Rectal Cancer were edited to help improve the diagnosis and comprehensive treatment in China. Methods This guideline has been prepared by consensuses reached by the CACA Committee of Colorectal Cancer Society, based on a careful review of the latest evidence including China’s studies, and referred to domestic and international relative guidelines, also considered China’s specific national conditions and clinical practice. Results The CACA Guidelines for Holistic Integrative Management of Rectal Cancer include the epidemiology of rectal cancer, prevention and screening, diagnosis, treatment of nonmetastatic and metastatic rectal cancer, follow-up, and whole-course rehabilitation management. Conclusion Committee of Colorectal Cancer Society, Chinese Anti-Cancer Association, standardizes the diagnosis and treatment of rectal cancer in China through the formulation of the CACA Guidelines.

Objective:To explore the clinical efficacy of radical resection for lung metastasis from colorectal cancer and the prognostic factors.Methods:The retrospective cohort study was conducted. The clinicopathological data of 63 colorectal cancer patients with lung metastasis who were admitted to Peking University Cancer Hospital from January 2004 to December 2015 were collected. There were 35 males and 28 females, aged (57±12)years. Patients underwent radical resection for primary lesion and lung metastasis from colorectal cancer. Observation indicators: (1) diagnosis and treatment; (2) follow-up and survival; (3) prognostic factors analysis. Follow-up was conducte by outpatient examination and telephone interview to detect the survival of patients after operation up to December 2018. Measurement data with normal distribution were represented as Mean±SD, and measurement data with skewed distribution were represented as M (range). Count data were described as absolute numbers or percentages. The Kaplan-Meier method was used to calculate survival rates and draw survival curves. Log-rank test was used for univariate analysis and COX proportional hazard model was used for multivariate analysis. Results:(1) Diagnosis and treatment: of 63 patients with lung metastasis from colorectal cancer, 6 had synchronous lung metastasis and 57 had metachronous lung metastasis. Eighteen cases of suspected lung metastasis were initially detected by chest X-ray, and further confirmed by computed tomography (CT). Forty-five cases of suspected lung metastasis were initially detected by chest CT. All the 63 patients underwent radical resection for primary and metastatic lesions. Two of 22 cases undergoing mediastinal lymph nodes dissection were detected one positive lymph node, respectively. All patients recovered well after operation, without severe complications. There were 57 of 63 patients receiving more than 6 months of postoperative adjuvant chemotherapy and targeted therapy based on fluorouracils. (2) Follow-up and survival: 63 patients were followed up for 8-143 months, with a median follow-up time of 58 months. During the follow-up, 19 of 63 patients died, 24 patients had secondary recurrence with a 5-year recurrence rate of 38.1%(24/63) and a recurrence interval of 18 months(range, 3-58 months). Of 24 patients with secondary recurrence, 19 had lung metastasis, 3 had brain metastasis, 2 had bone metastasis, 2 had liver metastasis; some patients had multiple metastases. Of 24 patients with secondary recurrence, 5 underwent reoperation and 19 underwent chemotherapy and radiochemotherapy. The 5-year overall survival rate of 63 patients was 62.7%. (3) Prognostic factors analysis: results of univariate analysis showed that location of primary lesion, the number of lung metastases and carcinoembryonic antigen (CEA) level before resection of lung metastasis were related factors for prognosis of patients with lung metastasis from colorectal cancer ( χ2=4.162, 7.175, 6.725, P<0.05). Results of multivariate analysis showed that the number of lung metastases and CEA level before resection of lung metastasis were independent influencing factors for prognosis of patients with lung metastasis from colorectal cancer ( hazard ratio=2.725, 2.778, 95% confidence interval as 1.051-7.064, 1.072-7.021, P<0.05). Conclusions:Radical resection for lung metastasis from colorectal cancer is safe and feasible. The number of lung metastases and CEA level before resection for lung metastasis are independent influencing factors for prognosis of patients with lung metastasis from colorectal cancer.

