Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients' values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Is restrictive transfusion sufficient in colorectal cancer surgery? A retrospective study before and during the COVID-19 pandemic in Korea

PURPOSE

Blood transfusion is one of the most common procedures used to treat anemia in colorectal surgery. Despite controversy regarding the adverse effects of blood products, surgeons have maintained standards for administering blood transfusions. However, this trend was restrictive during the COVID-19 pandemic because of a shortage of blood products. In this study, we conducted an analysis to investigate whether the restriction of blood transfusions affected postoperative surgical outcomes.

METHODS

Medical records of 318 patients who underwent surgery for colon and rectal cancer at Ewha Womans University Mokdong Hospital between June 2018 and March 2022 were reviewed retrospectively. The surgical outcomes between the liberal and restrictive transfusion strategies in pre- and post-COVID-19 groups were analyzed.

RESULTS

In univariate analysis, postoperative transfusion was associated with infectious complications (odds ratio [OR], 1.705; 95% confidence interval [CI], 1.015-2.865; P=0.044). However, postoperative transfusion was not an independent risk factor for the development of infectious complications in multivariate analysis (OR, 1.305; 95% CI, 0.749-2.274; P=0.348). In subgroup analysis, there was no significant association between infectious complications and the hemoglobin threshold level for the administration of a transfusion (OR, 1.249; 95% CI, 0.928-1.682; P=0.142).

CONCLUSION

During colorectal surgery, the decision to perform a blood transfusion is an important step in ensuring favorable surgical outcomes. According to the results of this study, restrictive transfusion is sufficient for favorable surgical outcomes compared with liberal transfusion. Therefore, modification of guidelines is suggested to minimize unnecessary transfusion-related side effects and prevent the overuse of blood products.

Long-term oncological outcomes of robotic versus laparoscopic approaches for right colon cancer: a systematic review and meta-analysis

PURPOSE

The short-term outcomes of robotic right hemicolectomy for right colon cancer have been extensively studied in comparison to conventional laparoscopic right hemicolectomy. However, the long-term oncological outcomes of the two approaches have not been investigated, except in single-center retrospective studies. Therefore, this meta-analysis aimed to investigate the long-term oncological outcomes of robotic right hemicolectomy compared with those of laparoscopic right hemicolectomy for right colon cancer.

METHODS

We searched PubMed, EMBASE, and Cochrane Library for studies comparing robotic right hemicolectomy with conventional laparoscopic right hemicolectomy for right colon cancer from the date of database inception to August 2022. For survival data extraction, hazard ratios (HRs) with 95% confidence intervals (CI) were calculated using random- or fixed-effects models from the Kaplan-Meier survival curves in the included studies. All calculations and statistical tests were performed using Review Manager software, version 5.4.

RESULTS

A total of 523 patients (robotic right hemicolectomy, 230; laparoscopic right hemicolectomy, 293) from five studies were included in this meta-analysis. There were no significant differences in patient characteristics between the two groups. In terms of pathological characteristics, TNM stage was not different and revealed no differences in the number of harvested lymph nodes even though a larger number of lymph nodes were harvested in the robotic group in one study. Pooled analyses demonstrated no significant difference in disease-free survival (HR 0.72, 95% CI 0.46-1.13, p = 0.15) and overall survival (HR 0.73, 95% CI 0.48-1.13, p = 0.16) between robotic and laparoscopic right hemicolectomy for right colon cancer.

CONCLUSION

Robotic right hemicolectomy for right colon cancer is comparable with conventional laparoscopic right hemicolectomy in terms of long-term oncological survival. More prospective, multicenter, randomized trials are necessary to determine the oncologic safety of robotic right hemicolectomy.

