Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines 2014 for treatment of colorectal cancer

Prognostic factors and long-term outcomes with endoscopic submucosal dissection for colorectal tumors in patients aged 75 years or older

Background

Studies regarding the long-term outcomes of endoscopic submucosal dissection (ESD) performed in older patients with colorectal tumors are limited. Therefore, in this study, we aimed to analyze the long-term outcomes of older patients with colorectal tumors who underwent ESD and identify prognostic factors.

Methods

The data of patients aged ≥ 75 years who underwent ESD for colorectal tumors (adenoma and Tis/T1 colorectal cancer) at a single center were retrospectively analyzed. Prognostic factors for overall survival were analyzed using the Kaplan-Meier method and the Cox proportional hazard model.

Results

Of the 156 patients included, 51 patients died during the follow-up period, among whom two deaths were due to colorectal cancer. The univariate analysis revealed that an age ≥83 years, Charlson Comorbidity Index ≥2, prognostic nutritional index <46, and neutrophil-to-lymphocyte ratio (NLR) ≥3 were associated with poor overall survival. The multivariate analysis identified Charlson Comorbidity Index ≥2 (hazard ratio: 2.26; 95% confidence interval (CI): 1.24-4.13; p = 0.0008) and NLR ≥3 (hazard ratio, 1.98; 95% CI: 1.02-3.81; p = 0.042) as independent prognostic factors.

Conclusions

CCI and NLR may be useful parameters for decision-making in older patients undergoing colorectal ESD.

Significance of preoperative mean corpuscular volume in patients with stage II/III colorectal cancer and anemia

BACKGROUND

Several studies have examined the relationship between mean corpuscular volume (MCV) and prognosis of patients with colorectal cancer (CRC); however, these findings have been inconsistent. This study aimed to investigate the association between the preoperative MCV and recurrence-free survival (RFS) in patients with CRC.

METHODS

We analyzed 1876 patients with stage II/III CRC who underwent R0 resection. The relationships between clinicopathological factors and RFS were investigated using univariate and multivariate analyses. The prognostic significance of the MCV was examined in various clinicopathological contexts. Anemia was defined as Hb < 13 g/dL in men and Hb < 12 g/dL in women.

RESULTS

The mean patient age was 69 ± 11 years. The 5-year RFS rate was 73.3%. Multivariate analysis showed that tumor location, histological grade, stage, serum carcinoembryonic antigen level, carbohydrate antigen 19-9, neutrophil/lymphocyte ratio, and MCV were significant independent risk factors for RFS. Hazard ratios for recurrence were 0.60 for MCV < 80 fL and 1.76 for MCV ≥ 100 fL, compared to MCV 80-100 fL (p < 0.033). The 5-year RFS rates were 83.4% and 58.9%, respectively. This trend was more pronounced in patients with anemia and was contradictory in those without anemia.

CONCLUSION

MCV < 80 fL and ≥ 100 fL can be an indicator of favorable and worse RFS, respectively, in patients with stage II/III CRC and anemia.

Short-term Outcomes of Robotic Lateral Pelvic Lymph Node Dissection for Lower Rectal Cancer

INTRODUCTION

Rectal cancer is among the main causes of cancer-related mortalities worldwide, necessitating more effective treatment strategies.　It is considered that lateral pelvic lymph node dissection (LPND) for rectal cancer patients can contribute to local tumor control and that robotic LPND (Rob-LPND) may be more suitable for LPND, due to technical advantages of precise manipulation in a narrow pelvic space.

METHODS

In this retrospective study, we evaluated the short-term outcomes of laparoscopic-LPND (Lap-LPND) versus Rob-LPND in patients undergoing radical surgery for rectal cancer.　Operative time, blood loss, urethral catheter reinsertion, duration of pelvic drainage tube placement, drainage volume, and postoperative hospital stay were compared between Lap-LPND and Rob-LPND.

RESULTS

Our findings revealed that Rob-LPND was associated with longer total operation time, but there was no significant difference in operation time between the two LPND techniques.　Urinary catheter re-insertion rates were lower in Rob-LPND; also, significant reductions in drainage tube duration, total drainage volume, and postoperative hospital stay were observed.

CONCLUSION

Rob-LPND may reduce postoperative total drainage volume and shorten postoperative hospital stays.　These improvement in short-term outcomes suggest potential clinical advantages of Rob-LPND.

Intestinal decompression and drainage in preventing post-endoscopic submucosal dissection electrocoagulation syndrome in colorectal ESD: a prospective study

Background and aims

This study explored the efficacy of a prophylactic intestinal decompression tube in reducing the incidence of post-endoscopic submucosal dissection electrocoagulation syndrome (PECS).

Methods

A total of 157 eligible patients with colorectal mucosal lesions scheduled for endoscopic submucosal dissection (ESD) were prospectively recruited; after drop out 11 patients, 146 patients were randomly assigned to an experimental group (group 1, n = 73) or control group (group 2, n = 73). Patients in the experimental group underwent placement of an intestinal decompression drainage tube after ESD, while the control group received no additional treatment after ESD. The primary outcome was the incidence of PECS. Secondary outcomes included the incidence of postoperative complications, time to removal of the intestinal decompression tube, the degree of abdominal pain as measured by the visual analog scale (VAS), and the participants' self-rated comfort level with the intestinal decompression tube.

Results

A total of 146 patients (n = 73 per group) were finally analyzed between July 2022 and February 2023. All tumors were successfully resected en bloc. A significant difference in the incidence of PECS was found between group 1 and group 2 (5.5% vs 16.4%; P = 0.034). Precisely, 61.6% of patients felt painless for intestinal decompression tube, and no severe or unbearable pain was reported.

Conclusions

The placement of intestinal decompression drainage tube could reduce the incidence of PECS after colorectal ESD, which might play a preventive role in the occurrence of PECS.

Cold snare endoscopic mucosal resection versus standard hot technique for large flat nonpedunculated colonic lesions: a randomized controlled trial

BACKGROUNDS

 Cold snare EMR (CS-EMR) in large flat nonpedunculated colonic lesions (LFNPCLs) is an alternative to the standard EMR procedure with a better safety profile, but scientific evidence on its efficacy is unavailable. This study aimed to compare the recurrence rate between the two techniques at 6 months. Secondary aims were comparison of the safety profile and procedure-related outcomes.

METHODS

 This was a noninferiority, multicenter, open-label, randomized controlled trial of consecutive large (≥ 20 mm) LFNPCLs without suspicious features of submucosal invasion.

RESULTS

 229 patients were randomized to receive CS-EMR (n = 115) or EMR (n = 114). The median lesion size was 25 mm and 74.6 % were adenomas. The trial was stopped early by clinical consensus according to a safety monitoring board. At first surveillance colonoscopy (n = 220) the recurrence rate was significantly greater in the CS-EMR group than in the EMR group: 33.0 % vs. 16.2 % (P = 0.004) and 34.7 % vs. 14.8 % (P = 0.001) in the intention-to-treat and per-protocol analyses, respectively. According to the subgroup analysis, the recurrence rate was significantly greater after CS-EMR for LFNPCLs ≥ 30 mm (43.1 % vs. 18.2 %). There was no difference in the rate of adverse events. The use of clips was more common in the EMR group (52.6 % vs. 27.8 %).

CONCLUSIONS

 The recurrence rate of LFNPCLs after CS-EMR was significantly greater than after the standard hot technique. A similar safety profile was found between groups.

The KRAS G12D mutation increases the risk of unresectable recurrence of resectable colorectal liver-only metastasis

PURPOSE

Unresectable recurrence is a critical predictor of outcomes for colorectal cancer patients. We attempted to identify the prognostic factors, especially for unresectable recurrence-free survival (URFS) as a new endpoint, in patients with resectable colorectal liver-only metastasis (CRLOM).

METHODS

We investigated patients with resectable CRLOM, who underwent an R0 resection for both CRC and CRLOM between January, 2014 and March, 2019 at a single institution. The exclusion criteria were patients who received neoadjuvant treatment, the absence of data for genetic analyses, and the presence of multiple cancers, synchronous CRC, or familial adenomatous polyposis. The prognostic factors were examined retrospectively using data on pre-hepatectomy factors, including primary tumor molecular profiling results.

RESULTS

We analyzed the data of 101 patients who underwent curative-intent surgery for CRLOM. Multivariate analysis revealed that KRAS G12D mutation-positivity (hazard ratio [HR]: 7.69; p < 0.01), RYR2 mutation-positivity (HR: 4.03; p < 0.01), and KRAS G12S mutation-positivity (HR: 3.96; p = 0.03), CA19-9 > 37 U/ml before hepatectomy (HR: 3.62; p < 0.01), and primary tumor pN2 stage (HR: 3.22; p = 0.03) were significant predictors of the URFS.

CONCLUSIONS

This is the first study to show that specific KRAS and RYR2 mutations were associated with the URFS.

Efficacy and safety of indocyanine green-fluorescence imaging guided liver resection: a single-arm prospective cohort study

PURPOSE

This study aimed to evaluate the efficacy of indocyanine green (ICG)-fluorescence imaging for the identification of hepatic boundaries during liver resection and its advantages in surgical outcomes over conventional methods.

METHODS

This prospective, exploratory, single-arm clinical trial included 47 patients with liver tumors who underwent liver resection using ICG-fluorescence imaging (ICG-LR) between 2019 and 2020. The primary outcome measure was the successful identification of hepatic boundaries during liver resection, from the perspective of both the hepatic surface and intrahepatic boundary, using ICG-fluorescence imaging. The secondary outcomes comprised surgical outcomes. Using propensity score matching (PSM), the surgical outcomes were subsequently compared between the ICG-LR group and patients who underwent conventional liver resection (C-LR, n = 100) between 2017 and 2018.

RESULTS

Hepatic boundaries were successfully identified in 28 patients (60%; 95% confidence interval, 45-72%), including 21 and 7 who underwent anatomical and non-anatomical liver resection, respectively. After PSM, 40 patients were included in each of the ICG-LR and C-LR groups. The surgical outcomes were similar between the groups. Subsequently, surgical outcomes were compared between the groups focusing on anatomical liver resection. After PSM, 21 patients were included in each group. The ICG-LR group had a lower rate of Clavien-Dindo grade ≥ IIIa complications (0% vs. 24%; P = 0.017), including ascites and bile leak, and a shorter hospital stay (12 vs. 14 days, P = 0.041) than the C-LR group did.

CONCLUSION

ICG-fluorescence imaging could be used to recognize hepatic boundaries during liver transection. Additionally, ICG-LR may be useful in preventing severe liver-associated complications.

