Identification of gene biomarkers to predict responses to neoadjuvant chemoradiotherapy in patients with rectal cancer and pathways enrichment analysis / 中华胃肠外科杂志

Objective@#To screen out the potential gene biomarkers to predict responses to neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer and to explore the main downstream pathways of resistance.@*Methods@#The gene expression profiles (GSE35452) of locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy from 46 specimens (24 responders, TRG 0/1, and 22 non-responders, TRG 2/3) were downloaded from the GEO database. The differentially expressed genes were identified to screen out the potential biomarkers by use of the GCBI platform. GO and KEGG pathways enrichment analysis were performed to integrate enrichment results of differentially expressed genes. Signal-signal interaction network was constructed and analyzed to screen out potential main downstream pathways.@*Results@#A total of 1079 differentially expressed genes were screened, including 657 up-regulated and 422 down-regulated ones. Among these genes, REG4 had the maximum fold change value of -6.029 491. In GO term, these differentially expressed genes were mainly enriched in molecule metabolic process, cell cycle, DNA-dependent transcription, signal transduction and apoptotic process. The KEGG pathways enrichment analysis showed that the differentially expressed genes were enriched in 65 KEGG pathways, including metabolic pathways, cell cycle and metabolism pathways. Signal-signal interaction network analysis showed that MAPK signaling pathway and cell cycle pathway might play a determinant role in the development of neoadjuvant chemoradiotherapy resistance. Further analysis showed that CDKN1B, CDKN2A, RBL1, TFDP1, CCND2, CCNE2, CDC6 and CDK6 in cell cycle might induce chemoradiotherapy resistance by blocking G1/S phase cell cycle arrest, decreasing the apoptosis of tumor cells and increasing S phase ratio of chemoradiotherapy resistance.@*Conclusion@#G1/S phase cell cycle arrest blocking plays an important role in the development of chemoradiotherapy resistance in patients with rectal cancer. Moreover, the key genes, such as REG4, may be useful in predicting responses to neoadjuvant chemoradiotherapy.

Efficacy analysis of radiotherapy combined with surgery for locally advanced rectal mucinous adenocarcinoma: a retrospective study based on data of Surveillance, Epidemiology, and End results population / 中华胃肠外科杂志

