Left Colon Cancer Research Articles

Location Has Prognostic Impact on the Outcome of Colorectal Mucinous Adenocarcinomas.

Mucinous (colloid) adenocarcinomas (MAs) are a rare histological subtype of tumors defined by extracellular mucin comprising more than 50% of the tumor. These tumors are on a continuum of mucin-producing malignancies with signet ring cell adenocarcinomas (SRCCs), which instead produce intracellular mucin. Mucin-containing cancers occur primarily in the stomach and colon, where for SRCCs, outcomes are relatively worse in the proximal stomach and the rectum. It is not known if MAs have similar outcomes. In this study, we use the Surveillance, Epidemiology, and End Results (SEER) database to examine the effects of tumor localization, age, sex, and stage on colorectal and gastric cancer outcomes for MAs. For right colon cancers, MAs are more common, particularly in females, and have slightly better or equivalent outcomes across all stages and ages compared to conventional adenocarcinomas, but outcomes are progressively worse compared to conventional adenocarcinomas for left colon and rectal cancers. Unlike SRCCs, MAs have similar outcomes to conventional adenocarcinomas in all stomach locations. Overall, these results suggest that MAs have an intrinsically different tumor biology in the left colon and rectum that promotes pathogenesis. Decoding this phenomenon could lead to more effectively tailored patient treatment regimens.

Fate of de-functioning ileostomy after left colon and rectal cancer resection: observation from a single unit of a cancer hospital.

Background: De-functioning ileostomy (DS) has been shown to reduce rate of anastomotic leak after left colon and rectal cancer resection and can avoid consequences of leak with its morbidity and possible mortality. Externalisation of bowel is not easily appreciated; patients always inquire about the timing of closure and not all stomas are closed. The aim of the study is to assess the timing of stoma closure and the reasons for stoma becoming permanent. Methods: Patients who underwent surgery for left colon and rectal cancer with de-functioning stoma from April 2019 to May 2022 in single unit of Bhaktapur Cancer Hospital, were assessed regarding timing of stoma closure. We have made a policy of stoma closure after completion of adjuvant therapy. De-functioning stoma that was not reversed at follow up were assessed regarding reason for it becoming permanent. Results: Forty-two patients underwent de-functioning stoma during the study period; 30 after rectal resection, 2 after pouch creation, 6 after anterior resection and 4 after left hemicolectomy. Twenty-eight (77%) stomas were closed, 5 are receiving adjuvant treatment. Closure was not done in 8 patients; 5 due to recurrence of disease; 1 due to patient wish, 2 deaths occurred prior to closure, one due to COVID-19 and another due to acute myocardial infraction. One patient with multiorgan resection died within 30 days of surgery due to other medical cause. The median time of stoma closure after completion of adjuvant treatment is 8 weeks, IQR (7-10). Patients had to stay with stoma for a median period of 6months, IQR (5-8). The median time for discharge after stoma reversal is 9 days, IQR (7-10). There were 4 Grade II Clavien-Dindo complications after stoma closure. Conclusion: Seventy- seven percent of patients with DS underwent closure in our series. Recurrence was the most common cause for it becoming permanent.

Retroperitoneal abscess as a presentation of colon cancer: The largest case set analysis to date, which extracted from our unit and the literature.

Colon cancer with retroperitoneal abscess is a rare and easily misdiagnosed disease and has only been reported via case. There is an urgent need to conduct a dataset analysis for such patients, which is crucial to improving the survival rate and quality of life of these patients. Patients with colon cancer associated with retroperitoneal abscess were extracted from our hospital and the PubMed, EMBASE and Web of Science databases. Clinical information, including the patients' basic characteristics, clinical symptoms, laboratory tests, imaging examinations, treatment methods and prognosis was analyzed. Sixty-one patients were analyzed, with an average age of 65 years. The proportions of right and left colon cancers were 63.9% and 36.1%, respectively. A total of 98.0% of the patients had adenocarcinoma. Many patients have insidious symptoms such as fever and weight loss. At the first medical visit, pain was the most common symptom (71%), with pain in the thigh (21.8%), abdomen (21.8%), and waist and back (14.5%) ranking among the top three. The misdiagnosis rate of the patients referred to our department was 75%, while the overall misdiagnosis rate in the literature was 43.9%. Laboratory tests show that these patients often have elevated white blood cells and anemia. CT examination showed that 87.2% of patients had an iliopsoas muscle abscess, and tumors were not simultaneously detected in 37.2%. A total of 33.9% of patients had local abscesses of the iliopsoas muscle, 26.4% had drainage into the subcutaneous tissue of the waist and upper buttocks, and 22.6% had drainage around the adductor muscle group of the thigh. These patients have a variety of treatments, and many patients have undergone multiple and unnecessary treatments. Thirteen patients died after surgery, and 6 died in the hospital, of whom four were patients undergoing direct surgery, and the other 7 died after discharge due to cachexia. Colorectal cancer with retroperitoneal abscess is a relatively rare and easily misdiagnosed subtype of colon cancer. It is more likely to occur in right-sided colon adenocarcinoma. The main clinical symptom is pain caused by the drainage of pus to the corresponding areas of the waist, abdomen, and legs. CT is the preferred diagnostic method. Actively treating the abscess and then transitioning to standard colon cancer treatment can prevent patient death and improve treatment quality.

