Association of gut microbiome with immune microenvironment in surgically treated colorectal cancer patients

This study explored the relationship between faecal microbiota distribution and local or systemic immune response in patients with colorectal cancer (CRC). The study population included 114 surgically treated CRC patients. Faeces were analysed using 16S rRNA gene sequencing. The immune score in tumour microenvironment was evaluated using CD3 and CD8 immunohistochemistry. Genetic alterations, microsatellite instability status and five systemic inflammatory markers were also analysed. Thirty of 114 (26.3%) CRC patients were categorised as the 'immune type' with a high density of T-cells. The immune type CRC cases showed lower angiolymphatic invasion and longer overall survival. Of the 123 selected bacterial species, Bacteroides fragilis and Collinsella aerofaciens were prevalent in immune CRC cases, whereas Odoribacter splanchnicus and Phascolarctobacterium succinatutens were prevalent in non-immune CRC patients. Bacteroides fragilis was associated with shorter disease free survival in univariable and multivariable survival analyses. Regarding systemic immunity, a high prevalence of C. aerofaciens was associated with a high modified Glasgow prognostic score. This study revealed a potential relationship among the gut microbiome, immune microenvironment, and disease progression in patients with CRC. Our findings suggest that abundant B. fragilis in patients with CRC is associated with a 'cold immune' tumour microenvironment.

Long-term clinical outcomes after high and low ligations with lymph node dissection around the root of the inferior mesenteric artery in patients with rectal cancer

PURPOSE

This study aimed to evaluate the long-term clinical outcomes based on the ligation level of the inferior mesenteric artery (IMA) in patients with rectal cancer.

METHODS

This was a retrospective analysis of a prospectively collected database that included all patients who underwent elective low anterior resection for rectal cancer between January 2013 and December 2019. The clinical outcomes included oncological outcomes, postoperative complications, and functional outcomes. The oncological outcomes included overall survival (OS) and relapse-free survival (RFS). The functional outcomes, including defecatory and urogenital functions, were analyzed using the Fecal Incontinence Severity Index, International Prostate Symptom Score, and International Index of Erectile Function questionnaires.

RESULTS

In total, 545 patients were included in the analysis. Of these, 244 patients underwent high ligation (HL), whereas 301 underwent low ligation (LL). The tumor size was larger in the HL group than in the LL group. The number of harvested lymph nodes (LNs) was higher in the HL group than in the LL group. There were no significant differences in complication rates and recurrence patterns between the groups. There were no significant differences in 5-year RFS and OS between the groups. Cox regression analysis revealed that the ligation level (HL vs. LL) was not a significant risk factor for oncological outcomes. Regarding functional outcomes, the LL group showed a significant recovery in defecatory function 1 year postoperatively compared with the HL group.

CONCLUSION

LL with LNs dissection around the root of the IMA might not affect the oncologic outcomes comparing to HL; however, it has minimal benefit for defecatory function.

Exfoliate cancer cell analysis in rectal cancer surgery: comparison of laparoscopic and transanal total mesorectal excision, a pilot study

PURPOSE

Minimally invasive surgery (MIS) is currently the standard treatment for rectal cancer. However, its limitations include complications and incomplete total mesorectal resection (TME) due to anatomical features and technical difficulties. Transanal TME (TaTME) has been practiced since 2010 to improve this, but there is a risk of local recurrence and intra-abdominal contamination. We aimed to analyze samples obtained through lavage to compare laparoscopic TME (LapTME) and TaTME.

METHODS

From June 2020 to January 2021, 20 patients with rectal cancer undergoing MIS were consecutively and prospectively recruited. Samples were collected at the start of surgery, immediately after TME, and after irrigation. The samples were analyzed for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) through a quantitative real-time polymerase chain reaction. The primary outcome was to compare the detected amounts of CEA and CK20 immediately after TME between the surgical methods.

RESULTS

Among the 20 patients, 13 underwent LapTME and 7 underwent TaTME. Tumor location was lower in TaTME (7.3 cm vs. 4.6 cm, P=0.012), and negative mesorectal fascia (MRF) was more in LapTME (76.9% vs. 28.6%, P=0.044). CEA and CK20 levels were high in 3 patients (42.9%) only in TaTME. There was 1 case of T4 with incomplete purse-string suture and 1 case of positive MRF with dissection failure. All patients were followed up for an average of 32.5 months without local recurrence.

CONCLUSION

CEA and CK20 levels were high only in TaTME and were related to tumor factors or intraoperative events. However, whether the detection amount is clinically related to local recurrence remains unclear.

Stratification of rate of lymph node metastasis according to risk factors and oncologic outcomes in patients who underwent radical resection for rectal neuroendocrine tumors

PURPOSE

Most predictive factors for lymph node metastasis in rectal neuroendocrine tumors (NETs) have been based on local and endoscopic resection. We aimed to evaluate the risk factors for lymph node metastasis in patients who underwent radical resection for rectal NETs and stratify the risk of lymph node metastasis.

METHODS

Sixty-four patients who underwent radical resection for rectal NETs between January 2001 and January 2018 were included. We investigated the risk factors of lymph node metastasis using clinicopathologic data. We also performed a risk stratification for lymph node metastases using the number of previously known risk factors. For oncologic outcomes, the 5-year overall survival and recurrence-free survival were evaluated in both groups.

RESULTS

Among the patients who underwent radical surgery, 32 (50.0%) had lymph node metastasis and 32 (50.0%) had non-lymph node metastasis. In the multivariable analysis, only the male sex was identified as a risk factor for lymph node metastasis (odds ratio, 3.695; 95% confidence interval, 1.128-12.105; P=0.031). When there were 2 or more known risk factors, the lymph node metastasis rate was significantly higher than when there were one or no risk factors (odds ratio, 3.667; 95% confidence interval, 1.023-13.143; P=0.046). There was also no statistical difference between the 2 groups in 5-year overall survival (P=0.431) and 5-year recurrence-free survival (P=0.144).

CONCLUSION

We found that the rate of lymph node metastasis increased significantly when the number of known risk factors is 2 or more.

Effects of prior endoscopic resection on recurrence in patients with T1 colorectal cancer who underwent radical surgery

PURPOSE

Endoscopic resection (ER) is a reliable treatment for early colorectal cancer without lymph node metastasis. We aimed to examine the effects of ER performed prior to T1 colorectal cancer (T1 CRC) surgery by comparing long-term survival after radical surgery with prior ER to that after radical surgery alone.

METHODS

This retrospective study included patients who underwent surgical resection of T1 CRC at the National Cancer Center, Korea, between 2003 and 2017. All eligible patients (n = 543) were divided into primary and secondary surgery groups. To ensure similar characteristics between the groups, 1:1 propensity score matching was used. Baseline characteristics, gross and histological features, along with postoperative recurrence-free survival (RFS) between the two groups were compared. Cox proportional hazard model was used to identify the risk factors affecting recurrence after surgery. Cost analysis was performed to examine the cost-effectiveness of ER and radical surgeries.

RESULTS

No significant differences were observed in 5-year RFS between the two groups in matched data (96.9% vs. 95.5%, p = 0.596) and in the unadjusted model (97.2% vs. 96.8%, p = 0.930). This difference was also similar in subgroup analyses based on node status and high-risk histologic features. ER before surgery did not increase the medical costs of radical surgery.

CONCLUSION

ER prior to radical surgery did not affect the long-term oncologic outcomes of T1 CRC or significantly increased the medical costs. Attempting ER first for suspected T1 CRC would be a good strategy to avoid unnecessary surgery without concerns of worsening cancer-related prognosis.

Subpopulation analysis of survival in high-risk T1 colorectal cancer: surgery versus endoscopic resection only

BACKGROUND AND AIMS

This study aimed to assess the long-term survival of patients with T1 colorectal cancer (CRC) after local or surgical resection considering the type and number of risk factors for lymph node metastasis.

METHODS

This study included patients with high-risk T1 CRC who underwent therapeutic resection at the National Cancer Center, Korea between January 2001 and December 2014. Risk factors included positive resection margin, high-grade histology, deep submucosal invasion, vascular invasion, budding, and no background adenoma (BGA). We statistically divided the population into favorable or unfavorable subpopulations. The favorable subpopulation included the following 5 combinations of risk factors: positive margin only or unconditional for margin status, deep submucosal invasion only, budding only, no BGA only, and budding + no BGA. We analyzed the survival rate according to the resection type (local or surgical) in the total cohort and in each subpopulation.