Short-term outcomes of single-incision robotic colectomy versus conventional multiport laparoscopic colectomy for colon cancer

Since the da Vinci SP (dVSP) surgical system was introduced, single-incision robotic surgery (SIRS) for colorectal diseases has gained increasing acceptance. Comparison of the short-term outcomes between SIRS using dVSP and those of conventional multiport laparoscopic surgery (CMLS) was performed to verify its efficacy and safety in colon cancer. The medical records of 237 patients who underwent curative resection for colon cancer by a single surgeon were retrospectively reviewed. Patients were divided into two groups according to surgical modality: SIRS (RS group) and CMLS (LS group). Intra- and postoperative outcomes were analyzed. Of the 237 patients, 140 were included in the analysis. Patients in the RS group (n = 43) were predominantly female, younger, and had better general performance than those in the LS group (n = 97). The total operation time was longer in the RS group than in the LS group (232.8 ± 46.0 vs. 204.1 ± 41.7 min, P < 0.001). The RS group showed faster first flatus passing (2.5 ± 0.9 vs. 3.1 ± 1.2 days, P = 0.003) and less opioid analgesic requirement (analgesic withdrawal within 3 postoperative days: 37.2% vs. 18.6%, P = 0.018) than the LS group. The RS group showed a higher immediate postoperative albumin level (3.9 ± 0.3 vs. 3.6 ± 0.4 g/dL, P < 0.001) and lower C-reactive protein level (6.6 ± 5.2 vs. 9.3 ± 5.5 mg/dL, P = 0.007) than the LS group during the postoperative period. On multivariate analysis after adjusting for deviated patient characteristics, no significant difference was observed in short-term outcomes, except for operation time. SIRS with dVSP showed short-term outcomes comparable with those of CMLS for colon cancer.

Body composition index obtained by using a bioelectrical impedance analysis device can be a predictor of prolonged operative time in patients undergoing minimally invasive colorectal surgery

PURPOSE

Obesity has been known to contribute to technical difficulties in surgery. Until now, body mass index (BMI) has been used to measure obesity. However, there are reports that BMI does not always correspond to the visceral fat. Recently, bioelectrical impedance analysis (BIA) has been used for body composition analysis. This study aimed to evaluate the usefulness of the body composition index obtained using a BIA device in predicting short-term postoperative outcomes.

METHODS

Data of patients who underwent elective major colorectal surgery using minimally invasive techniques were reviewed retrospectively. Body composition status was recorded using a commercial BIA device the day before surgery. The relationship between BMI, body composition index, and short-term postoperative outcomes, including operative time, was analyzed.

RESULTS

Sixty-six patients were enrolled in this study. In the correlation analysis, positive correlation was observed between BMI and body composition index. BMI and body composition index were not associated with short-term postoperative outcomes. Percent body fat (odds ratio, 4.226; 95% confidence interval [CI], 1.064-16.780; P=0.041) was found to be a statistically significant factor of prolonged operative time in the multivariate analysis. Correlation analysis showed that body fat mass was related to prolonged operative time (correlation coefficients, 0.245; P=0.048). In the area under curve analysis, body fat mass showed a statistically significant predictive probability for prolonged operative time (body fat mass: area, 0.662; 95% CI, 0.531-0.764; P=0.024).

CONCLUSION

The body composition index can be used as a predictive marker for prolonged operative time. Further studies are needed to determine its usefulness.

Single-incision robotic colorectal surgery with the da Vinci SP® surgical system: initial results of 50 cases

PURPOSE

The da Vinci SP® (dVSP) surgical system (Intuitive Surgical, Sunnyvale, CA, USA), a robotic platform designed for single-incision surgery, overcame the need for multiple ports in traditional robotic surgery and issues including triangulation and retraction in single-incision laparoscopic surgery. However, previous studies only included case reports or series with small sample sizes. The aim of this study was to assess the safety and performance of the dVSP surgical system and its instruments and accessories for colorectal procedures.

METHODS

The medical records of patients who had surgery with the dVSP from March 2019 to September 2021 at Ewha Womans University Seoul Hospital were investigated. The pathologic and follow-up data of patients who had malignant tumors were analyzed separately to evaluate oncological safety.