OBJECTIVE@#To explore the efficacy of radiotherapy combined with surgery for locally advanced rectal mucinous adenocarcinoma.@*METHODS@#Clinical data of patients with locally advanced rectal mucinous adenocarcinoma (T3-4 and/or N+) diagnosed by postoperative pathology from 1992 to 2013 were retrieved from the US Surveillance, Epidemiology, and End Results (SEER) database. Patients with local excision only, tumor biopsy or combined organ excision and incomplete follow-up information were excluded. All the enrolled patients were divided into three groups according to different treatments, including surgery alone (SA) group, preoperative radiotherapy combined with surgery (RT+S) group and surgery combined with postoperative radiotherapy (S+RT) group. The extracted data included basic data of patients and tumor, treatment status, and follow-up results. The χ² test was used to compare the count data. Kaplan-Meier method was used to draw the survival curve and calculate the survival rate. The survival was analyzed and compared by Log-rank test. The R language 2.8.1 was used to match the patients as 1:1 pairing through the propensity score matching (PSM). The matching variables included gender, age at diagnosis, year at diagnosis, ethnicity, degree of tissue differentiation, TNM stage, depth of invasion, making the baseline data of subgroups comparable. The Cox proportional hazard model was used for multivariate analysis of prognostic factors.@*RESULTS@#A total of 2 149 patients with locally advanced rectal mucinous adenocarcinoma were enrolled in the study, including 1 255 males (58.4%) and 894 females (41.6%). There were 706 patients (32.9%) in the SA group, 772 patients (35.9%) in the RT+S group and 671 patients (31.2%) in the S+RT group. In SA, RT+S and S+RT groups, the median overall survival time was 39, 85, and 74 months respectively; the 5-year overall survival (OS) rate was 38.7%, 56.5%, and 55.2% respectively; the median cancer-specific survival (CSS) time was 86, 127, and 111 months respectively, and the 5-year CSS rate was 53.7%, 62.2% and 60.7% respectively. In comparison among the 3 groups, the 5-year OS rate and CSS rate in the SA group were significantly lower than those in the RT+S group and S+RT group (all P<0.001); the 5-year OS rate and CSS rate between RT+S group and S+RT group were not significantly different (P=0.166 and 0.392,respectively). After the baseline data of subgroups were corrected through PSM, the 5-year OS rate and CSS rate in the SA group (n=375) were significantly lower than those in the RT+S group (n=375)(OS:40.1% vs. 54.5%, P<0.001; CSS:54.3% vs. 63.3%, P=0.023). The 5-year OS rate and CSS rate in the SA group (n=403) were also lower than those in the S+RT group (n=403) (OS:37.4% vs. 54.7%,P<0.001;CSS:51.6% vs. 61.0%,P=0.031). The 5-year OS rate and CSS rate between RT+S group (n=363) and S+RT group (n=363) were not significantly different (OS:51.7% vs. 55.5%, P=0.789; CSS:57.7% vs. 60.5%, P=0.484). Cox multivariate analysis showed that radiotherapy (HR=0.845, 95%CI: 0.790 to 0.903, P=0.001) was an independent prognostic factor for OS of locally advanced rectal mucinous adenocarcinoma; radiotherapy (HR=0.907, 95% CI: 0.835 to 0.985, P=0.021) was also an independent prognostic factor affecting CSS in patients with locally advanced rectal mucinous adenocarcinoma.@*CONCLUSION@#As compared with surgery alone, surgery combined with preoperative or postoperative radiotherapy is beneficial to the long-term survival of patients with locally advanced rectal mucinous adenocarcinoma.

Effects of the number of harvested lymph nodes in neoadjuvant chemoradiotherapy combined with surgery on prognosis of middle-low rectal cancer / 中华消化外科杂志

