Intracorporeal versus extracorporeal anastomosis in minimally invasive right hemicolectomy: systematic review and meta-analysis of randomized controlled trials.

Purpose: Compared with extracorporeal anastomosis (ECA), intracorporeal anastomosis (ICA) is expected to provide some benefits, including a shorter operation time and less intraoperative bleeding. Nevertheless, the benefits of ICA have mainly been evaluated in nonrandomized studies. Owing to the recent update of randomized controlled trials (RCTs) for minimally invasive surgery (MIS) of right hemicolectomy (RHC), the need to measure the actual effect by synthesizing the outcomes of these studies has emerged. Methods: We performed a comprehensive search of the PubMed, Embase, and Cochrane databases (from inception to January 30, 2023) for studies that applied ICA and ECA for RHC with MIS. We included 7 RCTs. The operation time, intraoperative blood loss, conversion rate, length of incision, and postoperative outcomes such as ileus, anastomosis leakage, length of hospitalization, and postoperative pain were compared between ICA and ECA. Results: A total of 740 patients were included in the study. Among them, 377 and 373 underwent ICA and ECA, respectively. There were significant differences in age (P = 0.003) and incision type (P < 0.001) between ICA and ECA. ICA was associated with a significantly longer operation time (P = 0.033). Although the postoperative pain associated with ICA was significantly lower than that associated with ECA on postoperative day 2 (POD 2) (P = 0.003), it was not different on POD 3 between the groups. Other perioperative outcomes were similar between the 2 groups. Conclusion: In this meta-analysis, ICA did not significantly improve short-term outcomes compared to ECA; other advantages to overcome ICA's longer operation time are not clear.

Unveiling the profound advantages of total neoadjuvant therapy in rectal cancer: a trailblazing exploration.

The standard treatments for locally advanced rectal cancer typically involved neoadjuvant therapy with either short-course radiation or long-course chemoradiation, followed by radical surgery and adjuvant chemotherapy. While the advancement of surgical techniques and the adoption of multimodal therapy have greatly contributed to reducing local failure, there has been limited improvement in overall survival, primarily due to the stagnation in systemic failure. In response to this challenge, a new strategy known as total neoadjuvant therapy (TNT) has emerged, involving the administration of both full-dose chemotherapy and radiation before surgery. It has shown promise in reducing systemic failure, enhancing tumor regression, and improving treatment adherence, ushering in a new era in the standard treatment of locally advanced rectal cancer. This review aims to summarize the evolution of multimodal treatments for locally advanced rectal cancer, ultimately converging into the current TNT strategy, and provides an assessment of the benefits and limitations of TNT based on available evidence, serving as a foundation for selecting the best treatment option.

Nomogram for predicting the overall survival of underweight patients with colorectal cancer: a clinical study.

BACKGROUND: An underweight individual is defined as one whose Body Mass Index (BMI) is < 18.5 kg/m2. Currently, the prognosis in patients with colorectal cancer (CRC) who are also underweight is unclear. METHODS: Information on South Korean patients who underwent curative resection for CRC without distant metastasis was collected from health insurance registry data between January 2014 and December 2016. We compared the overall survival (OS) of underweight and non-underweight (BMI ≥ 18.5 kg/m2) patients after adjusting for confounders using propensity score matching. A nomogram to predict OS in the underweight group was constructed using the significant risk factors identified in multivariate analysis. The predictive and discriminative capabilities of the nomogram for predicting 3- and 5-year OS in the underweight group were validated and compared with those of the tumor, node, and metastasis (TNM) staging system in the training and validation sets. RESULTS: A total of 23,803 (93.6%) and 1,644 (6.4%) patients were assigned to the non-underweight and underweight groups, respectively. OS was significantly worse in the underweight group than in the non-underweight group for each pathological stage (non-underweight vs. underweight: stage I, 90.1% vs. 77.1%; stage IIA, 85.3% vs. 67.3%; stage IIB/C, 74.9% vs. 52.1%; and stage III, 73.2% vs. 59.4%, P < 0.001). The calibration plots demonstrated that the nomogram exhibited satisfactory consistency with the actual results. The concordance index (C-index) and area under the receiver operating characteristic curve (AUC) of the nomogram exhibited better discriminatory capability than those of the TNM staging system (C-index, nomogram versus TNM staging system: training set, 0.713 versus 0.564, P < 0.001; validation set, 0.691 versus 0.548, P < 0.001; AUC for 3- and 5- year OS, nomogram versus TNM staging system: training set, 0.748 and 0.741 versus 0.610 and 0.601; validation set, 0.715 and 0.753 versus 0.586 and 0.579, respectively). CONCLUSIONS: Underweight patients had worse OS than non-underweight patients for all stages of CRC. Our nomogram can guide prognostic predictions and the treatment plan for underweight patients with CRC.