RESULTS

Fifty patients (26 male and 24 female) with a median age of 59 years (interquartile range 52.5-63.0 years) were enrolled. The procedures included low anterior resection with total mesorectal excision (n = 16), sigmoid colectomy with complete mesocolic excision and central vessel ligation (CME + CVL) (n = 14), right colectomy with CME + CVL (n = 9), left colectomy with CME + CVL (n = 4), right colectomy (n = 6), and sigmoid colectomy (n = 1). Operative time significantly decreased after 25 cases (early phase vs. late phase; operative time 295.0 min vs. 250.0 min, p = 0.015; docking time 16.0 min vs. 12.0 min, p = 0.001; console time 212.0 min vs. 190.0 min, p = 0.019). Planned procedures were successfully completed in all patients. Postoperative outcomes were acceptable with only six cases of mild adverse events through a 3-month follow-up. No local recurrence and only one case of systemic recurrence occurred within 1 year postoperatively.

CONCLUSIONS

This study demonstrated the surgical and oncological safety and feasibility of dVSP, which may be a novel surgical platform for colorectal surgery.

Exosomes Derived from Colon Cancer Cells Promote Tumor Progression and Affect the Tumor Microenvironment

Cancer-cell-derived exosomes confer oncogenic properties in their tumor microenvironment and to other cells; however, the exact mechanism underlying this process is unclear. Here, we investigated the roles of cancer-cell-derived exosomes in colon cancer. Exosomes were isolated from colon cancer cell lines, HT-29, SW480, and LoVo, using an ExoQuick-TC kit, identified using Western blotting for exosome markers, and characterized using transmission electron microscopy and nanosight tracking analysis. The isolated exosomes were used to treat HT-29 to evaluate their effect on cancer progression, specifically cell viability and migration. Cancer-associated fibroblasts (CAFs) were obtained from patients with colorectal cancer to analyze the effect of the exosomes on the tumor microenvironment. RNA sequencing was performed to evaluate the effect of the exosomes on the mRNA component of CAFs. The results showed that exosome treatment significantly increased cancer cell proliferation, upregulated N-cadherin, and downregulated E-cadherin. Exosome-treated cells exhibited higher motility than control cells. Compared with control CAFs, exosome-treated CAFs showed more downregulated genes. The exosomes also altered the regulation of different genes involved in CAFs. In conclusion, colon cancer-cell-derived exosomes affect cancer cell proliferation and the epithelial-mesenchymal transition. They promote tumor progression and metastasis and affect the tumor microenvironment.

Validity of C-Reactive Protein as a Surrogate Marker for Infectious Complications After Surgery for Colorectal Cancer

Abstract Background: This study aimed to establish a threshold of C-reactive protein (CRP) level for early detection of post-operative infectious complications after surgery for colorectal cancer. Patients and Methods: In this single-center, retrospective analysis, we studied the data of 178 patients who underwent surgery for colorectal cancer between January 2018 and February 2022. Elective surgery with curative intent was performed, and serum CRP levels were measured on five consecutive days after surgery. Receiver operating characteristic curves were utilized to assess the cutoff point of the CRP level with maximum predictive value, Results: A total of 59 cases of early post-operative complications, including pneumonia, wound infection, intra-abdominal infection, and anastomotic leakage were evaluated. During the monitoring period, patients with complications had higher CRP level than those without complications. The cutoff points on the five post-operative days were estimated to be 6.50, 10.83, 11.44, 6.67, and 5.71 mg/dL, respectively, and they were correlated to the occurrence of infectious complications. Higher CRP levels were associated with greater blood loss during surgery (p = 0.003) and increased length of hospital stay (p < 0.001) than did lower CRP levels. Conclusions: C-reactive protein monitoring in the early post-operative period is a cost-effective test that can be easily performed to predict the occurrence of infectious complications. It may be helpful in improving surgical outcomes, shortening the length of hospital stay and appropriate antibiotic administration.

