The impact of powered circular staplers on anastomotic leak in left-sided colorectal cancer surgeries.

BACKGROUND: Since the introduction of powered circular staplers in colorectal surgery, there has been growing interest in their impact on reducing complications, particularly anastomotic leakage. This study compared short-term postoperative outcomes between powered and manual circular staplers. METHODS: This retrospective study included colorectal cancer patients at the tertiary referral center from April to October 2023 who underwent anterior or low anterior resection (LAR) using a circular stapler. According to energy source, patients were divided into powered and manual groups, which used two powered and four types of manual staplers, respectively. All open, laparoscopic, and robotic approaches were included. Propensity score matching (PSM) analysis was used to reduce selection bias. Postoperative complications within 30 days, especially for anastomosis-related complications, were compared between the groups. RESULTS: Among 511 patients, the powered group was 161 (32%). After PSM, 143 pairs of 286 patients were analyzed. The proportions of LAR were 53.8% and 51.0%, and initial diverting stoma rates were 23.1% and 22.4% for the Powered and Manual groups, respectively. Comprehensive complication rates were similar between the Powered group and the Manual group, without statistical significance (13.3% vs. 21.0%, P = 0.063). Anastomotic leakage was not different between the Powered and Manual groups (4.2% vs. 4.9%, P = 0.782). There was no significant difference in other complications, including anastomotic bleeding, ileus, surgical site infection, and intra-abdominal hematoma. CONCLUSIONS: The study implies that powered circular staplers may not significantly reduce postoperative complications, including anastomotic leakages, compared to manual staplers in colorectal surgery of high-volume centers.

ERRATUM: Correction of the Conflict of Interest. Difference in prognostic impact of lateral pelvic lymph node metastasis between pre- and post-neoadjuvant chemoradiotherapy in rectal cancer patients.

[This corrects the article on p. 205 in vol. 104, PMID: 37051159.].

New anti-mesenteric delta-shaped stapled anastomosis: Technical report with short-term postoperative outcomes in patients with Crohn's disease.

BACKGROUND: Medical treatment for Crohn's disease (CD) has continuously improved, which has led to a decrease in surgical recurrence rates. Despite these advancements, 25% of patients will undergo repeat intestinal surgery. Recurrence of CD commonly occurs on the mesentery side of the anastomosis site. AIM: To compare the new anti-mesenteric side-to-side delta-shaped stapled anastomosis (DSA) with the conventional stapled functional end-to-end anastomosis (CSA). METHODS: This retrospective study included CD patients who underwent ileo-ileal or ileo-colic anastomosis between January 2020 and December 2023. The DSA technique employed a stapler to maintain the concept of anti-mesentery side-to-side anastomosis by performing a 90° vertical closure of the open window compared with the CSA technique. At the corner where the open window is closed, the DSA avoids forming a pouch and creates an anastomosis resembling a delta shape within the intestinal lumen. We compared demographics, preoperative condition, operative findings, and operative outcomes for the two techniques. RESULTS: The study included 175 patients, including 92 in the DSA group and 83 in the CSA group. The two groups were similar in baseline characteristics, preoperative medical treatment, and operative findings except for the Montreal classification location. The 30-days postoperative complication rate was significantly lower in the DSA group compared with the CSA group (16.3% vs 32.5%, P = 0.009). Ileus incidence was significantly lower in the DSA group than in the CSA group (4.3% vs 14.5%, P = 0.033), and the hospital stay was shorter in the DSA group than in the CSA group (5.67 ± 1.53 days vs 7.39 ± 3.68 days, P = 0.001). CONCLUSION: The DSA technique was feasible and showed comparable postoperative outcomes with lower short-term complications compared with the CSA technique. Further studies on CD recurrence and long-term complications are warranted.

Oncologic outcomes and associated factors of colon cancer patients aged 70 years and older.