RESULTS

Eighty-one and 466 patients underwent local and surgical resections, respectively. The distant recurrence-free survival (DRFS) and overall survival (OS) rates were significantly high in the surgical group (hazard ratio [HR], .20; 95% confidence interval [CI], .06-.61; P = .0045 and HR, .41; 95% CI, .25-.70; P = .0010, respectively). In the favorable subpopulation, both DRFS and OS rates were not significantly different between the surgical and local groups (HR, .26; 95% CI, .02-4.19; P = .3431 and HR, .58; 95% CI, .27-1.23; P = .1534, respectively).

CONCLUSIONS

Intensive surveillance without additional surgery may be another option in selected cases after of high-risk T1 CRC endoscopic resection.

The risk of surgical site infection of oral sulfate tablet versus sodium picosulfate for bowel preparation in colorectal cancer surgery: a randomized clinical trial

Purpose

Oral sulfate tablets are abundantly used for bowel preparation before colonoscopy. However, their efficiency and safety for bowel preparation before colorectal surgery remain ill-defined. Herein, we aimed to compare the surgical site infection rates and efficiency between oral sulfate tablets and sodium picosulfate.

Methods

We designed a prospective, randomized, phase 2 clinical trial. Patients with colorectal cancer aged 19–75 years who underwent elective bowel resection and anastomosis by minimally invasive surgery were administered oral sulfate tablets or sodium picosulfate. Eighty-three cases were analyzed from October 2020 to December 2021. Surgical site infection within 30 days after surgery was considered the primary endpoint. Postoperative morbidities, the degree of bowel cleansing, and tolerability were the secondary endpoints.

Results

Surgical site infection was detected in 1 patient (2.5%) in the oral sulfate tablet group and 2 patients (4.7%) in the sodium picosulfate group, indicating no significant difference between the 2 groups. Postoperative morbidity and the degree of bowel cleansing bore no statistically significant differences. Furthermore, none of the investigated tolerability criteria, namely bloating, pain, nausea, vomiting, and discomfort, differed significantly between the 2 groups. The patients’ willingness to reuse the drug was also not significantly different between the 2 groups.

Conclusion

Although we could not establish the noninferiority of oral sulfate tablets to sodium picosulfate, we found no evidence suggesting that oral sulfate tablets are less safe or tolerable than sodium picosulfate in preoperative bowel preparation.

Development and validation of a novel strong prognostic index for colon cancer through a robust combination of laboratory features for systemic inflammation: a prognostic immune nutritional index

BACKGROUND

Systemic inflammation is associated with survival outcomes in colon cancer. However, it is not well-known which systemic inflammatory marker is a powerful prognostic marker in patients with colon cancer.

METHODS

A total of 4535 colon cancer patients were included in this study. We developed a novel prognostic index using a robust combination of seven systemic inflammation-associated blood features of the discovery set. The predictability and generality of the novel prognostic index were evaluated in the discovery, validation and replication sets.

RESULTS

Among all combinations, the combination of albumin and monocyte count was the best candidate expression. The final formula of the proposed novel index is named the Prognostic Immune and Nutritional Index (PINI). The concordance index of PINI for overall and progression-free survival was the highest in the discovery, validation and replication sets compared to existing prognostic inflammatory markers. PINI was found to be a significant independent prognostic factor for both overall and progression-free survival.

CONCLUSIONS

PINI is a novel prognostic index that has improved discriminatory power in colon cancer patients and appears to be superior to existing prognostic inflammatory markers. PINI can be utilised for decision-making regarding personalised treatment as the complement of the TNM staging system.

Could A1 Aplasia or Hypoplasia Affect the Morphology and Rupture Risk of Anterior Communicating Artery Aneurysm?

Objective

Anterior communicating artery (Acom) aneurysm is one of the most common intracranial aneurysms, constituting approximately 30–35% of all aneurysm formation in the brain. Anatomically, the H-complex (the anatomic morphology of both A1 to A2 segments) is thought to affects the nature of the Acom aneurysm due to its close relationship with the hemodynamics of the vessel. Therefore, we investigated the relative risk factors of aneurysmal rupture, especially focusing on H-complex morphology of the Acom.

Methods

From January 2016 to December 2020, a total of 209 patients who underwent surgery, including clipping and coiling for Acom aneurysm in our institution were reviewed. There were 102 cases of ruptured aneurysm and 107 cases of unruptured aneurysm. The baseline morphology of aneurysms was investigated and the relationship between the H-complex and the clinical characteristics of patients with Acom aneurysms was assessed.

Results

Of the 209 patients, 109 patients (52.1%) had symmetrical A1, 79 patients (37.8%) had unilateral hypoplastic A1, and 21 patients (10.0%) had aplastic A1. The hypoplastic A1 group and the aplastic A1 group were grouped together as unilateral dominancy of A1, and were compared with the symmetrical A1 group. There was no significant difference in demographic characteristics and radiological findings of Acom aneurysms between two groups. However, when dichotomizing the patients into ruptured cases and unruptured cases, unilateral dominance of the A1 segment was associated with aneurysmal rupture with statistical significance (p=0.011).

Conclusion

These results suggest that the unilateral dominance of the A1 segment does not have a significant effect on the morphology of Acom aneurysms, but contributes to aneurysmal rupture. Thus, we can better understand the effects of hemodynamics on Acom aneurysm.

Assessment of the learning curve for the novel transanal minimally invasive surgery simulator model

BACKGROUND

Transanal minimally invasive surgery (TAMIS) is technically demanding and requires extensive training. We developed the TAMIS simulator model by remodeling an existing laparoscopic training system to educate trainees and analyzed their learning curves.

METHODS

Between March 2020 and June 2020, 12 trainees performed TAMIS simulator training sessions. The total operative time, including specimen removal and wound closure, was recorded. The wound closure and specimen quality, trainee self-confidence, and supervisor evaluation of technical performance were documented. A moving average was used to analyze the number of training sessions required to stabilize the procedure time, while a cumulative sum analysis was performed to identify that required to reach proficiency with each item.

RESULTS

Each trainee completed 20 TAMIS simulator training sessions. The median total procedure time was 13 min (range, 4-60 min), which stabilized after 15 training sessions. The median times for specimen removal and wound closure were 3 min (range, 1-18 min) and 10 min (range, 2-50 min), respectively, which stabilized after 7 and 15 training sessions, respectively. The mean specimen and wound closure quality scores were 2.9 ± 0.9 (on a scale from 1 to 4) and 2.3 ± 1.1 (on a scale from 1 to 4), respectively, competencies in which were achieved after 16 and 20 training sessions, respectively. The mean trainee self-confidence and supervisor evaluation of technical performance scores were 2.4 ± 1.2 (on a scale from 1 to 5) and 2.7 ± 1.2 (on a scale from 1 to 5), respectively, competencies in which were achieved after 20 and 17 training sessions, respectively.

CONCLUSION

Trainees required 15 training sessions to stabilize the procedure time and 16-20 training sessions to demonstrate competencies with the TAMIS simulator model. We expect this simulator model may help surgeons more rapidly acquire the skills required for TAMIS.

OUP accepted manuscript

Background

Method

Results

Conclusion

Comparison between early surgical treatment and conservative treatment of appendicitis in cancer patients

BACKGROUNDS

In cancer patients, the optimal appendicitis treatment has not been established. Therefore, we aimed to determine the ideal treatment option for appendicitis in cancer patients.

METHODS

This retrospective study included 185 cancer patients with acute appendicitis who were divided into the early surgical group (n = 152) involving surgery performed within 48 h following the appendicitis diagnosis or the conservative group (n = 33) involving intravenous antibiotics. We compared the appendicitis treatment efficacy between the groups.

RESULTS

In the early surgical group, the antibiotic duration [5.5 days (4.0-8.0) vs. 17.0 days (12.5-25.0), p < 0.001] and hospital stay length [7.0 days (5.0-11.75) vs. 10.0 days (8.0-32.0), p < 0.001] were significantly shorter. Regarding pathology, 16/171 (9.4%) patients who underwent surgery exhibited appendiceal tumours. During the 1-year follow-up period, one recurrence occurred in each group [1/152 (0.7%) vs. 1/33 (3.0%), p = 0.326]. The 1-year treatment success rate was higher in the early surgical group [99.3% (151/152) vs. 42.4% (14/33), p < 0.001].

CONCLUSION

Early surgical treatment yielded a significantly higher success rate than conservative treatment for appendicitis in cancer patients. Surgery for appendicitis in cancer patients should be considered not only for treatment but also for pathologic confirmation.

Diverting ileostomy itself may not increase the rate of postoperative readmission related to dehydration after low anterior resection

Purpose

This study was performed to evaluate the risk of readmission in the first year after low anterior resection (LAR) for patients with rectal cancer and to identify the contributing factors for readmission related to dehydration specifically.