Objective To investigate the effects of the number of harvested lymph nodes in neoadjuvant chemoradiotherapy (nCRT) combined with surgery on prognosis of middle-low rectal cancer.Methods The retrospective case-control study was conducted.The clinicopathological data of 373 patients with middle-low rectal cancer who underwent nCRT combined with surgery in the Fujian Medical University Union Hospital from January 2009 to December 2013 were collected.There were 241 males and 132 females,aged from 26 to 81 years,with the age of (55 ± 11) years.Observation indicators:(1) treatment situations;(2) follow-up and survival;(3)influencing factors for the number of harvested lymph nodes;(4) prognostic analysis of the different number of harvested lymph nodes as cut-off for grouping;(5) stratified analysis.Follow-up using telephone interview and outpatient examination was performed to detect postoperative survival of patients once every three months within postoperative 2 years and once every 6 months during the postoperative third year up to March 2016.The endpoint of follow-up was tumor recurrence,retastasis or death.Measurement data with normal distribution were represented as Mean±SD,and comparison between groups was done using the independent sample t test.Measurement data with skewed distribution were represented as M (range),and comparison between groups was done using the Kruska1-Wallis H test.Count data was described as absolute numbers.Univariate and multivariate analyses were done by the multiple linear regression model.Survival rate was calculated by the Kaplan-Meier method,and Logrank test was used for survival analysis.Results (l) Treatment situations:373 patients underwent nCRT combined with surgery,including 329 combined with sphincter-sparing rectal resection and 44 combined with abdominoperineal rectal resection.The number of harvested lymph nodes was 12 ± 6 in 373 patients.There were 185 patients with the number of harvested lymph nodes ＜ 12 and 188 with the number of harvested lymph nodes ≥ 12.(2) Follow-up and survival:373 patients were followed up for 5-77 months,with a median follow-up time of 43 months.During the follow-up,the 1-,3-,5-year disease-free survival rates were respectively 90.4％,76.3％,and 67.5％ in the 373 patients.(3) Influencing factors for the number of harvested lymph nodes:univariate analysis showed that distance between the tumor and anal verge,tumor diameter,tumor pathological N staging,and regression grade of rectal cancer were associated factors for the number of harvested lymph nodes (t =3.156,2.992,x2=8.183,10.839,P＜0.05).Multivariate analysis showed that distance between the tumor and anal verge,regression grade of rectal cancer,and tumor pathological N staging were independent factors for the number of harvested lymph nodes (t=3.308,2.690,2.584,95％ confidence interval:0.808-3.180,0.446-2.873,0.332-2.448,P＜0.05).(4) Prognostic analysis of the different number of harvested lymph nodes as cut-off for grouping:with the number of harvested lymph nodes of 6,7,8,9,10,11,12,13,14,15,and 16 as cut-off for grouping,there was no significant difference in the 3-year disease-free survival rate,cumulative local recurrence rate,and cumulative distant metastasis rate between ＜6 group and ≥6 group,between ＜7 group and ≥7 group,between＜8 group and ≥8 group,between ＜9 group and ≥9 group,between ＜10 group and ≥ 10 group,between ＜11 group and ≥ll group,between ＜12 group and ≥12 group,between ＜13 group and ≥13 group,between ＜ 14 group and ≥ 14 group,between ＜ 15 group and ≥ 15 group,between ＜ 16 group and ≥ 16 group,respectively (P＞0.05).(5) Stratified analysis:with the number of harvested lymph nodes of 7,8,9,and 10 as cut-off for grouping in 45 of 373 patients with Ⅱ-Ⅲ regression grade of rectal cancer and negative lymph nodes (NO staging),there was no significant difference in the 3-year disease-free survival rate between ＜7 group and ≥ 7group,between ＜8 group and ≥8 group,between ＜9 group and ≥9 group,between＜10 group and ≥ 10 group,respetively (x2 =3.946,5.346,6.375,4.297,P＜0.05).Conclusions The number of lymph nodes as 12 is not the independent factor for prognosis of patients with middle-low rectal cancer after nCRT combined with surgery.The number of harvested lymph nodes as 7 to 10 is the important factor for evaluating the prognosis of middle-low rectal cancer patients with Ⅱ-Ⅲ regression grade of rectal cancer and negative lymph nodes after nCRT combined with surgery.

A six-gene model using an artificial neural network to predict regional lymph node metastasis after neo-adjuvant chemoradiotherapy for locally advanced rectal cancer / 中华消化外科杂志

Objective To screen out the potential gene to predict regional lymph node metastasis after neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) and develop a 6-gene model using an artificial neural network (ANN).Methods The gene expression profiles (GSE46862) of locally advanced rectal cancer undergoing preoperative chemoradiotherapy from 64 specimens (21 with ypN-and 43 with ypN+) were downloaded from the gene expression omnibus (GEO) database.The differentially expressed genes were identified to screen out the potential biomarkers through the Gene-Cloud of Biotechnology Information (GCBI) platform.The top 6 genes were screened out for building model.An ANN model was trained and validated using the SPSS Modeler software.The study samples were allocated randomly into the training sample group and testing sample group with a 7∶3 ratio.The training samples and testing samples were respectively used for building an ANN model and independent back-substitution test.Observation indicators:(1) screening results of differentially expressed genes;(2) analysis results of ANN model.The receiver operating characteristic (ROC) curve was drawn and the area under the curve (AUC) was calculated to evaluate the predictive abilities of ANN and each biomarker.Results (1) Screening results of differentially expressed genes:A total of 50 genes were screened.Six top genes included IL6,AKR1B1,AREG,SELE,ROBO1 and CD274.(2) Analysis results of ANN model:Six top genes were selected to construct a three-layer ANN model with a 7-5-2 structure.The IL6 made the greatest effect on the ANN model,followed by ROBO1,AKR1B1,AREG,CD274 and SELE.The AUC was 0.929.The sensitivity and specificity of ANN model were 96.7％ and 85.7％,and accuracy of training samples was 93.2％.In the independent back-substitution test,sensitivity and specificity were 92.3％ and 85.7％,and accuracy of testing samples was 90.0％.Conclusion The prediction ANN model based on multiple molecular markers (IL6,ROBO1,AKR1B1,AREG,CD274 and SELE) for regional lymph node metastases in LARC patients after CRT would be beneficial in selecting potential candidates for rectum-preserving surgery following CRT for LARC.