TRIAL REGISTRATION NUMBER

This study is registered at the UMIN Clinical Trials Registry: UMIN0000180139 and Japan Registry of Clinical Trials: jRCT1051180070. The Registration Data Set is available at https://jrct.niph.go.jp/ .

Preoperative CT-Scan Angiography Reconstruction Before Right Colectomy with Complete Mesocolon Excision: A Systematic Review and Meta-analysis

BACKGROUND

Complete mesocolon excision (CME) and central vascular ligation for right colonic cancers have been developed to improve oncological outcomes. However, it has been linked with a higher risk of morbidity and technical difficulties in operating near major vessels. This study investigated the impact of preoperative surgical planning utilizing CT reconstruction on surgical outcomes in right colectomy with CME.

METHODS

This systematic review and meta-analysis followed PRISMA and AMSTAR 2 guidelines. The analysis included clinical trials and observational studies comparing outcomes after preoperative CT scan reconstruction (navigation group) vs. no preoperative CT reconstruction (control group).

RESULTS

Four eligible studies (published between 2013 and 2023) were included, comprising 420 patients (203 in the navigation group and 217 in the control group). Preoperative navigation was associated with significantly lower blood loss (SMD = - 77.50; 95% CI [- 126.77, - 28.22], p = 0.002), shorter operative time (SMD = - 24.44; 95% CI [- 33.33, - 15.55], p < 0.00001), and a higher number of harvested lymph nodes (SMD = 1.39; 95% CI [0.58, 2.20], p = 0.0007). There was no statistically significant difference between the two groups in terms of overall morbidity (OR = 0.82; 95% CI [0.28, 2.40], p = 0.71), intraoperative complications (OR = 1.39; 95% CI [0.37, 5.26], p = 0.63), anastomotic leak (OR = 1.10; 95% CI [0.16, 7.63], p = 0.92), or hospital stay (SMD = - 0.06; 95% CI [- 0.48, 0.37], p = 0.80).

CONCLUSION

Preoperative navigation using CT reconstruction could help better delineate the complex vascular anatomy of the right colon. It may reduce operative time and increase the yield of harvested lymph nodes.

Short-term outcomes of vessel-oriented D2 and D3 lymph node dissection for sigmoid colon cancer

BACKGROUND

Level of lymph nodes dissection (LND) and inferior mesenteric artery (IMA) ligation is still matter of debate of radical resection of colorectal cancer. This study aims to compare the short-term outcome of three different surgical techniques to treat sigmoid cancer: low ligation (LL) of the IMA with D3-LND, low IMA ligation with D2-LND, and high ligation (HL) of the IMA with D3-LND.

METHODS

Patients affected by sigmoid colon cancer, who underwent radical resection with three different techniques (LL and D3-LND Group A, HL and D3-LND Group B, and LL with D2 LND- Group C), were included. Operative time (min), blood loss (ml), early postoperative complications, and number of harvested lymph nodes were compared.

RESULTS

Thirty patients per group were enrolled. The median operation time was shorter in group C (130 min, interquartile range [IQR] 120-140), compared with the 245 min (IQR 193.8-295.5) of group A and 257 min (IQR 183-345) of group B, p < 0.005. No significant differences between A and B group were observed in the median intraoperative blood loss, while group C had higher intraoperative blood loss (200 ml, IQR 200-260, p = 0.002). Anastomotic leak occurred in three patients belonging to group B. A reduced number of harvested lymph nodes was registered in Group C (14 lymph nodes, IQR 10-17), p < 0.005.

CONCLUSIONS

Both high and low tie ligation with D3-LND for sigmoid cancer can be considered safe and feasible with low rate of postoperative complications, allowing a higher number of harvested lymph nodes compared to low tie ligation with D2 lymphadenectomy.

Allele frequency of genetic variations related to the UGT1A1 gene-drug pair in a group of Iranian population

Objectives

The efficacy and safety of drug treatments vary widely due to genetic variations. Pharmacogenomics investigates the impact of genetic variations on patient drug response. This research investigates the frequency of UGT1A1 genetic variations in the Iranian population, comparing them with global data to provide insights into the pharmacogenomic approach in the Iranian population.

Methods

The study was conducted using the data of the Bushehr Elderly Health (BEH) program, a population-based cohort study of the elderly population aged ≥ 60 years. Genotyping of three UGT1A1 variant alleles (UGT1A1*6, UGT1A1*27, and UGT1A1*80) was performed on a group of 2730 elderly Iranian participants with the Infinium Global Screening Array.

Results

The genotyping analysis revealed significant differences compared to major global populations that were addressed in the gnomAD database. UGT1A1*80 was found at a high frequency (32.34%), and followed by UGT1A1*6 (0.76%) and UGT1A1*27 (0.018) at a low frequency in the Iranian group.

Conclusions

The UGT1A1*80 was the more prevalent allele between investigated alleles in the present study which can be considered as an important allele for pharmacogenomic testing.

Long-Term Outcomes of Additional Surgery After Endoscopic Resection Versus Primary Surgery for T1 Colorectal Cancer

INTRODUCTION

There is considerable concern about whether endoscopic resection (ER) before additional surgery (AS) for T1 colorectal cancer (CRC) has oncologically potential adverse effects. Therefore, the aim of this study was to compare the long-term outcomes, including overall survival (OS), of patients treated with AS after ER vs primary surgery (PS) for T1 CRC using a propensity score-matched analysis from a large observational study.

METHODS

This study investigated 6,105 patients with T1 CRC treated with either ER or surgical resection between 2009 and 2016 at 27 high-volume Japanese institutions, with those undergoing surgery alone included in the PS group and those undergoing AS after ER included in the AS group. Propensity score matching was used for long-term outcomes of mortality and recurrence analysis.

RESULTS

After propensity score matching, 1,219 of 2,438 patients were identified in each group. The 5-year OS rates in the AS and PS groups were 97.1% and 96.0%, respectively (hazard ratio: 0.72, 95% confidence interval: 0.49-1.08), indicating the noninferiority of the AS group. Moreover, 32 patients (2.6%) in the AS group and 24 (2.0%) in the PS group had recurrences, with no significant difference between the 2 groups (odds ratio: 1.34, 95% confidence interval: 0.76-2.40, P = 0.344).

DISCUSSION

ER before AS for T1 CRC had no adverse effect on patients' long-term outcomes, including the 5-year OS rate. ER is a viable first-line treatment option for endoscopically resectable T1 CRC.

Outcomes of noncurative endoscopic submucosal dissection for T1 colorectal cancer: Prospective, multicenter, cohort study in Japan

OBJECTIVES

This study investigated the incidence of lymph node metastasis and long-term outcomes in patients with T1 colorectal cancer where endoscopic submucosal dissection (ESD) resulted in noncurative treatment. It is focused on those with deep submucosal invasion, a factor considered a weak predictor of lymph node metastasis in the absence of other risk factors.

METHODS

This nationwide, multicenter, prospective study conducted a post-hoc analysis of 141 patients with T1 colorectal cancer ≥20 mm where ESD of the lesion resulted in noncurative outcomes, characterized by poor differentiation, deep submucosal invasion (≥1000 μm), lymphovascular invasion, high-grade tumor budding, or positive vertical margins. Clinicopathologic features and patient prognoses focusing on lesion sites and additional surgery requirements were evaluated. Lymph node metastasis incidence in the low-risk T1 group, identified by deep submucosal invasion as the sole high-risk histological feature, was assessed.

RESULTS

Lymph node metastasis occurred in 14% of patients undergoing additional surgery post-noncurative endoscopic submucosal dissection for T1 colorectal cancer. In the low-risk T1 group, in the absence of other risk factors, the frequency was 9.7%. The lymph node metastasis rates in patients with T1 colon and rectal cancers did not differ significantly (14% vs. 16%). Distant recurrence was observed in one patient (2.3%) in the ESD only group and in one (1.0%) in the additional surgery group, both of whom had had rectal cancer removed.

CONCLUSION

The risk of lymph node metastasis or distant occurrence was not negligible, even in the low-risk T1 group. The findings suggest the need for considering additional surgery, particularly for rectal lesions (Clinical Trial Registration: UMIN000010136).

Clinical outcome and long‑term prognosis after endoscopic submucosal dissection for colorectal tumors in patients aged 75 years or older: a retrospective observational study

PURPOSE

To determine the clinical outcomes of endoscopic submucosal dissection (ESD) for colorectal tumors in older patients and predictors of mortality.

METHODS

We retrospectively evaluated 207 lesions in 195 consecutive older patients aged ≥ 75 years who underwent ESD for colorectal tumors between January 2007 and December 2018. Outcomes of ESD were evaluated, and the prognosis was assessed in terms of both curability and the patient's baseline physical condition as determined by several indices. Cox regression analyses were performed to identify factors associated with reduced overall survival (OS).

RESULTS

Treatment outcomes included a median procedure time of 55 min, en bloc resection rate of 97%, histological en bloc resection rate of 92%, postoperative bleeding rate of 2.4%, and intraoperative perforation rate of 3.4%. Postoperative bleeding and intraoperative perforation could be treated conservatively. Delayed perforation occurred in one patient and required emergency surgery. Three-year OS was 99.4% and 5-year OS was 95.8%. Overall, three patients experienced recurrence (one local, two distant metastasis), and one patient died of primary cancer. Multivariate analysis identified the Charlson Comorbidity Index (CCI) score ≥ 3 as the only independent predictor of reduced OS (hazard ratio 4.26; 95% confidence interval 1.60-11.38; P = 0.004).

CONCLUSION

Our results suggest that colorectal ESD is safe and effective in older patients aged ≥ 75 years. There was a significant independent association of reduced OS with high CCI score, but not with curability by ESD. The CCI score should be considered when determining the indications for ESD in older patients.

Differences in Prognosis and Recurrence Patterns Between Ulcerative Colitis-Associated Colorectal Cancer and Sporadic Colorectal Cancer: A Matched-Pair Analysis

BACKGROUND

Clinicopathological differences exist between ulcerative colitis-associated colorectal cancer (UC-CRC) and sporadic colorectal cancer (S-CRC). However, differences in the prognosis remain controversial, and the reason for these differences remains unclear. We therefore assessed the differences between patients with UC-CRC and S-CRC.

PATIENTS AND METHODS

This was a matched-pair analysis of the clinicopathological characteristics and prognosis of patients with UC-CRC and S-CRC who underwent colorectal resection between January 2000 and December 2021 at two institutions. Patients were matched according to age, sex, date of surgery, tumor location, and Union for International Cancer Control (UICC) stage.