Methods

This was a retrospective analysis of 570 patients who underwent LAR for rectal cancer at National Cancer Center, Republic of Korea. A diverting loop ileostomy was performed in 357 (62.6%) of these patients. Readmission was defined as an unplanned visit to the emergency room or admission to the ward. The reasons for readmission were reviewed and compared between the ileostomy (n = 357) and no-ileostomy (n = 213) groups. The risk factors for readmission and readmission due to dehydration were analyzed using multivariable logistic and Cox proportional hazard model.

Results

Dehydration was the most common cause of readmission in both groups (ileostomy group, 6.7%, and no-ileostomy group, 4.7%, P = 0.323). On multivariable analysis, risk factors for readmission were an estimated intraoperative blood loss of ≥400 mL (odds ratio [OR], 1.757; 95% confidence interval [CI], 1.058-2.918; P = 0.029), and postoperative chemotherapy (OR, 2.914; 95% CI, 1.824-4.653; P < 0.001). On multivariable analysis, postoperative chemotherapy, and not a diverting loop ileostomy, was an independent risk factor for dehydration-related readmission (OR, 5.102; 95% CI, 1.772-14.688; P = 0.003).

Conclusion

The most common cause of readmission after LAR for rectal cancer was dehydration, as reported previously. Postoperative chemotherapy, not the creation of a diverting ileostomy, was identified as the risk factor associated with readmission related to dehydration.

Comparison of patient-reported quality of life and functional outcomes following laparoscopic and transanal total mesorectal excision of rectal cancer

Purpose

The effect of transanal total mesorectal excision (TaTME) on patients' quality of life and functional outcomes is not fully understood. This study aimed to compare the quality of life and bowel, anorectal, and urogenital functions after laparoscopic and TaTME.

Methods

Laparoscopic or TaTME was performed for 202 propensity score-matched patient pairs with rectal cancer between January 2014 and December 2017 at the National Cancer Center, Korea. The outcomes for all patients were assessed using anorectal manometry, the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and Colorectal Cancer-Specific Quality of Life Questionnaire (QLQ-CR38), low anterior resection syndrome (LARS) score, Fecal Incontinence Severity Index, and International Prostate Symptom Score (IPSS). This retrospective comparative study included patients who completed anorectal manometry and the questionnaires before treatment and at 1 year after surgery.

Results

The EORTC QLQ-C30 and QLQ-CR38 showed comparable outcomes regarding the quality of life in both groups. More patients experienced major LARS in the transanal group at 1 year postoperatively (31.0% vs. 6.8% in the laparoscopic group, P = 0.004). Multivariable analysis revealed no significant difference in the LARS score between the groups at 1 year postoperatively (odds ratio, 2.30; 95% confidence interval, 0.79–6.72; P = 0.127). Significant differences in the IPSS were not noted between the groups.

Conclusion

The quality of life and functional outcomes were comparable between the laparoscopic and transanal approaches; however, our findings suggest a higher rate of LARS after TaTME.

Factors associated with diet failure after colon cancer surgery

BACKGROUND

Since the introduction of Enhanced Recovery After Surgery (ERAS), early diet after surgery has been emphasized and clinical outcomes have improved, though vomiting has been reported frequently. We defined diet failure based on clinical manifestation and images after colon cancer surgery and attempted to analyze underlying risk factors by comparing the early diet group with the conventional diet group.

METHODS

All consecutive patients underwent colectomy with curative intent at a single institution between August 2015 and July 2017. The early diet group was started on soft diet on the second day after surgery, while the conventional group started the same after flatulence. The primary outcome was the difference in the incidence of diet failure between the two groups. Secondary outcomes were analyzed to determine risk factors for diet failure and readmission due to ileus.

RESULTS

Overall, 293 patients were included in the conventional diet group and 231 in the early diet group. There were no significant differences between the two groups, except for shorter hospital stays in the early diet group (median 8 days, p < 0.001). A total of 46 patients (early diet, n = 20; conventional diet, n = 26, p = 1.000) had diet failure. Multivariate analysis showed that operation time (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.33-2.32) and side-to-side anastomosis compared with the end-to-end method (OR 4.41, 95% CI 2.10-9.24) were independent risk factors for diet failure. Sixteen patients were readmitted due to ileus that occurred within 2 months after surgical operation. Diet resumption time was not a risk factor for both diet failure and ileus.

CONCLUSIONS

Early diet resumption does not increase diet failure and can reduce hospital stay. Anastomosis and operation time may be related to diet failure. Our study suggests that evaluation of surgical factors is important for postoperative recovery, and well-designed follow-up studies are needed.

The prognostic impact of RAS and TP53 mutation according to primary tumor location in colorectal liver metastases

3582

Background: Somatic gene mutations have been suggested to impact survival following resection of colorectal liver metastases (CRLM). However, most studies included a selected population with known mutation data and did not employ homogeneous methods. This study aimed to determine the prognostic impact of somatic gene mutations and microsatellite instability (MSI) in CRLM using a standardized protocol and assess their survival effects according to primary tumor location. Methods: A total of 568 patients who underwent resection of CRLM during 2001-2014 were identified from a prospectively maintained registry of the National Cancer Center. MassARRAY based mutation profiling of cancer-related genes ( KRAS, NRAS, HRAS, BRAF, PIK3CA, MET, PTEN, APC, TP53)/MSI analysis was made in primary tumors from 538 (94.7%)/526 (92.6%) patients. Results: Primary tumor locations were: right colon for 51 (9.0%); transverse colon for 42 (7.4%); left colon for 238 (34.5%); rectum for 279 (49.1%) patients. Right sided tumors were associated shorter overall survival (OS) after liver resection compared to left colon primary tumors (5-year OS, 31.4% vs. 54.0% [ P = 0.011]). Mutation frequencies were: 45.9% for RAS ; 2.4% for BRAF ; 8.4% for PIK3CA ; 0.2% for PTEN ; 0.4% for MET ; 12.1% for APC ; 24.3% for TP53. RAS (5-year OS, 40.8% vs. 55.7% [ P = 0.001], PIK3CA (5-year OS, 31.1% vs. 50.5% [ P = 0.027]), and TP53 mutation (5-year OS, 42.7% vs. 50.8% [ P = 0.035]) were associated with worse OS after liver resection. On multivariable analyses, RAS (hazard rato [HR] 1.27; P = 0.033) and TP53 mutation (HR 1.35; P = 0.014) were significantly associated with poor OS after adjustment for covariates. Co-mutation in RAS/ TP53 (12.4%) was associated with the worst oncologic outcome (HR 1.81; P <.001). Notably, while the negative prognostic impact of RAS mutation did not differ significantly according to primary tumor location, the adverse effect of TP53 mutation was limited to rectal cancer (interaction P = 0.002). In this study, MSI-high (2.3%) was not associated with survival. Conclusions: Both RAS and TP53 mutation are associated with worse survival following CRLM resection. In contrast to RAS mutation, the negative prognostic impact of TP53 mutation appears to be limited to CRLM from the rectal origin.

Effect of lateral lymph node dissection on the quality of life and genitourinary function after neoadjuvant chemoradiotherapy for rectal cancer

Purpose

This study was performed to evaluate the quality of life and genitourinary function after total mesorectal excision with lateral lymph node dissection compared to those after total mesorectal excision alone following neoadjuvant chemoradiotherapy for rectal cancer.

Methods

Among patients who underwent rectal cancer surgery after completing neoadjuvant chemoradiotherapy between September 2011 and October 2018 at the National Cancer Center, Korea, patients who completed the validated questionnaires before initiation of neoadjuvant chemoradiotherapy and at 3 months and 1 year postoperatively were included in this study. The European Organization for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ-C30), colorectal cancer-specific quality of life questionnaire (QLQ-CR38), and International Prostate Symptom Score (IPSS) questionnaire were used for collecting data.

Results

The total mesorectal excision alone group and the total mesorectal excision with lateral lymph node dissection group included 52 and 38 patients, respectively. The second group included significantly younger patients (P = 0.024), had a higher incidence of clinical T4 stage disease (P = 0.033), estimated blood loss (P = 0.003), and longer operation time (P < 0.001). Significant differences were not observed between the groups with respect to the EORTC QLQ-C30, QLQ-CR38, and IPSS. Multivariable analysis showed that lateral lymph node dissection had no statistically significant association with postoperative urinary dysfunction (P = 0.953).

Conclusion

The overall quality of life and urinary function after total mesorectal excision does not differ significantly when lateral lymph node dissection is performed as well.

CORRIGENDUM: Correction of acknowledgements & funding/grant support: The effect of curative resection on fecal microbiota in patients with colorectal cancer: a prospective pilot study

[This corrects the article on p. 44 in vol. 99, PMID: 32676481.].