Impact of neoadjuvant treatment on rectal gastrointestinal stromal tumors.

Although gastrointestinal stromal tumors (GISTs) are rare disease and rectal GISTs is only 5% of total GISTs, they have the worst prognosis. Due to narrow pelvis, tumor rupture or positive resection margin are common in the management of rectal GISTs. The impact of neoadjuvant treatment on the clinical outcomes of rectal gastrointestinal stromal tumors (GISTs) remains unclear. Thus, we conducted a retrospective study to investigate the impact of neoadjuvant imatinib on rectal GIST. The cohort comprised 33 patients; of them, 10 and 23 belonged to the neoadjuvant (i.e., those who underwent neoadjuvant imatinib treatment) and the control group (i.e., those who underwent surgery without prior imatinib treatment), respectively. Neoadjuvant group was associated with more common levator ani muscle displacement (P = 0.002), and showed significantly larger radiologic tumor size (P = 0.036) than the control group. The mean tumor size was significantly decreased after imatinib treatment (6.8 cm to 4.7cm, P = 0.006). There was no significant difference in resection margin involvement (P >0.999), and sphincter preservation rates (P = 0.627) between the two groups. No difference was observed with respect to morbidities, hospital stay, local recurrence and disease-free survival. Neoadjuvant imatinib treated group had similar propensity with control group after treatment. We thought reduced tumor sized could enhance resectability and provide more chance to preserve sphincter for rectal GIST patients. Considering large tumor size and higher rate of sphincter invasion in the neoadjuvant group, imatinib treatment could be helpful as a conversion strategy to make huge and low-lying rectal GIST operable and achieve better surgical outcomes.

Prognosis and Sensitivity of Adjuvant Chemotherapy in Mucinous Colorectal Adenocarcinoma without Distant Metastasis.

In colorectal cancer, whereas mucinous adenocarcinoma (MAC) has several poor clinical prognostic factors compared to adenocarcinoma (AC), the prognosis of MAC remains controversial. We evaluated the prognosis of MAC without distant metastasis and the effects of adjuvant chemotherapy using health insurance registry data managed by South Korea. Patients with colorectal cancer between January 2014 and December 2016 were included (AC, 22,050 [96.8%]; MAC, 729 [3.2%]). We observed no difference in overall survival (OS) between AC and MAC in stages I and II. However, MAC showed a worse OS than AC in stage III disease, especially in patients administered chemotherapy (p < 0.001). These findings persisted after propensity score matching of clinical characteristics between AC and MAC. In addition, transcriptome analysis of The Cancer Genome Atlas (TCGA) data showed increased chemoresistance-associated pathways in MAC compared to AC. In consensus molecular subtypes (CMS) classification, unlike in AC, CMSs 1, 3, and 4 comprised most of MAC and the proportions of CMSs 3 and 4 increased with stage progression. These results suggest clues to overcome resistance to chemotherapy and develop targeted treatments in MAC.

Predictive factors for conservative treatment failure of right colonic diverticulitis.