RESULTS

A total of 5992 patients underwent surgery for CRC at the two institutions, and 288 patients (48 with UC-CRC and 240 with S-CRC) were matched in this study. Patients with UC-CRC underwent more invasive surgery and had a longer operative time than those with S-CRC, but there was no marked difference in postoperative complications or perioperative mortality. Long-term outcomes showed a similar 5-year overall survival (OS) for UC-CRC and S-CRC (86.5% versus 88.8%, p = 0.742); however, in stage 3 patients, patients with UC-CRC had a poorer 5-year OS than those with S-CRC (51.4% versus 83.8%, p = 0.032). The first recurrence sites in stage 3 UC-CRC were peritoneal dissemination followed by the bones, while those in S-CRC were the liver and pulmonary system.

CONCLUSIONS

Despite no significant differences in surgical outcomes, patients with UC-CRC had a poorer prognosis than those with S-CRC at stage 3. The recurrence patterns in UC-CRC differed from those in S-CRC, suggesting a possible prognostic difference.

Prognostic impact of lateral sentinel lymph node biopsy using indocyanine green on oncological outcomes for clinical stage II/III lower rectal cancer without suspected lateral lymph node metastasis

PURPOSE

Sentinel lymph node biopsy (SLNB) can detect occult nodal metastasis. We have previously reported the safety and feasibility of indocyanine green (ICG)-guided SLNB for clinical stage II/III lower rectal cancer (RC). However, little is known about the influence of lateral pelvic SLNB using ICG on oncological outcomes. The present study aimed to evaluate the prognostic impact of lateral pelvic SLNB on oncological outcomes compared with prophylactic lateral lymph node dissection (LLND).

METHODS

Participants comprised consecutive patients with clinical stage II/III lower RC who underwent lateral pelvic SLNB or prophylactic LLND (Non-SLNB) between January 2010 and December 2020. The primary outcome measure was the 5-year cumulative incidence of local recurrence (LR). Secondary endpoints included cancer-specific survival (CSS), overall survival (OS), recurrence-free survival (RFS), local recurrence-free survival (LRFS), and distant recurrence-free survival (DRFS).

RESULTS

Among the 150 eligible patients included, 79 patients underwent lateral pelvic SLNB. Of those 79 patients, 4 patients who were SLNB-positive underwent LLND. LLND was omitted for the 75 patients who were SLNB-negative. Median follow-up was 61.0 months (range, 1.3-143.2 months). The overall recurrence rate was 30.7% (46 patients), with LR in 12.0% (18 patients). LR comprised lateral lymph node recurrence in 2.6% and central pelvic recurrence in 9.4%. No significant differences were seen between groups in terms of the frequency of LR or in CSS, OS, RFS, LRFS, or DRFS.

CONCLUSION

Oncological outcomes were not different between the SLNB and Non-SLNB groups. ICG-guided SLNB appears promising as a method for determining indications for LLND.

Treatment Decision for Locally Resected T1 Colorectal Carcinoma-Verification of the Japanese Guideline Criteria for Additional Surgery Based on Long-Term Clinical Outcomes

INTRODUCTION

To verify the value of the pathological criteria for additional treatment in locally resected pT1 colorectal carcinoma (CRC) which have been used in the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines since 2009.

METHODS

We enrolled 4,667 patients with pT1 CRC treated at 27 institutions between July 2009 and December 2016 (1,257 patients with local resection alone [group A], 1,512 patients with additional surgery after local resection [group B], and 1,898 patients with surgery alone [group C]). All 5 factors of the JSCCR guidelines (submucosal resection margin, tumor histologic grade, submucosal invasion depth, lymphovascular invasion, and tumor budding) for lymph node metastasis (LNM) had been diagnosed prospectively.

RESULTS

Any of the risk factors were present in 3,751 patients. The LNM incidence was 10.4% (95% confidence interval 9.4-11.5) in group B/C patients with risk factors, whereas it was 1.8% (95% confidence interval 0.4-5.3) in those without risk factors ( P < 0.01). In group A, the incidence of recurrence was 3.6% in patients with risk factors, but it was only 0.4% in patients without risk factors ( P < 0.01). The disease-free survival rate of group A patients classified as risk positive was significantly worse than those of groups B and C patients. However, the 5-year disease-free survival rate in group A patients with no risk was 99.6%.

DISCUSSION

Our large-scale real-world multicenter study demonstrated the validity of the JSCCR criteria for pT1 CRC after local resection, especially regarding favorable outcomes in patients with low risk of LNM.

Trends in patterns of treatment and survival of colorectal cancer patients using cancer registry data in Japan: 1995-2015

Recent advances in treating colorectal cancer (CRC) have increased the importance of multidisciplinary treatment. This study aimed to clarify trends in the treatment and survival of CRC using population-based cancer registry data in Japan. We analyzed the survival of CRC cases diagnosed from 1995 through 2015 from a population-based cancer registry of six prefectures. The year of diagnosis was classified into five periods, and the trends in the detailed categorization of treatments and survival were identified. We calculated net survival and excess hazard of death from cancer using data on 256,590 CRC patients. The use of laparoscopic surgery has been increasing since 2005 and accounts for the largest proportion of treatment types in the most recent period. Net survival of CRC patients diagnosed after 2005 remained high for laparoscopic surgery and endoscopic surgery (endoscopic mucosal resection or endoscopic submucosal dissection). There was an upward trend in treatment with chemotherapy in addition to open and laparoscopic surgery. Using the excess hazard ratio at the regional stage since 2005, there has been a significant improvement in survival in the younger age group and the rectum cancer group. By type of treatment, there was a tendency toward significant improvement in the open surgery + chemotherapy group. We clarified the trends in treating CRC and the associated trends in survival. Continuous survey based on population-based data helps monitor the impact of developments in treatment.

Prognostic significance of Ishii's sarcopenia screening score for patients undergoing curative surgery for obstructive colorectal cancer after intraluminal decompression

PURPOSE

Sarcopenia influences the short- and long-term outcomes of various medical conditions including malignancy. Ishii's screening test estimates the probability of sarcopenia based on a score calculated by three simple variables: age, grip strength, and calf circumference. We investigated the clinical significance of Ishii's score for patients with non-metastatic obstructive colorectal cancer (OCRC) who underwent curative surgery after intraluminal decompression.

METHODS

Ishii's score was calculated in 79 patients with OCRC. Muscle volume loss and decreased muscle quality were evaluated by computed tomography (CT) images as skeletal muscle index (SMI) and intramuscular adipose tissue content (IMAC), respectively.

RESULTS

There were 46 men and 33 women, with a median age of 70 years old. The cutoff value for Ishii's score was 155.1 and 15 patients were in the high-score group. The high-score group was significantly associated with worse time to recurrence (TTR) and overall survival (OS), and a high Ishii's score was an independent negative prognostic factor for TTR (hazard ratio = 2.93, P = 0.015). A high Ishii's score was significantly associated with a low SMI value but not with the IMAC value.

CONCLUSION

A high Ishii's score was independently associated with poorer TTR in patients with non-metastatic OCRC.

MRI-based Radiomics Model for Preoperative Prediction of Lateral Pelvic Lymph Node Metastasis in Locally Advanced Rectal Cancer

RATIONALE AND OBJECTIVES

To develop a magnetic resonance imaging (MRI)-based radiomics model for preoperative prediction of lateral pelvic lymph node (LPLN) metastasis (LPLNM) in patients with locally advanced rectal cancer MATERIALS AND METHODS: We retrospectively enrolled 263 patients with rectal cancer who underwent total mesorectal excision and LPLN dissection. Radiomics features from the primary lesion and LPLNs on baseline MRI images were utilized to construct a radiomics model, and their radiomics scores were combined to develop a radiomics scoring system. A clinical prediction model was developed using logistic regression. A hybrid predicting model was created through multivariable logistic regression analysis, integrating the radiomics score with significant clinical risk factors (baseline Carcinoembryonic Antigen (CEA), clinical circumferential resection margin status, and the short axis diameter of LPLN). This hybrid model was presented with a hybrid clinical-radiomics nomogram, and its calibration, discrimination, and clinical usefulness were assessed.

RESULTS

A total of 148 patients were included in the analysis and randomly divided into a training cohort (n = 104) and an independent internal testing cohort (n = 44). The hybrid clinical-radiomics model exhibited the highest discrimination, with an area under the receiver operating characteristic (AUC) of 0.843 [95% confidence interval (CI), 0.706-0.968] in the testing cohort compared to the clinical model [AUC (95% CI) = 0.772 (0.589-0.856)] and radiomics model [AUC (95% CI) = 0.731 (0.613-0.849)]. The hybrid prediction model also demonstrated good calibration, and decision curve analysis confirmed its clinical usefulness.

CONCLUSION

This study developed a hybrid MRI-based radiomics model that incorporates a combination of radiomics score and significant clinical risk factors. The proposed model holds promise for individualized preoperative prediction of LPLNM in patients with locally advanced rectal cancer.

DATA AVAILABILITY STATEMENT

The data presented in this study are available on request from the corresponding author.

Implementable assay for monitoring minimum residual disease after radical treatment for colorectal cancer

Considering the cost and invasiveness of monitoring postoperative minimal residual disease (MRD) of colorectal cancer (CRC) after adjuvant chemoradiotherapy (ACT), we developed a favorable approach based on methylated circulating tumor DNA to detect MRD after radical resection. Analyzing the public database, we identified the methylated promoter regions of the genes FGD5, GPC6, and MSC. Using digital polymerase chain reaction (dPCR), we termed the "amplicon of methylated sites using a specific enzyme" assay as "AMUSE." We examined 180 and 114 pre- and postoperative serial plasma samples from 28 recurrent and 19 recurrence-free pathological stage III CRC patients, respectively. The results showed 22 AMUSE-positive of 28 recurrent patients (sensitivity, 78.6%) and 17 AMUSE-negative of 19 recurrence-free patients (specificity, 89.5%). AMUSE predicted recurrence 208 days before conventional diagnosis using radiological imaging. Regarding ACT evaluation by the reactive response, 19 AMUSE-positive patients during their second or third blood samples showed a significantly poorer prognosis than the other patients (p = 9E-04). The AMUSE assay stratified four groups by the altered patterns of tumor burden postoperatively. Interestingly, only 34.8% of cases tested AMUSE-negative during ACT treatment, indicating eligibility for ACT. The AMUSE assay addresses the clinical need for accurate MRD monitoring with universal applicability, minimal invasiveness, and cost-effectiveness, thereby enabling the timely detection of recurrences. This assay can effectively evaluate the efficacy of ACT in patients with stage III CRC following curative resection. Our study strongly recommends reevaluating the clinical application of ACT using the AMUSE assay.