Laparoscopic approach for T4 colon cancer can be associated with poor prognosis in right-sided T4b tumours

INTRODUCTION

Although recent studies have demonstrated the safety of laparoscopic surgery in T4 colon cancer, some patients could have poor prognosis. In this study, we aimed to analyse the risk factors affecting oncologic outcome of laparoscopic surgery.

MATERIALS AND METHODS

Among the 1033 T4 colon cancer patients collected from a multicentre database (2004-2017), 584 patients (458 T4a and 126 T4b) underwent laparoscopic approach for radical surgery. Risk factors associated with 3-year disease-free survival (DFS) and overall survival (OS) were evaluated through multivariate analysis. In addition, subgroups were classified using a combination of risk factors, and the survival rate was evaluated.

RESULTS

During this period, 188 (32.2%) had recurrence, and 151 (25.9%) died. In the multivariate analysis for oncologic outcome, elevated carcinoembryonic antigen level (hazard ratio [HR] 1.37) and absence of adjuvant chemotherapy (HR 1.60) were associated with poor DFS. T4b (HR 1.56, 1.46), right-sided location (HR 1.52, 1.42), and open conversion (HR 2.70, 2.12) were independently associated with both poor DFS and OS. When four subgroups were analysed through the combination of tumour location and T stage, the DFS and OS rates were significantly lower in patients with right-sided T4b cancer than in other groups (log-rank p < 0.001).

CONCLUSION

Right-sided T4b colon cancer for laparoscopic surgery may lead to poor oncologic outcome. This approach could be a caution in suspected cases preoperatively.

Quality of life after sphincter preservation surgery or abdominoperineal resection for low rectal cancer (ASPIRE): A long-term prospective, multicentre, cohort study

Background

The long-term effects of radical resection on quality of life may influence the treatment selection. The objective of this study was to determine whether abdominoperineal resection has a better effect on the quality of life than sphincter preservation surgery at 3 years after surgery

Methods

This prospective, cohort study included patients who underwent radical resection for low rectal cancer. The primary outcomes were European Organisation for Research and Treatment of Cancer QLQ-C30 and CR38 quality of life scores 3 years after surgery, which were compared with linear generalised estimating equations, after adjustment for baseline values, a time effect, and an interaction effect between time and treatment. The secondary outcomes included sexual-urinary functions and oncological outcomes. The study was registered with ClinicalTrials.gov (NCT01461525).

Findings

Between December 2011 and August 2016, 342 patients were enrolled: 268 (78•4%) underwent sphincter preservation surgery and 74 (21•6%) underwent abdominoperineal resection. The global quality of life scores did not differ between sphincter preservation surgery and abdominoperineal resection groups (adjusted mean difference, 4•2 points on a 100-point scale; 95% confidence interval  [CI], −1•3 to 9•7, p = 0•1316). Abdominoperineal resection was associated with a worse body image (9•8 points; 95% CI, 2•9 to 16•6, p = 0•0052), micturition symptoms (−8•0 points; 95% CI, -14•1 to −1•8, p = 0•0108), male sexual problems (−19•9 points; 95% CI, -33•1 to -6•7, p = 0•0032), less confidence in getting and maintaining an erection in males (0•5 points on a 5-point scale; 95% CI, 0•1 to 0•8, p = 0•0155), and worse urinary symptoms (−5•4 points on a 35-point scale; 95% CI, −8•0 to −2•7, p < 0•0001). The 5-year overall survival was worse with abdominoperineal resection in unadjusted (92•2% vs 80•9%; difference 11•3%, hazard ratio 2•38; 95% CI, 1•27 to 4•46, p = 0•0052), but did not differ after adjustment.

Interpretation

In this long-term prospective study, abdominoperineal resection failed to meet the superiority to sphincter preservation surgery in terms of quality of life. Although the global quality of life scores did not differ between groups, this study suggests that sphincter preservation surgery can be an acceptable alternative to abdominoperineal resection for low rectal cancer, offering a better quality of life and sexual-urinary functions, with no increased oncological risk even after 3 years.

Funding

Seoul National University Bundang Hospital, Korea

Dual modal spectroscopic tissue scanner for colorectal cancer diagnosis

BACKGROUND

Margin status is an important prognostic factor for treating colorectal cancer. This study aimed to investigate the usefulness of a multimodal spectroscopic tissue scanner for real-time cancer diagnosis without tissue staining.

PATIENTS AND METHODS

Diffuse reflectance spectra (DRS) and fluorescence spectra (FS) of < 1-mm-sized paired cancer and normal mucosa tissue were acquired using custom-built spectroscopic tissue scanners. For FS, we analyzed wavelengths and intensities at peaks and highest intensities near (± 1.25 nm) the known fluorescence spectral peaks of collagen (380 nm), reduced nicotinamide adenine dinucleotide (NADH, 460 nm), and flavin adenine dinucleotide (FAD, 550 nm). For DRS, we performed a similar analysis near the peaks of strong absorbers, oxyhemoglobin (oxyHb; 414 nm, 540 nm, and 576 nm) and deoxyhemoglobin (deoxyHb; 432 nm and 556 nm). Logistic regression analysis for these parameters was performed in the testing set.

RESULTS

We acquired 17,735 spectra of cancer tissues and 9438 of normal tissues from 30 patients. Intensity peaks of representative normal spectra for FS and DRS were higher than those of representative cancer spectra. Logistic regression analysis showed wavelength and intensity at peaks, and the intensities of the peak wavelength of NADH, FAD, deoxyHb, and oxyHb had significant coefficients. The area under the receiver operating characteristic curve was 0.927. The scanner had 100%, 64.3%, and 85.3% sensitivity, specificity, and accuracy, respectively.

CONCLUSIONS

The spectroscopic tissue scanner has high sensitivity and accuracy and provides real-time intraoperative resection margin assessments and should be further investigated as an alternative to frozen section.

Small Bowel Perforation Associated With Gastrointestinal Graft-Versus-Host Disease and Cytomegalovirus Enteritis in a Patient With Leukemia: A Case Report With Literature Review

Gastrointestinal graft-versus-host disease (GVHD) is a common complication after hematopoietic stem cell transplantation. Concomitant cytomegalovirus (CMV) enteritis worsens the prognosis of this condition. We report a case of small bowel perforation associated with gastrointestinal GVHD and CMV enteritis in a patient with leukemia who was successfully treated surgically. A 39-year-old man presented with intestinal perforation necessitating emergency surgical intervention. He was diagnosed with T-cell acute lymphoblastic leukemia and developed severe gastrointestinal GVHD and CMV enteritis after hematopoietic stem cell transplantation. His terminal ileum showed a perforation with diffuse wall thinning, and petechiae were observed over long segments of the distal ileum and the proximal colon. Small bowel segmental resection and a subtotal colectomy with a double-barreled ileocolostomy were performed. The patient recovered uneventfully after the operation. Based on reports described in the literature, surgery plays a minor role in the management of gastrointestinal GVHD; however, timely surgical intervention could be effective in selected patients.

Oncologic Risk of Rectal Preservation Against Medical Advice After Chemoradiotherapy for Rectal Cancer: A Multicenter Comparative Cross-Sectional Study with Rectal Preservation as Supported by Surgeon

BACKGROUND

Rectal preservation against medical advice after neoadjuvant chemoradiotherapy for rectal cancer may increase oncologic uncertainty. This study aimed to compare the oncologic outcomes of patients undergoing rectal preservation as intended by the surgeon, and the outcomes of patients refusing rectal resection against medical advice.

METHODS

The study population consisted of patients in whom the rectum was preserved after neoadjuvant chemoradiotherapy for clinical stage I-III mid or low rectal cancer between May 2003 and August 2017 (n = 2883); these patients were divided into those in whom rectal preservation was intended by their surgeon (intended rectal preservation, group A, n = 41) and those in whom the rectum was not resected against medical advice (unintended rectal preservation, group B, n = 101), defined as non-operative management or local excision.

RESULTS

The tumor distance, age, and performance status of patients were not significantly different between the groups, while the clinical T stage before chemoradiotherapy was lower in group A than in group B (P < 0.001). During the median follow-up period of 34 months (interquartile range 18.0-72.0 months), the 3-year overall survival in group B (59.7%) was worse than that in group A (90.1%; P < 0.001), and 80.2% of group B patients had residual or unknown disease status.

CONCLUSIONS

This study showed that unintended rectal preservation increases oncologic risk after neoadjuvant chemoradiotherapy for rectal cancer regardless of short-term follow-up. Therefore, these findings could be shared with rectal cancer patients who choose to ignore medical advice after chemoradiotherapy to preserve their rectum.