Gut microbiota profiles in feces and paired tumor and non-tumor tissues from Colorectal Cancer patients. Relationship to the Body Mass Index.

Colorectal Cancer (CRC) and Obesity constitute two of the most common malignancies in the western world, and previously have been associated with intestinal microbial composition alterations. Our main aim in this study is to provide molecular data on intestinal microbiota patterns in subjects with CRC, as well as to establish possible associations with their Body Mass Index (BMI). A total of 113 samples from 45 subjects were collected and submitted to metagenomics analysis for gut microbiota. This study was performed by 16S ribosomal RNA bacterial gene amplification and sequencing using the Ion Torrent™ technology. The same dominant phyla were observed in feces and colorectal tissues, although a greater proportion of Fusobacteriota was found in tumor samples. Moreover, at the genus level, LEfSe analysis allowed us to detect a significant increase in Fusobacterium and Streptococcus in colorectal tissues with respect to fecal samples, with a significant preponderance of Fusobacterium in tumor tissues. Also, our data revealed relevant associations between gut microbiota composition and tumor location. When comparing bacterial profiles between right and left colon cancers, those from the left-sided colon showed a significant preponderance, among others, of the order Staphylococcales. Moreover, phyla Firmicutes and Spirochaetota were more abundant in the group of right-sided CRCs and phylum Proteobacteria was increased in rectal cancers. In relation to BMI of patients, we detected significant differences in beta diversity between the normal weight and the obese groups of cases. Microbiota from obese patients was significantly enriched, among others, in Bacteroidales. Therefore, our results are useful in the molecular characterization of CRC in obese and non-obese patients, with a clear impact on the establishment of diagnostic and prognosis of CRC.

Subtotal and Total Colectomy as a One-Stage Surgical Treatment for Malignant Left-Sided Colonic Obstruction

Abstract Aim: We conducted this retrospective study in order to evaluate the short- and long-term results of Subtotal/Total Colectomy (STC/TC) and primary anastomosis for the treatment of occlusive left colon cancer. Methods: Data were retrospectively collected from the medical records from general surgery clinic in January 2016 to June 2022 period. The study included patients diagnosed with acute colonic occlusion produced by tumor located from the splenic flexure to the rectosigmoid junction. Results: During the study period, 40 patients who underwent STC/TC and primary anastomosis were included in the study. According to the Clavien-Dindo grades, major complication rate was 17.5%. Seven patients (17.5%) had synchronous adenocarcinoma. Adenoma was detected in 11 of 40 patients, and 18.1% of them were reported as high-grade dysplasia. Besides, incidental low grade appendiceal mucinous neoplasm was reported in one patient. Ischemia and perforation of proximal colon was found in 28 cases (70%). No patient had anastomotic leak. After one year of surgery, the average defecation was two stools per day. Three-year OS was 92.3% in stage II and 68.7% in stage III. There was no survival more than three years in stage IV patients. The three-year overall disease- free survival was 90.6%. Conclusion: Treatment of obstructive left colon cancer using STC/TC and primary anastomosis is a confident method resulting in a good bowel function. The method allows the resection of synchronous tumors. Besides, it removes the proximal colon with ischemic lesions, serosal tears and filled with stool.

Comparison of the short-term and long-term outcomes of three different types of inferior mesenteric artery ligation in left colonic and rectal cancers: a network meta-analysis.

To perform a network meta-analysis of the literature to assess the short-term and long-term outcomes of three operations for left colon and rectal cancer. Electronic literature searches were performed in the PubMed, Web of Science, EMBASE, and Cochrane Central Register of Controlled Trials databases up to August 2022. A Bayesian network meta-analysis using R software, ADDIS, and Review Manager 5.4 was conducted to compare outcomes of high ligation of the inferior mesenteric artery(IMA),low ligation of the IMA with D2 dissection (LLD2), and low ligation of the IMA with D3 dissection (LLD3). Sensitivity analysis was applied to investigate the influence of each primary study on the final result of the meta-analysis. Asymmetry of data was estimated by using Egger's tests. Publication bias corrected by trimming and filling method. A total of 44 studies, 5 randomized clinical trials (RCTs) and 39 non-RCTs, were included in this meta-analysis. HL was associated with a higher risk of anastomotic leakage (HL vs. LLD2, OR = 1.35, 95% CI 1.13-3.25, P = 0.001; HL vs. LLD3, OR = 1.65, 95% CI 1.35-2.01, P < 0.001), and required a longer postoperative hospital stay (HL vs. LLD3, SMD = 0.28, 95%CI 0.09-0.48, P = 0.01).However HL showed an advantage in terms of operation time(HL vs. LLD3, SMD = - 0.13, 95%CI - 0.26 to 0.01, P = 0.04). LLD3 is most likely to rank best in terms of short-term and long-term outcomes after surgery for left colon and rectal cancer. Caution should be taken in the risk of anastomotic leakage when treating colorectal cancer with LLD2. HL, LLD2 and LLD3 provide similar overall survival rates for left colon and rectal cancer.

