Short-course radiotherapy combined with CAPOX and PD-1 inhibitor for the total neoadjuvant therapy of locally advanced rectal cancer: the preliminary single-center findings of a prospective, multicentre, randomized phase II trial (TORCH) / 中华胃肠外科杂志

Objective: Total neoadjuvant therapy has been used to improve tumor responses and prevent distant metastases in patients with locally advanced rectal cancer (LARC). Patients with complete clinical responses (cCR) then have the option of choosing a watch and wait (W&W) strategy and organ preservation. It has recently been shown that hypofractionated radiotherapy has better synergistic effects with PD-1/PD-L1 inhibitors than does conventionally fractionated radiotherapy, increasing the sensitivity of microsatellite stable (MSS) colorectal cancer to immunotherapy. Thus, in this trial we aimed to determine whether total neoadjuvant therapy comprising short-course radiotherapy (SCRT) combined with a PD-1 inhibitor improves the degree of tumor regression in patients with LARC. Methods: TORCH is a prospective, multicenter, randomized, phase II trial (TORCH Registration No. NCT04518280). Patients with LARC (T3-4/N+M0, distance from anus ≤10 cm) are eligible and are randomly assigned to consolidation or induction arms. Those in the consolidation arm receive SCRT (25Gy/5 Fx), followed by six cycles of toripalimab plus capecitabine and oxaliplatin (ToriCAPOX). Those in the induction arm receive two cycles of ToriCAPOX, then undergo SCRT, followed by four cycles of ToriCAPOX. Patients in both groups undergo total mesorectal excision (TME) or can choose a W&W strategy if cCR has been achieved. The primary endpoint is the complete response rate (CR, pathological complete response [pCR] plus continuous cCR for more than 1 year). The secondary endpoints include rates of Grade 3-4 acute adverse effects (AEs) etc. Results: Up to 30 September 2022, 62 patients attending our center were enrolled (Consolidation arm: 34, Induction arm:28). Their median age was 53 (27-69) years. Fifty-nine of them had MSS/pMMR type cancer (95.2%), and only three MSI-H/dMMR. Additionally, 55 patients (88.7%) had Stage III disease. The following important characteristics were distributed as follows: lower location (≤5 cm from anus, 48/62, 77.4%), deeper invasion by primary lesion (cT4 7/62, 11.3%; mesorectal fascia involved 17/62, 27.4%), and high risk of distant metastasis (cN2 26/62, 41.9%; EMVI+ 11/62, 17.7%). All 62 patients completed the SCRT and at least five cycles of ToriCAPOX, 52/62 (83.9%) completing six cycles of ToriCAPOX. Finally, 29 patients achieved cCR (46.8%, 29/62), 18 of whom decided to adopt a W&W strategy. TME was performed on 32 patients. Pathological examination showed 18 had achieved pCR, four TRG 1, and 10 TRG 2-3. The three patients with MSI-H disease all achieved cCR. One of these patients was found to have pCR after surgery whereas the other two adopted a W&W strategy. Thus, the pCR and CR rates were 56.2% (18/32) and 58.1% (36/62), respectively. The TRG 0-1 rate was 68.8% (22/32). The most common non-hematologic AEs were poor appetite (49/60, 81.7%), numbness (49/60, 81.7%), nausea (47/60, 78.3%) and asthenia (43/60, 71.7%); two patients did not complete this survey. The most common hematologic AEs were thrombocytopenia (48/62, 77.4%), anemia (47/62, 75.8%), leukopenia/neutropenia (44/62, 71.0%) and high transaminase (39/62, 62.9%). The main Grade III-IV AE was thrombocytopenia (22/62, 35.5%), with three patients (3/62, 4.8%) having Grade IV thrombocytopenia. No Grade V AEs were noted. Conclusions: SCRT-based total neoadjuvant therapy combined with toripalimab can achieve a surprisingly good CR rate in patients with LARC and thus has the potential to offer new treatment options for organ preservation in patients with MSS and lower-location rectal cancer. Meanwhile, the preliminary findings of a single center show good tolerability, the main Grade III-IV AE being thrombocytopenia. The significant efficacy and long-term prognostic benefit need to be determined by further follow-up.