Background: BRCA1 and BRCA2 have been well studied for their roles in tumorigeneis, plus cancer diagnosis and treatment, but their prognostic value in colon cancer, especially for early-stage cancer, has not been fully illuminated. This study examined the expression levels of BRCA1 and BRCA2 proteins in sporadic colon cancer cases and investigated their value in prognosis. Methods: The expression levels of BRCA1 and BRCA2 in 275 colon cancer patients who underwent radical surgeries were assayed by immunohistochemical staining in dissected tumor samples. Also, its correlation with clinicopathological characteristics, disease-free survival, and overall survival was investigated. Results: Tumors with low expression levels of BRCA1, BRCA2, and both were 19.6%, 17.8%, and 6.5%, respectively. The levels of BRCA1/2 expression were not associated with clinicopathological parameters (gender, age, histological differentiation, and tumor node metastasis stage). Patients with low-levels of BRCA1 protein in their tumors demonstrated a lower chance of 5-year disease-free survival (55.6% vs. 69.7%, P=0.046), which was more obvious in the patients with stage I–II tumors without chemotherapy (52.6% vs. 82.6%, P=0.006). Neither BRCA1 nor BRCA2 affected overall survival in this cohort. Multivariate analysis revealed that pathologic stage and the level of BRCA1 protein were independent factors of long-term disease-free survival. Conclusion: This study highlights BRCA1 as an independent prognosticator of early-stage colon cancer.

Objective: To explore the safety and efficacy of watch and wait strategy and organ preservation surgery after total neoadjuvant treatment for MRI stratified low-risk rectal cancer. Methods: A prospective single arm phase Ⅱ trial developed at Department of Gastrointestinal Cancer, Peking University Cancer Hospital & Institute was preliminarily analyzed. Subjects were enrolled from August 2016 to January 2019. Low-risk rectal cancer with following MRI features were recruited: mid-low tumor, mrT2-3b, MRF (-), EMVI (-), CRM (-), differentiation grade 1-3. Patients received intensity-modulated radiotherapy (IMRT) 50.6 Gy/22f with concurrent capecitabine and 4 cycles of consolidation CAPEOX. Patients with cCR/near-cCR confirmed by physical examination, rectal MRI, endoscopy, and serum CEA were recommended for watch & wait approach or local excision (LE). The main study outcomes were 2-year organ preservation rate (OPR) and sphincter preservation rate (SPR). Results: Thirty-eight patients were eligible for analysis, including 24 males and 14 females with median age of 56 years; 9 cases of mrT2 (23.7%), 14 cases of mrT3a (36.8%) and 15 cases of mrT3b (39.5%); 5 cases of well differentiated adenocarcinoma (13.2%), 32 cases of moderately differentiated adenocarcinoma (84.2%) and 1 case of mucinous adenocarcinoma (2.6%). Carcinoemobryonic antigen (CEA) was elevated before treatment in 1 case. One case (2.6%) of grade 3 radiation dermatitis occurred during IMRT; 18 cases (47.4%) occurred grade 3 to 4 adverse events during consolidation chemotherapy. After total neoadjuvant treatment, the cCR and near-cCR rates were 42.1% (16/38) and 23.7% (9/38), respectively, while non-cCR rate was 34.2% (13/38). Twenty patients (20/38, 52.6%) of cCR or near-cCR underwent watch & wait approach, with a local regrowth rate of 20% (4/20). Four patients received LE, including one salvage LE. Thirteen patients (4 were ypCR) received radical resection, including 10 cases of initial low anterior resections (LAR), 1 cases of initial abdominal perineal resection (APR) and 2 cases of salvage LAR, four patients refused operation. The median follow-up time was 23.5 (8.5-38.3) months. At the last interview of follow-up, the OPR and SPR were 52.6% (20/38) and 84.2% (32/38), respectively. Only one patient developed lung metastasis and no local recurrence occurred after radical resection or LE. Conclusion: Total neoadjuvant treatment for low-risk rectal cancer achieves high cCR/near-cCR rate, with increased probability of receiving watch and wait approach and organ preservation in this subgroup.