Our Experience With Left Colon and Rectal Cancer Surgery and the Impact of Preoperative Sarcopenia on Complication Rates.

Evidence about the importance of sarcopenia in patients operated on for gastrointestinal cancers and that it may have both early and long-term impacts is expanding. In our study, we aimed to evaluate the impact of sarcopenia on the outcomes of the patients we operated on for left colon and rectum cancer. We retrospectively evaluated the electronic records of 38 patients operated on for left colon and rectal cancer between 2010 and 2020, and demographic variables, clinical stages, laboratory tests, body mass index (BMI), psoas muscle index (PMI), pathological stages, and Dindo Clavien complication scores were interpreted. We also assigned our patients into two groups according to their preoperative PMI values. We compared the first group of 12 patients with preoperative sarcopenia with the second group of 26 patients without preoperative sarcopenia. Of the 38 patients who underwent curative surgery for left colon and rectal cancer, 20 were female and 18 were male. The median age of the group was 59.9 years. The most common tumour localization was in the rectosigmoid region in 17 patients, and the tumour in 6 patients was in the left colon. Therapy had been initiated with neoadjuvant treatment in 19 patients. At the preoperative evaluation, sarcopenia was present in 12 patients. Thirty-four patients underwent robot-assisted surgery. Postoperative pathologies were reported as stage 3 in 15 patients. Complications were reported in 17 patients, and nine were minor (Dindo-Clavien score < 3), but in eight patients, they were moderate to severe (Dindo-Clavien score ≥ 3). When the first group, 12 patients with preoperative sarcopenia, and the second group, 26 patients without preoperative sarcopenia, were compared, the patients with sarcopenia were found to be older (p=0.001), and male patients were in the majority (p=0.017). The postoperative follow-up of 12 patients with preoperative sarcopenia revealed that 7 (58.8%) had complications. Complications were observed in 10 (38.4%) patients in the second group. When the two groups were compared, the risk of developing complications was significantly higher in the sarcopenia group (p=0.016). Only one patient in the first group had moderate to severe complications, but seven patients without sarcopenia had moderate to severe complications. Our study revealed that many patients we have operated on for left colon and rectal cancer have preoperative sarcopenia for which we should care. The sarcopenia rate was higher in males and elderly patients, and the risk of overall postoperative complications increased significantly in patients with preoperative sarcopenia. In consequence, the results of our study provide evidence that preoperative sarcopenia status is an important parameter to determine the risk status of the patient, and patients with preoperative sarcopenia should be monitored more closely. Thus, we may be able to diagnose and intervene early in the complications.

Colonic Resection, Stoma, or Self-expanding Metal Stents for Obstructive Left Colon Cancer: the CROSCO-1 study protocol.

Colorectal cancer (CRC) is one of the most common cancers worldwide. There are several causes of a mechanical left bowel obstructive but CRC accounts for approximately 50% of cases and in 10-30% of whom it is the presenting syndrome. In most cases, the left colon is involved. At present, the range of therapeutic alternatives in the management of obstructive left CRC in emergency conditions (primary resection vs. staged resection with applied self-expanding metallic stents) is broad, whereas internationally validated clinical recommendations in each condition are still lacking. This enormous variability affects the scientific evidence on both the immediate and long-term surgical and oncological outcomes. CROSCO-1 (Colonic Resection, Stoma or Self-expanding Metal Stents for Obstructive Left Colon Cancer) study is a national, multi-center, prospective observational study intending to compare the clinical results of all these therapeutic regimens in a cohort of patients treated for obstructive left-sided CRC. The primary aim of the CROSCO-1 study is the 1-year stoma rate of patients undergoing primary emergency surgical resection (Hartmann procedure or primary resection and anastomosis) compared with patients undergoing staged resection. Secondary outcomes are 30-day and 90-day major morbidity and mortality, 1-year quality of life and the timing of chemotherapy initiation in the two groups. Future CROSCO studies will follow in which, instead, we will evaluate the long-term oncological outcomes of the two treatment strategies. The results of a large prospective cohort study which will analyze what really happens in the common clinical practice of managing patients with obstructive left CRC will have the aim of understanding which is the best strategy in terms of surgical and oncological outcomes. Indeed, the CROSCO-1 study will analyze the early surgical outcomes for patients with obstructed left CRC. Future CROSCO studies will follow in which, instead, we will evaluate the long-term oncological outcomes of the two treatment strategies.

