Objective:To construct and validate a predictive model for pathological complete response (pCR) in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy.Methods:This retrospective observational study included 595 patients with stage T2-4 and (or) N+M0 LARC diagnosed in the Cancer Hospital of Chinese Academy of Medical Sciences and the Fourth Hospital of Hebei Medical University who had no metastases, tolerated neoadjuvant therapy, completed neoadjuvant therapy, and had undergone radical surgery after neoadjuvant therapy. The training set comprised 299 patients admitted to the Cancer Hospital of Chinese Academy of Medical Sciences from 2013 to 2018, the internal validation set 155 patients admitted from 2019 to 2023, and the external validation set 141 patients admitted to the Fourth Hospital of Hebei Medical University from 2013 to 2021. They were divided into pCR group and non-pCR groups according to postoperative pathology. Among the 299 patients in the training set, 247 were in the non-PCR and 52 in the pCR group; among the 155 patients verified internally, 113 were in the non-PCR and 42 in the pCR group; and among the 141 patients validated externally, 132 were in the non-pCR and nine in the pCR group. Logistic regression was used for univariate and multifactorial analysis to explore the factors associated with pCR and construct a nomogram prediction model. Receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA) were used to validate the performance of the predictive model.Results:Univariate and multivariate logistic regression analysis showed that carbohydrate antigen 19-9 ( P=0.040, OR=0.97, 95%CI: 0.93-0.99), neutrophil count ( P<0.001, OR=0.66, 95%CI: 0.52-0.84), tumor T stage: Stage IV ( P=0.011, OR=0.22, 95%CI: 0.07-0.70), tumor N stage: Stage I ( P=0.003, OR=0.22,95%CI:0.08-0.60), Stage II ( P<0.001, OR=0.03, 95%CI: 0.01-0.09) and involvement of mesorectal fascia ( P=0.004, OR=0.09, 95%CI: 0.02-0.47) were independent predictors of pCR. In the training set, the area under the receiver operating characteristic curve of the model was 0.92 (95%CI: 0.87-0.96), whereas in the internal and external validation sets, the AUCs were 0.78 and 0.81, respectively. The calibration curve showed that the prediction model had good prediction efficiency in both the training and verification sets. Decision curve analysis showed that the net benefit of the model was largest when the threshold probability was in the range of 5.2% to 89.7% (in the internal and external validation sets, the threshold probabilities were in the range of 15.7% to 92.3% and 2.2% to 84.1%, respectively). Conclusion:The nomogram model constructed in this study showed efficacy in predicting whether patients with LARC will achieve pCR after receiving neoadjuvant chemoradiotherapy.

Objective:To construct and validate a predictive model for pathological complete response (pCR) in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy.Methods:This retrospective observational study included 595 patients with stage T2-4 and (or) N+M0 LARC diagnosed in the Cancer Hospital of Chinese Academy of Medical Sciences and the Fourth Hospital of Hebei Medical University who had no metastases, tolerated neoadjuvant therapy, completed neoadjuvant therapy, and had undergone radical surgery after neoadjuvant therapy. The training set comprised 299 patients admitted to the Cancer Hospital of Chinese Academy of Medical Sciences from 2013 to 2018, the internal validation set 155 patients admitted from 2019 to 2023, and the external validation set 141 patients admitted to the Fourth Hospital of Hebei Medical University from 2013 to 2021. They were divided into pCR group and non-pCR groups according to postoperative pathology. Among the 299 patients in the training set, 247 were in the non-PCR and 52 in the pCR group; among the 155 patients verified internally, 113 were in the non-PCR and 42 in the pCR group; and among the 141 patients validated externally, 132 were in the non-pCR and nine in the pCR group. Logistic regression was used for univariate and multifactorial analysis to explore the factors associated with pCR and construct a nomogram prediction model. Receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA) were used to validate the performance of the predictive model.Results:Univariate and multivariate logistic regression analysis showed that carbohydrate antigen 19-9 ( P=0.040, OR=0.97, 95%CI: 0.93-0.99), neutrophil count ( P<0.001, OR=0.66, 95%CI: 0.52-0.84), tumor T stage: Stage IV ( P=0.011, OR=0.22, 95%CI: 0.07-0.70), tumor N stage: Stage I ( P=0.003, OR=0.22,95%CI:0.08-0.60), Stage II ( P<0.001, OR=0.03, 95%CI: 0.01-0.09) and involvement of mesorectal fascia ( P=0.004, OR=0.09, 95%CI: 0.02-0.47) were independent predictors of pCR. In the training set, the area under the receiver operating characteristic curve of the model was 0.92 (95%CI: 0.87-0.96), whereas in the internal and external validation sets, the AUCs were 0.78 and 0.81, respectively. The calibration curve showed that the prediction model had good prediction efficiency in both the training and verification sets. Decision curve analysis showed that the net benefit of the model was largest when the threshold probability was in the range of 5.2% to 89.7% (in the internal and external validation sets, the threshold probabilities were in the range of 15.7% to 92.3% and 2.2% to 84.1%, respectively). Conclusion:The nomogram model constructed in this study showed efficacy in predicting whether patients with LARC will achieve pCR after receiving neoadjuvant chemoradiotherapy.