Objective: This study aimed to evaluate the clinical and oncological outcomes of selected rectal cancer patients with massive stoma site tumors who underwent radical resection and reconstruction. Methods: We reviewed 8 cases of massive stoma site tumors in patients who had permanent gastrointestinal stoma in the abdominal wall following radical resection of rectal cancer between March 2013 and May 2018 at the Peking University Cancer Hospital and Peking University Shougang Hospital. Results: There were seven males and one female patient, with a median age of 50.6 years. The average time between the initial surgery and the development of a malignant tumor at the stoma site was 5 years (range, 0.5-14 years). The average diameter of the stoma site tumors was 8.1 cm, and the diameter of the largest tumor was 12 cm. After tumor resection, the area of the largest abdominal wall defect was about 15 x 14 cm(2). Abdominal wall repair included the use of a tensor fasciae latae muscle flap, local fasciocutaneous rotational flap, and pedicled anterolateral thigh flap. No patient died in the 30 days following surgery. The longest follow-up period was 81 months, and 5 patients died. Conclusions: Multidisciplinary clinical management fosters positive outcomes in treating massive stoma site tumors. Local RO resection and abdominal wall reconstruction are safe and feasible, and function to removes local disease, allowing patients to live a higher quality of life. (C) 2020 Published by Elsevier Ltd.

BACKGROUND Malignant bowel obstruction (MBO) is a common event for end-stage gastrointestinal cancer patients. Previous studies had demonstrated manifestations and clinical management of MBO with mixed malignancies. There still lack reports of the surgical treatment of MBO. AIM To analyze the short-term outcomes and prognosis of palliative surgery for MBO caused by gastrointestinal cancer. METHODS A retrospective chart review of 61 patients received palliative surgery between January 2016 to October 2018 was performed, of which 31 patients underwent massive debulking surgery (MDS) and 30 underwent ostomy/by-pass surgery (OBS). The 60-d symptom palliation rate, 30-d morbidity and mortality, and overall survival rates were compared between the two groups. RESULTS The overall symptom palliation rate was 75.4% (46/61); patients in the MDS group had significantly higher symptom palliation rate than OBS group (90% vs 61.2%, P = 0.016). Patients with colorectal cancer who were in the MDS group showed significantly higher symptom improvement rates compared to the OBS group (overall, 76.4%; MDS, 61.5%; OBS, 92%; P = 0.019). However, patients with gastric cancer did not show a significant difference in symptom palliation rate between the MDS and OBS groups (OBS, 60%; MDS, 80%; P = 1.0). The median survival time in the MDS group was significantly longer than in the OBS group (10.9 mo vs 5.3 mo, P = 0.05). CONCLUSION For patients with MBO caused by peritoneal metastatic colorectal cancer, MDS can improve symptom palliation rates and prolong survival, without increasing mortality and morbidity rates.

Background The aim of this study was to explore the impact of including or excluding the ischiorectal fossa (IRF) within the clinical target volume during neoadjuvant chemoradiotherapy (NCRT) using intensity modulated radiotherapy, in locally advanced lower rectal cancer (LALRC). Methods We retrospectively analysed the data of 220 LALRC patients who received NCRT followed by abdominoperineal resection between January 2009 and January 2015. Six patients were excluded because of loss to follow-up, 90 patients received IRF irradiation (IRF group) while 124 patients did not (NIRF group). Survival, patterns of recurrence, and treatment toxicities were compared between the two groups. Results Overall, patient/treatment variables were well balanced except for surgical technique. Perineal wound complications in the IRF and NIRF groups, were 40.0 and 24.2%, respectively (p = 0.010); corresponding 3-year perineal recurrence rates, local recurrence free survival, overall survival, and distant relapse free survival were 4.4% vs. 2.4% (p = 0.670), 88.1% vs. 95.0% (p = 0.079), 82.6% vs. 88.4% (p = 0.087), and 61.9% vs. 81.0% (p = 0.026), respectively. Multivariate analyses demonstrated the following factors to be significantly related to perineal wound complications: irradiation of the IRF (odds ratio [OR] 2.892, p = 0.002), anaemia (OR 3.776, p = 0.010), operation duration > 180 min (OR 2.486, p = 0.007), and interval between radiotherapy and surgery > 8 weeks (OR 2.400, p = 0.010). Conclusions Exclusion of the IRF from the clinical target volume during NCRT using intensity-modulated radiotherapy in LALRC could lower the incidence of perineal wound complications after abdominoperineal resection, without compromising oncological outcomes.