Complete Mesocolic Excision (CME) versus Conventional RT Hemicolectomy (CRH) in Patients with Right Sided Colon Cancer: A Systematic Review and Meta-Analysis

Abstract Background We live in an era with improved worldwide average living standards and increased access to adequate healthcare that has considerably improved the diagnosis and treatment of diseases. These measures have had an impact on average life expectancy in most regions of the world. Aim of the Work The aim of this study is to perform a systematic review and meta-analysis to investigate safety and long-term out- comes of Complete Mesocolic Excision (CME) Versus Conventional RT Hemicolectomy (CRH) in patients with right sided colon cancer. Materials and Methods This study is a systematic review and meta-analysis. Literature search, study design, and data analysis were performed following PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. Five medical databases were used in this research: MEDLINE, Cochrane Database of Systematic Reviews, Scopus, Web of Science, and Embase. The keyword was as follows: ―complete mesocolic excision.‖ I select studies published up to December 2020. I select only articles written in English and we did not include abstracts or unpublished data. After literature search, 30 studies have been recorded. Screening by titles and abstracts led to the identification of 20 possibly relevant articles. Of these records, 8 studies were excluded because patients with distal transverse and/or left colon cancer were also evaluated. Moreover, in 3 studies, only the most recently record was selected. Lastly, 8 studies, published between 2010 and 2020, met inclusion criteria. All selected studies were observational; 4 of them were prospective. Overall, 1762 patients were enrolled in qualitative and quantitative analysis, 700 in the CME group and 1062 in the CRH group. Results Postoperative complications were reported in 9 studies showing that no difference was observed between techniques. Six studies separately analyzed surgical and non-surgical postoperative complications. No significant variation was reported between the 2 groups in the 2 different types of complications (surgical complications OR 1.09, 95% CI 0.72–1.63, p = 0.69, no surgical complications OR 1.37, 95% CI 0.79–2.36, p = 0.26, respectively). No significant difference was al- so observed between the two groups in terms of anastomotic leakage, while a significant negative median was reported for intraoperative bleeding in favor of CME group. 4 studies evaluated the procedure time which was significantly shorter for CRH, although heterogeneity levels among studies was high. The analysis of postoperative length of stay showed no difference between the two groups of patients. Number of lymph node yield was reported in 8 studies. The pooled analysis of 1762 patients found a positive median retrieval of 9.17 in CME group. High heterogeneity among the included studies was detected. Seven studies reported data of 3-year OS with a significant OS benefit in CME group. This data was characterized by moderate between-study heterogeneity. Furthermore, 76.4% of patients undergoing CME surgery were alive at 5 years, compared with 68.2% of CRH. Meta-analysis of 3 studies reporting 5-year DFS con- firmed the significant DFS benefit for patients undergoing CME. No significant heterogeneity was observed between the 3 studies. Conclusion My study confirm that CME with CVL associated with D3 lymphadectomy in right-side colon cancer improved not only staging but also prognosis, particularly in II and III stage; CME was a significant independent predictive factor for disease-specific survival at 3 years and 5 years compared with CRH associated with D2 lymphadectomy. CME is a safe and reproducible procedure with acceptable morbi-mortality.

Overall Survival, BRAF, RAS, and MSI Status in Patients Who Underwent Cetuximab After Refractory Chemotherapy for Metastatic Colorectal Cancer.

Evaluate overall survival (OS), RAS, BRAF, and MSI frequencies in patients with metastatic colorectal cancer (mCRC), refractory to chemotherapy, and finally treated with cetuximab. A retrospective cohort study to evaluate 211 mCRC patients with wild-type KRAS treated with cetuximab. BRAF V600E, KRAS, NRAS gene mutations, and MSI status were identified using PCR techniques in a population of pre-treated patients who were refractory to fluoropyrimidines, oxaliplatin, and irinotecan. In addition, we evaluated the mutation frequency of the BRAF and NRAS genes and the MSI status of this population. Uni- and multivariate analyses were performed for independent prognostic factors of OS. The median OS was 10.4months, 6.6months for patients with right and 11.5months for left colon cancers (p = 0.02). The frequencies of mutations were BRAF at 3.9% (median OS of 4.9months), NRAS at 3.38% (median OS of 6.9months), and MSI-High status at 3.3% (median OS of 4.6months). The OS, NRAS, and MSI frequencies were similar to those found in other studies that evaluated cetuximab in poly-treated patients and were associated with lower survival rates in univariate analyses. The frequency of BRAF mutations was lower than that found in previous studies. The only variable that remained significant for OS in the multivariate model was tumour laterality, with patients with right colon cancer presenting a worse prognosis (HR = 2.81). Although BRAF, NRAS mutations, and MSI-High status were associated with shorter OS in univariate analyses, only tumour laterality remained an independent prognostic factor in the multivariate analysis.