Study on clinical value of three localization methods in laparoscopic colorectal tumor surgery / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical effectiveness of three localization methods, including methylene blue, metal clips and intraoperative colonoscopy in laparoscopic colorectal surgery.</p><p><b>METHODS</b>A retrospective analysis was performed to review the clinical data of 64 patients who underwent the laparoscopic colorectal operations in Cancer Hospital of Fudan University from December 2009 to June 2012. Three methods of tumor localization were used perioperatively, including 23 cases of methylene blue, 20 of metal clips and 21 of colonoscopy.</p><p><b>RESULTS</b>Operations were successfully performed in this cohort and there were no deaths or complications. In methylene blue group, intraoperative colonoscopy was performed in two cases because of the inability to visualize blue dye on the serosal surface of the intestinal wall, another 2 cases were converted to open operation because of methylene blue diffusion and inability to identify resection margin. Intraoperative colonoscopic localization was required for 3 cases of sigmoid colon or upper rectal tumor because of inaccurate tumor localization by metal clips. Poor operative exposure due to obvious bowel distension prompted the conversion to open surgery in 2 cases of colonoscopy localization group, and the accurate position of the lesion was not found in another 2 cases due to long pedunculated adenoma.</p><p><b>CONCLUSIONS</b>Colorectal tumor can be localized effectively by endoscopic methylene blue tattooing at a maximum of 2 tumors before operation and the method of 4-point positioning can significantly improve the accuracy of colorectal tumor localization. Tumor localization preoperatively on the day of surgery by metal clip is accurate for the right or left colon cancer. Intraoperative colonoscopy can localize tumor accurately and rapidly for rectosigmoid or descending tumor, and the incidence of bowel distension can be significantly reduced. Localization method should be considered according to the tumor location and surgical procedure.</p>

Prospective study on the use of nickel-titanium temperature-dependent memory-shape device (CAR27) for anastomosis after colorectal surgery / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To prospectively evaluate the safety and efficacy of nickel- titanium temperature-dependent memory-shape device(CAR27) for colorectal anastomosis.</p><p><b>METHODS</b>Sixty colorectal cancer patients were randomly divided into two groups and received colorectal anastomosis with CAR27 or traditional stapling device. Complications, bowel function return, and the extrusion of anastomosis ring were prospectively monitored.</p><p><b>RESULTS</b>Both CAR27 and stapler group had one case of anastomotic leakage. Other complications such as stricture or obstruction were not found. Time for anastomosis of the two groups were (10.1±1.2) minutes and (11.2±2.1) minutes respectively. Time to first flatus was(3.2±1.2) days and (3.5±1.4) days respectively. Time to food intake resumption was (4.0±1.4) days and (4.3±1.3) days respectively. The differences above between the two groups were not statistically significant(P>0.05). The ring was expelled with stool within 7-16 days. The two groups were similar in operative time and the return of bowel function.</p><p><b>CONCLUSION</b>CAR27 is safe and simple for colorectal anastomosis.</p>

Compression anastomosis ring: a novel technique for colorectal anastomosis / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the safety and efficacy of a novel nickel-titanium memory alloy compression anastomosis ring(CAR27) for colorectal anastomosis.</p><p><b>METHODS</b>One sigmoid cancer patient undergone lower anterior resection(LAR) received colorectal anastomosis with CAR27 on November 12, 2009. The following parameters were recorded during 4 weeks postoperative follow-up:colorectal anastomotic complication,first post-operation flatus and bowel movement, extrusion of ring device.</p><p><b>RESULTS</b>The total operation time was 42 minutes, including 11 minutes for colorectal anastomosis. The patient had flatus at the first day and began feeding at the second day postoperatively. The ring was expelled with stool at the 10th day postoperatively. Patient didn't have anastomotic complications such as leakage or obstruction during 1 month postoperative follow-up.</p><p><b>CONCLUSION</b>This case study primarily indicates CAR27 is safe and feasible for colorectal anastomosis.</p>