Objective: To understand the perceptions, attitudes and treatment selection of Chinese surgeons on the "watch and wait" strategy for rectal cancer patients after achieving a clinical complete response (cCR) following neoadjuvant chemoradiotherapy (nCRT). Methods: A cross-sectional survey was used in this study. Selection of subjects: (1) Domestic public grade III A (provincial and prefecture-level) oncology hospitals or general hospitals possessing the radiotherapy department and the diagnosis and treatment qualifications for colorectal cancer. (2) Surgeons of deputy chief physician or above. Using the "Questionnaire Star" online survey platform to create a questionnaire about cognition, attitude and treatment choice of the "watch and wait" strategy after cCR following nCRT for rectal cancer. The questionnaire contained 32 questions, such as the basic information of doctor, the current status of rectal cancer surgery, the management of pathological complete remission (ypCR) after nCRT for rectal cancer, the selection of examination items for diagnosis of cCR, the selection of suitable people undergoing "watch and wait" approach, the nCRT mode for promotion of cCR, the choice of evaluation time point, the willingness to perform "watch and wait" approach and the treatment choice, and the risk and monitoring of "watch and wait" approach. A total of 116 questionnaires were sent to the respondents via WeChat between January 31 and February 19, 2019. Statistical analysis was performed using Fisher's exact test for categorical variables. Results: Forty-eight hospitals including 116 surgeons meeting criteria were enrolled, of whom 77 surgeons filled the questionnaire with a response rate of 66.4%. "Watch and wait" strategy was carried out in 76.6% (59/77) of surgeons. Seventy surgeons (90.9%) were aware of the ypCR rate of rectal cancer after preoperative nCRT and 49 surgeons (63.6%) knew the 3-year disease-free survival of patients with ypCR in their own hospitals. Fifty-five surgeons (71.4%) believed that patients with ypCR undergoing radical surgery met the treatment criteria and were not over-treated. Three most necessary examinations in diagnosing cCR were colonoscopy (96.1%, 74/77), digital rectal examination (DRE) (90.9%,70/77) and DWI-MRI (83.1%, 64/77). Responders preferred to consider a "watch and wait" strategy for patients with baseline characteristics as mrN0 (77.9%, 60/77), mrT2 (68.8%, 53/77) and well-differentiated adenocarcinoma (68.8%, 53/77). Sixty-six surgeons (85.7%) believed that long-term chemoradiotherapy (LCRT) with combination or without combination of induction and/or consolidation of the CapeOX regimen (capecitabine + oxaliplatin) should be the first choice as a neoadjuvant therapy to achieve cCR. Forty-one surgeons (53.2%) believed that a reasonable interval of judging cCR after nCRT should be ≥ 8 weeks. Forty-four surgeons (57.1%) routinely, or in most cases, informed patient the possibility of cCR and proposed to "watch and wait" strategy in the initial diagnosis of patients with non-metastatic rectal cancer. Thirteen surgeons (16.9%) would take the "watch and wait" strategy as the first choice after the patient having cCR. Fifty-two surgeons (67.5%) would be affected by the surgical method, that was to say, "watch and wait" approach would only be recommended to those patients who would achieve cCR and could not preserve the anus or underwent difficult anus-preservation surgery. Sixteen surgeons (20.8%) demonstrated that "watch and wait" strategy would not be recommended to patients with cCR regardless of whether the surgical procedure involved anal sphincter. Eleven surgeons (14.3%) believed that the main risk of "watch and wait" approach came from distant metastasis rather than local recurrence or regrowth. Twenty-nine of surgeons (37.7%) did not understand the difference between "local recurrence" and "local regrowth" during the period of "watch and wait". Twenty-six surgeons (33.8%) thought that the monitoring interval for the first 3 years of "watch and wait" strategy was 3 months, and the follow-up monitoring interval could be 6 months to 5 years. Surgeons from cancer specialist hospitals had higher approval rate, notification rate, and referral rate of "watch and wait" strategy than those from general hospitals. Thirty-one surgeons (42.5%) considered that the difficulty and concern of carrying out "watch and wait" approach in the future was the disease progress leading to medical disputes. Twenty-six surgeons (35.6%) demonstrated that their concern was lack of uniform evaluation standard for cCR. Conclusions: Chinese surgeons seem to have inadequate knowledge of non-operative management for rectal cancer patients achieving cCR after nCRT and show relatively conservative attitudes toward the strategy. Chinese consensus needs to be formed to guide the non-operative management in selected patients. Chinese Watch & Wait Database (CWWD) is also needed to establish and provide more evidence for the use of alternative procedure after a cCR following nCRT.