Anatomical classification of and laparoscopic surgery for left-sided colorectal cancer with persistent descending mesocolon

Objective: To investigate anatomical morphology and classification of persistent descending mesocolon (PDM) in patients with left-sided colorectal cancer, as well as the safety of laparoscopic radical surgery for these patients. Methods: This is a descriptive study of case series. Relevant clinical data of 995 patients with left colon and rectal cancer who had undergone radical surgery in Fujian Medical University Union Hospital from July 2021 to September 2022 were extracted from the colorectal surgery database of our institution and retrospectively analyzed. Twenty-four (2.4%) were identified as PDM and their imaging data and intra-operative videos were reviewed. We determined the distribution and morphology of the descending colon and mesocolon, and evaluated the feasibility and complications of laparoscopic surgery. We classified PDM according to its anatomical characteristics as follows: Type 0: PDM combined with malrotation of the midgut or persistent ascending mesocolon; Type 1: unfixed mesocolon at the junction between transverse and descending colon; Type 2: PDM with descending colon shifted medially (Type 2A) or to the right side (Type 2B) of the abdominal aorta at the level of the origin of the inferior mesentery artery (IMA); and Type 3: the mesocolon of the descending-sigmoid junction unfixed and the descending colon shifted medially and caudally to the origin of IMA. Results: The diagnosis of PDM was determined based on preoperative imaging findings in 9 of the 24 patients (37.5%) with left-sided colorectal cancer, while the remaining diagnoses were made during intraoperative assessment. Among 24 patients, 22 were male and 2 were female. The mean age was (63±9) years. We classified PDM as follows: Type 0 accounted for 4.2% (1/24); Type 1 for 8.3% (2/24); Types 2A and 2B for 37.5% (9/24) and 25.0% (6/24), respectively; and Type 3 accounted for 25.0% (6/24). All patients with PDM had adhesions of the mesocolon that required adhesiolysis. Additionally, 20 (83.3%) of them had adhesions between the mesentery of the ileum and colon. Twelve patients (50.0%) required mobilization of the splenic flexure. The inferior mesenteric artery branches had a common trunk in 14 patients (58.3%). Twenty-four patients underwent D3 surgery without conversion to laparotomy; the origin of the IMA being preserved in 22 (91.7%) of them. Proximal colon ischemia occurred intraoperatively in two patients (8.3%) who had undergone high ligation at the origin of the IMA. One of these patients had a juxta-anal low rectal cancer and underwent intersphincteric abdominoperineal resection because of poor preoperative anal function. Laparoscopic subtotal colectomy was considered necessary for the other patient. The duration of surgery was (260±100) minutes and the median estimated blood loss was 50 (20-200) mL. The median number of No. 253 lymph nodes harvested was 3 (0-20), and one patient (4.2%) had No.253 nodal metastases. The median postoperative hospital stay was 8 (4-23) days, and the incidence of complications 16.7% (4/24). There were no instances of postoperative colon ischemia or necrosis observed. One patient (4.2%) with stage IIA rectal cancer developed Grade B (Clavien-Dindo III) anastomotic leak and underwent elective ileostomy. The other complications were Grade I-II. Conclusions: PDM is frequently associated with mesenteric adhesions. Our proposed classification can assist surgeons in identifying the descending colon and mesocolon during adhesion lysis in laparoscopic surgery. It is crucial to protect the colorectal blood supply at the resection margin to minimize the need for unplanned extended colectomy, the Hartmann procedure, or permanent stomas.

Lymph node retrieval colon cancer: Are we making the grade?

BackgroundAdequate lymph node (LN) excision is imperative for pathologic staging and determination of adjuvant treatment. Methodshe 2004–2017 National Cancer Database (NCDB) was queried for curative colon cancer resections. Tumors were categorized by location: left, right, and transverse colon cancers. Adequate (12–20 LNs) vs. inadequate (<12 LNs) lymphadenectomy was examined and sub-analysis of <12 LNs, 12–20 LNs or >20 LNs. Primary outcome was predictors of inadequate lymph node retrieval. ResultsOf 101,551 patients, 11.2% (11,439) had inadequate lymphadenectomy. The inadequate lymphadenectomy rate steadily decreased. On multivariable analysis, inadequate LN retrieval was associated with transverse (OR 1.49, CI [1.30–1.71]) and left colon cancers (OR 2.66, CI [2.42–2.93], whereas income >$63,333 had decreased likelihood of inadequate LN retrieval (OR 0.68, CI[0.56–0.82]. ConclusionWe are making the grade as NCDB data demonstrates a steady decrease in inadequate lymphadenectomy (2004–2017). There remain socioeconomic risk factors for inadequate lymphadenectomy that need to be addressed.

Efficacy and safety of fruquintinib plus investigator's choice of chemotherapy as second-line therapy in metastatic colorectal cancer: A multicenter, single-arm phase 2 trial.