Purpose: The aim of this study was to examine the prognosis and associated risk factors, including adjuvant chemotherapy (CTx), in elderly patients with colon cancer. Methods: This retrospective study included patients who underwent radical resection for colon cancer between January 2010 and December 2014 at Asan Medical Center. The effects of stage, risk factors, and chemotherapy on overall survival (OS) and recurrence-free survival (RFS) were compared in patients aged ≥70 and <70 years. Results: Of 3,313 patients, 933 (28.1%) was aged ≥70 years. Of the 1,921 patients indicated for adjuvant CTx, 1,294 of 1,395 patients (92.8%) aged <70 years and 369 of 526 patients (70.2%) aged ≥70 years received adjuvant CTx. Old age (≥70 years) was independently associated with RFS in overall cohort. Among patients aged ≥70 years indicated for adjuvant CTx, the 5-year OS (81.6% vs. 50.4%, P<0.001) and RFS (82.9% vs. 67.4%, P=0.025) rates were significantly higher in those who did than did not receive adjuvant CTx. Additionally, adjuvant CTx was confirmed as independent risk factor of both OS and RFS in patients aged ≥70 years indicated for adjuvant CTx. Conclusion: Old age was associated with poor RFS and adjuvant CTx had benefits in OS as well as RFS in elderly patients eligible for adjuvant CTx.

Effects of Adjuvant Chemotherapy on Oncologic Outcomes in Patients With Stage â ¡A Rectal Cancer Above the Peritoneal Reflection Who Did Not Undergo Preoperative Chemoradiotherapy.

PURPOSE: This study aimed to evaluate the effects of adjuvant chemotherapy (AC) on oncologic outcomes for patients with stage IIA upper rectal cancer and to investigate whether AC is associated with improved survival outcomes. METHODS: This retrospective study comprised 432 patients with rectal cancer above the peritoneal reflection who had undergone curative resection without preoperative chemoradiotherapy between 2008 and 2016. This study cohort was divided according to whether AC was received (AC group) or not (no-AC group). Risk factors included obstruction, perforation, poorly-differentiated tumor, lympho-vascular invasion, perineural invasion, resection margin involvement, and < 12 lymph nodes harvested. RESULTS: Among the 432 patients, 279 (64.6%) had received AC. The AC group had significantly higher 5-year overall survival (OS) rates than those of the no-AC group (93.2% vs. 84.6%, P = .001). Among patients with ≥ 1 risk factors, the AC group (n = 123) had significantly higher rates of 5-year recurrence-free survival (RFS) (81.6% vs. 64.1%, P = .01) and 5-year OS (88.8% vs. 69.0%, P = .001) than those of the no-AC group (n = 59). No significant difference in survival outcomes was observed between the 2 groups in patients aged > 65 years. CONCLUSION: AC was significantly associated with better 5-year RFS and 5-year OS rates in patients with stage IIA rectal cancer above peritoneal reflection who did not receive preoperative chemoradiotherapy, especially in those with ≥ 1 risk factors.

Complete Obstruction, a Real Risk Factor: A Comprehensive Study on Obstruction in Stage IIA Colon Cancer With Propensity Score Matching Analysis.

MICROABSTRACT: This study evaluates the prognostic significance of obstructions in stage IIA colon cancer, distinguishing between partial and complete obstructions. It employs a retrospective review of 1914 patients with propensity score matching to analyze oncologic outcomes. Findings reveal complete obstruction as a significant risk factor for poorer outcomes, emphasizing the necessity for further research to refine treatment strategies, particularly regarding the efficacy of adjuvant chemotherapy across obstruction types. BACKGROUND: This study examined the prognostic impact of obstructions in stage IIA colon cancer. The analysis specifically differentiated partial and complete obstructions, analyzing their distinct influences of both on oncologic outcomes. MATERIALS AND METHODS: A retrospective review was conducted of stage IIA colon cancer cases with the presence of an obstruction. Patients were stratified by whether it was partial or complete based on the severity of obstruction. Propensity score matching was employed to control for confounders. RESULTS: Among 1914 consecutive patients diagnosed with stage IIA colon cancer, 758 patients (597 patients with partial obstruction, 161 patients with complete obstruction) exhibited obstruction, while 1156 patients had no obstruction. The median follow-up period was 126 months. Complete obstruction was associated with poorer disease-free survival (Hazard ratio (HR) = 1.785, P < .001) and overall survival (HR = 1.853, P = .001). This trend persisted after propensity score matching, patients with complete obstruction showing a worsened disease-free survival (HR = 1.666, P = .028) and overall survival (HR = 1.732, P = .041). Adjuvant chemotherapy showed improved outcomes overall, but its efficacy varied across obstruction types. CONCLUSION: Differentiating between complete and partial obstructions in stage IIA colon cancer is an important clinical distinction, as our findings suggest that complete obstruction is a significant risk factor for poorer oncologic outcomes. While adjuvant chemotherapy generally improves prognosis in stage IIA colon cancer, the correlation of obstruction type with its efficacy remains uncertain, necessitating further research to refine treatment strategies.