目的 探讨中低位直肠癌新辅助放化疗后行经肛门局部切除的有效性和安全性.方法 回顾性分析2011年3月至2016年6月北京大学肿瘤医院胃肠肿瘤中心诊治的行新辅助放化疗并接受经肛门局部切除的19例中低位直肠癌病人的临床资料.主要的研究终点为:无病生存(disease free survival)、术后短期(1个月)并发症;次要研究终点为:术后1年的生活质量和肛门功能.结果 肿瘤直径为1.0(0.3～3.0)cm.8例(42.1％)肿瘤位于前壁,6例(31.6％)位于后壁,3例(15.8％)位于左侧壁,2例(10.5％)位于右侧壁;肿瘤距肛缘中位距离为4.0(1.5～12.0)cm;术后病理学检查示,ypT0 12例(63.2％),ypT1 3例(15.8％),ypT24例(21.1％).放化疗结束距手术的时间间隔为4.3(2.0～36.0)个月.局部切除手术时间为50(20～137)min,术中出血量为10(0～50)mL,术后住院时间为4(1～5)d.随访30(2～62)个月,1例局部复发,3例出现远处转移(1例腹盆腔和2例肺转移),肿瘤复发率为21.1％(4/19).局部切除病例肛门功能评分术前和术后差异无统计学意义(P＞0.05),而TME病例肛门功能评分术前和术后差异有统计学意义(P＜0.05).局部切除病例术后生活质量(EORTC QLQ-C30)和肛门功能(Wexner)评分低于同期TME手术组(P＜0.01).结论 中低位直肠癌新辅助放化疗后,ycT0～2N0病例行经肛门局部切除是一种安全可行的治疗选择,可获得较好的肛门功能保留和生活质量.

OBJECTIVE:To investigate the long-term outcome of organ preservation with local excision or "watch and wait" strategy for mid-low rectal cancer patients evaluated as clinical complete remission (cCR) or near-cCR following neoadjuvant chemoradiotherapy (NCRT).METHODS:Clinical data of 62 mid-low rectal cancer patients evaluated as cCR/near-cCR after NCRT undergoing organ preservation surgery with local excision or receiving "watch and wait" strategy at Department of Gastrointestinal Surgery, Peking University Cancer Hospital and Institute from March 2011 to August 2017 were retrospectively analyzed. According to the approximate 1:2 pairing, 123 patients who underwent radical resection with complete pathological remission(ypCR) after neoadjuvant chemotherapy during the same period were selected for prognosis comparison. The primary endpoint of the study was 3-year non-regrowth disease-free survival (NR-DFS) and tumor specific survival (CSS). Survival analysis was performed using the Kaplan-Meier curve (Log-rank method). The secondary endpoint of the study was 3-year organ preservation and sphincter preservation.RESULTS:The retrospective study included 38 male and 24 female patients. The median age was 60 (31-79) years and the median distance from tumor to anal verge was 4(1-8) cm. The ratio of cCR and near-cCR was 79.0%(49/62) and 21.0%(13/62) respectively. Local regrowth rate was 24.2%(15/62). Of 15 with tumor regrowth, 9 patients received salvage radical rectal resection and no local recurrence was found during follow-up; 4 patients received salvage local excision among whom one patient had a local recurrence occurred patient; 2 patients refused further surgery. The overall metastasis rate was 8.1%(5/62), including resectable metastasis(4.8%,3/62) and unresectable metastasis (3.2%,2/62). The valid 3-year organ preservation rate and sphincter preservation rate were 85.5%(53/62) and 95.2%(59/62) respectively. The median follow-up was 36.2(8.6-89.0) months. The 3-year NR-DFS of patients with cCR and near-cCR was 88.6% and 83.1% respectively, which was not significantly different to that of patients with ypCR (94.7%, P=0.217). The 3-year CSS of patients with cCR and near-cCR was both 100%, which was not significantly different to that of patients with ypCR(93.4%, P=0.186).CONCLUSIONS:Mid-low rectal cancer patients with cCR or near-cCR after NCRT undergoing organ preservation with local excision or receiving "watch and wait" strategy have good long-term prognosis with low rates of local tumor regrowth and distant metastasis, which is similar to those with ypCR after radical surgery. This treatment mode may be used as an option for organ preservation in mid-low rectal cancer patients with good tumor remission after NCRT.

