A Phase II Study of Preoperative Chemoradiotherapy with Capecitabine Plus Simvastatin in Patients with Locally Advanced Rectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The purpose of this phase II trial was to evaluate whether the addition of simvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, to preoperative chemoradiotherapy (CRT) with capecitabine confers a clinical benefit to patients with locally advanced rectal cancer (LARC). @*Materials and Methods@#Patients with LARC (defined by clinical stage T3/4 and/or lymph node positivity) received preoperative radiation (45-50.4 Gy in 25-28 daily fractions) with concomitant capecitabine (825 mg/m2 twice per day) and simvastatin (80 mg, daily). Curative surgery was planned 4-8 weeks after completion of the CRT regimen. The primary endpoint was pathologic complete response (pCR). The secondary endpoints included sphincter-sparing surgery, R0 resection, disease-free survival, overall survival, the pattern of failure, and toxicity. @*Results@#Between October 2014 and July 2017, 61 patients were enrolled; 53 patients completed CRT regimen and underwent total mesorectal excision. The pCR rate was 18.9% (n=10) by per-protocol analysis. Sphincter-sparing surgery was performed in 51 patients (96.2%). R0 resection was achieved in 51 patients (96.2%). One patient experienced grade 3 liver enzyme elevation. No patient experienced additional toxicity caused by simvastatin. @*Conclusion@#The combination of 80 mg simvastatin with CRT and capecitabine did not improve pCR in patients with LARC, although it did not increase toxicity.

Is a cutoff value of 12 still useful in stage II right-sided colon cancer without risk factors?

Purpose@#Various clinical practice guidelines recommend at least 12 regional lymph nodes should be removed for resected colon cancer. According to a recent study, the lymph node yield (LNY) in colon cancer surgery in the last 20 years has tended to increase from 14.91 to 21.30. However, it is unclear whether these guidelines adequately reflect recent findings on the number of harvested lymph nodes in colon cancer surgery. The aim of this study is to assess the impact of an LNY of more than 25 on survival in right-sided colon cancer. @*Methods@#We included 285 patients who underwent a right hemicolectomy during the period from January 2010 through December 2015. Patients were divided into two groups (<25 nodes and ≥25 nodes). Primary endpoints included 5-year and 10-year survival including disease-free and overall. @*Results@#We found that survival outcomes of patients with a harvest of ≥25 nodes were not significantly different compared with a <25 group. Large tumor size (5 cm) is significantly associated with poor 5-year and 10-year overall survival. @*Conclusion@#Survival outcomes of patients with a harvest of ≥25 nodes were not significantly different compared with the <25 group in stage II colon cancer with no risk.

Learning curve for single-port robot-assisted rectal cancer surgery

Purpose@#We analyzed the learning curve of single-port robotic (SPR)-assisted rectal cancer surgery. @*Methods@#Fifty-seven consecutive SPR-assisted rectal cancer surgery cases performed by the same surgeon were considered in surgical interventions for rectal cancer. Total operation time (OT), docking time (DT), and surgeon console time (SCT) measured during surgery were used to parametrize the learning curve. The parameters representing the learning curve were evaluated using the cumulative sum (CUSUM). @*Results@#The mean value of total OT was 241.8 ± 91.7 minutes, the mean value of DT was 20.6 ± 19.1 minutes, and the mean value of SCT was 135.9 ± 66.7 minutes. The learning curve was divided into phase 1 (initial 16 cases), phase 2 (second 16 cases), and phase 3 (subsequent 25 cases). The peak on the CUSUM graph occurred in the 21st case. The longest OT among phases was in phase 2. Complications were most frequent in phase 2. However, complications of Clavien-Dindo (CD) grade IIIb were most frequent in phase 3 with 2 patients. The most common complications were fluid collection and urinary retention (7 patients each). Complications of CD grade IIIb required one stomal revision due to stoma obstruction and one irrigation and loop ileostomy due to anastomosis leakage. @*Conclusion@#Improvement in surgical performance of SPR assisted rectal cancer operation was achieved after 21 cases.The three phases identified in the cumulative sum analysis showed a significant decrease in operative time after the middle stage of the learning curve without an increase in the complication rate.