Influence of additional prophylactic oral antibiotics during mechanical bowel preparation on surgical site infection in patients receiving colorectal surgery.

BACKGROUND: Prophylactic antibiotics (PAs) are standard for preventing surgical site infections (SSIs) post-colorectal surgery. This study aims to compare the effect of additional empiric oral antibiotics (OAs) alongside routine PAs to identify SSI risk factors. METHODS: A retrospective observatory analysis was conducted from January 2019 to December 2022 at Asan Medical Center, Seoul, Korea. The cohort was divided into two groups: PA given 1 h before surgery and discontinued within 24 h, and OA administered empiric OAs during mechanical bowel preparation in addition to PA. RESULTS: From a total of 6736 patients, 3482 were in the PA group and 3254 in the OA group. SSI incidence showed no significant intergroup difference (p = 0.374) even after propensity score matching (p = 0.338). The multivariable analysis revealed male sex [odds ratio (OR): 2.153, 95% confidence interval (CI): 1.626-2.852, and p = 0.001], open surgery (OR: 3.335, 95% CI: 2.456-4.528, and p = 0.001), dirty wound (OR: 2.171, 95% CI: 1.256-3.754, and p = 0.006), and an operation time of more than 145 min (OR: 2.110, 95% CI: 1.324-3.365, and p = 0.002) as SSI risk factors. In rectal surgery subgroup, OA demonstrated a protective effect against SSI (OR: 0.613, 95% CI: 0.408-0.922, and p = 0.019) and in laparoscopic approach (OR: 0.626, 95% CI: 0.412-0.952, and p = 0.028). CONCLUSIONS: OA did not affect SSI incidence in colorectal surgeries. Male sex, open surgery, dirty wounds, and longer operation time were risk factors for SSI. However, for rectal and laparoscopic surgery, OA was a protective factor for SSI.

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.

Somatostatin receptor 2 (SSTR2) expression is associated with better clinical outcome and prognosis in rectal neuroendocrine tumors.

Somatostatin analogues have recently been used as therapeutic targets for metastatic or surgically unresectable gastroenteropancreatic (GEP) neuroendocrine tumors (NETs), and associated somatostatin receptor (SSTR) expression has been well demonstrated in most GEP NETs, with the exception of rectal NETs. SSTR2 immunohistochemical expressions were evaluated in 350 surgically or endoscopically resected rectal NETs and compared to clinicopathologic factors. SSTR2 expression was observed in 234 (66.9%) rectal NET cases and associated tumors with smaller size (p = 0.001), low pT classification (p = 0.030), low AJCC tumor stage (p = 0.012), and absence of chromogranin expression (p = 0.009). Patients with rectal NET and SSTR2 expression had significantly better overall survival than those without SSTR2 expression both by univariable (p = 0.006) and multivariable (p = 0.014) analyses. In summary, approximately two-thirds of rectal NETs expressed SSTR2. SSTR2 expression was significantly associated with favorable behavior and good overall survival in patients with rectal NETs. Furthermore, SSTR2 expression can be used as prognostic factors. When metastatic disease occurs, SSTR2 expression can be used a possible target for somatostatin analogues.

Risk factors for the failure of endoscopic balloon dilation to manage anastomotic stricture from colorectal surgery: retrospective cohort study.

BACKGROUND: An anastomotic stricture after colorectal surgery is principally managed by endoscopic balloon dilation (EBD). Although this intervention is effective, however, subsequent procedures or surgical interventions are often required. This study aimed to assess the long-term outcomes of EBD for anastomotic stricture arising from colorectal cancer surgery. MATERIALS AND METHODS: We analyzed 173 patients who received curative surgery for colorectal cancer at our hospital between January 2000 and December 2022 and had undergone EBD to manage anastomotic stricture. The medical records of these cases were retrospectively reviewed to assess the outcomes and risk factors for restenosis and permanent stoma. RESULTS: Of the 173 study patients, 41 (23.7%) presented with restenosis with a median time to recurrence of 49 [37-150] days. The restenosis group was significantly younger (55.6 years versus 60.8 years), with a more prominent rectal location (80.5% versus 57.6%), a higher incidence of hand-sewn anastomosis (24.4% versus 5.3%), and a higher percentage of neoadjuvant radiotherapy (34.1% versus 5.3%, P < 0.001). Multivariable analysis indicated neoadjuvant radiotherapy (adjusted HR 2.48; 95% CI 1.03-5.95) and cerebral vascular disease (adjusted HR 6.97; 95% CI 2.15-22.54) as independent prognostic factors for restenosis. Fourteen patients (8.1%) required a permanent stoma due to treatment failure. All cases needing a permanent stoma were male (14 patients, 100%, P = 0.007) and this group had a higher rate of neoadjuvant radiotherapy, adjuvant chemotherapy, and hand-sewn anastomosis. CONCLUSION: Patients receiving neoadjuvant radiotherapy are most prone to restenosis after an EBD intervention to manage an anastomotic stricture. Neoadjuvant radiotherapy is also a strong risk factor for requiring a permanent stomas due to treatment failure.