Background High-risk patients with stage II colon cancer may benefit from adjuvant chemotherapy, but identifying this patient population can be difficult. We assessed the prognosis value for predicting tumor progression in patients with stage II colon cancer, of a panel of 2 biomarkers for colon cancer: tumor budding and preoperative carcinoembryonic antigen (CEA). Methods Consecutive patients (N = 134) with stage II colon cancer who underwent curative surgery from 2000 to 2007 were included. Multivariate analysis was used to evaluate the association of CEA and tumor budding grade with 5-year disease-free survival (DFS). The prognostic accuracy of CEA, tumor budding grade and the combination of both (CEA-budding panel) was determined. Results The study found that both CEA and tumor budding grade were associated with 5-year DFS. The prognostic accuracy for disease progression was higher for the CEA-budding panel (82.1%) than either CEA (70.9%) or tumor budding grade (72.4%) alone. Conclusions The findings indicate that the combination of CEA levels and tumor budding grade has greater prognostic value for identifying patients with stage II colon cancer who are at high-risk for disease progression, than either marker alone.

AIM:To develop predictive markers in blood for colorectal cancer liver metastasis.METHODS:Twenty colorectal cancer patients were selected and divided into two groups. Group A consisted of 10 patients whose pathological TNM stage was IIIC (T3-4N2M0), while another 10 patients with synchronous liver metastasis (TNM stage IV) were recruited for group B. During the surgical procedure, a 10-mL drainage vein (DV) blood sample was obtained from the DV of the tumor-bearing segment prior to the ligation of the DV. At the same time, a 10-mL peripheral vein (PV) blood sample was collected via peripheral venipuncture. The serum levels of 24 molecules that are potentially involved in the mechanism of liver metastasis in both DV blood and PV blood were analyzed by using high-throughput enzyme-linked immunosorbent assay technology.RESULTS:Univariate analysis revealed that platelet-derived growth factor AA (PDGFAA) in DV blood (dPDGFAA) (P = 0.001), PDGFAA in PV blood (pPDGFAA) (P = 0.007), and human epidermal growth factor receptor-2 in PV blood (pHER2) (P = 0.001), pMMP7 (P = 0.028), pRANTES (P = 0.013), and pEGF (P = 0.007) were significantly correlated with synchronous liver metastasis. Multivariate analysis identified dPDGFAA (HR = 1.001, P = 0.033) and pHER2 (HR = 1.003, P = 0.019) as independent predictive factors for synchronous liver metastasis. Besides, high peripheral HER2 level may also be a risk factor for metachronous liver metastasis, although the difference did not reach statistical significance (P = 0.06). Significant correlations were found between paired DV and PV blood levels for PDGFAA (r = 0.794, P < 0.001), but not for HER2 (r = 0.189, P = 0.424).CONCLUSION:PDGFAA in tumor drainage and HER2 in PV blood may be useful predictive factors for synchronous liver metastasis of colorectal cancer.