Verification of the role of exosomal microRNA in colorectal tumorigenesis using human colorectal cancer cell lines

Exosomes are a group of small membranous vesicles that are shed into the extracellular environment by tumoral or non-tumoral cells and contribute to cellular communication by delivering micro RNAs (miRNAs). In this study, we aimed to evaluate the role of exosomal miRNAs from colorectal cancer cell lines in tumorigenesis, by affecting cancer-associated fibroblasts (CAFs), which are vital constituents of the tumor microenvironment. To analyze the effect of exosomal miRNA on the tumor microenvironment, migration of the monocytic cell line THP-1 was evaluated via Transwell migration assay using CAFs isolated from colon cancer patients. The migration assay was performed with CAFs ± CCL7-blocking antibody and CAFs that were treated with exosomes isolated from colon cancer cell lines. To identify the associated exosomal miRNAs, miRNA sequencing and quantitative reverse transcription polymerase chain reaction were performed. The migration assay revealed that THP-1 migration was decreased in CCL7-blocking antibody-expressing and exosome-treated CAFs. Colon cancer cell lines contained miRNA let-7d in secreted exosomes targeting the chemokine CCL7. Exosomes from colorectal cancer cell lines affected CCL7 secretion from CAFs, possibly via the miRNA let-7d, and interfered with the migration of CCR2+ monocytic THP-1 cells in vitro.

Impact of laparoscopic surgical experience on the learning curve of robotic rectal cancer surgery

BACKGROUND

Robotic surgery has advantages in terms of the ergonomic design and expectations of shortening the learning curve, which may reduce the number of patients with adverse outcomes during a surgeon's learning period. We investigated the differences in the learning curves of robotic surgery and clinical outcomes for rectal cancer among surgeons with differences in their experiences of laparoscopic rectal cancer surgery.

METHODS

Patients who underwent robotic surgery for colorectal cancer were reviewed retrospectively. Patients were divided into five groups by surgeons, and their clinical outcomes were analyzed. The learning curve of each surgeon with different volumes of laparoscopic experience was analyzed using the cumulative sum technique (CUSUM) for operation times, surgical failure (open conversion or anastomosis-related complications), and local failure (positive resection margins or local recurrence within 1 year).

RESULTS

A total of 662 patients who underwent robotic low anterior resection (LAR) for rectal cancer were included in the analysis. Number of laparoscopic LAR cases performed by surgeon A, B, C, D, and E prior to their first case of robotic surgery were 403, 40, 15, 5, and 0 cases, respectively. Based on CUSUM for operation time, surgeon A, B, C, D, and E's learning curve periods were 110, 39, 114, 55, and 23 cases, respectively. There were no significant differences in the surgical and oncological outcomes after robotic LAR among the surgeons.

CONCLUSIONS

This study demonstrated the limited impact of laparoscopic surgical experience on the learning curve of robotic rectal cancer surgery, which was greater than previously reported curves.

Computed tomography based cross-sectional anatomy of the pelvis predicts surgical outcome after rectal cancer surgery

Purpose

Narrow pelvis has been considered an adverse factor for postoperative and oncologic outcomes after rectal cancer surgery. The aim of this study was to investigate the validity of using only axial CT scan images to calculate the pelvic cross-sectional area for the prediction of adverse outcomes after rectal cancer surgery.

Methods

The medical records of patients who underwent rectal cancer surgery were reviewed and analyzed retrospectively. Axial images of CT scan were used to measure the pelvic cross-sectional area. Pelvic surgical site infection (SSI), positive resection margin, and early local recurrence were adopted as end-points to analyze the impact of pelvimetry on surgical outcome.