3582 Background: Emerging evidence suggested that chemotherapy in combination with anti-angiogenic targeted agents can achieve higher response in multiple solid tumors. Fruquintinib is a highly selective small-molecule VEGFR inhibitor that has been approved for the third-line treatment in metastatic colorectal cancer (mCRC) patients in China. Here, we assessed the efficacy and safety of fruquintinib plus investigator's choice of chemotherapy as second-line therapy in pretreated advanced mCRC patients. Methods: In this prospective, open-label, multicenter, single-arm phase 2 trial (ChiCTR2200059280), patients with mCRC progressed after first-line prior systemic treatment were administered fruquintinib (5~3mg, D1-21, Q4w) and investigator's choice of chemotherapy (fluorouracil ± irinotecan ± oxaliplatin, Q3w) for up to 8 cycles. Patients without disease progression (PD) were followed by fruquintinib maintenance until PD or intolerable toxicity. The primary endpoint was progression-free survival (PFS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), duration of response (DOR), overall survival (OS), and safety. Results: As the data cutoff on February 10, 2023, 37 patients have been enrolled and treated, with 31 evaluable for efficacy. Median age was 63 years (range, 44-76) and 22 (59.5%) were male. The left colon cancer involved in 28 patients (75.7%). All patients were microsatellite-stable phenotype and 11 (29.7%) had mutations in KRAS gene. 16 (43.2%) patients received prior anti-VEGF therapy. 20 (54.1%) and 11 (29.7%) patients had liver and lung metastases respectively. At a median follow-up of 8.4 months, 28 patients are still on treatment. The ORR is 48.4%, with 15 partial response. The DCR is 90.3%. At data cutoff, median PFS has not yet reached. 23 patients (74.2%) remained progression free at 6 months. In terms of safety, the regimen was well tolerated, mainly grade 1/2 adverse events (AEs). Grade 3/4 AEs were neutropenia (21.6%), leukopenia (10.8%), thrombocytopenia (5.4%), proteinuria, diarrhea, hand-foot syndrome and hypertension accounted for 2.7% respectively. 5 pts received reduced doses of fruquintinib. No treatment-related deaths occurred. Conclusions: Fruquintinib combined with chemotherapy followed by fruquintinib maintenance shows promising efficacy and manageable safety profile for mCRC patients in second-line setting. Updated follow up data will be presented in the future. Clinical trial information: ChiCTR2200059280 .

Less demand on stem cell marker-positive cancer cells may characterize metastasis of colon cancer.

CD44 and CD133 are stem cell markers in colorectal cancer (CRC). CD44 has distinctive isoforms with different oncological properties like total CD44 (CD44T) and variant CD44 (CD44V). Clinical significance of such markers remains elusive. Sixty colon cancer were examined for CD44T/CD44V and CD133 at mRNA level in a quantitative PCR, and clarified for their association with clinicopathological factors. (1) Both CD44T and CD44V showed higher expression in primary colon tumors than in non-cancerous mucosas (p<0.0001), while CD133 was expressed even in non-cancerous mucosa and rather decreased in the tumors (p = 0.048). (2) CD44V expression was significantly associated with CD44T expression (R = 0.62, p<0.0001), while they were not correlated to CD133 at all in the primary tumors. (3) CD44V/CD44T expressions were significantly higher in right colon cancer than in left colon cancer (p = 0.035/p = 0.012, respectively), while CD133 expression were not (p = 0.20). (4) In primary tumors, unexpectedly, CD44V/CD44T/CD133 mRNA expressions were not correlated with aggressive phenotypes, but CD44V/CD44T rather significantly with less aggressive lymph node metastasis/distant metastasis (p = 0.040/p = 0.039, respectively). Moreover, both CD44V and CD133 expressions were significantly decreased in liver metastasis as compared to primary tumors (p = 0.0005 and p = 0.0006, respectively). Our transcript expression analysis of cancer stem cell markers did not conclude that their expression could represent aggressive phenotypes of primary and metastatic tumors, and rather represented less demand on stem cell marker-positive cancer cells.

Efficacy of left colic artery preservation with D3 lymph node dissection in laparoscopic surgery for advanced sigmoid and rectal cancer.

For advanced left colon cancer, lymph node dissection at the root of the inferior mesenteric artery is recommended. Whether the left colic artery (LCA) should be preserved or resected remains contentious. The 367 patients who underwent laparoscopic sigmoidectomy or anterior resection and who were pathologically node-positive were reviewed. Patients were divided into LCA-preserving group (LCA-P, n = 60) and LCA-non-preserving group (LCA-NP, n = 307). Propensity score matching was applied to minimize selection bias and 59 patients were matched. Before matching, the rates of poor performance status and cardiovascular disease were higher in the LCA-P group (p < 0.001). After matching, operation time was longer (276 vs. 240min, p = 0.001), the frequency of splenic flexure mobilization (62.7% vs. 33.9%, p = 0.003) and lymphovascular invasion (84.7% vs. 55.9%, p = 0.001) was higher in the LCA-P group. Severe postoperative complications (CD ≥ 3) occurred only in the LCA-NP group (0% vs. 8.4%, p = 0.028). The median follow-up period was 38.5months (range 2.0-70.0months). The 5-year RFS rates (67.8% vs. 66.0%, p = 0.871) and OS rates (80.4% vs. 74.9%, p = 0.308) were comparable between the groups. Laparoscopic LCA-sparing surgery for left-sided colorectal cancer reduces the risk of severe complications and offers a favorable long-term prognosis.

Left-Sided Colon Cancer and Right-Sided Colon Cancer: Are They the Same Cancer or Two Different Entities?