Single-port robot-assisted abdominoperineal resection: a case review of the first four experiences

Recently, abdominoperineal resection (APR) using a robot has been demonstrated in other studies. However, there has been no report on APR for rectal cancer using the single-port robot (SPR) platform. In response to this research gap, we described the clinical experience of APR using a SPR. From April 2019 to March 2020, APR using a SPR platform was performed in a total of 4 patients. Three patients had a transumbilical approach, and 1 patient had a transstoma site approach. The average operation time was 307 minutes, and the patient docking time to the SPR platform was 133.5 minutes. There were no complications during the operation, and no laparoscopy or open conversion. No reoperation occurred within 30 days. Mild postoperative complications occurred in 2 patients. We found that APR has safety and feasibility in surgery using an SPR platform. There was no intraoperative event and severe postoperative complications.

Molecular characterization of dysplasia-initiated colorectal cancer with assessing matched tumor and dysplasia samples

Purpose@#Ulcerative colitis (UC) is known to have an association with the increased risk of colorectal cancer (CRC), and UC-associated CRC does not follow the typical progress pattern of adenoma-carcinoma. The aim of this study is to investigate molecular characteristics of UC-associated CRC and further our understanding of the association between UC and CRC. @*Methods@#From 5 patients with UC-associated CRC, matched normal, dysplasia, and tumor specimens were obtained from formalin-fixed paraffin-embedded (FFPE) samples for analysis. Genomic DNA was extracted and whole exome sequencing was conducted to identify somatic variations in dysplasia and tumor samples. Statistical analysis was performed to identify somatic variations with significantly higher frequencies in dysplasia-initiated tumors, and their relevant functions were investigated. @*Results@#Total of 104 tumor mutation genes were identified with higher mutation frequencies in dysplasia-initiated tumors. Four of the 5 dysplasia-initiated tumors (80.0%) have TP53 mutations with frequent stop-gain mutations that were originated from matched dysplasia. APC and KRAS are known to be frequently mutated in general CRC, while none of the 5 patients have APC or KRAS mutation in their dysplasia and tumor samples. Glycoproteins including mucins were also frequently mutated in dysplasia-initiated tumors. @*Conclusion@#UC-associated CRC tumors have distinct mutational characteristics compared to typical adenoma-carcinoma tumors and may have different cancer-driving molecular mechanisms that are initiated from earlier dysplasia status.

Proteomic identification of arginine-methylated proteins in colon cancer cells and comparison of messenger RNA expression between colorectal cancer and adjacent normal tissues

Purpose@#Identification of type I protein arginine methyltransferase (PRMT) substrates and their functional significance during tumorigenesis is becoming more important. The present study aimed to identify target substrates for type I PRMT using 2-dimensional (2D) gel electrophoresis (GE) and 2D Western blotting (WB). @*Methods@#Using immunoblot analysis, we compared the expression of type I PRMTs and endogenous levels of arginine methylation between the primary colorectal cancer (CRC) and adjacent noncancerous tissues paired from the same patient. To identify arginine-methylated proteins in HCT116 cells, we carried out 2D-GE and 2D-WB with a type I PRMT product-specific antibody (anti-dimethyl-arginine antibody, asymmetric [ASYM24]). Arginine-methylated protein spots were identified by mass spectrometry, and messenger RNA (mRNA) levels corresponding to the identified proteins were analyzed using National Center for Biotechnology Information (NCBI) microarray datasets between the primary CRC and noncancerous tissues. @*Results@#Type I PRMTs and methylarginine-containing proteins were highly maintained in CRC tissues compared to noncancerous tissues. We matched 142 spots using spot analysis software between a Coomassie blue (CBB)-stained 2D gel and 2D-WB, and we successfully identified 7 proteins that reacted with the ASYM24 antibody: CACYBP, GLOD4, MAPRE1, CCT7, TKT, CK8, and HSPA8. Among these proteins, the levels of 4 mRNAs including MAPRE1, CCT7, TKT, and HSPA8 in CRC tissues showed a statistically significant increase compared to noncancerous tissues from patients using the NCBI microarray datasets. @*Conclusion@#Our results indicate that the method shown here is useful in identifying arginine-methylated proteins, and significance of arginine modification in the proteins identified here should be further identified during CRC development.