Objectives:This study aims to explore the clinical significance of lateral pelvic sentinel lymph node biopsy (SLNB) using indocyanine green (ICG) fluorescence navigation in laparoscopic lateral pelvic lymph node dissection (LLND) and evaluate the accuracy and feasibility of this technique to predict the status of lateral pelvic lymph nodes (LPLNs).Methods:The clinical and pathological characteristics, surgical outcomes, lymph node findings and perioperative complications of 16 rectal cancer patients who underwent SLNB using ICG fluorescence navigation in laparoscopic LLND in the Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College during April 2017 and October 2022 were retrospectively collected and analyzed. The patients did not receive preoperative neoadjuvant radiotherapy and presented with LPLNs but without LPLN enlargement (MRI showed the maximum short axes of the LPLNs were ≥5 mm and <10 mm at first visit).Results:All 16 patients were successfully performed SLNB using ICG fluorescence navigation in laparoscopic LLND. Three patients underwent bilateral LLND and 13 patients underwent unilateral LLND. The lateral pelvic sentinel lymph nodes (SLNs) were clearly fluorescent before dissection in 14 patients and the detection rate of SLNs for these patients was 87.5%. Lateral pelvic SLN metastasis was diagnosed in 2 patients and negative results were found in 12 patients by frozen pathological examinations. Among the 14 patients in whom lateral pelvic SLNs were detected, the dissected lateral pelvic non-SLNs were all negative. All dissected LPLNs were negative in two patients without fluorescent lateral pelvic SLNs. The specificity, sensitivity, negative predictive value, and accuracy was 85.7%, 100%, 100%, and 100%, respectively.Conclusions:This study indicates that lateral pelvic SLNB using ICG fluorescence navigation shows promise as a safe and feasible procedure with good accuracy. This technique may replace preventive LLND for locally advanced lower rectal cancer.