PURPOSE: Conservative treatment is the first-line therapy for acute colonic diverticulitis without severe complications, but treatment failure may increase hospitalization duration, medical costs, and morbidities. Usage of the modified Hinchey classification is insufficient to predict the outcome of conservative management. We aimed to investigate the clinical efficacy of the modified Hinchey classification and to evaluate predictive factors such as inflammatory markers for the failure of conservative management. METHODS: Patients diagnosed with right colonic diverticulitis undergoing conservative treatment at 3 hospitals between 2017 and 2019 were included. Patients were categorized into conservative treatment success (n = 494) or failure (n = 46) groups. Clinical characteristics and blood inflammatory markers were assessed. RESULTS: The conservative treatment failure group presented with more elderly patients (>50 years, P = 0.002), more recurrent episodes (P < 0.001), a higher lymphocyte count (P = 0.021), higher C-reactive protein (CRP) levels (P = 0.044), and higher modified Glasgow prognostic scores (P = 0.021). Multivariate analysis revealed that age of >50 years (odds ratio [OR], 2.54; 95% confidence interval [CI], 1.27-5.08; P = 0.008), recurrent episodes (OR, 4.78; 95% CI, 2.38-9.61; P < 0.001), and higher CRP levels (OR, 1.08; 95% CI, 1.03-1.12; P = 0.001) were predictive factors for conservative treatment failure, but not the modified Hinchey grade (P = 0.159). CONCLUSION: Age of >50 years, recurrent episodes, and CRP levels are potential predictors for conservative management failure of patients with right-sided colonic diverticulitis. Further studies are warranted to identify candidates requiring early surgical intervention.

Prognostic value of changes in serum carcinoembryonic antigen levels for preoperative chemoradiotherapy response in locally advanced rectal cancer.

BACKGROUND: Preoperative chemoradiotherapy (CRT) is a standard treatment modality for locally advanced rectal cancer. However, CRT alone cannot improve overall survival. Approximately 20% of patients with CRT-resistant tumors show disease progression. Therefore, predictive factors for treatment response are needed to identify patients who will benefit from CRT. We theorized that the prognosis may vary if patients are classified according to pre- to post-CRT changes in carcinoembryonic antigen (CEA) levels. AIM: To identify patients with locally advanced rectal cancer for preoperative chemoradiotherapy based on carcinoembryonic antigen levels. METHODS: We retrospectively included locally advanced rectal cancer patients who underwent preoperative CRT and curative resection between 2011 and 2017. Patients were assigned to groups A, B, and C based on pre- and post-CRT serum CEA levels: Both > 5; pre > 5 and post ≤ 5; and both ≤ 5 ng/mL, respectively. We compared the response to CRT based on changes in serum CEA levels. Receiver operating characteristic curve analysis was performed to determine optimal cutoff for neutrophil-lymphocyte ratio and platelet-lymphocyte ratio. Multivariate logistic regression analysis was used to evaluate the prognostic factors for pathologic complete response (pCR)/good response. RESULTS: The cohort comprised 145 patients; of them, 27, 43, and 65 belonged to groups A, B, and C, respectively, according to changes in serum CEA levels before and after CRT. Pre- (P < 0.001) and post-CRT (P < 0.001) CEA levels and the ratio of down-staging (P = 0.013) were higher in Groups B and C than in Group A. The ratio of pathologic tumor regression grade 0/1 significantly differed among the groups (P = 0.003). Group C had the highest number of patients showing pCR (P < 0.001). Most patients with pCR showed pre- and post-CRT CEA levels < 5 ng/mL (P < 0.001, P = 0.008). Pre- and post-CRT CEA levels were important risk factors for pCR (OR = 18.71; 95%CI: 4.62-129.51, P < 0.001) and good response (OR = 5.07; 95%CI: 1.92-14.83, P = 0.002), respectively. Pre-CRT neutrophil-lymphocyte ratio and post-CRT T ≥ 3 stage were also prognostic factors for pCR or good response. CONCLUSION: Pre- and post-CRT CEA levels, as well as change in CEA levels, were prognostic markers for treatment response to CRT and may facilitate treatment individualization for rectal cancer.

Differences in biological behaviors between young and elderly patients with colorectal cancer.