Background Colon cancer is one of the most common cancers in the world and one of the main causes of cancer-related deaths. In Morocco, it occupies the first place among digestive cancers. Right-sided and left-sided colon cancers have different embryological, epidemiological, pathological, genetic, and clinical characteristics. This distinction leads to differences in the evolution and prognosis of the disease. This study aimed to identify epidemiological factors and clinical and pathological characteristics that can influence perioperative and prognostic outcomes in patients with right-sided colon cancer compared to those with left-sided colon cancer. Methodology We conducted a retrospective cohortstudy over a period of nine years from January 2012 until December 2020. We included 277 patients divided into two groups, namely, right colon cancer (group 1) (n = 99) and left colon cancer (group 2) (n = 178). Results The average age of our series was 57.4 years, with extremes ranging from 19 to 89 years old (SD = ±13.6451 years). The average age in the right colon group was 55.97 (SD = ±13.341 years). The average age in the left colon group was 58.18 (SD = ±13.69 years). The male gender had a predominance, with a sex ratio of 1.3 for both groups. Among the patients in group 2, 65% showed lymph node involvement on the CT scan, whereas only 34% of patients in group 1 displayed the same condition. The recurrence rate in the right-sided colon cancer group was 22.2% compared to 24.9% in the left-sided group. The five-year overall survival was estimated for the right-sided and left-sided colon cancer groups at 87% and 96.5%, respectively. In patients with stage III and IV cancer, overall survival was better for those who underwent surgery for left-sided colon cancer compared to those who underwent surgery for right-sided colon cancer (p = 0.029). In the case of vascular emboli or involvement of the perineural sheath, there was no significant difference in overall survival (p = 0.446 and p = 0.655, respectively). The three-month survival without recurrence was almost identical in both groups (31% for right-sided colon cancers and 30.9% for left-sided colon cancers). Age over 61 years was a predictive factor of poor prognosis in recurrence-free survival (hazard ratio = 3.245; p = 0.023). Conclusions We identified factors that can influence perioperative outcomes and prognosis in patients with right-sided colon cancer compared to those with left-sided colon cancer. Our findings suggest that age and lymph node involvement along with other factors play a role in the overall survival and recurrence outcomes of these patients. Further research is necessary to explore these differences and develop personalized treatment plans for patients with colon cancer.

Differences Between Right and Left Colon Cancer in Beira Interior.

Introduction Colorectal cancer (CRC) is the second most common cancer in Portugal and worldwide, with a high mortality rate, especially in more advanced stages. In recent decades, there has been a growing interest in the distinction between right colorectal carcinoma (RCC) and left colorectal carcinoma (LCC) due to the different presentation, treatment, and prognosis. Studies show that RCC and LCC have different clinical and biological characteristics, being considered two distinct entities. Material and methods This cross-sectional, descriptive, and comparative retrospective study included data collection at the three hospitals of Beira Interior - Centro Hospitalar Cova de Beira, Hospital Amato Lusitano, and Hospital Sousa Martins - over a 6-year period. Results The proportion of RCC cases was higher. The proportion of women was higher in the RCC group compared to the LCC (46.2%, 121/262 vs. 39%, 76/195). Anemia was statistically higher in the RCC group (p <0.01). On the other hand, intestinal occlusion tends to appear in patients with LCC (p <0.001). The most frequent surgery was elective. The proportion of emergency surgery was higher in the LCC group (LCC vs RCC: 27.2% vs 18.3%; p = 0.03). Discussion and conclusion In both the RCC and LCC groups, the male sex is the most frequently observed in Beira Interior and in Portugal, opposite from the world population, in which the female sex predominates in patients with RCC. The RCC presents alterations in bowel habits more often (p> 0.05). On the other hand, anemia is more common in RCC and intestinal occlusion in LCC, following the current literature. Conducting targeted studies and optimizing the screening and treatment processes are key to reducing mortality associated with CRC.

Abstract 3040: A modified microbiota-accessible carbohydrates diet could change gut microbiota in patients with colorectal cancer after surgery