Results

The mean pelvic cross-sectional area was 84.3 ± 10.9 cm². Males had significantly smaller pelvic areas than females (P < 0.001). Comparing pelvic cross-sectional areas according to the surgical outcomes, the results indicated that patients with pelvic SSI and local failure (positive resection margin or local recurrence within 1 year) have significantly smaller cross-sectional-area than SSI and local failure-free patients (P = 0.013 and P = 0.031). A calculated cross-sectional area of 88.8 cm² was determined as the cutoff value for the prediction of pelvic SSI and/or local failure, which was significant in a validating analysis.

Conclusion

The pelvic cross-sectional area obtained from a routine axial CT scan image was associated with pelvic SSI, positive resection margin, and early local recurrence. It might be an intuitive, feasible, and easily adoptable method for predicting surgical outcomes.

Initial clinical experience of single-incision robotic colorectal surgery with da Vinci SP platform

BACKGROUND

The da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA) was introduced to overcome the limitations of single-incision laparoscopic surgery, which is challenging due to its restrictions regarding triangulation and retraction. The purpose of this article is to describe the initial experience with single-incision surgery using the da Vinvci Single-Port Platform (dVSP).

METHODS

The medical records of patients with colorectal disease, who underwent single-incision robotic surgery using the dVSP, were retrospectively reviewed.

RESULTS

Five patients with appendiceal and colorectal cancer, and two with diverticulitis were enrolled. All procedures were completed using a pure single-incision approach, with an exception for low anterior resection. There were two minor complications. For patients with colorectal cancer, the number of retrieved lymph nodes and status of the resection margin were acceptable, and cosmetic results were satisfactory.

CONCLUSION

The dVSP is a novel surgical platform that can be used as an alternative surgical modality for colorectal surgery.

The impact of early adjuvant chemotherapy in rectal cancer

PURPOSES

Although adjuvant chemotherapy (AC) has been established as a standard of treatment for advanced rectal cancer, there is no guideline regarding the timing of AC initiation. In this study, we aimed to evaluate the oncologic outcome of early AC initiation and clarify the ideal time to AC among rectal cancer patients receiving preoperative chemo-radiotherapy (preCRT).

METHODS

The medical records of 719 patients who underwent curative resection followed by AC for rectal cancer were analyzed retrospectively. Data distributions were compared according to the calculated cut-off for AC initiation, survival results, and chemotherapy-induced toxicity. Additionally, patients were divided into two groups according to preCRT status and compared with respect to differences in the optimal time to AC.

RESULTS

Overall, a cut-off time point of 20 days after surgery for AC initiation was identified as the optimal interval; this yielded a significant difference in disease-free survival but no significant difference in AC toxicity. In the cut-off analysis of patients treated without preCRT, 19 days was identified as the optimal time to AC. However, for patients treated with preCRT, no significant value affected the survival outcome.

CONCLUSIONS

Earlier initiation of AC (within approximately 3 weeks) was associated with better oncological outcomes among patients with rectal cancer. Additionally, the optimal timing of AC was unclear among patients who received preCRT; this might be attributable to an undetermined role of AC after preCRT or the effects of complications such as anastomotic leakage.

Factors affecting pouch-related outcomes after restorative proctocolectomy

Purposes

Restorative proctocolectomy (RPC) with ileal pouch anal anastomosis (IPAA) is the procedure of choice for patients with familial adenomatous polyposis (FAP) and ulcerative colitis (UC) despite morbidities that can lead to pouch failure. We aimed to identify factors associated with pouch-related morbidities.

Methods

A retrospective analysis of patients who underwent RPC with IPAA was performed. To investigate the factors associated with pouch-related morbidities, patients' preoperative demographic and clinical factors, and intraoperative factors were included in the analysis.

Results

A total of 49 patients with UC, FAP, and colorectal cancer were included. Twenty patients (40.8%) experienced leakage-related, functional, and/or pouchitis-related morbidities. Patients with American Society of Anesthesiologists (ASA) grade 2 or 3 had a higher risk of functional morbidity than those with grade 1. Intraoperative blood loss exceeding 300.0 mL was associated with an increased risk of pouchitis-related morbidity.