BACKGROUND: We investigated the differences in biological behaviors of sporadic colorectal cancer (CRC) between young and elderly patients. CRC is a common cancer, with a mean age at onset of > 65 years. However, recent reports indicate increasing rates in younger populations. The biological behaviors of sporadic CRC in elderly patients could differ from those in young patients. METHODS: Between September 2007 and August 2012, we selected 723 CRC patients from our institution. The patients were divided into Group Y (n = 127, aged ≤50 years) and Group O (n = 596, aged >50 years). The clinicopathologic and oncologic outcomes in the two groups were compared. RESULTS: Group Y tumors were characterized by higher incidences of mucin production (13.4% vs. 6.7%; P = 0.017), high microsatellite instability (MSI-H) (19.8% vs. 5.2%; P < 0.001), and N2 stage (32.3% vs. 22.1%; P = 0.020) than those in Group O. The recurrence rates were similar in both groups (14.9% vs. 17.3%; P = 0.665). The 5-year overall survival and disease-free survival did not differ. Multivariate analysis indicated that cellular differentiation and pathologic stage were significant prognostic factors for 5-year overall survival. CONCLUSION: Although age was not a prognostic factor for overall survival and young patients did not show a worse prognosis, there were differences in mucin production, MSI-H, and N2 stage between the two groups. Further studies are needed to clarify the clinical and biological characteristics of CRC, improve its treatment strategies, and promote better outcomes in young patients.

Ultralow Anterior Resection and Coloanal Anastomosis for Low-Lying Rectal Cancer: An Appraisal Based on Bowel Function.

BACKGROUNDS/AIMS: On the basis of acceptable oncologic results, ultralow anterior resection (ULAR) and colo-anal anastomosis plus hand-sewn coloanal anastomosis have been performed for treating very low-lying rectal cancer. However, many patients experience bowel dysfunction after ULAR. Studies have provided inadequate data on bowel dysfunctions and only a few functional studies have focused on low rectal cancer. Therefore, we aimed to elucidate the severity of bowel dysfunction after ULAR in a single-surgeon cohort. METHODS: In this prospective observational study, we analyzed data of 203 patients who underwent sphincter-preserving surgery for low-lying rectal cancer (tumor located within 5 cm from the anus) between January 2011 and December 2014. During routine follow-up, examinations (3-6 months interval) after ileostomy closure, patients were asked about their bowel functions based on the Wexner incontinence and LAR syndrome (LARS) scores. Patients were divided into 2 groups: LAR group (LAR with double-stapled anastomosis) and ULAR group (ULAR with coloanal anastomosis), and functional scores were compared between 6 and 36 months. Seven risk factors for major LARS were analyzed. RESULTS: At 36 months after surgery, 94.2 and 70.6% of patients in the ULAR group still had moderate to severe incontinence and major LARS respectively. Fecal incontinence improved significantly over time (ULAR group, 14.4 vs. 7.2, p = 0.045; LAR group, 13.9 vs. 5.4, p < 0.05). However, improvement in LARS over time was observed in the LAR group only (26.5 vs. 19.7, p = 0.045). In the ULAR group, the difference did not reach a statistical significance (33.6 vs. 26.0, p = 0.10). Major LARS and moderate incontinence were significantly higher in the ULAR group than in the LAR group (70.6 vs. 47.6%, p = 0.001; 82.4 vs. 32.0%, p = 0.012 respectively). Among the 7 factors evaluated in multivariable analysis, old age (> 70), male sex, ULAR per se, and chemoradiation therapy were found to be meaningful risk factors for major LARS. CONCLUSION: In patients with low rectal cancers undergoing ULAR plus coloanal anastomosis, bowel dysfunctions were severe. Bowel dysfunctions improved over time, but most patients still experienced major bowel dysfunctions even 36 months after surgery. Risk factors for bowel dysfunctions were old age, male sex, adjuvant chemoradiation therapy, and ULAR. Therefore, ULAR should be performed in carefully selected patients with low-lying rectal cancer.

Perianal Paget disease: a report of 2 cases.