Recurrence of rectal cancer on the pelvic sidewall after lateral lymph node dissection

PURPOSE

Although lateral lymph node dissection has been performed to prevent lateral pelvic recurrence in locally advanced lower rectal cancer, the incidence of lateral pelvic recurrence after this procedure has not been investigated. Therefore, this study aimed to investigate the long-term outcomes of patients who underwent lateral pelvic lymph node dissection, with a particular focus on recurrence patterns.

METHODS

This was a retrospective study conducted at a single high-volume cancer center in Japan. A total of 493 consecutive patients with stage II-III rectal cancer who underwent lateral lymph node dissection between January 2005 and August 2022 were included. The primary outcome measures included patterns of recurrence, overall survival, and relapse-free survival. Patterns of recurrence were categorized as lateral or central pelvic.

RESULTS

Among patients who underwent lateral lymph node dissection, 18.1% had pathologically positive lateral lymph node metastasis. Lateral pelvic recurrence occurred in 5.5% of patients after surgery. Multivariate analysis identified age > 75 years, lateral lymph node metastasis, and adjuvant chemotherapy as independent risk factors for lateral pelvic recurrence. Evaluation of the recurrence rate by dissection area revealed approximately 1% of recurrences in each area after dissection.

CONCLUSION

We demonstrated the prognostic outcome and limitations of lateral lymph node dissection for patients with advanced lower rectal cancer, focusing on the incidence of recurrence in the lateral area after the dissection. Our study emphasizes the clinical importance of lateral lymph node dissection, which is an essential technique that surgeons should acquire.

Additional staining for lymphovascular invasion is associated with increased estimation of lymph node metastasis in patients with T1 colorectal cancer: Systematic review and meta-analysis

OBJECTIVES

Lymphovascular invasion (LVI) is a critical risk factor for lymph node metastasis (LNM), which requires additional surgery after endoscopic resection of T1 colorectal cancer (CRC). However, the impact of additional staining on estimating LNM is unclear. This systematic review aimed to evaluate the impact of additional staining on determining LNM in T1 CRC.

METHODS

We searched five electronic databases. Outcomes were diagnostic odds ratio (DOR), assessed using hierarchical summary receiver operating characteristic curves, and interobserver agreement among pathologists for positive LVI, assessed using Kappa coefficients (κ). We performed a subgroup analysis of studies that simultaneously included a multivariable analysis for other risk factors (deep submucosal invasion, poor differentiation, and tumor budding).

RESULTS

Among the 64 studies (18,097 patients) identified, hematoxylin-eosin (HE) and additional staining for LVI had pooled sensitivities of 0.45 (95% confidence interval [CI] 0.32-0.58) and 0.68 (95% CI 0.44-0.86), specificities of 0.88 (95% CI 0.78-0.94) and 0.76 (95% CI 0.62-0.86), and DORs of 6.26 (95% CI 3.73-10.53) and 6.47 (95% CI 3.40-12.32) for determining LNM, respectively. In multivariable analysis, the DOR of additional staining for LNM (DOR 5.95; 95% CI 2.87-12.33) was higher than that of HE staining (DOR 1.89; 95% CI 1.13-3.16) (P = 0.01). Pooled κ values were 0.37 (95% CI 0.22-0.52) and 0.62 (95% CI 0.04-0.99) for HE and additional staining for LVI, respectively.

CONCLUSION

Additional staining for LVI may increase the DOR for LNM and interobserver agreement for positive LVI among pathologists.

Intrabiliary metastasis of colorectal mucinous adenocarcinoma mimicking choledocholithiasis 18 years after the primary tumor

This case report presents a 62-year-old male who had previously undergone curative colectomy and neoadjuvant chemotherapy in 2005 for colorectal cancer. He presented with jaundice, which was initially attributed to choledocholithiasis. After cholecystectomy and repeat ERCPs, hyperbilirubinemia persisted. There was persistent dilation of the right posterior duct on imaging, concerning for biliary stricture, possibly due to cholangiocarcinoma or intraductal papillary neoplasm. During a right posterior hepatectomy, a peripheral liver lesion was found in association with the dilated bile duct. On frozen evaluation, the lesion was found to be invasive adenocarcinoma. The final pathology was compatible with a metastatic mucinous adenocarcinoma of colonic origin. A repeat colonoscopy was done with no recurrence or new lesion in the colon. This case underscores the challenges associated with diagnosing biliary issues and assessing liver lesions in patients with a remote history of cancer. It raises the question of when and whether, after primary cancer treatment, it becomes safe to explore alternative diagnoses without immediately suspecting metastasis. Another significant challenge arises in ascertaining the most suitable therapeutic approaches for these patients. This is because these extremely late recurrences might be linked to an indolent, slow-growing type of tumor, but also have been linked to cancer stem cells, and as any recurrence, demands attention.

Endoscopic submucosal dissection for colorectal neoplasms: Risk factors for local recurrence and long-term surveillance

Objectives

Endoscopic submucosal dissection (ESD) is an effective procedure for the en bloc resection of colorectal neoplasms. However, risk factors for local recurrence after ESD have not been identified. This study aimed to evaluate such risk factors after ESD for colorectal neoplasms.

Methods

This retrospective study included 1344 patients with 1539 consecutive colorectal lesions who underwent ESD between September 2003 and December 2019. We investigated various factors associated with local recurrence in these patients. The main outcomes were the incidence of local recurrence and its relationship with clinicopathological factors during long-term surveillance.

Results

The en bloc resection rate was 98.6%, the R0 resection rate was 97.2%, and the histologically complete resection rate was 92.7%. Local recurrence was observed in 7/1344 (0.5%) patients and the median follow-up period was 72 months (range 4-195 months). The incidence of local recurrence was significantly higher in lesions ≥40 mm in diameter (hazard ratio [HR] 15.68 [1.88-130.5]; p = 0.011), piecemeal resection (HR 48.42 [10.7-218.7]; p < 0.001), non-R0 resection (HR 41.05 [9.025-186.7]; p < 0.001), histologically incomplete resection (HR 16.23 [3.627-72.63]; p<0.001), and severe fibrosis (F2; HR 9.523 [1.14-79.3]; p = 0.037).

Conclusions

Five risk factors for local recurrence after ESD were identified. Patients with such factors should undergo careful surveillance colonoscopy.

Sex Disparities in Rectal Cancer Surgery: An In-Depth Analysis of Surgical Approaches and Outcomes

Anatomical and physiological differences exist between sex, leading to variations in how diseases, such as rectal cancer, are prevalence and treatment outcomes of diseases including rectal cancer. In particular, in the case of rectal cancer, anatomical differences may be associated with surgical challenges, and these factors are believed to be important contributors to potential disparities in postoperative recovery, associated complications, and oncological outcomes between male and female patients. However, there is still ongoing debate regarding this matter. Significantly, the male pelvic anatomy is distinguished by its narrower dimensions, which can present surgical challenges and impede visual access during operative procedures, rendering it more complex than surgical interventions in the female pelvis. As a result, this anatomical difference leads to a greater occurrence of postoperative complications, such as anastomotic leakage. Moreover, the pelvis houses nerves that are vital for urinary and genital functions, underscoring the need to assess the potential risks of sexual and urinary dysfunction in rectal cancer surgery. These postoperative complications can significantly impact the quality of life; therefore, it is imperative to perform surgery with an understanding of the structural differences between sexes. Therefore, to address the limitations imposed by anatomical structures, new approaches such as robotic surgery, trans-anal total mesorectal excision, and intraoperative neuromonitoring are being introduced. Furthermore, it is essential to conduct research into fundamental mechanisms that may give rise to differences in surgical outcomes and oncological results between sexes. By comprehending the disparities between males and females, we can advance toward personalized treatments. Consequently, this review outlines variations in surgical approaches, complications, and treatments for rectal cancer in male and female patients.

The Risk of Metastatic Recurrence after Non-Curative Endoscopic Resection with Negative Deep Margins for Early Colorectal Cancer: Two-Center Retrospective Cohort Study

INTRODUCTION

Non-curative endoscopic resection of T1 colorectal cancer (CRC) carries a substantial risk of recurrence. However, previous studies have reported a significant proportion of cases in which the deep margin of endoscopic resection was positive for cancer due to the technical difficulties of colorectal endoscopic submucosal dissection (ESD). With the advancement of endoscopic technology and techniques resulting in the reduction of positive resection margins, it is important to reassess the long-term prognosis and major risk factors for recurrence in cases of negative deep margins.

METHODS

We conducted a retrospective cohort study of consecutive patients with T1 CRC who underwent endoscopic resection between January 2006 and December 2021 with negative deep margins. The histological findings of the resected specimens were analyzed to determine the risk factors associated with the primary outcomes of this study, including recurrence and cancer-related deaths.

RESULTS

The median age of the 190 patients was 70 years, of which 63% were male, and endoscopic treatment was performed in 64% by endoscopic mucosal resection and 36% by ESD. Eighty-two patients were in the curative resection (CR) group and 108 were in the non-curative resection (NCR) group, wherein the latter comprised 79 patients who underwent additional surgery (AS) and 29 patients who did not receive AS. Five-year recurrence-free survival rates were 98.4% (95% CI: 89.3-99.8) for CR, 98.3% (95% CI: 88.8-99.8) for NCR with AS, and 73.7% (95% CI: 46.5-88.5) for NCR without AS. Lymphatic invasion and budding grade 2/3 were the major risk factors for recurrence, with hazard ratios of 40.7 (p < 0.001) and 23.1 (p = 0.007), respectively. Of the patients in the NCR group without AS, the 5-year recurrence-free rate was 85.6% (95% CI: 52.5-96.3) if there were no major risk factors (i.e., no lymphatic invasion or budding grade 2/3) (n = 21), whereas the prognosis was poor in the presence of one or more of the major risk factors, with a median recurrence-free survival and disease-specific survival of 2.5 and 3.1 years, respectively (n = 8).

DISCUSSION

In endoscopically resected T1 CRC with negative deep margins, lymphatic invasion or budding grade 2/3 may indicate a higher risk of recurrence when followed up without AS.