Do Laparoscopic Approaches Ensure Oncological Safety and Prognosis for Serosa-Exposed Colon Cancer? A Comparative Study against the Open Approach.

The adoption of laparoscopic surgery in the management of serosa-exposed colorectal cancer has raised concerns. This study aimed to investigate whether laparoscopic surgery is associated with an increased risk of postoperative recurrence in patients undergoing resection for serosa-exposed colon cancer. A retrospective analysis was conducted on a cohort of 315 patients who underwent curative resection for pathologically confirmed T4a colon cancer without distant metastases at the Asan Medical Center between 2006 and 2015. Patients were categorized according to the surgical approach method: laparoscopic surgery (MIS group) versus open surgery (Open group). Multivariate analysis was employed to identify risk factors associated with overall survival (OS) and disease-free survival (DFS). The MIS group included 148 patients and the Open group had 167 patients. Of the total cohort, 106 patients (33.7%) experienced recurrence during the follow-up period. Rates, patterns, and time to recurrence were not different between groups. The MIS group (55.8%) showed more peritoneal metastasis compared to the Open group (44.4%) among recurrence sites, but it was not significant (p = 0.85). There was no significant difference in the five-year OS (73.5% vs. 78.4% p = 0.374) or DFS (62.0% vs. 64.6%; p = 0.61) between the Open and MIS groups. Age and the pathologic N stage were independently associated with OS, and the pathologic N stage was the only associated risk factor for DFS. The laparoscopic approach for serosa-exposed colon cancer did not compromise the DFS and OS. This study provides evidence that laparoscopic surgery does not compromise oncologic outcomes of patients with T4a colon cancer although peritoneal seeding is the most common type of disease failure of serosa-exposed colon cancer.

Preoperative sequential short-course radiation therapy and FOLFOX chemotherapy versus long-course chemoradiotherapy for locally advanced rectal cancer: a multicenter, randomized controlled trial (SOLAR trial).

BACKGROUND: Preoperative (chemo)radiotherapy has been widely used as an effective treatment for locally advanced rectal cancer (LARC), leading to a significant reduction in pelvic recurrence rates. Because early administration of intensive chemotherapy for LARC has more advantages than adjuvant chemotherapy, total neoadjuvant therapy (TNT) has been introduced and evaluated to determine whether it can improve tumor response or treatment outcomes. This study aims to investigate whether short-course radiotherapy (SCRT) followed by intensive chemotherapy improves oncologic outcomes compared with traditional preoperative long-course chemoradiotherapy (CRT). METHODS: A multicenter randomized phase II trial involving 364 patients with LARC (cT3-4, cN+, or presence of extramural vascular invasion) will be conducted. Patients will be randomly assigned to the experimental or control arm at a ratio of 1:1. Participants in the experimental arm will receive SCRT (25 Gy in 5 fractions, daily) followed by four cycles of FOLFOX (oxaliplatin, 5-fluorouracil, and folinic acid) as a neoadjuvant treatment, and those in the control arm will receive conventional radiotherapy (45-50.4 Gy in 25-28 fractions, 5 times a week) concurrently with capecitabine or 5-fluorouracil. As a mandatory surgical procedure, total mesorectal excision will be performed 2-5 weeks from the last cycle of chemotherapy in the experimental arm and 6-8 weeks after the last day of radiotherapy in the control arm. The primary endpoint is 3-year disease-free survival, and the secondary endpoints are tumor response, overall survival, toxicities, quality of life, and cost-effectiveness. DISCUSSION: This is the first Korean randomized controlled study comparing SCRT-based TNT with traditional preoperative LC-CRT for LARC. The involvement of experienced colorectal surgeons ensures high-quality surgical resection. SCRT followed by FOLFOX chemotherapy is expected to improve disease-free survival compared with CRT, with potential advantages in tumor response, quality of life, and cost-effectiveness. TRIAL REGISTRATION: This trial is registered at Clinical Research Information under the identifier Service KCT0004874 on April 02, 2020, and at Clinicaltrial.gov under the identifier NCT05673772 on January 06, 2023.