Although 5-fluorouracil (5-FU) is known to interfere with the synthesis of ribonucleic acid and deoxyribonucleic acid, the mechanism underlying its therapeutic efficacy in colorectal cancer (CRC) has not been fully elucidated. We aimed to investigate the influence of 5-FU on histone acetylation, a well-established anti-cancer target, to reveal novel pharmacological effects of 5-FU and their significance for CRC therapy. Results demonstrated that 5-FU induces global histone de-acetylation in multiple CRC cell lines. We identified that 5-FU reduces the binding ability of histone acetyltransferases p300 and CBP to chromatin, and induces their degradation through lysosome. Further work revealed that the degradation of p300/CBP induced by 5-FU was dependent on chaperone-mediated autophagy, mediated by heat-shock cognate protein 70 kDa (hsc70) and lysosomal-associated membrane protein 2A (LAMP2A). Moreover, the degradation of p300/CBP is relevant to cellular resistance to 5-FU, since blocking the degradation enhances 5-FU's cytotoxicity in CRC cells. From clinical data, we demonstrated that low expression of p300/CBP in CRC tissue was closely associated with poor clinical response to 5-FU based-chemotherapy, based on the analysis of 262 colorectal samples from the patients receiving 5-FU treatment: compared to cases with high expression of p300/CBP, those with low expression had lower long-term disease-free survival rate and increased early-progression. These results elucidate a novel pharmacological effect of 5-FU involving global histone de-acetylation by promoting the degradation of p300/CBP, and highlights p300 and CBP as promising predictors of chemo-sensitivity to 5-FU treatment.

3610 Background: It has been reported that non-operative treatment (wait and see) is feasible for the selected rectal cancer cases with a complete clinical response (cCR) following neoadjuvant therapy (NT). The aim of this study is to determine whether "wait and see" policy is efficient for the cCR patients in China. Methods: We designed a prospective cohort study in China (ChiCTR-TRC-12002488). From Jul 2012 to August 2016, totally 45 patients with locally advanced rectal cancer who were cCR following NT were enrolled in the study; within whom, 32 patients were assigned to wait and see group, and the remaining 13 patients were assigned to surgery group (intent-to-treat grouping). Results: The median follow-up time was 24 months (range: 3-51). Of the patients who were followed up more than 12 months (n=37), 8 patients developed tumor progression (7 in wait and see group and 1 in surgery group, respectively). In the wait and see group, the local regrowth took an account of 23.1% (6/26), while the distant metastasis rate was 3.8% (1/26). In the surgery group, there were 23.1% (3/13) of patients who has residual cancer confirmed by postoperative pathological assessment. All the patients with tumor regrowth underwent radical surgery and no body died of cancer. Conclusions: Wait and see policy has an acceptable safety and efficiency, it may become an alternative treatment for the patients who were cCR following NT. Clinical trial information: ChiCTR-TRC-12002488. [Table: see text]

OBJECTIVE:To investigate the safety and efficacy of organ preservation surgery or "watch and wait" strategy for rectal cancer patients who are evaluated as clinical complete response(cCR) or near-cCR following neoadjuvant chemoradiotherapy (nCRT).METHOD:From March 2011 to June 2016, 35 patients with mid-low rectal cancers who were diagnosed as cCR or near-cCR following nCRT underwent organ preservation surgery with local excision or surveillance following "watch and wait" strategy in the Peking University Cancer Hospital. All the patients received re-evaluation and re-staging 6-12 weeks after the completion of nCRT, according to Habr-Gama and MSKCC criteria for the diagnosis of cCR or near-cCR. The near-cCR patients who received local excision and were pathologically diagnosed as T0Nx were also regarded as cCR. The end-points of this study included organ-preservation rate (OPR), sphincter-preservation rate (SPR), non-re-growth disease-free survival (NR-DFS), stoma-free survival, cancer-specific survival (CSS) and overall survival(OS). Kaplan-Meier curve was used to estimate the survival data at 3 years.RESULTS:A total of 35 cases were analyzed including 24 males (68.6%) and 11 females (31.4%). The median age was 60 (range 37-79) years and the median distance from tumor to anal edge was 4(2-8) cm. Thirty-three patients received 50.6 Gy/22f IMRT with capecitabine and two patients received 50 Gy/25f RT with capecitabine. The cCR and near-cCR rates were 74.3%(26/35) and 25.7%(9/35) respectively. Excision biopsy was performed in 4 near-cCR cases to confirm the diagnosis of cCR. The non-re-growth DFS rate was 14.3%(5/35) and the median time of tumor re-growth was 6.7 (4.7-37.4) months. In five patients with tumor re-growth, four were salvaged by radical rectal resections and one received local excision. The distant metastasis rate was 5.7%(2/35), one patient presented resectable liver metastasis and received radical resection, another patient presented multiple bone metastases and was still alive. The median follow-up time was 43.7(6.1-71.4) months. At three years, the organ-preservation rate was 88.6%(31/35), the sphincter-preservation rate was 97.1% (34/35). No local recurrence was observed in five patients who received salvage surgery. The non-re-growth DFS was 94.0%. Three patients died of non-rectal cancer related events. The cancer-specific survival was 100%, the overall survival was 92.7% and the stoma-free survival rate was 90.0%.CONCLUSIONS:Organ preservation surgery or "watch and wait" strategy for cCR or near-cCR patients is feasible and achieves good outcomes. This strategy can be an alternative to standard care, improve patient's quality of life and facilitate tailored treatment for mid-low rectal cancer following nCRT, however, it should be cautiously applied in near-cCR patients before local excision biopsy.