Objectives:This study aims to explore the clinical significance of lateral pelvic sentinel lymph node biopsy (SLNB) using indocyanine green (ICG) fluorescence navigation in laparoscopic lateral pelvic lymph node dissection (LLND) and evaluate the accuracy and feasibility of this technique to predict the status of lateral pelvic lymph nodes (LPLNs).Methods:The clinical and pathological characteristics, surgical outcomes, lymph node findings and perioperative complications of 16 rectal cancer patients who underwent SLNB using ICG fluorescence navigation in laparoscopic LLND in the Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College during April 2017 and October 2022 were retrospectively collected and analyzed. The patients did not receive preoperative neoadjuvant radiotherapy and presented with LPLNs but without LPLN enlargement (MRI showed the maximum short axes of the LPLNs were ≥5 mm and <10 mm at first visit).Results:All 16 patients were successfully performed SLNB using ICG fluorescence navigation in laparoscopic LLND. Three patients underwent bilateral LLND and 13 patients underwent unilateral LLND. The lateral pelvic sentinel lymph nodes (SLNs) were clearly fluorescent before dissection in 14 patients and the detection rate of SLNs for these patients was 87.5%. Lateral pelvic SLN metastasis was diagnosed in 2 patients and negative results were found in 12 patients by frozen pathological examinations. Among the 14 patients in whom lateral pelvic SLNs were detected, the dissected lateral pelvic non-SLNs were all negative. All dissected LPLNs were negative in two patients without fluorescent lateral pelvic SLNs. The specificity, sensitivity, negative predictive value, and accuracy was 85.7%, 100%, 100%, and 100%, respectively.Conclusions:This study indicates that lateral pelvic SLNB using ICG fluorescence navigation shows promise as a safe and feasible procedure with good accuracy. This technique may replace preventive LLND for locally advanced lower rectal cancer.

In colorectal cancer surgery, loop ileostomy is sometimes necessary to prevent anastomotic leakage. Although ileostomy reversal is relatively simple, postoperative complication is inevitable. In recent years, laparoscopic surgery has been gradually applied in ileostomy reversal due to its small trauma, fast recovery, and low complications, exhibiting satisfactory short-term outcomes. This review analyzes the application of the laparoscopic technique in ileostomy surgery and explores the potential of total laparoscopic surgery, aiming to provide a new perspective for the clinical application of laparoscopic ileostomy reversal.

Cetuximab has become an important molecular targeted drug for the treatment of metastatic colorectal cancer (mCRC), which increases the curative effect of chemotherapy and prolongs the survival time. However, some patients develop insensitiveness or resistance to cetuximab, while the complicated molecular mechanisms are not quite clear. With the deep research in epidermal growth factor receptor (EGFR) signaling pathway, the genetic alteration of KRAS, BRAF, PTEN and PIK3CA and polymorphism of microRNA (miRNA) have been proved to associated with cetuximab resistance. Wnt signaling pathway with its negative regulator RNF43 is also considered to be related with cetuximab resistance in recent studies. The review of the progress on molecular mechanisms of cetuximab resistance in mCRC can establish theoretical basis for finding out reasonable drugs to overcome the resistance.

Objective:In laparoscopic-assisted left hemicolectomy, previous studies have suggested that preserving the inferior mesenteric artery (IMA) may improve intestinal blood flow and reduce the incidence of anastomotic leakage. However, whether IMA should be retained is controversial currently. This study aims to investigate the short-term efficacy of the inferior mesenteric artery preservation (IMAP) and the inferior mesenteric artery resection (IMAR) on the laparoscopic-assisted radical resection of left hemicolon cancer.Methods:A retrospective cohort study was conducted to collect the clinical data of 195 patients with left colon cancer who underwent laparoscopic surgery in the Colorectal Surgery Department of Cancer Hospital of Chinese Academy of Medical Sciences from October 2012 to February 2019. After D3 radical resection for left semicolon cancer, they were divided into the IMAR group (91 cases), and the IMAP group (104 cases). In IMAR group, the left colon artery (LCA) and 1-2 branches of sigmoid artery (SA) were identified about 5 cm away from the root of the IMA, then the main IMA trunk was transected at the distal end. In IMAP group, the main trunk of IMA was dissected and the lymph nodes around IMA were cleaned. After the LCA and the first branch of SA (SA1) were separated, the LCA and SA1 were closed and cut off at the root. The intraoperative and postoperative data were compared between two groups, including the morbidity of complications within 30 days after operation, postoperative follow-up recovery, operation time, intraoperative blood loss, number of harvested lymph nodes, length of specimens, postoperative passage of gas and hospital stay.Results:The operation was successfully completed in all the cases without any death related to the operation. Compared with the IMAP group, the operation time was shorter [(161.8±48.0) minutes vs. (182.9±49.4) minutes, t=2.985, P=0.003], the intraoperative blood loss was less [(38.5±30.8) ml vs.(52.9±32.2) ml, t=2.088, P=0.038], the length of the resected bowel was longer [(19.2±6.0) cm vs.(17.2±5.4) cm, t=-2.447, P=0.015] in the IMAR group, whose differences were statistically significant (all P<0.05). There were no significant differences in the number of harvested lymph nodes, time of postoperative passage of gas and postoperative hospital stay between two groups (all P>0.05). There was no significant difference in overall morbidity of postoperative complications between the two group [6/91 (6.6%) vs. 7/104 (6.7%), χ 2=0.001, P=0.969]. In the IMAR group, one case developed postoperative abdominal infection, two cases developed incision infection, one case developed lung infection, two cases developed intestinal obstruction, and no anastomotic bleeding occurred. In IMAP group, one case developed postoperative lung infection, one case developed incision infection, one case developed abdominal bleeding, two cases developed intestinal obstruction and two cases developed anastomotic bleeding. There was no anastomotic leakage in either group. All complications were treated by conservative treatment successfully. After a median follow-up of 12 (range 3-24) months, patients in the two groups had good intestinal blood supply after surgery, and there was no clear manifestation of congestive or ischemic enteritis under colonoscopy. Conclusion:Laparoscopic-assisted left hemicolectomy with IMA resection in patients with left hemicolon cancer provides better short-term efficacy safely and feasibly, including shorter operative time, less intraoperative bleeding and without increasing postoperative complications.