Clinical Outcomes of Neoadjuvant Chemotherapy in Colorectal Cancer Patients With Synchronous Resectable Liver Metastasis: A Propensity Score Matching Analysis

Purpose@#The survival benefit of neoadjuvant chemotherapy (NAC) prior to surgical resection in colorectal cancer with liver metastases (CRCLM) patients remains controversial. The aim of this study was to compare overall outcome of CRCLM patients who underwent NAC followed by surgical resection versus surgical treatment first. @*Methods@#We retrospectively analyzed 429 patients with stage IV colorectal cancer with synchronous liver metastases who underwent simultaneous liver resection between January 2008 and December 2016. Using propensity score matching, overall outcome between 60 patients who underwent NAC before surgical treatment and 60 patients who underwent surgical treatment first was compared. @*Results@#Before propensity score matching, metastatic cancer tended to involve a larger number of liver segments and the primary tumor size was bigger in the NAC group than in the primary resection group, so that a larger percentage of patients in the NAC group underwent major hepatectomy (P<0.001). After propensity score matching, demographic features and pathologic outcomes showed no significant differences between the 2 groups. In addition, there was no significant difference in short-term recovery outcomes such as postoperative morbidity (P=0.603) and oncologic outcome, including 3-year overall survival rate (P=0.285) and disease-free survival rate (P=0.730), between the 2 groups. @*Conclusion@#NAC prior to surgical treatment in CRCLM is considered a safe treatment that does not increase postoperative morbidity, and its impact on oncologic outcome was not inferior.

Has the COVID-19 Pandemic Caused Upshifting in Colorectal Cancer Stage?

Purpose@#Coronavirus disease 2019 (COVID-19) has affected many parts of daily life and healthcare, including cancer screening and diagnosis. The purpose of this study was to determine whether there was an upshift in the colorectal cancer stage at diagnosis due to delays related to the COVID-19 outbreak. @*Methods@#From January to June of each year from 2017 to 2020, a total of 3,229 patients who were first diagnosed with colorectal cancer were retrospectively reviewed. Those enrolled from 2017 to 2019 were classified as the ‘pre-COVID’ group, and those enrolled in 2020 were classified as the ‘COVID’ group. The primary outcome was the rate of stage IV disease at the time of diagnosis. @*Results@#There was no statistically significant difference in the proportion of stage IV patients between the pre-COVID and COVID groups (P=0.19). The median preoperative carcinoembryonic antigen level in the COVID group was higher than in the pre-COVID group in all stages (all P<0.05). In stage I, II patients who underwent radical surgery, the lymphatic invasion was more presented in COVID patients (P=0.009). @*Conclusion@#We did not find significant stage upshifting in colorectal cancer during the COVID-19 outbreak. However, there were more initially unresectable stage IV colorectal cancer patients with a low conversion rate to resectable status, and more patients had factors related to poor prognosis. These results may become more apparent over time, so it is vital not to neglect cancer screening to not delay the diagnosis during the COVID-19 epidemic.

Clinical Outcomes of Neoadjuvant Chemotherapy in Colorectal Cancer Patients With Synchronous Resectable Liver Metastasis: A Propensity Score Matching Analysis

Purpose@#The survival benefit of neoadjuvant chemotherapy (NAC) prior to surgical resection in colorectal cancer with liver metastases (CRCLM) patients remains controversial. The aim of this study was to compare overall outcome of CRCLM patients who underwent NAC followed by surgical resection versus surgical treatment first. @*Methods@#We retrospectively analyzed 429 patients with stage IV colorectal cancer with synchronous liver metastases who underwent simultaneous liver resection between January 2008 and December 2016. Using propensity score matching, overall outcome between 60 patients who underwent NAC before surgical treatment and 60 patients who underwent surgical treatment first was compared. @*Results@#Before propensity score matching, metastatic cancer tended to involve a larger number of liver segments and the primary tumor size was bigger in the NAC group than in the primary resection group, so that a larger percentage of patients in the NAC group underwent major hepatectomy (P<0.001). After propensity score matching, demographic features and pathologic outcomes showed no significant differences between the 2 groups. In addition, there was no significant difference in short-term recovery outcomes such as postoperative morbidity (P=0.603) and oncologic outcome, including 3-year overall survival rate (P=0.285) and disease-free survival rate (P=0.730), between the 2 groups. @*Conclusion@#NAC prior to surgical treatment in CRCLM is considered a safe treatment that does not increase postoperative morbidity, and its impact on oncologic outcome was not inferior.