Fluorescence-guided colorectal surgery: applications, clinical results, and protocols.

In recent years, the rise of minimally invasive surgery has driven the development of surgical devices. Indocyanine green (ICG) fluorescence imaging is receiving increased attention in colorectal surgery for improved intraoperative visualization and decision-making. ICG, approved by the U.S. Food and Drug Administration in 1959, rapidly binds to plasma proteins and is primarily intravascular. ICG absorption of near-infrared light (750-800 nm) and emission as fluorescence (830 nm) when bound to tissue proteins enhances deep tissue visualization. Applications include assessing anastomotic perfusion, identifying sentinel lymph nodes, and detecting colorectal cancer metastasis. However, standardized protocols and research on clinical outcomes remain limited. This study explores ICG's role, advantages, disadvantages, and potential clinical impact in colorectal surgery.

Short-term outcomes of da Vinci SP versus Xi for colon cancer surgery: a propensity-score matching analysis of multicenter cohorts.

Recent advancements in robotic systems have led to the introduction of the da Vinci SP system, which allows surgeons to perform colon cancer surgery through fewer ports. This study aimed to evaluate the perioperative outcomes of colon cancer surgeries conducted using the da Vinci SP and Xi systems. Patients who underwent robotic colon cancer surgeries between November 2020 and December 2022 at two tertiary referral centers were considered for inclusion. Following propensity-score matching, short-term outcomes between the two systems were retrospectively analyzed. Out of 189 patients included in the study, 106 from 53 propensity-score matched pairs were analyzed. Patients operated on with the SP system exhibited smaller incision lengths (5.0 cm vs. 9.4 cm, p < 0.001) experienced less pain at 8 h (3.0 vs. 3.5, p < 0.001) and at 24 h post-operation (2.9 vs. 3.3, p = 0.001) and had a shorter duration of hospital stay (5 days vs. 6 days, p = 0.002). The overall rate of postoperative complications was 10.4%, with no significant difference between the SP and Xi groups (7.5% vs. 13.2%). Robotic-assisted colon cancer surgery using the da Vinci SP system is feasible and demonstrates favorable short-term outcomes. Compared to the Xi system, the SP system offers advantages in terms of cosmesis, postoperative pain, and recovery duration for colon cancer patients.

Deciphering the DNA methylation landscape of colorectal cancer in a Korean cohort.

Aberrant DNA methylation plays a pivotal role in the onset and progression of colorectal cancer (CRC), a disease with high incidence and mortality rates in Korea. Several CRC-associated diagnostic and prognostic methylation markers have been identified; however, due to a lack of comprehensive clinical and methylome data, these markers have not been validated in the Korean population. Therefore, in this study, we aimed to obtain the CRC methylation profile using 172 tumors and 128 adjacent normal colon tissues of Korean patients with CRC. Based on the comparative methylome analysis, we found that hypermethylated positions in the tumor were predominantly concentrated in CpG islands and promoter regions, whereas hypomethylated positions were largely found in the open-sea region, notably distant from the CpG islands. In addition, we stratified patients by applying the CpG island methylator phenotype (CIMP) to the tumor methylome data. This stratification validated previous clinicopathological implications, as tumors with high CIMP signatures were significantly correlated with the proximal colon, higher prevalence of microsatellite instability status, and MLH1 promoter methylation. In conclusion, our extensive methylome analysis and the accompanying dataset offers valuable insights into the utilization of CRC-associated methylation markers in Korean patients, potentially improving CRC diagnosis and prognosis. Furthermore, this study serves as a solid foundation for further investigations into personalized and ethnicity-specific CRC treatments. [BMB Reports 2023; 56(10): 569-574].

Human Neuralized is a novel tumour suppressor targeting Wnt/ß-catenin signalling in colon cancer.