Objective:In laparoscopic-assisted left hemicolectomy, previous studies have suggested that preserving the inferior mesenteric artery (IMA) may improve intestinal blood flow and reduce the incidence of anastomotic leakage. However, whether IMA should be retained is controversial currently. This study aims to investigate the short-term efficacy of the inferior mesenteric artery preservation (IMAP) and the inferior mesenteric artery resection (IMAR) on the laparoscopic-assisted radical resection of left hemicolon cancer.Methods:A retrospective cohort study was conducted to collect the clinical data of 195 patients with left colon cancer who underwent laparoscopic surgery in the Colorectal Surgery Department of Cancer Hospital of Chinese Academy of Medical Sciences from October 2012 to February 2019. After D3 radical resection for left semicolon cancer, they were divided into the IMAR group (91 cases), and the IMAP group (104 cases). In IMAR group, the left colon artery (LCA) and 1-2 branches of sigmoid artery (SA) were identified about 5 cm away from the root of the IMA, then the main IMA trunk was transected at the distal end. In IMAP group, the main trunk of IMA was dissected and the lymph nodes around IMA were cleaned. After the LCA and the first branch of SA (SA1) were separated, the LCA and SA1 were closed and cut off at the root. The intraoperative and postoperative data were compared between two groups, including the morbidity of complications within 30 days after operation, postoperative follow-up recovery, operation time, intraoperative blood loss, number of harvested lymph nodes, length of specimens, postoperative passage of gas and hospital stay.Results:The operation was successfully completed in all the cases without any death related to the operation. Compared with the IMAP group, the operation time was shorter [(161.8±48.0) minutes vs. (182.9±49.4) minutes, t=2.985, P=0.003], the intraoperative blood loss was less [(38.5±30.8) ml vs.(52.9±32.2) ml, t=2.088, P=0.038], the length of the resected bowel was longer [(19.2±6.0) cm vs.(17.2±5.4) cm, t=-2.447, P=0.015] in the IMAR group, whose differences were statistically significant (all P<0.05). There were no significant differences in the number of harvested lymph nodes, time of postoperative passage of gas and postoperative hospital stay between two groups (all P>0.05). There was no significant difference in overall morbidity of postoperative complications between the two group [6/91 (6.6%) vs. 7/104 (6.7%), χ 2=0.001, P=0.969]. In the IMAR group, one case developed postoperative abdominal infection, two cases developed incision infection, one case developed lung infection, two cases developed intestinal obstruction, and no anastomotic bleeding occurred. In IMAP group, one case developed postoperative lung infection, one case developed incision infection, one case developed abdominal bleeding, two cases developed intestinal obstruction and two cases developed anastomotic bleeding. There was no anastomotic leakage in either group. All complications were treated by conservative treatment successfully. After a median follow-up of 12 (range 3-24) months, patients in the two groups had good intestinal blood supply after surgery, and there was no clear manifestation of congestive or ischemic enteritis under colonoscopy. Conclusion:Laparoscopic-assisted left hemicolectomy with IMA resection in patients with left hemicolon cancer provides better short-term efficacy safely and feasibly, including shorter operative time, less intraoperative bleeding and without increasing postoperative complications.