Relationship between CpG island methylator phenotype and genetic instability in sporadic colorectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the relationship between CpG island methylator phenotype(CIMP) and genetic instability in sporadic colorectal cancer(SCRC).</p><p><b>METHODS</b>Seventy-one SCRC patients were enrolled in this study. Promotor methylation status of five genes including P14(ARF ), hMLH1, P16(INK4a), MGMT and MINT1 was detected with methylation specific PCR to confirm CIMP. Microsatellite instability (MSI) status was evaluated with two microsatellite loci of BAT25 and BAT26, and the ploidy was detected with flow cytometry. The association between CIMP and MSI as well as chromosomal instability(CIN) was examined.</p><p><b>RESULTS</b>The positive rates of CIMP, MSI and aneuploidy were 21.1% (15/71), 9.9% (7/71) and 73.5% (50/68) respectively. The positive rate of MSI in positive CIMP patients was higher than that in negative CIMP ones, but the difference was not significant (20.0% vs 7.1%,P=0.158). The positive rate of MSI was 57.1% in patients with hMLH1 gene promotor hypermethylation, which was significantly higher than that (4.7%) in patients without hMLH1 gene promotor hypermethylation (P=0.001). SCRCs with positive CIMP displayed significant inclination of diploidy (P=0.003). The positive rate of diploidy among SCRCs with CIMP was 61.5% while only 18.2% of cases without CIMP demonstrated diploid.</p><p><b>CONCLUSIONS</b>SCRCs with positive CIMP are significantly more likely to be diploid. Simultaneous multiple genes hypermethylation represented by CIMP may be an epigenetic mechanism competing with the genetic mechanism of CIN.</p>

Study on the germline mutation of MSH6 gene in Chinese hereditary nonpolyposis colorectal cancer pedigrees using PCR based sequencing / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the germline mutation of mismatch repair gene (MSH6) in hereditary nonpolyposis colorectal cancer (HNPCC) kindreds fulfilling different clinical criteria.</p><p><b>METHODS</b>The germline mutations of MSH6 gene were detected by PCR based DNA sequencing in 39 unrelated HNPCC probands fulfilling different clinical criteria in which MSH2 and MLH1 mutations were excluded. The exons with missense mutations were analyzed using PCR sequencing in the germline genomic DNA of 137 healthy persons. The expression of MSH6 protein was detected by Envision immunohistochemistry staining in the tumor tissues of the mutational probands.</p><p><b>RESULTS</b>Six germline mutations of MSH6 gene were detected in 39 probands of Chinese HNPCC kindreds, and the mutations distributed in the exon 4, 6, 9 and 10. Four out of six mutations were missense mutation, one was nonsense mutation and the remaining one was insertion mutation in splice site. The results of sequecing for the exons with above four missense mutations in 137 healthy persons' genomic DNA showed that 5 of 137 persons had the missense mutation of c.3488 A to T at codon 1163 of the 6th exon. The mutational rate was approximately 3.65% (5/137), so the mutation could be a single nucleotide polymorphism (SNP). The remaining missense mutations were not found in any germline genomic DNA of 137 healthy persons. Positive expression of MSH6 protein had been identified in the tumor of the SNP proband while the tumors had negative MSH6 protein expression in the rest probands of germline mutation MSH6 gene. The types of mutations and their potential significance were determined by comparing the following databases: http://www.ncbi.nlm.nih.gov/, http://www.ensembl.org/homo-sapies, and http://www.insight-group.org. Five out of the six mutations had not been reported previously and they were new pathological mutations, the rest one was a new SNP.</p><p><b>CONCLUSION</b>Germline mutations of MSH6 gene may play an important role in Chinese HNPCC kindreds fulfilling different clinical criteria. It is necessary to analyze the germline mutations of MSH6 gene using sequencing to identify HNPCC families in the probands in which MSH2 and MLH1 mutation were excluded.</p>