Validation and update of a clinical score model to predict technical difficulty of colorectal endoscopic submucosal dissection: a multicenter prospective cohort study

BACKGROUND AND AIMS

The Zhongshan colorectal endoscopic submucosal dissection (CR-ESD) score model was proposed to grade the technical difficulty of CR-ESD. The objective of this study was to prospectively validate and update the score model.

METHODS

A multicenter prospective cohort analysis of CR-ESD was conducted. Individual data on patients, lesions, and outcomes of CR-ESD were used to validate the original model and further refine the difficulty of the prediction model. Data were randomly divided into discovery and internal validation cohorts. A multivariate Cox regression analysis was conducted on the discovery cohort to develop an updated risk-scoring system, which was then validated.

RESULTS

Five hundred forty-eight patients with 565 colorectal lesions treated by ESD from 4 hospitals were included. In the prospective validation cohort, the area under the receiver-operating characteristic (ROC) curve for the original model was .707. Six risk factors were identified and assigned point values: tumor size (2 points for 30-50 mm, 3 points for ≥50 mm), at least two-thirds circumference of the lesion (3 points), tumor location in the cecum (2 points) or flexure (2 points), laterally spreading tumor-nongranular lesions (1 point), preceding biopsy sampling (1 point), and NBI International Colorectal Endoscopic type 3 (3 points). The updated model had an area under the ROC curve of .738 in the discovery cohort and of .782 in the validation cohort. Cases were categorized into easy (score = 0-1), intermediate (score = 2-3), difficult (score = 4-6), and very difficult (score ≥7) groups. Satisfactory discrimination and calibration were observed.

CONCLUSIONS

The original model achieved an acceptable level of prediction in the prospective cohort. The updated model exhibited superior performance and can be used in place of the previous version. (Clinical trial registration number: ChiCTR2100047087.).

Expression Analysis of Early Metastatic Seeding of Colorectal Cancer

BACKGROUND

Distant metastasis is the leading cause of death in patients with colorectal cancer (CRC). Tumor dissemination for metastasis formation occurs in advanced cancers and also during early stages of tumorigenesis. Here, we investigated the genes involved in early metastatic seeding of CRC using gene expression analysis.

PATIENTS AND METHODS

We performed a cDNA microarray using specimens resected from stages I-II CRC with and without metachronous metastatic recurrence. For the candidate genes, we immunohistochemically validated protein expression using a tissue microarray of stages I-III CRC.

RESULTS

The expression of TROP2, VWCE, and BMP7 was upregulated in the recurrence group rather than in the non-recurrence group. Protein expression analysis revealed significant association of these genes with distant metastatic recurrence. The specimens with high expression of BMP7 showed worse recurrence-free survival (RFS; p = 0.02). Those with high expression of TROP2 and VWCE showed worse overall survival (OS) and RFS (TROP2: p = 0.01 and p = 0.03; VWCE: p < 0.05 and p < 0.001, respectively). In the multivariate analysis, high expression of VWCE and BMP7 was an independent predictor of recurrence [VWCE: hazard ratio (HR) 3.41, p < 0.001; BMP7: HR 2.93, p = 0.005]. In contrast, TROP2 was an independent prognostic factor for OS (HR 4.58, p = 0.03).

CONCLUSIONS

Gene expression analysis revealed that TROP2, VWCE, and BMP7 were involved in early metastatic seeding. The high expression of these genes may warrant careful surveillance or adjuvant therapy, even in stages I-II CRC cases.

Prognostic value of lymph node distribution after laparoscopic colectomy with Japanese D3 dissection

PURPOSE

Positive pathologic lymph nodes in colorectal cancer represent an important prognostic indicator. Whether lymph node distribution or the number of metastatic nodes is more strongly associated with survival prediction remains controversial.

METHODS

Among 3449 colorectal cancer surgeries performed at Nagasaki University Hospital and five affiliated institutions from April 2016 to March 2022, we investigated 604 patients who underwent laparoscopic radical resection and were diagnosed with pathological stage III cancer. Patients were divided into two groups according to whether they had central vessel metastasis (LND3 group, n=42) or not (LND1/2 group, n=562). After adjusting for background factors using propensity score matching, the LND3 group included 42 patients and the LND1/2 group included 40 patients. Patient background characteristics and prognosis were compared between these two groups.

RESULTS

Before matching, frequencies of right-side colon cancer (64.3% vs 38.1%, p=0.001), multivisceral resection (11.9% vs 4.4%, p=0.039), clinical N2 status (40.5% vs 22.6%, p=0.032), and pathological N2 (73.8% vs 22.6%, p<0.001) were all greater, and the number of lymph nodes retrieved was higher (24 vs 19, p=0.042) in the LND3 group. After matching, no differences in any clinical factors were evident between groups. Five-year RFS (44.8% vs 77.1%, p=0.004) and OS (43.1% vs 83.2%, p<0.001) were worse in the LND3 group. Adjuvant chemotherapy improved RFS (adjuvant chemotherapy (+) vs adjuvant chemotherapy (-): 62.1% vs 27.7%, p=0.047) in the LND3 group.

CONCLUSION

LND3-positive patients show poorer prognosis than LND1/2 patients and should be treated with an appropriate perioperative treatment strategy.

Development of a Diagnostic Artificial Intelligence Tool for Lateral Lymph Node Metastasis in Advanced Rectal Cancer

BACKGROUND

Metastatic lateral lymph node dissection can improve survival in patients with rectal adenocarcinoma, with or without chemoradiotherapy. However, the optimal imaging diagnostic criteria for lateral lymph node metastases remain undetermined.

OBJECTIVE

To develop a lateral lymph node metastasis diagnostic artificial intelligence tool using deep learning, for patients with rectal adenocarcinoma who underwent radical surgery and lateral lymph node dissection.

DESIGN

Retrospective study.

SETTINGS

Multicenter study.

PATIENTS

A total of 209 patients with rectal adenocarcinoma, who underwent radical surgery and lateral lymph node dissection at 15 participating hospitals, were enrolled in the study and allocated to training (n = 139), test (n = 17), or validation (n = 53) cohorts.

MAIN OUTCOME MEASURES

In the neoadjuvant treatment group, images taken before pretreatment were classified as baseline images and those taken after pretreatment as presurgery images. In the upfront surgery group, presurgery images were classified as both baseline and presurgery images. We constructed 2 types of artificial intelligence, using baseline and presurgery images, by inputting the patches from these images into ResNet-18, and we assessed their diagnostic accuracy.

RESULTS

Overall, 124 patients underwent surgery alone, 52 received neoadjuvant chemotherapy, and 33 received chemoradiotherapy. The number of resected lateral lymph nodes in the training, test, and validation cohorts was 2418, 279, and 850, respectively. The metastatic rates were 2.8%, 0.7%, and 3.7%, respectively. In the validation cohort, the precision-recall area under the curve was 0.870 and 0.963 for the baseline and presurgery images, respectively. Although both baseline and presurgery images provided good accuracy for diagnosing lateral lymph node metastases, the accuracy of presurgery images was better than that of baseline images.

LIMITATIONS

The number of cases is small.

CONCLUSIONS

An artificial intelligence tool is a promising tool for diagnosing lateral lymph node metastasis with high accuracy.

DESARROLLO DE UNA HERRAMIENTA DE INTELIGENCIA ARTIFICIAL PARA EL DIAGNSTICO DE METSTASIS EN GANGLIOS LINFTICOS LATERALES EN CNCER DE RECTO AVANZADO

ANTECEDENTES:Disección de nódulos linfáticos laterales metastásicos puede mejorar la supervivencia en pacientes con adenocarcinoma del recto, con o sin quimiorradioterapia. Sin embargo, aún no se han determinado los criterios óptimos de diagnóstico por imágenes de los nódulos linfáticos laterales metastásicos.OBJETIVO:Nuestro objetivo fue desarrollar una herramienta de inteligencia artificial para el diagnóstico de metástasis en nódulos linfáticos laterales mediante el aprendizaje profundo, para pacientes con adenocarcinoma del recto que se sometieron a cirugía radical y disección de nódulos linfáticos laterales.DISEÑO:Estudio retrospectivo.AJUSTES:Estudio multicéntrico.PACIENTES:Un total de 209 pacientes con adenocarcinoma del recto, que se sometieron a cirugía radical y disección de nódulos linfáticos laterales en 15 hospitales participantes, se inscribieron en el estudio y se asignaron a cohortes de entrenamiento (n = 139), prueba (n = 17) o validación (n = 53).PRINCIPALES MEDIDAS DE RESULTADO:En el grupo de tratamiento neoadyuvante, las imágenes tomadas antes del tratamiento se clasificaron como imágenes de referencia y las posteriores al tratamiento, como imágenes previas a la cirugía. En el grupo de cirugía inicial, las imágenes previas a la cirugía se clasificaron como imágenes de referencia y previas a la cirugía. Construimos dos tipos de inteligencia artificial, utilizando imágenes de referencia y previas a la cirugía, ingresando los parches de estas imágenes en ResNet-18. Evaluamos la precisión diagnóstica de los dos tipos de inteligencia artificial.RESULTADOS:En general, 124 pacientes se sometieron a cirugía solamente, 52 recibieron quimioterapia neoadyuvante y 33 recibieron quimiorradioterapia. El número de nódulos linfáticos laterales removidos en los cohortes de entrenamiento, prueba y validación fue de 2,418; 279 y 850, respectivamente. Las tasas metastásicas fueron 2.8%, 0.7%, y 3.7%, respectivamente. En el cohorte de validación, el área de recuperación de precisión bajo la curva fue de 0.870 y 0.963 para las imágenes de referencia y antes de la cirugía, respectivamente. Aunque tanto las imágenes previas a la cirugía como las iniciales proporcionaron una buena precisión para diagnosticar metástasis en los nódulos linfáticos laterales, la precisión de las imágenes previas a la cirugía fue mejor que la de las imágenes iniciales.LIMITACIONES:El número de casos es pequeño.CONCLUSIÓN:La inteligencia artificial es una herramienta prometedora para diagnosticar metástasis en los nódulos linfáticos laterales con alta precisión. (Traducción-Dr. Aurian Garcia Gonzalez ).

An artificial intelligence prediction model outperforms conventional guidelines in predicting lymph node metastasis of T1 colorectal cancer

Background

According to guidelines, a lot of patients with T1 colorectal cancers (CRCs) undergo additional surgery with lymph node dissection after being treated by endoscopic resection (ER) despite the low incidence of lymph node metastasis (LNM).

Aim

The aim of this study was to develop an artificial intelligence (AI) model to more effectively identify T1 CRCs at risk for LNM and reduce the rate of unnecessary additional surgery.