Establishment of nomogram model to predict peritoneal metastasis in colon cancer patients without distant metastasis by preoperative imaging examination / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To establish a nomogram model to predict the peritoneal metastasis in colon cancer patients without distant metastasis by preoperative imaging examination.</p><p><b>METHODS</b>Clinicopathological data of colon cancer patients without distant metastasis by preoperative imaging examination who underwent surgery in our department between January 2000 and December 2014 were retrospectively analyzed. Predictors of peritoneal carcinomatosis were analyzed by univariate and Logistic multivariate analyses. Base on the independent predictors by multivariable analysis results, a nomogram model was formulated with further use of R software. The total score was calculated by the addition of each predictor score, indicating the corresponding risk of peritoneal metastasis. The score was greater in the nomogram, and the risk was higher in peritoneal implantation metastasis. A receiver operating characteristic(ROC) curve was then constructed to evaluate the predictive abilities of the various preoperative factors and nomogram.</p><p><b>RESULTS</b>A total of 1 417 patients were defined as above and enrolled in the study. The median age was (60.5±13.3) years, 835 cases (58.9%) were male, and 132 cases (9.3%, 132/1417) were diagnosed with synchronous peritoneal carcinomatosis during operation. Univariate analysis showed that peritoneal metastasis was associated with age, incidence of abdominal pain, incidence of mucous bloody stool, CEA level, traversible rate, tumor diameter, ratio of infiltrating type cancer, differentiation, histological type, cT staging and cN staging (all P<0.05). Logistic multivariate analysis revealed that younger age (OR:0.974, 95%CI: 0.958 to 0.990, P=0.001), later clinical T stage (OR: 2.949, 95%CI: 1.588 to 5.476, P=0.001), lesion not traversible(OR: 0.519, 95%CI: 0.314 to 0.858, P=0.011), infiltrative gross type (OR: 1.812, 95%CI: 1.099 to 2.987, P=0.020), larger tumor (OR: 1.044, 95%CI: 0.998 to 1.093, P=0.061), higher preoperative serum CEA level(OR:1.004,95%CI: 1.001 to 1.007, P=0.007) and histopathologic type of mucinous or signet ring cell adenocarcinoma (OR:1.642, 95%CI: 1.009 to 2.673, P=0.046) were independent risk factors. The nomogram model was further established based on above 7 independent risk factors, whose total score was 350 and area under the ROC curve was 0.753(P=0.000).</p><p><b>CONCLUSION</b>The nomogram model can be helpful to screen the colon cancer patients with high risk of peritoneal metastasis and to avoid unnecessary laparotomy for colon cancer patients without distant metastasis by preoperative imaging examination.</p>

Rectum-preserving surgery in the era of neoadjuvant chemoradiotherapy / 中华消化外科杂志

Neoadjuvant chemoradiotherapy (nCRT)and subsequent radical resection have become the standard care of locally advanced rectal cancer (LARC).However,conventional radical surgery is associated with high intra-and postoperative morbidities,and a temporary or permanent stoma in some cases,impaired sexual and urinary function,and it eventually impair the quality of life.Rectum-preserving surgery is a novel concept in the era of nCRT,which will maximally benefit patients through the minimized injuries.This strategy has been increasingly utilized in LARC following nCRT.Nevertheless,it lacks high-level evidence of evidence-based medicine,and the long-term oncological safety remains to be determined by larger,multicenter,randomized clinical trials.The crucial aspect of rectum-preserving surgery is to accurately evaluate the status of primary tumor and metastatic lymph nodes,and thus to selective patients who could benefit from this strategy most.