Has the COVID-19 Pandemic Caused Upshifting in Colorectal Cancer Stage?

Purpose@#Coronavirus disease 2019 (COVID-19) has affected many parts of daily life and healthcare, including cancer screening and diagnosis. The purpose of this study was to determine whether there was an upshift in the colorectal cancer stage at diagnosis due to delays related to the COVID-19 outbreak. @*Methods@#From January to June of each year from 2017 to 2020, a total of 3,229 patients who were first diagnosed with colorectal cancer were retrospectively reviewed. Those enrolled from 2017 to 2019 were classified as the ‘pre-COVID’ group, and those enrolled in 2020 were classified as the ‘COVID’ group. The primary outcome was the rate of stage IV disease at the time of diagnosis. @*Results@#There was no statistically significant difference in the proportion of stage IV patients between the pre-COVID and COVID groups (P=0.19). The median preoperative carcinoembryonic antigen level in the COVID group was higher than in the pre-COVID group in all stages (all P<0.05). In stage I, II patients who underwent radical surgery, the lymphatic invasion was more presented in COVID patients (P=0.009). @*Conclusion@#We did not find significant stage upshifting in colorectal cancer during the COVID-19 outbreak. However, there were more initially unresectable stage IV colorectal cancer patients with a low conversion rate to resectable status, and more patients had factors related to poor prognosis. These results may become more apparent over time, so it is vital not to neglect cancer screening to not delay the diagnosis during the COVID-19 epidemic.

Prognostic Factors and Treatment of Recurrence after Local Excision of Rectal Cancer

Purpose@#Indications for local excision in patients with rectal cancer remain controversial. We reviewed factors affecting survival rate and treatment effectiveness in cancer recurrence after local excision among patients with rectal cancer. @*Materials and Methods@#A total of 831 patients was enrolled. Of these, 391 patients were diagnosed with primary rectal cancer and underwent local excision. A retrospective observational study was performed on patients who underwent full-thickness local excision for rectal cancer. @*Results@#The median duration of follow-up was 61 months. The overall recurrence rate was 11.5%. The rate of local recurrence was 5.1%. Five-year overall survival rate among recurrent patients was 66.8%; the rate among patients who underwent salvage operation due to recurrence was 84.7%, compared with 44.2% among patients treated with non-operative management (p<0.001).Multivariate analysis of disease-free survival identified distance from the anal verge (p=0.038) and histologic grade (p=0.047) as factors predicting poor prognosis. Multivariate analysis of overall survival showed that age (p<0.001), serum carcinoembryonic antigen (CEA) levels (p=0.001), and histologic grade (p=0.013) also affected poor prognosis. In subgroup analysis of patients with recurrence, 25 patients underwent reoperation, while 20 patients did not. For 5-year overall survival rate, there was a significant difference between 84.7% of the reoperation group and 44.2% of the non-operation group (p<0.001). @*Conclusion@#The risk factors affecting overall survival rate after local excision were age 65 years or older, preoperative CEA level 5 or higher, and high histologic grade. In cases of recurrence after local excision of rectal cancer, salvage operation might improve overall survival.

Carcinoembryonic Antigen Improves the Performance of MagneticResonance Imaging in the Prediction of Pathologic Response afterNeoadjuvant Chemoradiation for Patients with Rectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The purpose of this study was to investigate the role of carcinoembryonic antigen (CEA) levelsin improving the performance of magnetic resonance imaging (MRI) for the predictionof pathologic response after the neoadjuvant chemoradiation (NCRT) for patients with rectalcancer. @*Materials and Methods@#We retrospectively reviewed the medical records of 524 rectal cancer patients who underwentNCRT and total mesorectal excision between January 2009 and December 2014. Theperformances of MRI with or without CEA parameters (initial CEA and CEA dynamics) forprediction of pathologic tumor response grade (pTRG) were compared by receiver-operatingcharacteristic analysis with DeLong’s method. Cox regression was used to identify the independentfactors associated to pTRG and disease-free survival (DFS) after NCRT. @*Results@#The median follow-up was 64.0 months (range, 3.0 to 113.0 months). On multivariate analysis,poor tumor regression grade on MRI (mrTRG; p < 0.001), initial CEA (p < 0.001) andthe mesorectal fascia involvement on MRI before NCRT (mrMFI; p=0.054) showed associationwith poor pTRG. The mrTRG plus CEA parameters showed significantly improved performancesin the prediction of pTRG than mrTRG alone. All of mrTRG, mrMFI, and initial CEAwere also identified as independent factors associated with DFS. The initial CEA further discriminatedDFS in the subgroups with good mrTRG or that without mrMFI. @*Conclusion@#The CEA parameters significantly improved the performance of MRI in the prediction ofpTRG after NCRT for patients with rectal cancer. The DFS was further discriminated by initialCEA level in the groups with favorable MRI parameters.

