Advances in tumor regression patterns and safe distance of distal resection margin after neoadjuvant therapy for rectal cancer / 中华胃肠外科杂志

Neoadjuvant therapy has been widely applied in the treatment of rectal cancer, which can shrink tumor size, lower tumor staging and improve the prognosis. It has been the standard preoperative treatment for patients with locally advanced rectal cancer. The efficacy of neoadjuvant therapy for rectal cancer patients varies between individuals, and the results of tumor regression are obviously different. Some patients with good tumor regression even achieve pathological complete response (pCR). Tumor regression is of great significance for the selection of surgical regimes and the determination of distal resection margin. However, few studies focus on tumor regression patterns. Controversies on the safe distance of distal resection margin after neoadjuvant treatment still exist. Therefore, based on the current research progress, this review summarized the main tumor regression patterns after neoadjuvant therapy for rectal cancer, and classified them into three types: tumor shrinkage, tumor fragmentation, and mucin pool formation. And macroscopic regression and microscopic regression of tumors were compared to describe the phenomenon of non-synchronous regression. Then, the safety of non-surgical treatment for patients with clinical complete response (cCR) was analyzed to elaborate the necessity of surgical treatment. Finally, the review studied the safe surgical resection range to explore the safe distance of distal resection margin.

A prospective cohort study on the clinical value of pelvic peritoneal reconstruction in laparoscopic anterior resection for middle and low rectal cancer / 中华胃肠外科杂志

Objective: To investigate the safety and efficacy of pelvic peritoneal reconstruction and its effect on anal function in laparoscopy-assisted anterior resection of low and middle rectal cancer. Methods: A prospective cohort study was conducted. Consecutive patients with low and middle rectal cancer who underwent laparoscopy-assisted transabdominal anterior resection at Naval Military Medical University Changhai Hospital from February 2020 to February 2021 were enrolled. Inclusion criteria: (1) the distance from tumor to the anal verge ≤10 cm; (2) laparoscopy-assisted transabdominal anterior resection of rectal cancer; (3) complete clinical data; (4) rectal adenocarcinoma diagnosed by postoperative pathology. Exclusion criteria: (1) emergency surgery; (2) patients with a history of anal dysfunction or anal surgery; (3) preoperative diagnosis of distant (liver, lung) metastasis; (4) intestinal obstruction; (5) conversion to open surgery for various reasons. The pelvic floor was reconstructed using SXMD1B405 (Stratafix helical PGA-PCL, Ethicon). The first needle was sutured from the left anterior wall of the neorectum to the right. Insertion of the needle was continued to suture the root of the sigmoid mesentery while the Hemo-lok was used to fix the suture. The second needle was started from the beginning of the first needle, after 3-4 needles, a drainage tube was inserted through the left lower abdominal trocar to the presacral space. Then, the left peritoneal incision of the descending colon was sutured, after which Hemo-lok fixation was performed. The operative time, perioperative complications, postoperative Wexner anal function score and low anterior resection syndrome (LARS) score were compared between the study group and the control group. Three to six months after the operation, pelvic MRI was performed to observe and compare the pelvic floor anatomical structure of the two groups. Results: A total of 230 patients were enrolled, including 58 who underwent pelvic floor peritoneum reconstruction as the study group and 172 who did not undergo pelvic floor peritoneum reconstruction as the control group. There were no significant differences in general data between the two groups (all P>0.05). The operation time of the study group was longer than that of control group [(177.5±33.0) minutes vs. (148.7±45.5) minutes, P<0.001]. There was no significant difference in the incidence of perioperative complications (including anastomotic leakage, anastomotic bleeding, postoperative pneumonia, urinary tract infection, deep vein thrombosis, and intestinal obstruction) between the two groups (all P>0.05). Eight cases had anastomotic leakage, of whom 2 cases (3.4%) in the study group were discharged after conservative treatment, 5 cases (2.9%) of other 6 cases (3.5%) in the control group were discharged after the secondary surgical treatment. The Wexner score and LARS score were 3.1±2.8 and 23.0 (16.0-28.0) in the study group, which were lower than those in the control group [4.7±3.4 and 27.0 (18.0-32.0)], and the differences were statistically significant (t=-3.018, P=0.003 and Z=-2.257, P=0.024). Severe LARS was 16.5% (7/45) in study group and 35.5% (50/141) in control group, and the difference was no significant differences (Z=4.373, P=0.373). Pelvic MRI examination 3 to 6 months after surgery showed that the incidence of intestinal accumulation in the pelvic floor was 9.1% (3/33) in study group and 46.4% (64/138) in control group (χ(2)=15.537, P<0.001). Conclusion: Pelvic peritoneal reconstruction using stratafix in laparoscopic anterior resection of middle and low rectal cancer is safe and feasible, which may reduce the probability of the secondary operation in patients with anastomotic leakage and significantly improve postoperative anal function.