Establishment of a prognostic nomogram to predict long-term survival in non-metastatic colorectal cancer patients / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To establish a nomogram to predict long-term survival in non-metastatic colorectal cancer patients.</p><p><b>METHODS</b>A retrospective analysis was conducted in patients with non-metastatic colorectal cancer who underwent radical surgery in the Department of Colorectal Surgery of Affiliated Union Hospital of Fujian Medical University between January 2000 and December 2014. Univariate and multivariate analyses on disease-free survival (DFS) were performed using the Cox proportional regression model. Based on the multivariate analysis results, a prognostic nomogram was formulated to predict the probability for DFS. Concordance index was applied in predictive evaluation of the nomogram and calibration curves were drawn to test the nomogram's prediction and actual observation of the 5-year DFS rate. The predictive ability of nomogram was compared with AJCC-7 staging system.</p><p><b>RESULTS</b>A total of 2 641 patients were identified. The median age was 59.3 years old, and 60.3% of cases were men. The number of patients with TNM stage 0, I(, II( and III( was 96, 505, 923 and 1043, respectively. The most common tumor site was the rectum, accounting for 43.2%. A total of 413 (15.6%) patients underwent neoadjuvant treatment. The most common gross type of tumor was ulcerative type, accounting for 79.5%. The 3- and 5-year DFS rate was 85.8% and 79.8%, respectively. Based on the Cox proportional regression model, the following six factors were independently associated with reduced DFS rate and were selected for the nomogram: older age, higher pathologic T stage, higher pathologic N stage, higher preoperative serum CEA level, infiltrative gross type and perineural invasion. The results of the nomogram showed that the score of T0, T1, T2, T3 and T4 stage was 0, 2.2, 3.9, 4.1 and 6, respectively, and the score of N0, N1 and N2 was 0, 3.8 and 9.3, respectively. For gross type, the score of expanding type, ulcerative type and infiltrative type was 6, 9 and 10, respectively. The score of perineural invasion was 5.2. Higher scores were added to older age and higher CEA level. The total scores were calculated by taking the sum of the points from all predictors. Higher total score was associated with poor DFS. The prognostic nomogram differentiated well and showed a concordance index of 0.718, which was better than AJCC-7 staging system (concordance index=0.683). Also, the calibration of nomogram predictions was good.</p><p><b>CONCLUSIONS</b>A nomogram based on 6 independently prognostic factors to predict long-term survival in non-metastatic colorectal cancer patients is established successfully. The nomogram can be conveniently used to facilitate the accurate individualized prediction of DFS rates in patients with non-metastatic colorectal cancer.</p>