Long-term Oncologic Outcome of Postoperative Complications After Colorectal Cancer Surgery

Purpose@#The impact of postoperative complications on long-term oncologic outcome after radical colorectal cancer surgery is controversial. The aim of this study was to examine the risk factors and oncologic outcomes of surgery-related postoperative complication groups. @*Methods@#From January 2010 to December 2010, 310 patients experienced surgery-related postoperative complications after radical colorectal cancer surgery. These stage I–III patients were classified into 2 subgroups, minor (grades I, II) and major (grades III, IV) complication groups, according to extended Clavien-Dindo classification system criteria. Clinicopathologic differences between the 2 groups were analyzed to identify risk factors for major complications. The diseasefree survival rates of surgery-related postoperative complication groups were also compared. @*Results@#Minor and major complication groups were stratified with 194 patients (62.6%) and 116 patients (37.4%), respectively. The risk factors influencing the major complication group were pathologic N category and operative method. The prognostic factors associated with disease-free survival were preoperative perforation, perineural invasion, tumor budding, and receiving neoadjuvant therapy. With a median follow-up period of 72.2 months, the 5-year disease-free survival rates were 84.4% in the minor group and 78.5% in the major group, but there was no statistical significance between the minor and major groups (P = 0.392). @*Conclusion@#Advanced cancer and open surgery were identified as risk factors for increased surgery-related major complications after radical colorectal cancer surgery. However, severity of postoperative complications did not affect disease-free survival from colorectal cancer.

High preoperative serum CA 19-9 levels can predict poor oncologic outcomes in colorectal cancer patients on propensity score analysis

PURPOSE: The purpose of this study is to evaluate the prognostic value of preoperative serum CA 19-9 levels in colorectal cancer patients. METHODS: Between 2008 and 2011, 4,794 consecutive patients who underwent curative resection for colorectal cancer were analyzed. These patients were classified into 2 groups according to preoperative CA 19-9 (high CA 19-9: ≥37 ng/mL, n = 440; normal CA 19-9: <37 ng/mL, n = 4,354). We used 1:20 propensity score matching to adjust for potential baseline confounders between groups. RESULTS: After matching, 424 patients (10.5%) among 4,021 patients with colorectal cancer showed a high pre-CA 19-9 level (≥37 ng/mL). There were no significant differences between these 2 groups in age, sex, preoperative CEA level, or T, N, and M stage after matching. Of the 424 patients with high pre-CA 19-9, 141 (33.3%) exhibited cancer recurrence more frequently than patients with normal preoperative CA 19-9 (18.5%). Patients with an elevated preoperative CA 19-9 level showed significantly poorer survival than those with normal levels. The 5-year overall survival rate was 79.7% in the high preoperative CA 19-9 group and 91.9% in the normal preoperative CA 19-9 group (P < 0.001). The 5-year disease-free survival rate was 70.2% in the high preoperative CA 19-9 group and 82.7% in the normal preoperative CA 19-9 group (P < 0.001). CONCLUSION: Patients with an elevated preoperative CA 19-9 level in colorectal cancer have a significantly poorer prognosis than those with normal levels of CA 19-9. We therefore suggest preoperative CA 19-9 level can be used as an additional prognostic indicator of poor outcomes in colorectal cancer.