Extramammary Paget disease (EMPD) is a rare cutaneous neoplasm. Perianal Paget disease (PPD) is a subset of EMPD manifesting perianal lesions. Two cases of PPD in Severance Hospital are described in this article. A 65-year-old female and 78-year-old male patients visited our institution because of an unhealed perianal skin lesion despite treatment for a long period with topical agents. PPD was diagnosed by skin biopsies in both cases, and the patients underwent surgical treatment. Clinical manifestations, preoperative work-ups, and surgical treatments including different reconstruction methods are described in detail. As only sporadic PPD cases have been reported and no standard treatment has been established, we hope that our experience could contribute to improving the diagnosis and treatment of PPD patients.

Minimally Invasive Surgery for Rectal Cancer: Current Status and Future Perspectives.

Although laparoscopic resection for colon cancer has been proven safe and feasible when compared with open resection, currently no clear evidence is available regarding minimally invasive surgery for rectal cancer. This type of surgery may benefit patients by allowing fast recovery of normal dietary intake and bowel function, reduced postoperative pain, and shorter hospitalization. Therefore, minimally invasive surgeries such as laparoscopic or robot surgery have become the predominant treatment option for colon cancer. Specifically, the proportion of laparoscopic colorectal cancer surgery in Korea increased from 42.6 to 64.7% until 2013. However, laparoscopic surgery for rectal cancer is more difficult and technically demanding. In addition, the procedure requires a prolonged learning curve to achieve equivalent outcomes relative to open surgery. It is very challenging to approach the deep and narrow pelvis using laparoscopic instruments. However, robotic surgery provides better vision with a high definition three-dimensional view, exceptional ergonomics, Endowrist technology, enhanced dexterity of movement, and a lack of physiologic tremor, facilitated by the use of an assistant in the narrow and deep pelvis. Recently, an increasing number of reports have compared the outcomes of laparoscopic and open surgery for colon cancer. Such reports have prompted a discussion of the outcomes of minimally invasive surgery, including robotic surgery, for rectal cancer. The aim of this review is to summarize current data regarding the clinical outcomes, including oncologic outcomes, of minimally invasive surgery for rectal cancer.

Novel anal sphincter saving procedure with partial excision of levator-ani muscle in rectal cancer invading ipsilateral pelvic floor.

PURPOSE: Tumors at the level of the anorectal junction had required total levator-ani muscle excision to achieve an adequate resection margin. However, in the cases of tumor invading ipsilateral levator-ani muscle and intact external sphincter, en bloc resection of rectum with levator-ani muscle including tumor would be possible. This hemilevator excision (HLE) technique enables preserving the anal sphincter function while obtaining oncologic clearance and avoiding permanent colostomy in those patients. This study aimed to evaluate the surgical outcomes and feasibility of HLE. METHODS: Data on 13 consecutive patients who underwent HLE for pathologically proven low rectal cancer were retrospectively collected. All 13 patients presented low rectal cancer at the anorectal ring level that was suspected to invade or abut to the ipsilateral side of the levator-ani muscle. RESULTS: A secure resection margin was achieved in all cases, and anastomotic leakage occurred in 2 patients. During follow-up, 3 patients experienced tumor recurrence (2 systemic and 1 local). Among 6 patients who underwent diverting ileostomy closure after the index operation, 2 complained of fecal incontinence. The other 4 patients without fecal incontinence showed <10 times of bowel movement per day. Accessing their incontinence scale, mean Wexner score was 9.4. CONCLUSION: HLE is a novel sphincter-preserving technique that can be a treatment option for low rectal cancer invading ipsilateral levator-ani muscle, which has been an indication for abdominoperineal resection (APR) or extralevator APR. However, the long-term oncologic and functional outcomes of this procedure still need to be assessed to confirm its validity.

Accuracy of Preoperative Local Staging of Primary Colorectal Cancer by Using Computed Tomography: Reappraisal Based on Data Collected at a Highly Organized Cancer Center.