Short-term efficacy comparison of laparoscopic versus open transabdominal intersphincteric resection for low rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To compare the short-term efficacy of laparoscopic and open transabdominal intersphincteric resection (ISR) for low rectal cancer.</p><p><b>METHODS</b>Clinicopathological data of 246 patients with low rectal cancer undergoing transabdominal ISR in our department from January 2005 to January 2015 were retrospectively analyzed. According to gender, age, ASA score, neoadjuvant chemoradiotherapy or not, pathological T stage, pathologic N stage, and tumor differentiation, propensity score matching was performed by R plug-in(version 2.8.1). Finally, 74 cases treated by laparoscopic transabdominal ISR(laparoscopic group) and 74 cases by open transabdominal ISR(open group) were enrolled. Short-term efficacy and anal function were compared between two groups.</p><p><b>RESULTS</b>No perioperative death was found in the two groups. Compared to open group, laparoscopic group had longer operation time [(236±45) minutes vs. (200±46) minutes, P=0.000], less median blood loss [50(10 to 200) ml vs. 100(20 to 400) ml, P=0.000] and shorter hospital stay [(7.8±2.4) days vs. (10.5±6.9) days, P=0.002]. Laparoscopic group and open group had similar morbidity of total complication [17.6%(13/74) vs. 28.4%(21/74), P=0.118]. Incidence of pneumonia was significantly lower in laparoscopic group [4.1%(3/74) vs. 13.5%(10/74), P=0.042), while incidence of anastomotic leakage and stenosis, and complication grading were not significantly different between the two groups (all P>0.05). During a mean follow-up of 52.0 months, anal function analysis was performed in 102 patients with stoma closure and the result showed that the ratio of patients with good continence was 87.1%(54/62) and 87.5%(35/40) in laparoscopic and open group respectively (P=0.066).</p><p><b>CONCLUSION</b>Laparoscopic transabdominal ISR is safe and feasible, which is minimally invasive with fast recovery, and is worth clinical application.</p>

Risk factors and clinical features of delayed anastomotic fistula following sphincter-preserving surgery for rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the risk factors and clinical features of delayed anastomotic fistula (DAF) following sphincter-preserving operation for rectal cancer.</p><p><b>METHODS</b>Clinical data of 1 594 patients with rectal cancer undergoing sphincter-preserving operation in our department from January 2008 to May 2015 based on the prospective database of Dpartment of Colorectal Surgery, Fujian Medical University Union Hospital were retrospectively analyzed. Sixty patients(3.8%) developed anastomotic fistula. Forty-one patients (2.6%) developed early anastomotic fistula (EAF) within 30 days after surgery while 19(1.2%) were DAF that occurred beyond 30 days. Univariate analyses were performed to compare the clinical features between EAF and DAF group.</p><p><b>RESULTS</b>DAF was diagnosed at a median time of 194(30-327) days after anastomosis. As compared to EAF group, DAF group had lower tumor site [(6.1±2.3) cm vs. (7.8±2.8) cm, P=0.023], lower anastomosis site [(3.6±1.8) cm vs. (4.8±1.6) cm, P=0.008], higher ratio of patients receiving neoadjuvant chemoradiotherapy (84.2% vs. 34.1%, P=0.000), and receiving preventive stoma (73.7% vs. 14.6%, P=0.000). According to ISREC grading system for anastomotic fistula, DAF patients were grade A and B, while EAF cases were grade B and C(P=0.000). During the first hospital stay for anastomosis, DAF group did not have abdominal pain, general malaise, drainage abnormalities, peritonitis but 8 cases(42.1%) had fever more than 38centi-degree. In EAF group, 29 patients(70.7%) had abdominal pain and general malaise, and 29(70.7%) had drainage abnormalities. General or circumscribed peritonitis were developed in 25(61.0%) EAF patients, and fever occurred in 39(95.1%) EAF cases. There were 13(68.4%) cases with sinus or fistula formation and 9(47.4%) with rectovaginal fistula in DAF group, in contrast to 5 (12.2%) and 5 (12.2%) in EAF group respectively. In DAF group, 5 (26.3%) patients received follow-up due to stoma (no closure), 5 (26.3%) received bedside surgical drainage, while 9(47.4%) patients underwent operation, including diverting stoma in 3 patients, Hartmann procedure in 1 case, intersphincteric resection, coloanal anastomosis plus ileostomy in 1case because of pelvic fibrosis and stenosis of neorectum after radiotherapy, mucosal advancement flap repair with a cellular matrix interposition in 3 rectovaginal fistula cases, incision of sinus via the anus in 1 case. During a median follow-up of 28 months, 14(73.7%) DAF patients were cured.</p><p><b>CONCLUSIONS</b>It is advisable to be cautious that patients with lower site of tumor and anastomosis, neoadjuvant chemoradiotherapy and preventive stoma are at risk of DAF. DAF is clinically silent and most patients can be cured by effective surgical treatment.</p>