Analysis of metachronous colorectal neoplasms and survival following segmental or extended resection in patients with hereditary non-polyposis colorectal cancer

PURPOSE

The high incidence of metachronous colorectal tumours in patients with hereditary non-polyposis colorectal cancer (HNPCC) encourages extended resection (ER); however, the optimal surgical approach remains unclear. We evaluated the incidences of metachronous colorectal neoplasms following curative colorectal cancer segmental resection (SR) vs ER in patients with HNPCC and investigated patients' oncologic outcomes according to surgical modality and mismatch repair status.

METHODS

We retrospectively investigated medical records of patients with HNPCC (per the Amsterdam II criteria) treated for primary colon cancer at our institution between 2001 and 2017. All patients underwent intensive endoscopic surveillance.

RESULTS

We included 87 patients (36 who underwent SR and 51 who underwent ER). The cumulative incidence of metachronous adenoma was higher in the SR group. One patient in the SR group (2.8%) and 3 in the ER group (5.9%) developed metachronous colon cancer; the difference was not significant (P = 0.693). Four patients in the SR group (11.1%) and 1 in the ER group (2.0%) developed distant recurrences; again, the difference was not significant (P = 0.155). Moreover, no significant differences were observed in the 5-year overall survival rates of patients in the SR and ER groups (88.2% vs 95.5%, P = 0.446); the same was true for 5-year disease-free survival rates (79.5% vs 91.0%, P = 0.147).

CONCLUSION

The incidence of metachronous cancer was not significantly different between the ER and SR groups; however, that of cumulative metachronous adenoma was higher in the SR group. Hence, intensive surveillance colonoscopy may be sufficient for patients with HNPCC after non-extensive colon resection.

The effect of curative resection on fecal microbiota in patients with colorectal cancer: a prospective pilot study

Purpose

Although many studies have evaluated the association between intestinal microorganisms and the risk of colorectal cancer (CRC), only a few studies have investigated the changes in microorganisms following curative treatment for CRC. The current study analyzed changes in intestinal microbiota following curative surgery in CRC patients.

Methods

Stool samples were collected before and 6 months after surgery, from 11 patients with clinical stage III CRC, who underwent curative surgery between May 2017 and June 2017. Next, 16S rRNA gene sequencing was performed. Operational taxonomic units (OTUs) and alpha diversity were evaluated using the Shannon index. The bacterial compositions of the stools were analyzed according to taxonomic rank at genus and phylum levels.

Results

OTUs and alpha diversity were significantly decreased following surgery (P < 0.001 and P = 0.019, respectively). The compositions of several bacterial taxa changed after surgery. At genus level, proportions of pathogens such as Campylobacter, Fusobacterium, Haemophilus, Porphyromonas, and Prevotella, decreased after surgery (adjusted P < 0.05). At phylum level, the proportion of Fusobacteria decreased after surgery (adjusted P < 0.001).

Conclusion

Significant changes in intestinal microbial communities were noted following curative resection of CRC patients. Especially, decreases in pathogenic bacterial populations, such as Fusobacterium and Prevotella, which are known to be associated with CRC development, were detected even though OTUs and alpha diversity were decreased following curative resection. To determine and validate the clinical significance of these findings, large scale, prospective studies that include cancer prognoses are required.

Oncological Impact of Lateral Lymph Node Dissection After Preoperative Chemoradiotherapy in Patients with Rectal Cancer

PURPOSE

To evaluate the efficacy of selective lateral lymph node dissection (LLND) and the effect of preoperative chemoradiotherapy (PCRT) in patients with LLN ≥ 5 mm.

METHODS

Patients who underwent PCRT for rectal cancer were classified: (A) total mesorectal excision (TME)-only with LLN < 5 mm (2001-2009, n = 474), (B) TME-only with LLN < 5 mm (2011-2016, n = 273), (C) TME-only with LLN ≥ 5 mm (2001-2009, n = 102), and (D) TME-LLND with LLN ≥ 5 mm (2011-2016, n = 69). Subgroup analysis was performed in patients with LLN ≥ 5 mm based on the reduction in LLN size to < 5 mm or not on restaging MRI after PCRT.

RESULTS

Oncological outcomes did not differ between groups A and B. Group D had lower 3-year local recurrence (LR) (20.13% vs 5.39%, P = 0.0013) and higher relapse-free survival (RFS) (65.83% vs 77.11%, P = 0.0436) than group C, while the 3-year overall survival (OS) was not significantly different between the two groups (87.64% vs 93.53%, P = 0.0670). In patients with reduction of LLN size from ≥ 5 mm to < 5 mm, LLND significantly reduced LR than did TME alone, but there were no significant differences in survival outcomes. In patients without reduction of LLN size to < 5 mm, LLND reduced LR and improved RFS compared with TME alone.

CONCLUSIONS

Selective LLND reduced LR and improved RFS in patients with LLN ≥ 5 mm. Selective LLND reduced LR in patients with reduction of LLN size from ≥ 5 mm to < 5 mm after PCRT, and improved both LR and RFS in patients without reduction of LLN size to < 5 mm.

Long-term mortality of patients with tuberculosis in Korea

BACKGROUND: Long-term mortality following tuberculosis (TB) diagnosis in Korea remains unclear.METHODS: The present study used data from the National Health Insurance Service database, an extensive health-related database including most Korean residents. TB patients were identified using International Classification of Diseases, Tenth Revision coding (A15-19, U88.0-88.1) and the type of anti-TB drug(s) between 2003 and 2016. Long-term mortality and causes of death in TB patients were analysed.RESULTS: A total of 357 211 individuals had TB over the period from 2003 to 2016 and 103 682 died. The mean age of the cohort was 54.7 ± 20.7 years, and 59.8% were male. The survival probability of TB patients at 1, 5, and 10 years after diagnosis was 87.8%, 75.3%, and 63.3%, respectively. High mortality and TB-related death rates were especially prominent in the early stages after TB diagnosis. The overall standardized mortality ratio of TB patients to the general Korean population was 3.23 (95% confidence interval 3.21-3.25).CONCLUSION: Mortality in TB patients was especially high in the early stages of disease after TB diagnosis, and mostly due to TB. This figure was approximately three-times higher than the mortality rate in the general population.

Efficacy of health coaching and a web-based program on physical activity, weight, and distress management among cancer survivors: A multi-centered randomised controlled trial

OBJECTIVES

To investigate the efficacy of health coaching and a web-based program on survivor physical activity (PA), weight, and distress management among stomach, colon, lung and breast cancer patients.

METHODS

This randomised, controlled, 1-year trial conducted in five hospitals recruited cancer survivors within 2 months of completing primary cancer treatment who had not met ≥1 of these behavioural goals: (i) conducting moderate PA for at least 150 minutes/week or strenuous exercise for over 75 minutes per week or, in the case of lung cancer patients, low or moderate intensity exercise for over 12.5 MET per week, (ii) maintaining normal weight, and (iii) attaining a score >72 in the Post Traumatic Growth Inventory (PTGI). Participants were randomly assigned to one of three groups: the control group, a web-only group, or a health coaching + web group. The primary endpoint was based on a composite of PA, weight, and PTGI score at 12 months.

RESULTS

Patients in the health coaching + web group (difference = 6.6%, P = .010) and the web-only group (difference = 5.9%, P = .031) had greater overall improvements across the three-outcome composite than the control group. The health coaching + web group had greater overall improvement in PTGI (difference = 12.6%; P < .001) than the control group, but not in PA and weight.

CONCLUSION

The web-based program, with or without health coaching, may improve health behaviours including PA, weight, and distress management among cancer survivors within 2 months of completing primary cancer treatment. The web-based program with health coaching was mainly effective for reducing psychological distress.

Characteristics of minute T1 colorectal cancer in relevance to pathology and treatment

Purpose

Minute T1 colorectal cancer (CRC) lesions (≤5 mm) are rare; however, little is known about their characteristics and aggressiveness. In this study, we evaluated the characteristics of minute T1 CRC in relevance to pathology and treatment.

Methods

This retrospective study included 849 patients with T1 CRC endoscopically or surgically treated between January 2001 and December 2016. The patients were stratified into 4 groups according to tumor size; minute group (≤5 mm), small group (6–10 mm), medium group (11–20 mm), and large group (≥21 mm). Clinicopathological variables were evaluated with respect to tumor size.

Results

The incidence of the minute T1 CRC was 2.4% (20 of 849). Minute T1 CRC was significantly associated with flat type (minute, 25%; small, 12.6%; medium, 8.8%; large, 12.6%; P = 0.016), right-sided cancer (30%, 15.4%, 15.4%, 15.1%, P = 0.002) and the absence of background adenoma (BGA) (50%, 40.7%, 32.8%, 18.1%, P < 0.001). In patients who underwent surgery, lymph node metastasis (LNM) was significantly higher in the minute group (36.4%, 15.9%, 15.7%, 9.2%, P = 0.029).