PURPOSE: In patients with colorectal cancer, preoperative staging using various imaging technologies is important for establishing the treatment plan and predicting the prognosis. Although computed tomography (CT) has been used most widely, the versatility of CT accuracy was primarily because of the lack of specialization. In this study, we aimed to identify whether any advancement in abdominal CT accuracy in the prediction of local staging has occurred. METHODS: Between December 2014 and November 2015, patients with colorectal cancer were retrospectively enrolled. All CT findings were retrospectively reported. A total of 285 patients were included, and their retrospectively collected data were retrospectively reviewed, focusing on a comparison between preoperative and postoperative staging. RESULTS: The overall prediction accuracy of the T stage was 55.1%, with overstaging occurring in 63 (22.1%) and understaging in 65 patients (22.8%). The sensitivity and specificity were 90.0% and 68.4%, respectively. The overall prediction accuracy of the N stage was 54.7%, with overstaging occurring in 89 (31.2%) and understaging in 40 patients (14.1%). The sensitivity and specificity were 71.9% and 63.2%, respectively. The CT accuracies by pathologic stage were 0%, 62.2%, 25.3%, and 81.2% for stages 0 (Tis N0), I, II, and III, respectively. CONCLUSION: CT has good sensitivity for detecting colon cancers with tumor invasion beyond the bowel wall. However, detection of nodal involvement using CT is unreliable. In our opinion, abdominal CT alone has limitations in predicting the local staging of colorectal cancer, and additional technologies, such as CT plus positron emission tomography and/or colonography, will improve its accuracy.

Transanal Endoscopic Operation Versus Conventional Transanal Excision for Rectal Tumors: Case-Matched Study with Propensity Score Matching.

BACKGROUNDS: Although transanal endoscopic surgery is practiced worldwide, there is no consensus on comparative outcomes between transanal endoscopic operation (TEO) and transanal excision (TAE). In this study, we reviewed our experiences with these techniques and compared patients who underwent TEO and TAE using propensity score matching (PSM). METHODS: A total of 207 patients underwent local rectal tumor excision between January 2008 and November 2015. To overcome selection bias, we used PSM to achieve a one-to-one TEO: TAE ratio. We included baseline characteristics, age, sex, surgeon, American Society of Anesthesiologists score, tumor location (clockwise direction), involved circumference quadrants, tumor size, and pathology. RESULTS: After PSM, 72 patients were included in each group. The tumor distance from the anal verge was higher in the TEO group (8.0 [5-10] vs. TAE: 4.0 [3-5], p < 0.001). Complication rates did not differ between the groups (TEO: 8.3% vs. TAE: 11.1%, p = 0.39). TEO was associated with a shorter hospital stay (3.01 vs. 4.68 days, p = 0.001), higher negative margin rate (95.8 vs. 86.1%, p = 0.039), and non-fragmented specimen rate vs. TAE (98.6 vs. 90.3%, p = 0.029). CONCLUSIONS: TEO was more beneficial for patients with higher rectal tumors. Regardless of tumor location, involved circumference quadrants, and tumor size, TEO may more effectively achieve negative resection margins and non-fragmented specimens. Consequently, although local excision method according to tumor distance may be important, TEO will become the standard for rectal tumors.

Universal suprapubic approach for complete mesocolic excision and central vascular ligation using the da Vinci Xi® system: from cadaveric models to clinical cases.

There has been little enthusiasm for performing robotic colectomy for colon cancer in recent years due to multiple factors, one being that the previous robotic systems such as the da Vinci Si® (dVSi) were poorly designed for multi-quadrant surgery. The new da Vinci Xi® (dVXi) system enables colectomy with central mesocolic excision to be performed easily in a single docking procedure. We developed a universal port placement strategy to allow right and left hemicolectomies to be performed via a suprapubic approach and a Pfannensteil extraction site. This proof of concept paper describes the development and subsequent clinical application of this setup. After extensive training on the dVXi system concepts in collaboration with clinical development engineers, we developed a port placement strategy which was tested and adapted after performing experimental surgery in three cadaveric models. Subsequently our port placement was used for two clinical cases of suprapubic right and left hemicolectomy. With some modifications of port placements after the initial cadaveric colectomies, we have developed a potentially universal suprapubic port placement strategy for robotic colectomy with complete mesocolic excision and central vascular ligation using the dVXi robotic system. This port placement strategy was applied successfully in our first two clinical cases. Based on our cadaveric laboratory as well as our initial clinical application, the suprapubic port placement strategy for the dVXi system with its improved features over the dVSi can feasibly perform right and left hemicolectomy with complete mesocolic excision and central vascular ligation. Further studies will be required to establish efficacy as well as safety profile of these procedures.