BACKGROUND:In patients with colorectal cancer, a defunctioning ileostomy is commonly constructed to reduce anastomotic complications. However, many patients do not undergo a subsequent procedure to have their temporary stoma closed. OBJECTIVE:This study investigated the incidence of nonclosure of ileostomies and identified factors associated with nonclosure. DESIGN:This study is a retrospective analysis of prospectively collected data. SETTING:This study was conducted at a tertiary referral cancer hospital. PATIENTS:A total of 296 patients who received anterior resection with a defunctioning ileostomy with protective intention from 2006 to 2013 were included. MAIN OUTCOME MEASURES:The primary outcomes measured were the incidence of nonclosure of ileostomy and associated risk factors. RESULTS:Patients were followed for a median time of 29 months (range, 21-100 months). At the end of the study, 51 (17.2%) patients were left with a permanent ileostomy. The median time interval from the creation of a defunctioning ileostomy to closure was 192 days (range, 14-865 days). Multivariate analyses using a logistic regression model showed that metastatic diseases (OR, 0.179, p < 0.001), Charlson Comorbidity Index score >1 (OR, 0.268; p < 0.01), and complications from the index surgery (OR, 0.391; p = 0.013) were significant independent risk factors for failing to close a defunctioning ileostomy. LIMITATIONS:Although our study has a large patient cohort, it is limited by its retrospective nature. It is difficult to fully evaluate stoma complications after hospital discharge, and the prevalence may be underestimated. CONCLUSION:One in 6 temporary ileostomies constructed during an elective anterior resection for rectal cancer was not closed. Patients should be told before the index surgery that there is a risk of nonclosure and possible complications associated with permanent ileostomy.

Objective To evaluate if mucinous subtype has a relevant impact on disease-free survival (DFS) of patients with rectal carcinoma.Methods The clinicopathological data of patients with rectal adenocarcinomas (ring cell carcinoma were excluded)undergoing radical surgery at Beijing Cancer Hospital from Jan 2010 to Jan 2012 were retrospectively studied,survival analysis was done to detect potential prognostic predictors.Results 353 patients with stage Ⅰ-Ⅲ rectal cancer were included in this study,of whom 28 (7.9％) had mucinous histology.The 3-year DFS for patients with a mucinous adenocarcinoma was 50.0％ and 83.4％ for patients with nonmucinous adenocarcinoma (P ＜ 0.001).Mucinous adenocarcinoma was associated with advanced pathologic T (T3/4,100％ vs 52.3％,P ＜0.001) and N stage (N1/2,64.3％ vs.32.6％,P =0.001).More patients were diagnosed under 40 years in mucinous adenocarcinoma group (21.4％ vs.5.5％,P =0.005).Conclusions Patients with mucinous adenocarcinoma more often present at a younger age,mucinous adenocarcinomas are associated with more advanced tumor stages,and should be regarded as a dismal prognostic factor for the survival of patients with rectal cancer.