Analysis of risk factors of distant metastasis in rectal cancer patients who received total mesorectal excision following neoadjuvant chemoradiotherapy / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To clarify the natural course and explore impact factors of distant metastasis in rectal cancer patients who received total mesorectal excision(TME) following neoadjuvant chemoradiotherapy (CRT).</p><p><b>METHODS</b>Between Januray 2008 and December 2013, 317 patients with locally advanced rectal cancer who underwent radical surgical resection following neoadjuvant CRT (pre- and postoperative simple fluorouracil or fluorouracil combined with oxaliplatin plus preoperative three dimensional conformal radiotherapy) at Department of Colorectal Surgery in Fujian Medical University Union Hospital were included. Univariate analysis and Cox regression were performed to evaluate the clinicopathological parameters that may be associated with distant metastasis.</p><p><b>RESULTS</b>During a median follow-up of 39 months(range 15 - 89 months), 72 patients(22.7%) had disease recurrence, including local recurrence in 8 patients, and distant metastasis in 67 patients (among whom 3 patients had both). Distant metastasis occurred in 86.5%(58/67) patients during the first three years after surgery. The 3-year cumulative distant metastatic rate in all the patients was 22.4%. The 5-year overall survival rate in distant metastatic patient was significantly lower than that of non-distant metastatic patients following neoadjuvant CRT (36.2% vs. 81.2%, P=0.000). Univariate analysis showed that ypT stage (χ(2)=13.304, P=0.010), ypN stage(χ(2)=23.416, P=0.000), ypTNM stage (χ(2)=31.765, P=0.000) and RCRG(χ(2)=16.246, P=0.000) were associated with distant metastasis. Cox regression revealed that ypTNM stage(HR=1.959, 95% CI:1.171 ~ 3.277, P=0.010) was the only independent risk factor of distant metastasis.</p><p><b>CONCLUSIONS</b>Distant metastasis is the early event during the progression in rectal cancer. ypTNM stage is the only independent risk factor of distant metastasis in locally advanced rectal cancer patients who undergo TME following neoadjuvant CRT.</p>

Influence of anastomotic leakage on long-term survival after resection for rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the influence of anastomotic leakage (AL) on long-term survival after resection for rectal cancer.</p><p><b>METHODS</b>Clinicopathological data of 653 rectal cancer cases confirmed by pathology and undergoing R0 resection for rectal cancer in our department from January 2007 to December 2011 were retrospectively analyzed. Anastomotic leakage was found in 40 cases (AL group) and not in the other 613 cases (non-AL group). After median 47 (1-91) months of follow-up, 5-year disease-free survival rate, distant metastasis rate and local recurrence rate were compared between the two groups. Risk factors affecting long-term prognosis were also analyzed.</p><p><b>RESULTS</b>The 5-year disease-free survival rate, 5-year distant metastasis rate, and 5-year local recurrence rate were 78.1%, 14.2% and 4.2% in the non-AL group, and 74.5%, 20.1% and 8.4% in the AL group respectively, and the differences were not statistically significant (P=0.808, P=0.965, P=0.309). Multivariate analysis showed that preoperative neoadjuvant radiochemotherapy, TNM staging, abnormal CA199, preoperative low level of albumin were independent prognostic factors of rectal cancer patients after R0 resection, while AL was not an independent factor of 5-year disease-free survival (P=0.910). Further multivariate analysis on 507 cases receiving postoperative adjuvant chemotherapy also revealed that AL was not an independent factor of 5-year disease-free survival (P>0.05). Percentage difference of patients finishing postoperative chemotherapy between the two groups was not statistically significant (79.4% vs. 76.3%, P=0.681).</p><p><b>CONCLUSION</b>AL is not an independent predictor of long-term survival for rectal cancer.</p>