Mucinous carcinoma is a predictive factor for the risk of open conversion from laparoscopic colectomy in colorectal cancer

PURPOSE: Although laparoscopic surgery is widely accepted in the treatment of colorectal cancer, conversion to open surgery is associated with the rate of unfavorable outcomes. The aim of this study was to determine the factors associated with open conversion from laparoscopic surgery for colorectal cancer.METHODS: A total of 3,002 patients who underwent laparoscopic colectomy as an initial plan for the treatment of colorectal cancer located from the sigmoid colon to the rectum were retrospectively evaluated between January 2009 and December 2018 at Samsung Medical Center in Korea. Risk factors significantly associated with open conversion were determined using univariate and multivariate regression models.RESULTS: Among the 3,002 patients, open conversion was performed in 120 patients (4%). Age >60 years (adjusted odds ratio [AOR], 2.370), preoperative bowel obstruction (AOR, 2.348), clinical T4 stage (AOR, 2.201), and serum carcinoembryonic antigen level >5 ng/mL (AOR, 2.289) were significantly associated with open conversion. Moreover, mucinous carcinoma was a significantly more frequent histopathologic type than adenocarcinoma (10.0% vs. 3.2%, P<0.001) in the open conversion group with an AOR of 2.549 (confidence interval, 1.259–5.159; P=0.009).CONCLUSION: The present study presented a novel finding, i.e. mucinous carcinoma as the histopathologic type could be an independent predictive factor for conversion from laparoscopic colectomy to open surgery. Identifying patients with mucinous carcinoma will help stratify the risk of open conversion preoperatively.

Risk factors for locoregional recurrence in patients with pathologic T3N0 rectal cancer with negative resection margin treated by surgery alone

PURPOSE: This study aimed to identify prognostic factors for locoregional recurrence (LRR) in pT3N0 rectal cancer patients who were treated with surgery alone and had negative resection margin including circumferential resection margin (CRM) for optimal indication of adjuvant radiotherapy. MATERIALS AND METHODS: We reviewed patients with pT3N0 rectal cancer who were treated via upfront surgery and had no other adjuvant treatment from January 2003 to December 2012. In total, 122 patients who had negative resection margin including negative CRM were included in the analysis. RESULTS: The median follow-up period after surgery was 60 months (range, 3 to 161 months). During this time, 6 patients (4.9%) experienced LRR at the anastomotic site (4 patients), and regional lymphatic area (2 patients). The estimated 5-year rates of overall survival, recurrence-free survival, and LRR-free survival were 96.7%, 84.6%, and 94.0%, respectively. Multivariate analysis showed that level of tumor ≤5 cm was a significant prognostic factor for LRR-free survival (LRRFS) (p = 0.04; hazard ratio = 7.08; 95% confidence interval, 1.06–47.30). Patients with level of tumor ≤5 cm had an estimated 5-year LRRFS of 66.8%, which was much higher than 2.3% in patients with level of tumor >5 cm. There was no significant factor for recurrence-free survival or overall survival. CONCLUSION: In T3N0 rectal cancer, adjuvant chemoradiotherapy should be recommended in patients with level of tumor ≤5 cm for better local control. However, in patients with pT3N0 disease, negative resection margin, and level of tumor >5 cm, adjuvant chemoradiotherapy should be carefully suggested.

Congenital Cholesteatoma of Mastoid Temporal Bone and Posterior Cranial Fossa Treated with Transmastoid Marsupialization / 대한이비인후과학회지

A congenital cholesteatoma is a benign mass formed from the keratinizing stratified squamous epithelium. It usually occurs in young children's anterosuperior part of the middle ear. A congenital cholesteatoma which originates from mastoid temporal bone or expands to posterior cranial fossa is rare. Standard treatment of an intracranial cholesteatoma is surgical removal with craniotomy. A 69-year-old woman was diagnosed with a congenital cholesteatoma of mastoid temporal bone that expanded to the posterior cranial fossa, which was successfully treated with transmastoid marsupialization without craniotomy. This is a first documented case of a congenital cholesteatoma of mastoid temporal bone that expanded to posterior cranial fossa, which was successfully treated with transmastoid marsupialization without craniotomy.