Conclusion

Minute T1 CRC is significantly associated with flat type, right-sided cancers, as well as with the absence of BGA and LNM. These results suggested the minute T1 CRC lesions are often aggressive and are likely to be missed during colonoscopy.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy With Mitomycin C Used for Colorectal Peritoneal Carcinomatosis

Purpose

This study aimed to assess the evaluation of clinical outcomes and consequences of complications after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for the peritoneal carcinomatosis (PC) from colorectal cancer.

Methods

A total 26 patients underwent CRS and HIPEC for PC from colorectal cancer between March 2009 and April 2018. All the patients underwent CRS with the purpose of complete or near-complete cytoreduction. Intraoperative HIPEC was performed simultaneously after the CRS. Mitomycin C was used as chemotherapeutic agent for HIPEC.

Results

Median disease-free survival was 27.8 months (range, 13.4–42.2 months). Median overall survival was 56.0 months (range, 28.6–83.5 months). The mean peritoneal cancer index (PCI) was 8.73 ± 5.54. The distributions thereof were as follows: PCI <10, 69.23%; PCI 10–19, 23.08%; and PCI ≥20, 7.69%. The completeness of cytoreduction was 96.2% of patients showed CC-0, with 3.8% achieved CC-1. The mean operation time was 8.5 hours, and the mean postoperative hospital stay was 21.6 days. The overall rate of early postoperative complications was 88.5%; the rate of late complications was 34.6%. In the early period, most complications were grades I–II complications (65.4%), compared to grades III–V (23.1%). All late complications, occurring in 7.7% of patients, were grades III–V. There was no treatment-related mortality.

Conclusion

Although the complication rate was approximately 88%, but the rate of severe complication rate was low. In selective patients with peritoneal recurrence, more aggressive strategies for management, such as CRS with HIPEC, were able to be considered under the acceptable general condition and life-expectancy.

Nomogram Development and External Validation for Predicting the Risk of Lymph Node Metastasis in T1 Colorectal Cancer

PURPOSE

Predicting lymph node metastasis (LNM) risk is crucial in determining further treatment strategies following endoscopic resection of T1 colorectal cancer (CRC). This study aimed to establish a new prediction model for the risk of LNM in T1 CRC patients.

MATERIALS AND METHODS

The development set included 833 patients with T1 CRC who had undergone endoscopic (n=154) or surgical (n=679) resection at the National Cancer Center. The validation set included 722 T1 CRC patients who had undergone endoscopic (n=249) or surgical (n=473) resection at Daehang Hospital. A logistic regression model was used to construct the prediction model. To assess the performance of prediction model, discrimination was evaluated using the receiver operating characteristic (ROC) curves with area under the ROC curve (AUC), and calibration was assessed using the Hosmer-Lemeshow (HL) goodness-of-fit test.

RESULTS

Five independent risk factors were determined in the multivariable model, including vascular invasion, high-grade histology, submucosal invasion, budding, and background adenoma. In final prediction model, the performance of the model was good that the AUC was 0.812 (95% confidence interval [CI], 0.770 to 0.855) and the HL chi-squared test statistic was 1.266 (p=0.737). In external validation, the performance was still good that the AUC was 0.771 (95% CI, 0.708 to 0.834) and the p-value of the HL chi-squared test was 0.040. We constructed the nomogram with the final prediction model.

CONCLUSION

We presented an externally validated new prediction model for LNM risk in T1 CRC patients, guiding decision making in determining whether additional surgery is required after endoscopic resection of T1 CRC.

Magnetic Resonance-Based Texture Analysis Differentiating KRAS Mutation Status in Rectal Cancer

Purpose

Mutation of the Kirsten Ras (KRAS) oncogene is present in 30%-40% of colorectal cancers and has prognostic significance in rectal cancer. In this study, we examined the ability of radiomics features extracted from T2-weighted magnetic resonance (MR) images to differentiate between tumors with mutant KRAS and wild-type KRAS.

Materials and Methods

Sixty patients with primary rectal cancer (25 with mutant KRAS, 35 with wild-type KRAS) were retrospectively enrolled. Texture analysis was performed in all regions of interest on MR images, which were manually segmented by two independent radiologists. We identified potentially useful imaging features using the two-tailed t test and used them to build a discriminant model with a decision tree to estimate whether KRAS mutation had occurred.

Results

Three radiomic features were significantly associated with KRAS mutational status (p < 0.05). The mean (and standard deviation) skewness with gradient filter value was significantly higher in the mutant KRAS group than in the wild-type group (2.04±0.94 vs. 1.59±0.69). Higher standard deviations for medium texture (SSF3 and SSF4) were able to differentiate mutant KRAS (139.81±44.19 and 267.12±89.75, respectively) and wild-type KRAS (114.55±29.30 and 224.78±62.20). The final decision tree comprised three decision nodes and four terminal nodes, two of which designated KRAS mutation. The sensitivity, specificity, and accuracy of the decision tree was 84%, 80%, and 81.7%, respectively.

Conclusion

Using MR-based texture analysis, we identified three imaging features that could differentiate mutant from wild-type KRAS. T2-weighted images could be used to predict KRAS mutation status preoperatively in patients with rectal cancer.

Antioxidant, antibacterial, and anti-adhesive activities of biosurfactants isolated from Bacillus strains

Biosurfactants are surface-active compounds that display a range of physiological functions. The present study investigated the antioxidant, antimicrobial, and anti-adhesive or anti-biofilm potential of biosurfactants isolated from Bacillus subtilis VSG4 and Bacillus licheniformis VS16. The antioxidant activity of the biosurfactants was studied in vitro using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. At 5 mg/mL of the biosurfactant concentration, the scavenging of DPPH and hydroxyl radicals was found to be between 69.1-73.5% and 63.3-69.8%, respectively. The biosurfactants also displayed significant antibacterial activities against both Gram-positive and Gram-negative bacteria. The anti-adhesive activities of the biosurfactants were evaluated against Staphylococcus aureus ATCC 29523, Salmonella typhimurium ATCC 19430, and Bacillus cereus ATCC 11778. The biosurfactants exhibited anti-adhesive activity, even at concentrations of 3-5 mg/mL. Moreover, both biosurfactants displayed notable anti-biofilm activities with a biofilm eradication percentage ranging from 63.9 to 80.03% for VSG4 biosurfactant, and from 61.1-68.4% for VS16 biosurfactant. Furthermore, VSG4 biosurfactant exhibited emulsification and surface tension stability over a wide range of pH (4-10) and temperature up to 100 °C. These results show that VSG4 and VS16 biosurfactants can be potentially used as natural antioxidants, antimicrobials, and/or anti-adhesive agents for food and biomedical applications.

Female Sex and Right-Sided Tumor Location Are Poor Prognostic Factors for Patients With Stage III Colon Cancer After a Curative Resection

Purpose

Stage-IIIC colon cancer is an advanced disease; however, its oncologic outcomes and prognostic factors remain unclear. In this study, we aimed to determine the predictors of disease-free survival (DFS) in patients with stage-IIIC colon cancer.

Methods

From a multicenter database, we retrospectively enrolled 611 patients (355 men and 256 women) who had undergone a potentially curative resection for a stage-IIIC colon adenocarcinoma between 2003 and 2011. The primary end-point was the 5-year DFS.

Results

The median age was 62 years; 213 and 398 patients had right-sided colon cancer (RCC) and left-sided colon cancer (LCC), respectively. The 5-year DFS in all patients was 52.0%; median follow-up time was 35 months (range, 1–134 months). A multivariate Cox regression revealed that female sex (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.19–1.90; P < 0.01), right-sided tumor location (HR, 1.65; 95% CI, 1.29–2.11; P < 0.01), lymphatic invasion (HR, 1.52; 95% CI, 1.08–2.15; P < 0.01) and a high (≥0.4) metastatic lymph node ratio (HR, 3.72; 95% CI, 2.63–5.24; P < 0.01) were independent predictors of worse 5-year DFS. Female patients with RCC were 1.79 fold more likely to experience recurrence than male patients with LCC.

Conclusion

Female sex and right-sided tumor location are associated with higher tumor recurrence rates in patients with stage-IIIC colon cancers. Aggressive treatment and close surveillance should be planned for patients in these groups.

Analysis of Pre-transplant Resuscitation Factors Influencing Immediate Graft Function After Deceased Donor Kidney Transplantation

BACKGROUND

The management of a deceased donor in the intensive care unit before organ transplantation is important for the outcome of the recipient. Herein, we analyze the pre-transplant resuscitation factors managed before procurement that could influence graft function immediately after deceased-donor kidney transplantation (DDKT).