Conclusions

Our study demonstrated associations of higher ASA grade and increased intraoperative blood loss with poor functional outcomes and pouchitis, respectively.

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.

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.

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.

The availability of computed tomography for pulmonary staging in colorectal cancer

Purpose

Chest computed tomography is performed frequently for the preoperative pulmonary staging in colorectal cancers (CRCs) regardless of the result of chest x-ray (CXR) due to its high sensitivities and specificities. The advancement of CT technology detects more indeterminate lung lesions that may require further investigations, referrals and follow-up. The aim of this study was to suggest a guideline for performing chest CT for preoperative pulmonary staging in colorectal cancer.

Methods

We performed a retrospective analysis of the records of patients who had chest CT preformed without the evidence of metastasis on CXR for preoperative pulmonary staging.

Results

Of 21 patients with metastatic nodules on chest CT, 23.8% showed pulmonary metastasis on positron emission tomography, 47.6% showed extrapulmonary metastasis on preoperative evaluation and 61.9% showed elevated serum carcinoembryonic antigen level above 10 ng/mL. These results showed significant value compared to patients without metastatic nodules. But, in analyzing patients with or without indeterminate nodules in the three contents listed above, there was no significance.

Conclusion

In the patients with CRC who show normal CXR and exhibit positivity in PET, preoperative extrapulmonary metastasis and elevated serum CEA level above 10 ng/mL preoperatively, chest CT would be helpful in preoperative staging.

Optimal time of initiating adjuvant chemotherapy after curative surgery in colorectal cancer patients

Purpose

Adjuvant chemotherapy is routinely recommended for locally advanced colorectal cancer (CRC). There are very few data for the optimal starting date of adjuvant chemotherapy after the surgery. This study aimed to evaluate the effectiveness of earlier adoption of adjuvant chemotherapy after curative surgery for stage III CRC.

Methods

In this study, 159 patients with stage III CRC, who had undergone a curative resection, were enrolled retrospectively. Patients were categorized into 3 groups representing different timings to initiate the chemotherapy; less than 2 weeks (group 1), 3 to 4 weeks (group 2), and more than 5 weeks (group 3). The overall survival rate (OS) and the relapse-free survival rate (RFS) were analyzed to evaluate the effectiveness of adjuvant chemotherapy.

Results

The 5-year OSs of the patients were 73.7% in group 1, 67.0% in group 2, and 55.2% in group 3. The 5-year RFSs of the patients were 48.8% in group 1, 64.7% in group 2, and 57.1% in group 3. There were no significant differences in either the OS or the RFS (P = 0.200, P = 0.405).

Conclusion

Starting chemotherapy earlier than 6 weeks after surgery does not show any significant difference. Thus, although adjuvant chemotherapy should preferably begin within 6 weeks, the starting date should not necessarily be hastened, and the patient's general condition should be taken into consideration.

Extensive bowel ischemia with heavy alcohol consumption: report of a case

Alcohol is well-recognized systemic toxin that causes numerous adverse effects, including psychosocial problems, fatal myocardial infarction, stroke and atherosclerosis. The intra-abdominal complications caused by acute alcohol consumption have not been defined. We report an 80-year-old man with sub-acute small bowel and colonic ischemia after heavy alcohol intake in one sitting. We performed a resection of gangrenous bowel segments. Microscopically, there were diffuse infarction, with vasoconstriction of the mesenteric vessels in the ileum and colon without any thrombotic occlusion of the intestinal vessels. The clinicians should always be assured by confirmation of a history of recent substance abuse in patients with unexplained abdominal pain, and mesenteric ischemia should be considered in the differential diagnosis of acute or chronic abdominal pain in consumers of alcohol.