Methods

We retrospectively analyzed 651 patients with T1 CRCs. The patient cohort was randomly divided into a training set (546 patients) and a test set (105 patients) (ratio 5:1), and a classification and regression tree (CART) algorithm was trained on the training set to develop a predictive AI model for LNM. The model used 12 clinicopathological factors to predict positivity or negativity for LNM. To compare the performance of the AI model with the conventional guidelines, the test set was evaluated according to the Japanese Society for Cancer of the Colon and Rectum (JSCCR) and National Comprehensive Cancer Network (NCCN) guidelines. Finally, we tested the performance of the AI model using the test set and compared it with the JSCCR and NCCN guidelines.

Results

The AI model had better predictive performance (AUC=0.960) than the JSCCR (AUC=0.588) and NCCN guidelines (AUC=0.850). The specificity (85.8% vs. 17.5%, p<0.001), balanced accuracy (92.9% vs. 58.7%, p=0.001), and the positive predictive value (36.3% vs. 9.0%, p=0.001) of the AI model were significantly better than those of the JSCCR guidelines and reduced the percentage of the high-risk group for LNM from 83.8% (JSCCR) to 20.9%. The specificity of the AI model was higher than that of the NCCN guidelines (85.8% vs. 82.4%, p=0.557), but there was no significant difference between the two. The sensitivity of the NCCN guidelines was lower than that of our AI model (87.5% vs. 100%, p=0.301), and according to the NCCN guidelines, 1.2% of the 105 test set patients had missed diagnoses.

Conclusion

The AI model has better performance than conventional guidelines for predicting LNM in T1 CRCs and therefore could significantly reduce unnecessary additional surgery.

Risk factors for lateral pelvic lymph node metastasis in patients with lower rectal cancer: a systematic review and meta-analysis

Background and objective

Lateral pelvic lymph node (LPLN) metastasis is one of the prominent reasons for local recurrence (LR) in patients with rectal cancer (RC). The evaluation criteria of lateral lymph node dissection (LLND) for patients in eastern (mainly in Japan) and western countries have been controversial. The aim of this study was to analyse the risk factors for LPLN metastasis in order to guide surgical methods.

Methods

We searched relevant databases (Embase (Ovid), Medline (Ovid), PubMed, Cochrane Library, and Web of Science) for articles published between 1 January 2000 and 05 October 2022 to evaluate the risk factors for LPLN metastasis in patients with RC in this meta-analysis.

Results

A total of 24 articles with 5843 patients were included in this study. The overall results showed that female sex, age <60 years, pretherapeutic CEA level >5 ng/ml, clinical T4 stage (cT4), clinical M1 stage (cM1), distance of the tumour from the anal verge (AV) <50 mm, tumour centre located below the peritoneal reflection (Rb), short axis (SA) of LPLN ≥8 mm before nCRT, short axis (SA) of LPLN ≥5 mm after nCRT, border irregularity of LPLN, tumour size ≥50 mm, pathological T3-4 stage (pT3-4), pathological N2 stage (pN2), mesorectal lymph node metastasis (MLNM), lymphatic invasion (LI), venous invasion (VI), CRM (+) and poor differentiation were significant risk factors for LPLN metastasis (P <0.05).

Conclusion

This study summarized almost all potential risk factors of LPLN metastasis and expected to provide effective treatment strategies for patients with LRC. According to the risk factors of lateral lymph node metastasis, we can adopt different comprehensive treatment strategies. High-risk patients can perform lateral lymph node dissection to effectively reduce local recurrence; In low-risk patients, we can avoid overtreatment, reduce complications and trauma caused by lateral lymph node dissection, and maximize patient survival and quality of life.

Preoperative mechanical bowel preparation using conventional versus hyperosmolar polyethylene glycol-electrolyte lavage solution before laparoscopic resection for colorectal cancer (TLUMP test): a phase III, multicenter randomized controlled non-inferiority trial

BACKGROUND

A hyperosmolar ascorbic acid-enriched polyethylene glycol-electrolyte (ASC-PEG) lavage solution ensures excellent bowel preparation before colonoscopy; however, no study has demonstrated the efficacy of this lavage solution before surgery. This study aimed to establish the non-inferiority of ASC-PEG to the standard polyethylene glycol-electrolyte solution (PEG-ELS) in patients undergoing laparoscopic resection for colorectal cancer.

METHODS

This was a prospective, single-blind, multicenter, randomized, controlled, non-inferiority clinical trial. Overall, 188 patients scheduled for laparoscopic colorectal resection for single colorectal adenocarcinomas were randomly assigned to undergo preparation with different PEG solutions between August 2017 and April 2020 at four hospitals in Japan. Participants received ASC-PEG (Group A) or PEG-ELS (Group B) preoperatively. The primary endpoint was the ratio of successful bowel preparations using the modified Aronchick scale, defined as "excellent" or "good."

RESULTS

After exclusion, 86 and 87 patients in Groups A and B, respectively, completed the study, and their data were analyzed. ASC-PEG was not inferior to PEG-ELS in terms of effective bowel preparation prior to laparoscopic colorectal resection (0.93 vs. 0.92; 95% confidence interval, - 0.078 to 0.099, p = 0.007). The total volume of cleansing solution intake was lower in Group A than in Group B (1757.0 vs. 1970.1 mL). Two and three severe postoperative adverse events occurred in Groups A and B, respectively. Patient tolerance of the two solutions was almost equal.

CONCLUSIONS

ASC-PEG is effective for preoperative bowel preparation in patients undergoing laparoscopic resection for colorectal cancer and is non-inferior to PEG-ELS.

Early-stage sigmoid colon cancer resection followed by liver metastasis recurrence 1 year later and mesenteric recurrence more than 5 years later: a case report

BACKGROUND

Early-stage colorectal cancer (CRC) is often treated endoscopically, but additional surgical resection may be considered depending on pathological findings.

CASE PRESENTATION

A 73-year-old man was found to have early-stage sigmoid colon cancer by colonoscopy during a medical examination, and endoscopic mucosal resection (EMR) was performed. The lesion was a 7-mm-sized sessile polyp, and the pathological diagnosis was well-differentiated tubular adenocarcinoma, pT1 (submucosal invasion of 400 μm), with no lymphovascular invasion, low budding grade, and negative horizontal and vertical margins. Therefore, the patient was observed without postoperative treatment. One year later, a computed tomography (CT) scan showed multiple liver metastases. After five courses of preoperative chemotherapy with folinic acid, 5-fluorouracil and oxaliplatin (FOLFOX) and panitumumab, liver metastases were reduced. The patient underwent extended right hepatic lobectomy. The pathological finding was well-to-moderately differentiated tubular adenocarcinoma, and immunohistochemistry findings were consistent with liver metastases from sigmoid colon cancer. Postoperatively, the patient received five courses adjuvant chemotherapy with FOLFOX. Although the patient had been recurrence-free for 5 years after liver resection, a CT scan revealed a nodular lesion in the sigmoid mesentery. Positron emission tomography (PET) showed abnormal accumulation in the same lesion. Therefore, the mesenteric nodules diagnosed as lymph metastasis and recurrence of sigmoid colon cancer and performed laparoscopic sigmoid colon resection with lymph node dissection. The pathological findings showed that the recurrent lesion in the mesentery formed a nodular infiltrate with venous, lymphatic, and neural invasion, but lymph node structures were not found, and it was assumed to be metastasis or recurrence due to lymphovascular invasion. The pathologic specimen of the sigmoid colon had no neoplastic lesions, which are considered to be a local recurrence on the mucosal surface. After sigmoid colectomy, adjuvant chemotherapy with CapeOX was conducted, and the patient has been recurrence-free for 13 months at present.

CONCLUSION

Even early-stage CRCs that have no pathological indications for additional resection have risks of metastases and recurrences, and we may need to consider that the criteria for additional resection should not be limited to pathological findings alone.

Changing trends in gastric and colorectal cancer among surgical patients over 85 years old: A multicenter retrospective study, 2001-2021

BACKGROUND

Whether patients over 85 years old with gastrointestinal cancer should undergo surgery remains controversial. We aimed to describe the changing trends of characteristics to provide more information to decision makers, and strive to find appropriate surgical plan.

AIM

To describe the changing trends of characteristics to provide more information to decision makers, and strive to find appropriate surgical plan.

METHODS

A total of 218 gastric cancer (GC) patients and 563 colorectal cancer (CRC) patients who underwent surgery between 2001 and 2021 were enrolled in this retrospective analysis. Changes in clinicopathological features, surgical treatments, and survival status were analyzed longitudinally at 5-year intervals.

RESULTS

Only 14 GC patients underwent laparoscopic surgery where 219 CRC patients had this procedure. Cardia and esophagogastric junction cancer increased in GC patients, and the proportion of sigmoid colon cancer decreased in CRC patients. Pulmonary infection gradually became the most common postoperative complication, its incidence in period 4 reached 48.79%. However, the incidence of anastomotic leakage decreased from 26.79% to 9.38% (P < 0.01). Additionally, 30-d mortality significantly decreased from 32.14% to 9.01%. Increases were observed in 5-year overall survival (OS) in GC patients from period 1 to period 4 (18.18% vs 33.32%, respectively) and CRC patients (0 vs 36.32%, respectively). Disease-free survival (DFS) also increased in GC and CRC patients (7.14% vs 27.74% and 0 to 36.03%, respectively). The average survival time of GC patients following radial lymphadenectomy was higher than in patients that underwent limited lymphadenectomy (26 vs 22 mo, respectively), the same was seen in CRC patients (44 vs 33 mo, respectively). This advantage was particularly evident in patients with TNM I, but not in patients with TNM II/III period cancer.

CONCLUSION

The safety as well as effectiveness of surgery in ultra-elderly patients is increasing. Radical lymphadenectomy has advantages in patients with TNM I gastrointestinal cancer, but not TNM II/III.

Radiomic Features Are Predictive of Response in Rectal Cancer Undergoing Therapy

BACKGROUND

Rectal cancer is a major mortality cause in the United States (US), and its treatment is based on individual risk factors for recurrence in each patient. In patients with rectal cancer, accurate assessment of response to chemoradiotherapy has increased in importance as the variety of treatment options has grown. In this scenario, a controversial non-operative approach may be considered in some patients for whom complete tumor regression is believed to have occurred. The recommended treatment for locally advanced rectal cancer (LARC, T3-4 ± N+) is total mesorectal excision (TME) after neoadjuvant chemoradiotherapy (nCRT). Magnetic resonance imaging (MRI) has become a standard technique for local staging of rectal cancer (tumor, lymph node, and circumferential resection margin [CRM] staging), in both the US and Europe, and it is getting widely used for restaging purposes.