Corrigendum: Correction of the IRB Approval Number. Accuracy of Preoperative Local Staging of Primary Colorectal Cancer by Using Computed Tomography: Reappraisal Based on Data Collected at a Highly Organized Cancer Center.

[This corrects the article on p. 192 in vol. 33, PMID: 29159167.].

The number of retrieved lymph nodes needed for accurate staging differs based on the presence of preoperative chemoradiation for rectal cancer.

The aim of this study is to investigate if retrieval of 12 lymph nodes (LNs) is sufficient to avoid stage migration as well as to evaluate the prognostic impact of insufficient LN retrieval in different treatment settings of rectal cancer, particularly in the case of preoperative chemoradiotherapy (pCRT).The data of all patients with biopsy proven rectal adenocarcinoma who underwent curative surgery between January 2005 and December 2012 were analyzed. Univariate and multivariate analyses for oncologic outcomes were performed in LN metastasis or no LN metastasis (LN-) group. Subgroup analyses were performed according to whether a patient had received pCRT.A total of 1825 patients were enrolled into the study. The maximal Chi-square method revealed the minimum number of harvested LNs required to be 12. Univariate and multivariate analyses found LNs ≥ 12 to be an independent prognostic factor for both overall survival (OS) (hazard ratio [HR] = 0.5, 95% confidence intervals [CIs]: 0.3-0.8; P = 0.002) and disease-free survival (DFS) (HR = 0.6, 95% CI: 0.4-0.7; P < 0.001) in the LN- group. In the LN- group, LNs ≥ 12 continued to be a significant prognostic factor both for OS and DFS in the subgroup of patients who did not undergo pCRT. However, in the subgroup of the LN- patients who underwent pCRT, LN ≥ 8 was significant for DFS and OS.Retrieval of LNs ≥ 12 and LNs ≥ 8 should be achieved to obtain accurate staging and optimal treatment for the non-pCRT and pCRT groups in rectal cancer, respectively.

Impact of anastomotic leakage on long-term oncologic outcome and its related factors in rectal cancer.

Anastomotic leakage (AL) is a well-known cause of morbidity after low anterior resection (LAR) for rectal cancer, but its impact on oncologic outcome is not well understood. The aim of this study is to investigate the impact of AL on long-term oncologic outcome and to identify factors associated with AL that may affect prognosis after LAR for rectal cancer.A retrospective analysis of patients who underwent curative resection for rectal cancer without diverting stoma was performed. To investigate AL related factors that may be associated with oncologic outcome, Clavien-Dindo grades, prognostic nutritional indices (PNI) and inflammatory indices were included.One hundred and one patients out of a total of 1258 patients developed postoperative AL, giving an AL rate of 8.0%. Patients with AL showed poorer disease-free survival (DFS), than patients without AL (hazard ratio [HR] = 1.6; 95% confidence intervals [CI]: 1.1-2.5; P = 0.01). In patients who developed AL, age over 60 (HR = 2.2; 95% CI: 1.1-4.7; P = 0.033), advanced pathologic stage (HR = 2.4; 95% CI: 1.4-4.0; P = 0.001), suppressed neutrophil-proportion (≤80%) (HR = 2.6; 95% CI: 1.2-5.8; P = 0.019) and PNI <36 (HR = 3.5; 95% CI: 1.2-9.6; P = 0.018) were associated with poorer DFS.AL was associated with poorer DFS. In patients with AL, a suppressed neutrophil-proportion and decreased PNI below 36 were associated with tumor recurrence.