METHODS

A total of 271 DDKTs performed at Seoul St. Mary's Hospital, Korea, from January 2009 to March 2016 were reviewed. We divided the patients into a delayed graft function (DGF) group and a non-DGF group, and compared postoperative outcomes between the 2 groups. We also analyzed the predisposing factors of DGF using multivariate analysis.

RESULTS

A total of 36 cases developed DGF while 235 patients did not, and the demographic characteristics of the recipients in the two groups had no significant difference. Of the pre-transplant resuscitation factors, preoperative polyuria, the maximal levels of serum sodium and BUN, and transfer times were significantly higher in the DGF group (P < .001). In a multivariable analysis, preoperative polyuria (odds ratio 4.835, P = .036), elevated preoperative level of sodium (odds ratio 1.227, P = .001), and extended transfer times (odds ratio 1.001, P < .001) were the independent risk factors of the donor in pre-transplant resuscitation management associated with DGF.

CONCLUSIONS

Polyuria, high levels of sodium before procurement, and prolonged transfer times are independent risk factors for DGF after a DDKT. Active intervention and early implementation of the intensivist can help in managing these factors effectively and thus ultimately improve graft function.

Clinical Outcomes of Reduced-Port Laparoscopic Surgery for Patients With Sigmoid Colon Cancer: Surgery With 1 Surgeon and 1 Camera Operator

Purpose

This study compared the perioperative clinical outcomes of reduced-port laparoscopic surgery (RPLS) with those of conventional multiport laparoscopic surgery (MPLS) for patients with sigmoid colon cancer and investigated the safety and feasibility of RPLS performed by 1 surgeon and 1 camera operator.

Methods

From the beginning of 2010 until the end of 2014, 605 patients underwent a colectomy for sigmoid colon cancer. We compared the characteristics, postoperative outcomes, and pathologic results for the patients who underwent RPLS and for the patients who underwent MPLS. We also compared the clinical outcomes of single-incision laparoscopic surgery (SILS) and 3-port laparoscopic surgery.

Results

Of the 115 patients in the RPLS group, 59 underwent SILS and 56 underwent 3-port laparoscopic surgery. The MPLS group included 490 patients. The RPLS group had shorter operating time (137.4 ± 43.2 minutes vs. 155.5 ± 47.9 minutes, P < 0.001) and shorter incision length (5.3 ± 2.2 cm vs. 7.8 ± 1.2 cm, P < 0.001) than the MPLS group. In analyses of SILS and 3-port laparoscopic surgery, the SILS group showed younger age, longer operating time, and shorter incision length than the 3-port surgery group and exhibited a more advanced T stage, more lymphatic invasion, and larger tumor size.

Conclusion

RPLS performed by 1 surgeon and 1 camera operator appears to be a feasible and safe surgical option for the treatment of patients with sigmoid colon cancer, showing comparable clinical outcomes with shorter operation time and shorter incision length than MPLS. SILS can be applied to patients with favorable tumor characteristics.

Laparoscopic approach for left-sided T4 colon cancer is a safe and feasible procedure, compared to open surgery

BACKGROUND

A laparoscopic approach can be attempted for pathologic T4 (pT4) colon cancer. Our aim was to evaluate the clinico-oncologic outcomes following laparoscopic versus open surgery for right and left-sided pT4 colon cancer.

METHODS

From a multicentric collaborative database, we enrolled 245 patients with right-sided colon cancer (RCC, 128 laparoscopy and 117 open) and 338 with left-sided colon cancer (LCC, 176 laparoscopy and 162 open). All patients underwent intended curative surgery for histologically proven T4 adenocarcinoma, between 2004 and 2013. The primary end-point of our analysis was the oncologic outcome, including the 5-year disease-free survival (5 year-DFS) and the 5-year overall survival (5 year-OS). The secondary end-points included the R0 resection rate and postoperative complications.

RESULTS

Our study group included 224 T4N0 and 359 T4N+ tumors. The median follow-up was 53 months. For patients with RCC, the rate of postoperative morbidities was lower for the laparoscopy than that for the open surgery group (12.5 vs. 22.2%, p = 0.044). There was no difference in the R0 resection rate (94.5 vs. 96.6%, p = 0.425) between the groups. The 5 year-DFS and 5 year-OS rates were lower for the laparoscopy than that in the open group (48.9% vs. 59.2%, p = 0.093; 60.0% vs. 70.0%, p = 0.284, respectively), but this difference was not statistically significant. Among patients with LCC, there were no differences in the rate of postoperative complication and R0 resection (15.3 vs. 21.0%, p = 0.307; 96.0 vs. 95.7%, p = 0.875, respectively). Both groups had comparable 5 year-DFS and 5 year-OS rates (62.7% vs. 61.1%, p = 0.552; 72.0% vs. 71.8%, p = 0.611, respectively).

CONCLUSIONS

Laparoscopic surgery appears to be a safe procedure for patients with pT4 LCC, but requires careful consideration for patients with pT4 RCC.

Colonoscopy learning curves for colorectal surgery fellow trainees: experiences with the 15-year colonoscopy training program

Purpose

This study aimed to analyze the learning curves for colorectal surgery fellows in a colonoscopy training program.

Methods

Between May 2003 and February 2017, 60 surgical fellows joined our 1-year colonoscopy training program as trainees and performed 43,784 cases of colonoscopy. All trainees recorded their colonoscopy experiences prospectively into the database. After excluding 6 trainees, who had experience with performing more than 50 colonoscopies before participating in our training program or who discontinued our training program with experience performing less than 300 colonoscopies, this study included 54 trainees who had performed 39,539 colonoscopy cases. We analyzed the cecal intubation rate (CIR) and cecal intubation time (CIT) using the cumulative sum (Cusum) technique and moving average method to assess the technical colonoscopy competence.

Results

Overall, the CIR by the trainees was 80.7%. The median number of cases of colonoscopy performed during the training period for each trainee was 696 (range, 322–1,669). The trainees were able to achieve a 90% CIR with 412 and 493 procedures when analyzed using the moving average and the Cusum, respectively. Using the moving average method, CIRs after 150, 300, and 400 procedures were 67.0%, 84.1%, and 89.2%, respectively. The CIT of trainees continuously decreased until 400 successful cases. Median CITs were 9.4, 8.3, and 7.4 minutes at 150, 300, and 400 successful cases, respectively.

Conclusion

We found that more than 400 cases of experience were needed for technical competence in colonoscopy. Continuous teaching and monitoring is required until trainees become sufficiently competent.

Patterns of failure in rectal cancer with positive circumferential resection margin after surgery following preoperative chemoradiation: a propensity score matching analysis

OBJECTIVE:

To compare the patterns of failure between rectal cancer patients with negative and positive circumferential resection margin (CRM) after surgery following preoperative chemoradiation.

METHODS:

Of 944 stage II-III rectal cancer patients treated with radical surgery following preoperative chemoradiation, 74 patients (7.8%) showed positive CRM. Each 72 patients from negative and positive CRM groups were identified by propensity score matching and compared in terms of survival outcomes and patterns of failure. Local failure was defined as recurrence at the anastomosis site or adjacent to the mesorectal fascia.

RESULTS:

The median follow-up was 46 months (range, 4-155). No difference was observed in 5-year local recurrence-free survival (93.4% vs 89.6%, p = 0.442) in the negative and positive CRM groups. There was statistically significant difference in relapse-free survival (57.1% vs 39.1%, p = 0.042). Negative CRM group showed favorable outcomes than positive CRM in distant metastasis-free survival (59.4% vs 43.3%, p = 0.069) and overall survival (67.5% vs 55.8%, p = 0.186), but the difference was not statistically significant. As the initial failure pattern, there were 30 and 43 recurrences in the negative and positive CRM groups (local 6.6 and 7.3%, regional 12.8 and 14.4%, and distant 38.5 and 54.9%). Isolated local recurrence was identified in two with negative CRM and in none with positive CRM (p = 0.497).

CONCLUSION:

Distant metastasis was the major pattern of failure regardless of CRM involvement in rectal cancer patients treated with surgery following preoperative chemoradiation. It would be taken account of our finding on adjuvant treatment for the patient with positive CRM.

ADVANCES IN KNOWLEDGE:

Investigation of the patterns of failure in patients with CRM involvement after preoperative chemoradiation followed by surgery can be conducive to selecting the appropriate approach to additional treatment for them.

Preoperative Tattooing Using Indocyanine Green in Laparoscopic Colorectal Surgery

Purpose

The aim of the present study was to evaluate the usefulness of indocyanine green (ICG) as a preoperative marking dye for laparoscopic colorectal surgery.