Could tumor characteristics identified by colonoscopy predict the locally advanced rectal carcinoma? / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Neoadjuvant chemoradiation is now considered the standard care for locally advanced rectal carcinoma (T3-4 or/and N1-2 lesions), but the accuracy of staging examinations including endorectal ultrasonography (ERUS) and MRI is far from excellent. In addition, the above staging equipment or professionals who perform the examinations may not be available in some hospitals, while preoperative colonoscopy and biopsy are usually obtainable in most hospitals. The objective of the present study was to investigate the clinical and pathological characteristics of locally advanced rectal carcinoma and identify candidates for neoadjuvant chemoradiation.</p><p><b>METHODS</b>This was a retrospective study. Patients who were treated for rectal cancer at Changhai Hospital from January 1999 to July 2008 were identified from our prospectively collected database. Statistical analysis was performed using SPSS Software System (version 15.0). The Mann-Whitney test, chi-square test and multivariate Logistic regression analysis were performed.</p><p><b>RESULTS</b>A total of 1005 cases were included in this research, of which 761 cases were identified as locally advanced rectal carcinoma depending on postoperative TNM staging. The results of multivariate Logistic regression analysis indicated seven independent risk factors that could be used to predict a locally advanced rectal carcinoma independently: a high grade (including poor differentiation and undifferentiation) (OR: 3.856; 95% CI: 2.064 to 7.204; P = 0.000); large tumor size (OR: 2.455; 95% CI: 1.755 to 3.436; P = 0.000); elevated preoperative serum CEA level (OR: 1.823; 95% CI: 1.309 to 2.537; P = 0.000); non-polypoid tumor type (OR: 1.758; 95% CI: 1.273 to 2.427; P = 0.001); the absence of synchronous polyps (OR: 1.602; 95% CI: 1.103 to 2.327; P = 0.013); the absence of blood in stool (OR: 1.659; 95% CI: 1.049 to 2.624; P = 0.030); and a greater circumferential tumor extent (OR: 1.813; 95% CI: 1.055 to 3.113; P = 0.031). Based on these findings, a Logistic equation was established, the accuracy of which was 64% according to the information of the additional 50 cases.</p><p><b>CONCLUSIONS</b>Some independent risk factors related with locally advanced rectal carcinoma were identified, based on which it is possible to establish a Logistic equation as a tool to predict candidates of neoadjuvant chemoradiation. Further research about optimization of the equation is warranted.</p>

Impact of meticulousness of pathologists on lymph node harvest after radical resection of invasive rectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To analyze the impact of meticulousness of pathologists on the lymph node harvest after radical resection of invasive rectal carcinoma.</p><p><b>METHODS</b>From January 2008 to May 2009, the clinical data of rectal cancer patients undergone operation were reviewed retrospectively. After multidisciplinary cooperation on rectal cancer, a new rule was applied to request the pathologists to find no less than 15 nodes in single colorectal specimen from January 2009. Patients were divided into two groups (2008 group and 2009 group) and the node harvest numbers were compared. Excluded criteria were recurrent colorectal tumor, Tis tumor, R(1) or R(2) resection, tumor resection transanally or endoscopically, the cases enrolled in other prospective research, synchronous diseases affecting the surgical procedure for the rectal cancer (familial adenomatous polyposis, synchronous colorectal carcinoma) and rectal cancer receiving neoadjuvant chemoradiation. Statistical analysis was performed using One-Sample Kolmogorov- Smirnov test, Mann-Whitney test, Independent-Samples T test and Chi-Square test(SPSS 15.0).</p><p><b>RESULTS</b>A total of 232 patients were identified, including 76 cases in the 2009 group and 156 cases in 2008 group. The lymph node retrieval in the 2009 group was significantly more than that in 2008 group (16.0+/-0.3 vs 11.4+/-0.3, P<0.01). A significantly higher percentage of patients was found in 2009 group with a lymph node harvest equal to or more than 12 nodes (72/76 vs 71/156, P<0.01). There were no significant differences in gender (46/76 vs 86/156, P=0.436), age (58.1+/-1.3 vs 59.2+/-1.1, P=0.527), distance from tumor to anal verge (7.4+/-0.4 vs 7.1+/-0.3, P=0.761), proportion of sphincter-sparing surgery (67/76 vs 140/156, P=0.715), ratio of well and moderate differentiated tumors (68/76 vs 125/156, P=0.074) and overall TNM stage (P=0.167) between the two groups.</p><p><b>CONCLUSIONS</b>The lymph node harvest in 2009 group is significantly more than that in 2008 group. The good performance of pathologists could produce adequate number of lymph nodes for rectal cancer without neoadjuvant chemoradiation.</p>