Two novel germline mutations of MLH1 in hereditary nonpolyposis colorectal cancer family / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore germline mutations of MLH1 in hereditary nonpolyposis colorectal cancer (HNPCC), and to investigate the pathobiology of novel detectable mutations of MLH1.</p><p><b>METHOD</b>RNA was extracted from the peripheral blood of 12 patients from 12 different families fulfilling the Amsterdam II Criteria of HNPCC. Germline mutations of MLH1 were determined by RT-PCR with gene specific primers, heat-resistance reverse transcriptase and long-template PCR polymerase, followed by cDNA sequencing analysis. PCR-Genescan analysis was used to further investigate microsatellite instability with a panel of 5 microsatellite markers (BAT26, BAT25, D5S346, D2S123 and Mfd15), along with immunohistochemistry staining to detect the expression of MLH1 protein in the tumor tissues.</p><p><b>RESULTS</b>Four germline mutations were found in 4 patients, 2 of which were previously reported GTT-->GAT mutation at codon 384 of exon 12, and the other two were novel mutations: CGC-->TGC at codon 217 of exon 8 and CCG-->CTG at codon 581 of exon 16. Two tumors with the novel mutations had high frequency microsatellite instability showing more than 2 instable loci (RER + phenotype), and both tumors lost their MLH1 protein expression.</p><p><b>CONCLUSION</b>The two novel germline mutations of MLH1 identified in this study, i.e. CGC-->TGC at codon 217 of exon 8 and CCG-->CTG at codon 581 of exon 16, are very likely to have pathological significance.</p>

Real-time PCR analysis of beta-catenin mRNA in sporadic colorectal cancers / 中华病理学杂志

<p><b>OBJECTIVE</b>To detect beta-catenin mRNA levels in sporadic colorectal cancers (SCRC) and adjacent normal colorectal mucosa, and to investigate the association between the beta-catenin mRNA level and its aberrant expression and clinicopathological parameters.</p><p><b>METHODS</b>The concentration of beta-catenin mRNA in 81 SCRCs and 28 adjacent normal colorectal mucosa specimens was determined by TaqMan real-time quantitative RT-PCR. The ratio of beta-catenin cDNA copies/GAPDH cDNA copies was used to represent the mRNA expression level in different tissues. The beta-catenin protein expression was determined by the EnVision two-step immunohistochemical method.</p><p><b>RESULTS</b>beta-catenin mRNA levels in SCRCs (2.527 +/- 2.284) were lower than those in the adjacent normal colorectal mucosa (5.003 +/- 3.326), P < 0.05. In addition, beta-catenin mRNA levels in lymph node-positive cases and tumors with ulcerative and infiltrating growth types were significantly lower (1.827 +/- 1.288, 2.202 +/- 2.035) than those in lymph node-negative cases and polypoid growth type tumors (3.359 +/- 2.881, 3.108 +/- 2.610), P < 0.05. No significant difference of beta-catenin mRNA level was found between cases with aberrant beta-catenin cytoplasm or nuclear expression and those without.</p><p><b>CONCLUSIONS</b>SCRCs express lower levels of beta-catenin mRNA than normal colorectal mucosa. Such lower level expression is associated with lymph node metastasis and tumors with ulcerative and infiltrative growth pattern. Aberrant cytoplasmic and nuclear expression of beta-catenin appears unrelated to the lower mRNA levels. Quantitative detection of beta-catenin mRNA may be a useful approach to monitor the biological behavior of SCRCs.</p>