Objective: The aim of this study was to explore the clinical safety, feasibility and short-term effect of overlapped delta-shaped anastomosis in total laparoscopic transverse colectomy. Methods: The records, which were based on China National Cancer Center, of 20 and 31 patients who underwent total laparoscopic transverse colectomy with overlapped delta-shaped anastomosis and laparoscopic-assisted transverse colectomy with conventional extracorporeal anastomosis, from March 2017 to May 2018 were reviewed retrospectively. Data regarding surgical outcomes, postoperative recovery, pathological outcomes and perioperative complications were collected and compared. Results: There was no difference between the two groups in overall operation time, anastomosis time and intraoperative blood loss (P>0.05), however, the length of incision was significantly shorter in overlapped delta-shaped group [(4.7±0.6) cm vs. (5.5±1.0) cm, P=0.002]. The time to ground activities, first flatus and postoperative hospitalization did not differ between the two groups (P>0.05). The postoperative visual analogue scale was lower in the overlapped delta-shaped group than the control group on postoperative day 1 (3.7±0.7 vs. 4.2±0.9, P=0.015) and postoperative day 3 (2.7±0.5 vs. 3.2±0.9, P=0.040). The perioperative complication rates were 10.0% and 12.9% in the overlapped delta-shaped group and the control group, respectively, and the difference was not significant (P=0.753). Conclusion Compared to conventional extracorporeal anastomosis, total laparoscopic transverse colectomy with overlapped delta-shaped anastomosis was a safe and feasible procedure with satisfactory short-term effect, shorter incision and less postoperative pain.

Objective: To explore the clinical safety and feasibility of enterostomy using running suture of dermis and seromuscular layer in laparoscopic-assisted radical resection for rectal carcinoma. Methods: From May 1, 2017 to May 1, 2018, 46 patients who underwent laparoscopic-assisted radical resection for rectal carcinoma with enterostomy using running suture of dermis and seromuscular layer in Cancer Hospital, Chinese Academy of Medical Sciences were retrospectively enrolled in this study. Data regarding clinicopathologic characteristics, operation and postoperative outcomes, stoma-related complications and functions of stoma were collected and analyzed. Results: All of the 46 patients successfully underwent this operation. Among them, 30 patients underwent laparoscopic-assisted abdominoperineal resection for rectal cancer with sigmoidostomy and 16 patients underwent laparoscopic-assisted low anterior resection for rectal cancer with loop ileostomy. The mean operation time was 115.3 minutes and intraoperative blood loss was 86.1 ml. The mean time for enterostomy was 14.1 minutes. The average time to flatus, time to fluid diet intake and length of hospital stay were 1.8 days, 2.9 days and 6.5 days, respectively. During the follow-up period, three patients suffered from stomal edema, two patients suffered from parastomal hernia, and two patients suffered from skin inflammation surrounding stoma. None of re-operation related stoma and severe mobility such as stomal stenosis, stomal necrosis, stomal prolapse, stomal retraction and stomal mucocutaneous separation occurred. Thirty-five patients recovered with satisfactory stomal function, two with middle function and one with poor function. Conclusion Enterostomy using running suture of dermis and seromuscular layer in laparoscopic-assisted radical resection for rectal carcinoma is a safe and feasible procedure with a satisfactory short-term effect.