Risk factors of anal function after transabdominal intersphincteric resection for low rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the risk factors of anal function after transabdominal intersphincteric resection(ISR) for low rectal cancer.</p><p><b>METHODS</b>Clinical and follow-up data of 96 patients with low rectal cancer who underwent transabdominal ISR in our department from January 2005 to December 2012 were analyzed retrospectively. The Wexner scoring scale was used to evaluate the anal function and the risk factors of anal function were analyzed by the Cox proportional hazard model.</p><p><b>RESULTS</b>Ninety-six patients completed Wexner scoring scale with mean follow-up of 32.7 months. Eighty-three cases(86.5%) presented good continence with a Wexner score less than 10. There was negative correlation between Wexner score and follow-up duration (Pearson coefficient, -0.078, P=0.003). Univariate analysis suggested the distance less than 5 cm from tumor to anal verge(P=0.043), height less than 2 cm from anastomosis to anal verge (P=0.001) and neoadjuvant chemoradiotherapy(P=0.001) were the risk factors. Multivariate analysis revealed that distance less than 2 cm from anastomosis to anal verge(P=0.020) and neoadjuvant chemoradiotherapy(P=0.001) were independent risk factors for fecal incontinence.</p><p><b>CONCLUSIONS</b>Most patients have good continence after transabdominal ISR. A distance of less than 2 cm from anastomosis to anal verge and neoadjuvant chemoradiotherapy are independent risk factors for poor anal function after transabdominal ISR.</p>

Predictive factors associated with pathologic complete response after neoadjuvant chemoradiotherapy in rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore predictive factors associated with pathologic complete response (pCR) after neoadjuvant chemoradiotherapy for rectal cancer.</p><p><b>METHODS</b>Clinicopathological data of 163 patients with locally advanced rectal cancer who were treated with neoadjuvant chemoradiotherapy followed by radical surgical resection from January 2007 to May 2013 were analyzed retrospectively. Univariate analysis and multivariate logistic regression analysis were performed to analyze associated factors of pCR, including age, gender, body mass index (BMI), diabetes, anemia, tumor diameter, distance of the tumor from the anal verge, circumferential extent of the tumor, tumor pathological types, tumor differentiation, pre-chemoradiotherapy T stage, pre-chemoradiotherapy N stage, pre-chemoradiotherapy CEA level, pre-chemoradiotherapy CA199 level, per-operation CEA level, pre-operation CA199 level, radiation dose, chemotherapy modality, time interval from completion of chemoradiotherapy to surgery, etc.</p><p><b>RESULTS</b>Twenty-nine patients(17.8%) achieved pCR after neoadjuvant chemoradiotherapy for rectal cancer. Univariate analysis showed circumferential extent of tumor(≥1/2 cycle)(P=0.018), tumor pathological types(adenocarcinoma)(P=0.036), tumor differentiation (moderate or high)(P=0.021) and pre-chemoradiotherapy CEA level(≤2.5 μg/L)(P=0.007) were significantly correlated with pCR after neoadjuvant chemoradiotherapy for rectal cancer. Logistic regression revealed that circumferential extent of tumor (≥1/2 cycle)(OR=2.901, P=0.020) and pre-chemoradiotherapy CEA level (≤2.5 μg/L)(OR=2.775, P=0.022) were independent predictive factors of pCR after neoadjuvant chemoradiotherapy for rectal cancer.</p><p><b>CONCLUSION</b>Patients with circumferential extent of tumor ≤1/2 and pre-chemoradiotherapy CEA level ≤2.5 μg/L are more likely to achieve pCR after neoadjuvant chemoradiotherapy for rectal cancer, and these two indices can be used to predict pCR after neoadjuvant chemoradiotherapy for rectal cancer.</p>