Mutation analysis of hMSH2 and hMLH1 genes in Chinese hereditary nonpolyposis colorectal cancer families / 中华病理学杂志

<p><b>OBJECTIVES</b>To determine the germ-line mutations of hMSH2 and hMLH1 genes in Chinese hereditary nonpolyposis colorectal cancer (HNPCC) families' probands or in patients fulfilling different clinical criteria or guidelines; to clarify the nature and distribution of the mutations; to evaluate the sensitivity of different clinical criteria in mutation prediction.</p><p><b>METHODS</b>The entire coding regions (35 exons including exon-intron boundaries) of hMSH2 and hMLH1 genes were directly sequenced in 24 Amsterdam criteria (AC) probands, 15 Japanese criteria (JC) probands (except AC kindreds) and 19 Bethesda guidelines (BG) patients (except two former groups). All available affected and unaffected members from families of those with mutations were screened for mutation.</p><p><b>RESULTS</b>In 16 unrelated families selected by the different clinical criteria, 17 germ-line mutations were found with 11 (64.7%) of hMLH1 and 6 (35.3%) of hMSH2. Two mutations were identified in one of the families. Among the 17 germ-line mutations, 12 had not been reported previously. A diversified mutation spectrum was found, but 6 hMLH1 mutations were found to be concentrated in the region encompassing exon 14, 15 and 16. There was a wide spectrum of mutation type including frame shift, nonsense, splice site mutation, in frame insertion or deletion and missense mutations. The mutation detection rate of hMSH2 and hMLH1 in the AC group was significantly higher than that in the JC group (12/24 vs. 3/15). On the other hand, a low mutation rate (1/19) was detected in 19 BG patients. The mutation cosegregated with disease. Besides, three different genotypes in tumors from probands of mutation-positive families were found.</p><p><b>CONCLUSIONS</b>hMSH2 and hMLH1 mutations in Chinese HNPCC families show a wide spectrum. It seems that hMLH1 gene is involved more frequently than hMSH2 gene in Chinese HNPCC families. Different clinical criteria predict mutations with different sensitivities. The Amsterdam Criteria are most sensitive, while Japanese Criteria are highly practical and the Bethesda Guidelines are also practical to some extent. Gene mutations cosegregate with the disease phenotype. Carriers with no symptom in HNPCC families are most vulnerable groups, follow-ups are required for this group to get early diagnosis and to prevent the development of CRCs.</p>

Analysis of clinicopathological featurs in patients with Chinese hereditary nonpolyposis colorectal kindreds / 中华消化杂志

Objective To explore clinical features and prognosis of patients with hereditary nonpolypnsis colorectal cancer(HNPCC).Methods Twenty-four kindreds of Chinese HNPCC according to Amsterdam standard were enrolled and their pedigree trees were drawn.Clinicopathological and follow- up data were collected,clinical features and prognosis of 24 kindreds of Chinese HNPCC were analyzed as well.Results Among 24 H NPCCkindreds,there were 116 cases of cancer including 16 cases of multiple cancers in probands and 9 cases of multiple cancers in the members of kindreds.The age of patients ranged from 19 to 74.Of all the patients,there were 120 loci of colorectal cancers and 32 foci of HNPCC related extracolonic cancers.Among probands of 24 HNPCC kindreds,the average incidence age of onset- ring first colorectal cancer was 42.5,the male and right-side colon cancer patiens were more than female and left-side colon cancer patiens,respectively.The most pathologic type was tubular adenocarcinomas with moderately differentiation,which accounted for 45.8%(11/24).Up to the deadline of follow-up, 14 cases had survived for more than 5 years accounting for 58.3%(14/24) Of them,9 cases survived for more than 10 years and 1 case survived for 27 years.Conclusions Chinese patients with HNPCC have special characteristics such as moderately differentiated tubular adenocarcinomas,early onset of coloreetal cancer,right-side colon involvement.