AIM

In our study, we aimed to use an MRI radiomic model to identify features linked to the different responses of chemoradiotherapy of rectal cancer before surgery, and whether these features are helpful to understand the effectiveness of the treatments.

METHODS

We retrospectively evaluated adult patients diagnosed with LARC who were subjected to at least 2 MRI examinations in 10-12 weeks at our hospital, before and after nCRT. The MRI acquisition protocol for the 2 exams included T2 sequence and apparent diffusion coefficient (ADC) map. The patients were divided into 2 groups according to the treatment response: complete or good responders (Group 1) and incomplete or poor responders (Group 2). MRI images were segmented, and quantitative features were extracted and compared between the two groups. Features that showed significant differences (SF) were then included in a LASSO regression method to build a radiomic-based predictive model.

RESULTS

We included 38 patients (26 males and 12 females), who are classified from T2 and T4 stages in the rectal cancer TNM. After the nCRT, the patients were divided into Group 1 (13 patients), complete or good responders, and Group 2 (25 patients), incomplete or poor responders. Analysis at baseline generated the following significant features for the Mann-Whitney test (out of a total of 107) for each sequence. Also, the analysis at the end of the follow-up yielded a high number of significant features for the Mann-Whitney test (out of a total of 107) for each image. Features selected by the LASSO regression method for each image analyzed; ROC curves relative to each model are represented.

CONCLUSION

We developed an MRI-based radiomic model that is able to differentiate and predict between responders and non-responders who went through nCRT for rectal cancer. This approach might identify early lesions with high surgical potential from lesions potentially resolving after medical treatment.

Development and validation of an online calculator to predict the pathological nature of colorectal tumors

BACKGROUND

No single endoscopic feature can reliably predict the pathological nature of colorectal tumors (CRTs).

AIM

To establish and validate a simple online calculator to predict the pathological nature of CRTs based on white-light endoscopy.

METHODS

This was a single-center study. During the identification stage, 530 consecutive patients with CRTs were enrolled from January 2015 to December 2021 as the derivation group. Logistic regression analysis was performed. A novel online calculator to predict the pathological nature of CRTs based on white-light images was established and verified internally. During the validation stage, two series of 110 images obtained using white-light endoscopy were distributed to 10 endoscopists [five highly experienced endoscopists and five less experienced endoscopists (LEEs)] for external validation before and after systematic training.

RESULTS

A total of 750 patients were included, with an average age of 63.6 ± 10.4 years. Early colorectal cancer (ECRC) was detected in 351 (46.8%) patients. Tumor size, left semicolon site, rectal site, acanthosis, depression and an uneven surface were independent risk factors for ECRC. The C-index of the ECRC calculator prediction model was 0.906 (P = 0.225, Hosmer–Lemeshow test). For the LEEs, significant improvement was made in the sensitivity, specificity and accuracy (57.6% vs 75.5%; 72.3% vs 82.4%; 64.2% vs 80.2%; P < 0.05), respectively, after training with the ECRC online calculator prediction model.

CONCLUSION

A novel online calculator including tumor size, location, acanthosis, depression, and uneven surface can accurately predict the pathological nature of ECRC.

Prognosis for Metastatic Colorectal Cancer Patients Achieving Complete Response After Systemic Chemotherapy

PURPOSE

Despite marked recent advances in chemotherapy, few reports have focused on the prognosis for patients with metastatic colorectal cancer (mCRC) achieving complete response (CR) after systemic chemotherapy. This study investigated the clinical course of mCRC patients achieving CR and evaluated the role of chemotherapy in CR.

METHODS

This retrospective study searched a prospectively maintained database at the author's institute to identify medical records for mCRC patients achieving CR after systematic chemotherapy from January 2007 to March 2020.

RESULTS

The search yielded 23 patients with confirmed CR to systemic chemotherapy. Median time to CR from treatment initiation was 6.8 months. Maintenance chemotherapy was continued for 22 of 23 patients. Median duration of maintenance chemotherapy was 11.1 months. Disease progression occurred for 17 (73.9%) patients at a median 48.1-month follow-up. Median progression-free survival was 26.6 months. Median overall survival was 91.7 months.

CONCLUSIONS

Patients with CR to chemotherapy had a high probability of disease progression, but a relatively long-term prognosis. Treatment strategies after achievement of CR should be based an understanding of the high potential that tumor cells will remain. Use of maintenance chemotherapy after achievement of CR is still unclear, and the recent data do not demonstrate a negative impact for continuing maintenance chemotherapy after CR.

Nomogram as a novel predictive tool for lymph node metastasis in T1 colorectal cancer treated with endoscopic resection: a nationwide, multicenter study

BACKGROUND AND AIMS

Since 2009, the Japanese Society for Cancer of the Colon and Rectum guidelines have recommended that tumor budding and submucosal invasion depth, in addition to lymphovascular invasion and tumor grade, be included as risk factors for lymph node metastasis (LNM) in patients with T1 colorectal cancer (CRC). In this study, a novel nomogram was developed and validated by usirge-scale, real-world data, including the Japanese Society for Cancer of the Colon and Rectum risk factors, to accurately evaluate the risk of LNM in T1 CRC.

METHODS

Data from 4673 patients with T1 CRC treated at 27 high-volume institutions between 2009 and 2016 were analyzed for LNM risk. To prepare a nonrandom split sample, the total cohort was divided into development and validation cohorts. Pathologic findings were extracted from the medical records of each participating institution. The discrimination ability was measured by using the concordance index, and the variability in each prediction was evaluated by using calibration curves.

RESULTS

Six independent risk factors for LNM, including submucosal invasion depth and tumor budding, were identified in the development cohort and entered into a nomogram. The concordance index was .784 for the clinical calculator in the development cohort and .790 in the validation cohort. The calibration curve approached the 45-degree diagonal in the validation cohort.

CONCLUSIONS

This is the first nomogram to include submucosal invasion depth and tumor budding for use in routine pathologic diagnosis based on data from a nationwide multi-institutional study. This nomogram, developed with real-world data, should improve decision-making for an appropriate treatment strategy for T1 CRC.

Underwater versus conventional EMR of large nonpedunculated colorectal lesions: a multicenter randomized controlled trial

BACKGROUND AND AIMS

Underwater EMR (UEMR) is an alternative procedure to conventional EMR (CEMR) to treat large, nonpedunculated colorectal lesions (LNPCLs). In this multicenter, randomized controlled clinical trial, we aimed to compare the efficacy and safety of UEMR versus CEMR on LNPCLs.

METHODS

We conducted a multicenter, randomized controlled clinical trial from February 2018 to February 2020 in 11 hospitals in Spain. A total of 298 patients (311 lesions) were randomized to the UEMR (n = 149) and CEMR (n = 162) groups. The main outcome was the lesion recurrence rate in at least 1 follow-up colonoscopy. Secondary outcomes included technical aspects, en bloc resection rate, R0 resection rates, and adverse events, among others.

RESULTS

There were no differences in the overall recurrence rate (9.5% UEMR vs 11.7% CEMR; absolute risk difference, -2.2%; 95% CI, -9.4 to 4.9). However, considering polyp sizes between 20 and 30 mm, the recurrence rate was lower for UEMR (3.4% UEMR vs 13.1% CEMR; absolute risk difference, -9.7%; 95% CI, -19.4 to 0). The R0 resection showed the same tendency, with significant differences favoring UEMR only for polyps between 20 and 30 mm. Overall, UEMR was faster and easier to perform than CEMR. Importantly, the techniques were equally safe.

CONCLUSIONS

UEMR is a valid alternative to CEMR for treating LNPCLs and could be considered the first option of treatment for lesions between 20 and 30 mm due to its higher en bloc and R0 resection rates. (Clinical trial registration number: NCT03567746.).

A DNA Methylation-based Epigenetic Signature for the Identification of Lymph Node Metastasis in T1 Colorectal Cancer

OBJECTIVE

This study aimed to unravel the lymph node metastasis (LNM)-related methylated DNA (mDNA) landscape and develop a mDNA signature to identify LNM in patients with T1 colorectal cancers (T1 CRC).

BACKGROUND

Considering the invasiveness of T1 CRC, current guidelines recommend endoscopic resection in patients with LNM-negative, and radical surgical resection only for high-risk LNM-positive patients. Unfortunately, the clinicopathological criteria for LNM risk stratification are imperfect, resulting in frequent misdiagnosis leading to unnecessary radical surgeries and postsurgical complications.

METHODS

We conducted genome-wide methylation profiling of 39 T1 CRC specimens to identify differentially methylated CpGs between LNM-positive and LNM-negative, and performed quantitative pyrosequencing analysis in 235 specimens from 3 independent patient cohorts, including 195 resected tissues (training cohort: n=128, validation cohort: n=67) and 40 pretreatment biopsies.

RESULTS

Using logistic regression analysis, we developed a 9-CpG signature to distinguish LNM-positive versus LNM-negative surgical specimens in the training cohort [area under the curve (AUC)=0.831, 95% confidence interval (CI)=0.755-0.892; P <0.0001], which was subsequently validated in additional surgical specimens (AUC=0.825; 95% CI=0.696-0.955; P =0.003) and pretreatment biopsies (AUC=0.836; 95% CI=0.640-1.000, P =0.0036). This diagnostic power was further improved by combining the signature with conventional clinicopathological features.

CONCLUSIONS

We established a novel epigenetic signature that can robustly identify LNM in surgical specimens and even pretreatment biopsies from patients with T1 CRC. Our signature has strong translational potential to improve the selection of high-risk patients who require radical surgery while sparing others from its complications and expense.

Prognostic significance of the Naples prognostic score in colorectal cancer patients undergoing curative resection: a propensity score matching analysis

BACKGROUND

Systemic inflammation is recognized as a hallmark of cancer that contributes to tumor development and progression in various malignancies. The Naples prognostic score (NPS) was established as a prognostic indicator for colorectal cancer (CRC). This study aims to examine the predictive value of the NPS for survival in CRC patients undergoing curative resection by a propensity score matching (PSM) analysis.