While there is growing evidence that many epigenetically silenced genes in cancer are tumour suppressor candidates, their significance in cancer biology remains unclear. Here, we identify human Neuralized (NEURL), which acts as a novel tumour suppressor targeting oncogenic Wnt/ß-catenin signalling in human cancers. The expression of NEURL is epigenetically regulated and markedly suppressed in human colorectal cancer. We, therefore, considered NEURL to be a bona fide tumour suppressor in colorectal cancer and demonstrate that this tumour suppressive function depends on NEURL-mediated oncogenic ß-catenin degradation. We find that NEURL acts as an E3 ubiquitin ligase, interacting directly with oncogenic ß-catenin, and reducing its cytoplasmic levels in a GSK3ß- and ß-TrCP-independent manner, indicating that NEURL-ß-catenin interactions can lead to a disruption of the canonical Wnt/ß-catenin pathway. This study suggests that NEURL is a therapeutic target against human cancers and that it acts by regulating oncogenic Wnt/ß-catenin signalling.

Clinical implication of tissue carcinoembryonic antigen expression in association with serum carcinoembryonic antigen in colorectal cancer.

This study aimed to evaluate the prognostic significance of carcinoembryonic antigen (CEA) expression in tumor tissues of patients with colorectal cancer (CRC). The cohort included 7,412 patients with CRC from January 2010 to December 2015. Survival outcomes were assessed based on tissue CEA (t-CEA) patterns and intensities. Three-year (76.7% versus 81.3%) and 5-year (71.7% versus 77.6%, p < 0.001) disease-free survival (DFS) rates were significantly (p < 0.001) poorer in patients with a diffuse-cytoplasmic pattern than an apicoluminal pattern. Three-year (79% versus 86.6%) and 5-year (74.6% versus 84.7%) DFS rates were also significantly (p < 0.001) poorer in patients with high than low t-CEA intensity. Three-year (84.6% versus 88.4%) and 5-year (77.3% versus 82.6%) overall survival (OS) rates were significantly (p < 0.001) poorer in patients with diffuse-cytoplasmic than apicoluminal pattern of CEA expression, and both 3-year (86.7% versus 91.2%) and 5-year (80.1% versus 87.7%) OS rates were significantly (p < 0.001) poorer in patients with high than low t-CEA intensity. Multivariate analyses showed that high-intensity t-CEA was independently associated with DFS (p = 0.02; hazard ratio [HR] = 1.233) and OS (p = 0.032; HR = 1.228). Therefore, high-intensity t-CEA is a significant prognostic factor in CRC, independent of serum CEA (s-CEA), and can complement s-CEA in predicting survival outcomes after CRC resection.

Difference in prognostic impact of lateral pelvic lymph node metastasis between pre- and post-neoadjuvant chemoradiotherapy in rectal cancer patients.

Purpose: The prognostic significance and treatment of lateral pelvic lymph node metastasis (mLPLN) in rectal cancer patients receiving neoadjuvant chemoradiotherapy (nCRT) are not well understood. In this study, we evaluated the impact of mLPLN identified in imaging modality on outcomes. Methods: Between January 2008 and December 2016, 1,535 patients who underwent radical resection following nCRT were identified. The association between mLPLN and disease-free survival (DFS), overall survival (OS), local recurrence-free survival (LRFS), and pelvic recurrence-free survival (PRFS) was analyzed, along with risk factors associated with OS and DFS. Results: Overall, 329 (21.4%) of the 1,535 patients experienced disease recurrence; 71 (4.6%) had local recurrence, 25 (1.6%) had pelvic recurrence, and 312 (20.3%) had distant recurrence. The pre- and post-nCRT mLPLN (-) groups had better DFS, LRFS, PRFS, and OS than the (+) groups. LPLN sampling (LPLNs) was implemented in 24.0% of the pre-nCRT mLPLN (+) group and in 28.8% of the post-nCRT mLPLN (+) group. There was no significant difference in OS and LRFS between LPLNs group and no LPLNs group in pre- and post-nCRT mLPLN (+) groups. Pre-nCRT mLPLN was associated with poor OS (hazard ratio [HR], 1.43; P = 0.009) and post-nCRT mLPLN was associated with poor DFS (HR, 1.49; P = 0.002). Conclusion: Pre- and post-nCRT mLPLN (+) have different prognostic effects. Post-nCRT mLPLN appears to be more important for disease control. However, pre-nCRT mLPLN should not be disregarded when devising a treatment strategy since it is an independent risk factor for OS.