Are We Predicting Disease Progress of the Rectal Cancer Patients without Surgery after Neoadjuvant Chemoradiotherapy? / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: There are patients who do not undergo surgery, regardless of tumor response for neoadjuvant chemoradiotherapy (nCRT) in rectal cancer. However, there have been few reports focused on how oncologic outcomes are worse in these patients. We sought to investigate oncologic outcomes for these non-operated patients with rectal cancer after nCRT. MATERIALS AND METHODS: A total of 1,063 records of patients with rectal cancer who were treated with nCRT from January 2002 to December 2013 were retrospectively reviewed. We categorized patients into the non-operated group (n=77), transanal local excision (TLE) group (n=54), ortotal mesorectal excision (TME) group (n=932) and compared each group using propensity score matching. RESULTS: In the non-operated group, the most common reason for no surgery was patient refusal (n=64). Eleven patients were considered to have achieve clinical complete response (cCR), which was an independent prognostic factor of progression-free survival (p=0.045). In patients with disease progression in the non-operated group, the overall survival did not improved according to salvage treatments (p=0.451). The non-operated group showed worse survivals compared to the TLE or TME group before and after matching (p < 0.001). This finding was also noted in the analysis of survival only in patients with cCR. CONCLUSION: In this study, non-operated patients did not secure oncologic safety regardless of cCR after nCRT. Our results suggest that a non-operative management must be carefully considered even if cCR is achieved.

Repeat Single Incision Laparoscopic Surgery after Primary Single Incision Laparoscopic Surgery for Colorectal Disease

PURPOSE: Single-incision laparoscopic surgery (SILS) for colorectal surgery is widely performed for many disease entities. However, there are few reports about the role of repeat single-incision laparoscopic surgery (R-SILS). The aim of this study is to analyze R-SILS data to evaluate the feasibility and safety of the occurrence and review its outcomes. METHODS: This is a retrospective review of the prospectively collected SILS database in Samsung Medical Center, Seoul, Korea, between April 2009 and December 2015. A retrospective review of 38 patients who underwent R-SILS from 2,207 patients who underwent primary SILS for colorectal surgery was performed. RESULTS: The indications of R-SILS were 23 primary SILS-related complications, 10 cancer-related, and 5 other surgical indications. Of the 38 repeat surgeries, 24 were emergent operations, and 14 were elective operations. Fecal diversion for anastomotic leakage after rectal surgery was the most common reason for reoperation. There were 2 cases of conversions: one case was converted to conventional multi-port, and the other case was converted to open surgery. Mean operative time was 137.9±64.1 min, estimated blood loss (EBL) was 105±98 ml, and length of hospital stay was 10.1±8.1 days. Post-operative complication was noted in 5 (13.2%) of 38 R-SILS cases, and there was no 30-day postoperative mortality. CONCLUSION: Repeat single-incision laparoscopy surgery is feasible and safe in select patients when performed by an experienced surgeon.

Transanal Endoscopic and Transabdominal Robotic Total Mesorectal Excision for Mid-to-Low Rectal Cancer: Comparison of Short-term Postoperative and Oncologic Outcomes by Using a Case-Matched Analysis

PURPOSE: This study aimed to compare short-term postoperative and oncologic outcomes of a transanal endoscopic total mesorectal excision (TME) to those of a transabdominal robotic TME. METHODS: A total of 62 patients with rectal cancer underwent transanal (n = 26) or robotic (n = 36) TME between June 2013 and December 2014. After case-matching by tumor location and TNM stage, 45 patients were included for analysis. The median follow-up period was 21.3 months. Operative, histopathologic and postoperative outcomes and recurrences were analyzed. RESULTS: Patients younger than 60 years of age were more frequently observed in the robotic TME group (75.0% vs. 47.6%, P = 0.059), but tumor location, cT and cN category, and preoperative chemoradiotherapy were not different between the 2 groups. Estimated blood loss was greater in the transanal group (283 mL vs. 155 mL, P = 0.061); however, the operation time and the rate of a diverting ileostomy and subsequent ileostomy repair were not different between the groups. The proximal resection margin was longer in the transanal TME group (20.8 cm ± 16.0 cm, P = 0.030), but the distal resection margins, involvements of the circumferential resection margin, TME quality, numbers of retrieved lymph nodes, postoperative complications, including anastomotic leak and voiding difficulty, and recurrence rates for the 2 groups were not statistically different. CONCLUSION: Transanal endoscopic and transabdominal robotic TME showed similar histopathologic and postoperative outcomes with the exception of the estimated blood loss and the proximal resection margin for a select group of patients.