Abstract Dietary factors have important role in modulating the gut microbiome, which in-turn regulates the molecular events in colonic mucosa. The composition and resulting metabolism of the gut microbiome are decisive factors in colorectal cancer (CRC) tumorigenesis. Microbiota-Accessible Carbohydrates (MAC) refer to carbohydrates that the human intestine cannot digest, but that can be digested by intestinal microbes. During that process, short chain fatty acid (SCFA) is produced, which is known to increase beneficial intestinal bacteria and decrease inflammation around intestinal cells. This prospective, longitudinal study aims to explore the changes in the composition and diversity of intestinal microbiota according to the diet pattern in patients with stage I to lll CRC. Participants were assigned to 3-week modified MAC diet group or free diet group followed by diet switching for 3 weeks. Modified MAC diet was designed to adapt to a high fiber diet including 30g of dietary fiber daily and delivered to the patient’s home for 3 weeks as a meal kit supported by Dr. Kitchen Corp. We collected 113 fecal samples from 40 CRC patients before and after diet switching. To explore the effect of diet on the composition of the microbiota and pattern of defecation, 16S rRNA sequencing were performed using fecal samples. Biological information was processed by Qiime2 plugins, DESeq2 and Lefse. Among total 40 participants, 26 (65%) were male. There were 11 (27.5%) with right colon cancer and 29 patients with left colon and rectal cancer. 18 patients without adjuvant chemotherapy were lower stage and higher compliance to modified MAC diet (median 89%) than 22 patients with adjuvant chemotherapy (median 60%). In all participants, protein and dietary fiber intake increased by more than 90% and sodium intake decreased by more than half during modified MAC diet compared to the free diet. There was no difference in alpha diversity change between chemotherapy group and non-chemotherapy group but a significant difference was observed in beta diversity change. Especially, Lachnospiraceae Eubacterium hallii were enriched in non-chemotherapy group. During the modified MAC diet in the group not receiving chemotherapy, Lactobacillaceae Pediococcus, Prevotellaceae Prevotella, Streptococcaceae Lactococcus were increased and Ruminococcaceae Eubacterium siraeum group, Ruminococcaceae UBA1819 were decreased. This study results showed that 3 weeks dietary intake influences the structure and activity of gut microbiome even though the dietary responsiveness of the individual’s microbiota varied substantially. The joint study of microbiome and metabolome has been ongoing now as the most promising approach to evaluate host-microbiome interaction. In order to prove the importance of a balanced diet after colorectal cancer surgery, it will be necessary to analyze the relationship with clinical outcomes. Citation Format: Boyeon Kim, Jiwon Lee, Jin Kim, Jung-Myun Kwak, Hye-Jin Cho, Eun Sung Jung, Sunyoung Lee, Dong Ho Suh, Yu Jin Park, Soohyeon Lee. A modified microbiota-accessible carbohydrates diet could change gut microbiota in patients with colorectal cancer after surgery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3040.

Validation of algorithms to identify colorectal cancer patients from administrative claims data of a Japanese hospital

BackgroundAdministrative claims data are a valuable source for clinical studies; however, the use of validated algorithms to identify patients is essential to minimize bias. We evaluated the validity of diagnostic coding algorithms for identifying patients with colorectal cancer from a hospital’s administrative claims data.MethodsThis validation study used administrative claims data from a Japanese university hospital between April 2017 and March 2019. We developed diagnostic coding algorithms, basically based on the International Classification of Disease (ICD) 10th codes of C18–20 and Japanese disease codes, to identify patients with colorectal cancer. For random samples of patients identified using our algorithms, case ascertainment was performed using chart review as the gold standard. The positive predictive value (PPV) was calculated to evaluate the accuracy of the algorithms.ResultsOf 249 random samples of patients identified as having colorectal cancer by our coding algorithms, 215 were confirmed cases, yielding a PPV of 86.3% (95% confidence interval [CI], 81.5–90.1%). When the diagnostic codes were restricted to site-specific (right colon, left colon, transverse colon, or rectum) cancer codes, 94 of the 100 random samples were true cases of colorectal cancer. Consequently, the PPV increased to 94.0% (95% CI, 87.2–97.4%).ConclusionOur diagnostic coding algorithms based on ICD-10 codes and Japanese disease codes were highly accurate in detecting patients with colorectal cancer from this hospital’s claims data. The exclusive use of site-specific cancer codes further improved the PPV from 86.3 to 94.0%, suggesting their desirability in identifying these patients more precisely.

Colectomía derecha ampliada. Lugar en el tratamiento del cáncer de colón izquierdo proximal obstructivo

The resu lts obtained about ni neteen (19) patients operated by left colon cancer with variable grade obstruction have buen analysed. Seventeen (17) patients operated doe tu obstructive leO colon cancer situated: Ove (5) ni distal transvcrse colon, other Ove (5) at splenic tiexure and seven (7) in proximal descending colon but threc of theni with right synchronic neoplasias. The reniaining two (2) that showed a cancer located at splenic [lexure and the other une m proximal descendi ig colon veie reuperated thrce weeks later than a ansverse colostomy liad been performecl owing lo an obstructive condition. (i)ne patienthad tu be reoperatcd because a generalised peritonitis fioni a tistula with partial disruption oil end tu end ¡leo-col ic anastomosisExteriorisation of both ends vas carried out with fiivourable evulution and subseclueni reanastomosis. An exteriorised patient bysplenic fiex ure cancer a Isu liad tu lic dra ned ten days later for a retroperitoneal ahsccss through a percutaneous puneture and a lesion grade 1 in lower pule of spleen vas resolved with electrofulguration. No patient has showed invalidating diarrhea and all themselves llave heen stabilised with two uy ifree stools daily about two rnonth afier surgery. Amplifying right colcctomy is a safe procedure with low surgical morbimortality and lake privileged place in the treatment of dic patients undergoing synchron ical neoplasias and/or carcinomas associatcd with polyps, specially in all those cases when a variable grade of obstruction have occurred.