Methods

Between March 2013 and March 2015, 174 patients underwent preoperative colonoscopic tattooing using 1.0 to 1.5 mL of ICG and saline solution before laparoscopic colorectal surgery. Patients’ medical records and operation videos were retrospectively assessed to evaluate the visibility, duration, and adverse effects of tattooing.

Results

The mean age of the patients was 65 years (range, 34–82 years), and 63.2% of the patients were male. The median interval between tattooing and operation was 1.0 day (range, 0–14 days). Tattoos placed within 2 days of surgery were visualized intraoperatively more frequently than those placed at an earlier date (95% vs. 40%, respectively, P < 0.001). For tattoos placed within 2 days before surgery, the visualization rates by tattoo site were 98.6% (134 of 136) from the ascending colon to the sigmoid colon. The visualization rates at the rectosigmoid colon and rectum were 84% (21 of 25) and 81.3% (13 of 16), respectively (P < 0.001). No complications related to preoperative ICG tattooing occurred.

Conclusion

Endoscopic ICG tattooing is more useful for the preoperative localization of colonic lesions than it is for rectal lesions and should be performed within 2 days before laparoscopic surgery.

Kidney Transplantation Using Expanded-Criteria Deceased Donors: A Comparison With Ideal Deceased Donors and Non-Expanded-Criteria Deceased Donors

PURPOSE

The use of expanded-criteria deceased-donor (ECD) kidneys must be evaluated within the objective perspective of critical organ shortage and graft function and survival. In this study, we aimed to compare the clinical outcomes of ECD reliance with concurrent use of ideal-criteria deceased donors (IDDs) and non-ECDs in adult renal transplantation.

METHODS

Between February 2000 and December 2015, we analyzed 405 deceased-donor renal transplants, specifically 129 grafts (31.9%) from ECDs, 233 grafts (57.5%) from non-ECDs, and 43 grafts (10.6%) from IDDs. ECDs were classified according to the United Network for Organ Sharing guidelines, while an IDD was defined as a younger person (10-39 years of age) with no medical risk factors who died from a traumatic head injury. Donor and recipient risk factors were separately analyzed and correlated with recipient graft function, and survival was evaluated.

RESULTS

ECDs were older (56.8 ± 6.3 years); showed increased incidence of hypertension, diabetes, and cerebrovascular brain death; and had a higher pre-retrieval serum creatinine level than the other groups. ECD kidney recipients were also older (50.6 ± 9.8 years), had a shorter waiting time (P = .031), and demonstrated a low frequency of re-transplantation (P = .028). Long-term renal function followed longitudinally was lower in ECD kidney recipients until five years after transplantation, while the glomerular filtration rate (GFR) level at 7 and 10 years did not differ significantly among the groups (P = .074 and .262, respectively). There were no significant differences in terms of graft survival (P = .394) or patient survival (P = .737) among the groups.

CONCLUSIONS

Although the long-term renal function followed longitudinally was lower in ECD kidney recipients, the use of renal grafts from ECDs is an acceptable method to resolve the disparity of critical organ shortage. However, the classification of the high-risk group should be updated with consideration given to differences in regional characteristics.

Risk of recurrence after endoscopic resection of early colorectal cancer with positive margins

BACKGROUND AND STUDY AIM

Additional surgery is recommended if an endoscopically resected T1 colorectal cancer (CRC) specimen shows a positive resection margin. We aimed to investigate the significance of a positive resection margin in endoscopically resected T1 CRC.

PATIENTS AND METHODS

We enrolled 265 patients with T1 CRC who underwent endoscopic resection between January 2001 and December 2016. The inclusion criteria were: 1) complete resection by endoscopy, and 2) pathology of a positive margin. Among the 265 patients, 213 underwent additional surgery and 52 did not. In the additional surgery group, various clinicopathological factors were evaluated with respect to the presence or absence of residual tumor. The follow-up results were assessed in the group that did not undergo additional surgery.

RESULTS

In the 213 patients who underwent additional surgery, residual tumor was detected in 13 patients (6.1 %), and none of the clinicopathological factors was significantly associated with the presence of residual tumor. Among the 52 patients who did not undergo additional surgery, recurrence was detected in 4 (7.7 %), and all 4 underwent salvage surgery. Among these four patients, three had no risk factors for lymph node metastasis and recurrence was at the previous resection site; pathology was high grade dysplasia, rpT3N0M0, and rpT1N0M0, respectively.

CONCLUSIONS

A positive resection margin in endoscopically resected T1 CRC is related to a relatively low incidence of residual tumor (6.1 %). Although current guidelines recommend additional surgery for such cases, surveillance and timely salvage surgery could be another option in selected cases.

Feasibility of transanal total mesorectal excision in cases with challenging patient and tumor characteristics

Purpose

To assess the feasibility of transanal total mesorectal excision in difficult cases including obese patients or patients with bulky tumors or threatened mesorectal fascias.

Methods

We performed laparoscopy-assisted transanal total mesorectal excision in patients with biopsy-proven rectal adenocarcinoma located 3–12 cm from the anal verge as part of a prospective, single arm, pilot trial. The primary endpoint was resection quality and circumferential resection margin involvement. Secondary endpoints included the number of harvested lymph nodes and 30-day postoperative complications.

Results

A total of 12 patients (9 men and 3 women) were enrolled: one obese patient, 7 with large tumors and 8 with threatened mesorectal fascias (4 patients had multiple indications). Tumors were located a median of 5.5 cm from the anal verge, and all patients received preoperative chemoradiotherapy. Median operating time was 191 minutes, and there were no intraoperative complications. One patient needed conversion to open surgery for ureterocystostomy after en bloc resection. Complete or near-complete excision and negative circumferential resection margins were achieved in all cases. The median number of harvested lymph nodes was 15.5. There was no postoperative mortality and 3 cases of postoperative morbidity (1 postoperative ileus, 1 wound problem near the stoma site, and 1 anastomotic dehiscence).

Conclusion

This pilot study showed that transanal total mesorectal excision is also feasible in difficult laparoscopic cases such as in obese patients or those with bulky tumors or tumors threatening the mesorectal fascia. Additional larger studies are needed.

First report of carp oedema virus infection of koi (Cyprinus carpio haematopterus) in the Republic of Korea

Twenty-five koi (Cyprinus carpio haematopterus) bought from a wholesale fish market in Korea, showed lethargic behaviour and 100% mortality within 20 days. Carp oedema virus (CEV) was detected by PCR in all 25 koi. Results of detailed histopathological and clinical examinations of 17 koi indicated loss of body balance, severe infiltration of inflammatory cells into the inter-lamellar spaces of the gills and vacuolization and inclusion bodies in gill epithelial cells. Sequence analysis of PCR products of these koi showed up to 99% identity to the previously reported sequences, suggesting that the observed mass mortality resulted from koi sleepy disease (KSD) due to CEV infection. To the best of our knowledge, this study is the first report of KSD in the Republic of Korea. Partial sequences of 4a protein from the virus indicated that the present CEV detected in koi from Korea is more closely related to that from the UK and Poland than from Japan. The present findings indicate that the prevalence and spread of KSD must be closely monitored in both European and Asian countries to avoid potential economic losses to the global koi industry.

Endoscopic assessment of tumor regression after preoperative chemoradiotherapy as a prognostic marker in locally advanced rectal cancer

PURPOSE

This study was designed to evaluate tumor regression endoscopic criteria for predicting the post-chemoradiotherapy (CRT) prognosis of patients with locally advanced rectal cancer.

MATERIAL AND METHODS

A total of 425 patients with rectal cancer who received radical surgery after CRT were included in this study. All patients were divided into two groups according to post-CRT preoperative endoscopic findings: 1) good response (E-GR): scar, telangiectasia, or erythema; 2) minimal or no response (E-MR): nodules, ulcers, strictures, or remnant tumor. Cox proportional hazard models were used to analyze the effect of preoperative clinicopathological variables on disease-free survival (DFS) and overall survival (OS).

RESULTS

The independent prognostic factors for DFS were tumor location less than 5 cm from anal verge (hazard ratio [HR] 1.92, 95% confidence interval [CI] 1.27 to 2.88), pre-CRT carcinoembryonic antigen (CEA) > 5 ng/mL (HR 2.10, 95% CI 1.41 to 3.14), histologic high grade (HR 2.96, 95% CI 1.51 to 5.81), and E-GR (HR 0.26, 95% CI 0.08 to 0.83). The independent prognostic factors for OS were age over 65 years, tumor location, pre-CRT CEA, histologic grade, and E-GR (HR 0.13, 95% CI 0.02 to 0.99).

CONCLUSIONS

Post-CRT endoscopic findings were predictors of prognosis in patients with rectal cancer. If endoscopic findings are simultaneously used with certain preoperative prognostic factors, rectal cancer patients will potentially have more treatment options.