METHODS

A total of 533 CRC patients were enrolled in this study. Overall survival (OS) and disease-free survival (DFS) were compared between high-NPS and low-NPS groups. A time-dependent receiver operator characteristic (ROC) curve analysis was conducted to calculate the area under curve (AUC) of the NPS for OS. A multivariable Cox-proportional hazards regression analysis and PSM analysis were used to identify independent prognostic factors for OS and DFS. We compared the predictive value of the NPS to that of the neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), Onodera prognostic nutritional index (PNI), and controlling nutritional status score (CONUT) for OS.

RESULTS

High-NPS was significantly associated with worse OS and DFS. After PSM, 123 patients were included in each group. A multivariate analysis revealed that Age ≥ 68, ASA-PS ≥ 3, high NPS and undifferentiated tumor type were independently associated with OS, while high NPS, advanced T and N stage were independently associated with DFS after PSM. The NPS had the greatest AUC for OS in comparison to the NLR, LMR, PNI and CONUT.

CONCLUSIONS

We successfully validated the prognostic utility of the NPS for CRC patients after curative resection.

Predictive value of the Naples prognostic score on postoperative outcomes in patients with rectal cancer

PURPOSE

The Naples prognostic score (NPS) is a prognostic index based on the nutritional and inflammatory status. However, its utility in predicting postoperative complications (POCs) has not been examined in rectal cancer (RC). We evaluated the predictive value of the preoperative NPS for POCs in RC.

METHODS

We retrospectively analyzed 235 patients who underwent surgery for RC. The NPS was calculated based on serum albumin, serum total cholesterol, the neutrophil-to-lymphocyte ratio (NLR) and the lymphocyte-to-monocyte ratio (LMR). Severe POCs were defined as Clavien-Dindo classification grade ≥ III. The optimal cut-off value of the NPS was determined by a receiver operator characteristic (ROC) curve analysis. The NPS, NLR, LMR, platelet-to-lymphocyte ratio (PLR), C-reactive protein (CRP)-to-albumin ratio (CAR), Glasgow prognostic score (GPS), Onodera prognostic nutritional index (PNI) and controlling nutritional status score (CONUT) were investigated as inflammation-based and/or nutritional markers. Predictors of severe POCs were analyzed by logistic regression modeling.

RESULTS

Severe POCs were observed in 64 patients (27.2%). Male sex, operation time (> 257 min), blood loss (≥ 30 mL), albumin (< 4.0 g/dL), CRP (≥ 1.0 mg/dL), total cholesterol (≤ 180 mg/dL), NPS (≥ 2), LMR (≥ 3.48), PLR (≥ 103.6), CAR (> 0.025), GPS (≥ 1), PNI (< 48.1) and CONUT (≥ 2) were significantly associated with severe POCs. The multivariate analysis revealed that male sex, operation time (> 257 min), and a high NPS (≥ 2) were independent predictors of severe POCs. The ROC curve analysis revealed that the NPS had the greatest predictive value among the inflammation-based and/or nutritional markers.

CONCLUSION

The NPS is a valuable predictor of severe POCs in RC.

A new approach: Laparoscopic right hemicolectomy with priority access to small bowel mesentery

Background

For laparoscopic right hemicolectomy, the intermediate approach is commonly employed. However, this approach possesses several disadvantages. In this study, we compare priority access to the small bowel mesentery and the intermediate approach.

Methods

The clinical data of 196 patients admitted to the First Hospital of Chongqing Medical University for laparoscopic right hemicolectomy from January 2019 to January 2022 were retrospectively collected and divided into the small bowel mesenteric priority access and traditional intermediate access groups. The operative time, intraoperative bleeding, number of lymph node dissection, postoperative anal venting time, toleration of solid and liquid intake, and postoperative hospital stay and complications were compared between the two different approaches.

Results

In total, 81 cases of small bowel mesenteric priority access and 115 cases of intermediate approach for right hemi-colonic radical resection were compared. The operative time was 191.98 ± 46.05 and 209.48 ± 46.08 min in the small bowel mesenteric priority access and intermediate access groups, respectively; the difference was statistically significant. There were no significant differences in the intraoperative bleeding and lymph node clearance. However, the scatter plot analysis showed that severe intraoperative bleeding was relatively less frequent in the small mesenteric priority access group, compared with that in the intermediate approach group. Additionally, there were no statistically significant differences in the first exhaust and defecation times, hospital stay after operation, toleration of solid and liquid intake, and postoperative complication between the two groups.

Conclusion

In laparoscopic right hemicolectomy, the small bowel mesenteric priority approach can significantly shorten the operation time compared with the intermediate approach. It can reduce intraoperative bleeding and the operation is simple and safe to perform, making it suitable for less experienced surgeons. Therefore, the small bowel mesenteric priority approach has the potential to be a suitable alternative and deserves further clinical promotion and application.

Do postoperative infectious complications really affect long-term survival in colorectal cancer surgery? A multicenter retrospective cohort study

Aim

To investigate the impact of postoperative infection (PI), surgical site infection, and remote infection (RI), on long-term outcomes in patients with colorectal cancer (CRC).

Methods

The Japan Society for Surgical Infection conducted a multicenter retrospective cohort study involving 1817 curative stage I/II/III CRC patients from April 2013 to March 2015. Patients were divided into the No-PI group and the PI group. We examined the association between PI and oncological outcomes for cancer-specific survival (CSS) and overall survival (OS) using Cox proportional hazards models and propensity score matching.

Results

Two hundred and ninety-nine patients (16.5%) had PIs. The 5-year CSS and OS rates in the No-PI and PI groups were 92.8% and 87.6%, and 87.4% and 83.8%, respectively. Both the Cox proportional hazards models and propensity score matching demonstrated a significantly worse prognosis in the PI group than that in the No-PI group for CSS (hazard ratio: 1.60; 95% confidence interval: 1.10-2.34; P = .015 and P = .031, respectively) but not for OS. RI and the PI severity were not associated with oncological outcomes. The presence of PI abolished the survival benefit of adjuvant chemotherapy.

Conclusions

These results suggest that PI after curative CRC surgery is associated with impaired oncological outcomes. This survival disadvantage of PI was primarily derived from surgical site infection, not RI, and PI induced lower efficacy of adjuvant chemotherapy. Strategies to prevent PI and implement appropriate postoperative treatment may improve the quality of care and oncological outcomes in patients undergoing curative CRC surgery.

Can patients with good tumor regression grading after neoadjuvant chemoradiotherapy be exempted from lateral lymph node dissection?

OBJECTIVE

To investigate whether lateral lymph node (LLN) dissection (LLND) can be exempted in patients with good tumor regression grading (TRG) after neoadjuvant chemoradiotherapy (nCRT)?

METHODS

A retrospective study was conducted on consecutive patients with advanced rectal cancer who underwent nCRT and total mesorectal resection plus selective LLND at our institution. The primary outcomes are the relationship between LLN metastasis (LLNM) and magnetic resonance imaging TRG (mrTRG) and the relationship between LLNM and pathological TRG (pTRG).

RESULTS

A total of 91 patients were included, of which 24 patients (26.4%) had LLNM, 67 patients (73.6%) had no LLNM. There were significant differences of the maximum short-axis of LLN before and after nCRT, short-axis reduction rate of the LLN with maximum short-axis, length diameter reduction rate of primary tumor, mrTRG, and pTRG between the two groups. Multivariate logistic regression showed that mrTRG (P = 0.026) and pTRG (P = 0.013) were independent predictors for LLNM. The combination used by mrTRG and the maximum short-axis of LLNs ≥ 8 mm before nCRT and the maximum short-axis of LLN ≥ 5 mm after nCRT achieved specificity of 0.970, positive predictive value (PPV) of 0.867, and negative predictive value (NPV) of 0.855. The same combination used by pTRG achieved the specificity of 0.970, PPV of 0.857 and NPV of 0.844.

CONCLUSION

The suspected positive LLNs tend to be sterilized by nCRT in patients who have a very good response to nCRT. It is rational to avoid LLND in patients whose primary tumor and LLNs both show good response to nCRT.

Left Perforated Colonic Tumor with Synchronous Locally Advanced Right Colonic Tumor

Colorectal cancer is one of the most common malignant neoplasms worldwide. Overall mortality is 33%. Synchronous colorectal cancer refers to more than one malignant tumor detected in different segments of the colon, simultaneously or within 6 months of initial diagnosis. The development of colorectal cancer is a multistep process that originates with a genetic mutation leading to a malignant phenotype and generating a growth advantage. Colorectal cancer presents up to 16% of hypermutations, of which 75% are characterized by microsatellite instability which in turn leads to poorer cell differentiation. Patients with synchronous tumors appear to have a higher proportion of microsatellite instability than patients with single tumors. The clinical case of a 35-year-old man with a perforated left colon tumor and a locally advanced synchronous tumor of the right colon and signs of acute abdomen is presented. The treatment should be based on the location of the synchronous tumors, stage at the time of approach, and the patient's condition. However, when faced with a complication secondary to colonic cancer, adhering to the principles of oncological surgery can be overcome by the nature of the emergency.

Risk of recurrence after endoscopic resection of nonpedunculated T1 colorectal cancer

BACKGROUND

The long-term outcome after local excision of T1 colorectal cancer (CRC) remains unknown. The aim of this study was to examine clinical and histopathological risk factors for recurrence in patients with T1 CRC undergoing endoscopic resection.

METHODS

This was a retrospective registry-based population study on prospectively collected data of all patients with nonpedunculated T1 CRC undergoing only local excision (no salvage surgery) in Sweden between 2009 and 2018. Potential risk factors for recurrence, including age, sex, tumor location, resection margins, lymphovascular, perineural, and submucosal invasion, grade of differentiation, and mucinous subtype, were analyzed using univariate and multivariate cox regression.

RESULTS

Median follow-up time was 60 months, and 28 /602 patients (4.7 %) had a recurrence (13 local and 18 distant). Recurrence rate stratified by submucosal invasion was: Sm1 3.5 % (14 /397), Sm2 6.0 % (8 /133), and Sm3 8.3 % (6 /72), with no significant differences. Resection margins, lymphovascular and perineural invasion, grade of differentiation, mucinous subtype, and age were not significant risk factors for recurrence. In contrast, rectal location was found to be a significant risk factor for tumor recurrence in multivariate analysis (hazard ratio 3.08, P = 0.006). The 3- and 5-year disease-free survival was 96.2 % and 91.1 %, respectively, in T1 CRC patients undergoing endoscopic resection.

CONCLUSION

Tumor recurrence was rare (4.7 %) in this large population-based study on recurrence after local excision of nonpedunculated T1 CRC. Rectal location was an independent risk factor for recurrence, suggesting the need for strict surveillance after endoscopic resection of early rectal cancer.