Right-sided versus left-sided colorectal cancer in elderly patients: a sub-analysis of a large multicenter case-control study in Japan.

PURPOSE: This study investigated the impact of sidedness of colorectal cancer (CRC) in elderly patients on the prognosis. METHODS: In a sub-analysis of a multicenter case-control study of CRC patients who underwent surgery at ≥ 80 years old conducted in Japan between 2003 and 2007, both short- and long-term outcomes were compared between right-sided colon cancers (RCCs) and left-sided colorectal cancers (LCCs). RCCs were defined as those located from the cecum to the transverse colon. RESULTS: Among the 1680 patients who underwent curative surgery, 812 and 868 had RCCs and LCCs, respectively. RCCs were more frequent than LCCs in those who were female, had renal comorbidities, and had a history of abdominal surgery. Regarding tumor characteristics, RCCs were larger, invaded more deeply, and were diagnosed as either mucinous or signet ring-cell carcinoma more frequently than LCCs. Regarding the prognosis, patients with RCCs had a significantly longer cancer-specific survival (CS-S) and cancer-specific relapse-free survival (CS-RFS) than those with LCCs. Furthermore, sidedness was determined to be an independent prognostic factor for CS-S and CS-RFS. CONCLUSION: RCCs, which accounted for half of the cases in patients ≥ 80 years old, showed better long-term outcomes than LCCs.

Risk factors for postoperative pneumonia in elderly patients with colorectal cancer: a sub-analysis of a large, multicenter, case-control study in Japan.

PURPOSE: Postoperative pneumonia affects the length of stay and mortality after surgery in elderly patients with colorectal cancer (CRC). We aimed to determine the risk factors of postoperative pneumonia in elderly patients with CRC, and to evaluate the impact of laparoscopic surgery on elderly patients with CRC. METHODS: We retrospectively investigated 1473 patients ≥ 80 years of age who underwent surgery for stage 0-III CRC between 2003 and 2007. Using a multivariate analysis, we determined the risk factors for pneumonia occurrence from each baseline characteristic. RESULTS: Among all included patients, 26 (1.8%) experienced postoperative pneumonia, and restrictive respiratory impairment, obstructive respiratory impairment, history of cerebrovascular events, and open surgery were determined as risk factors (odds ratio [95% confidence interval], 2.78 [1.22-6.20], 2.71 [1.22-6.30], 3.60 [1.37-8.55], and 3.57 [1.22-15.2], respectively). Furthermore, postoperative pneumonia was more frequently accompanied by increasing cumulative numbers of these risk factors (area under the receiver operating characteristic curve = 0.763). CONCLUSIONS: Laparoscopic surgery may be safely performed in elderly CRC patients, even those with respiratory impairment and a history of cerebrovascular events.

Multiple primary malignancies involving primary sporadic colorectal cancer in Japan: incidence of gastric cancer with colorectal cancer patients may be higher than previously recognized.

BACKGROUND: Improvement in the prognosis of colorectal cancer (CRC) patients has led to increasing occurrences of multiple primary malignancies (MPMs) alongside CRC but little is known about their characteristics. This study was undertaken to clarify the clinical and pathological features of MPMs, especially those at extra colonic sites, in patients with CRC. METHODS: We reviewed 1,111 patients who underwent operations for primary sporadic CRC in Saitama Medical Center, Jichi Medical University between April 2007 and March 2012. Two patients with familial adenomatous polyposis, one with hereditary non-polyposis colorectal cancer, two with colitic cancer, and any patients with metastasis from CRC were excluded. We compared the clinicopathological features of CRC patients with and without MPMs. As a control, we used a database compiled of patients with gastric cancer (GC) detected by mass screening performed in the Saitama Prefecture in Japan 2010 and compared these with CRC patients with synchronous GC. RESULTS: Multiple primary malignancies at extracolonic sites were identified in 117 of 1,111 CRC patients (10.5%). The median age was 68 (range, 29 to 96) versus 71 (50 to 92) (P < 0.001). The incidence of GC (44.4% (52 of 117)) was the highest of all MPMs. All CRC patients with GC were older than 57 years. Synchronous GC was detected in 26 patients. By contrast, out of 200,007 screened people, 225 people were diagnosed as having GC in the Saitama Prefecture. The age-standardized incidence of synchronous GC in CRC patients was significantly higher (0.53%) than in the control group (0.03%) (odds ratio, 18.8; 95% confidence interval, 18.6 to 19.0; P < 0.001). CONCLUSION: Patients with CRC who were older than 50 years preferentially developed GC synchronously and metachronously. Thus, this patient group should undergo careful perioperative screening for GC.

Short-term surgical outcomes from a randomized controlled trial to evaluate laparoscopic and open D3 dissection for stage II/III colon cancer: Japan Clinical Oncology Group Study JCOG 0404.

OBJECTIVE: A randomized controlled trial to confirm the non-inferiority of laparoscopic surgery to open surgery in terms of overall survival was conducted, and short-term surgical outcomes are demonstrated. BACKGROUND: The efficacy and safety outcome of laparoscopic surgery for clinical stages II/III colon cancer undergoing Japanese D3 dissection are still unclear. METHODS: Eligibility criteria included colon cancer; tumor located in the cecum, ascending, sigmoid, or rectosigmoid colon; T3 or T4 without involvement of other organs; N0-2; and M0. Patients were randomized preoperatively and underwent tumor resection with D3 dissection. Safety analyses were conducted by per-protocol set. RESULTS: A total of 1057 patients were randomized between October 2004 and March 2009. By per-protocol set, 524 patients who underwent open surgery and 533 patients who underwent laparoscopic surgery were analyzed. D3 dissection was performed in 521 (99.4%) patients in the open surgery arm and 529 (99.2%) patients in the laparoscopic surgery arm. Conversion to open surgery was needed for 29 (5.4%) patients. Patients assigned to laparoscopic surgery had less blood loss (P < 0.001), although laparoscopic surgery lasted 52 minutes longer (P < 0.001). Laparoscopic surgery was associated with a shorter time to pass first flatus, decreased use of analgesics after 5 postoperative days, and a shorter hospital stay. Morbidity [14.3% (76/533) vs 22.3% (117/524), P < 0.001] was lower in the laparoscopic surgery arm. CONCLUSIONS: Short-term surgical safety and clinical benefits of laparoscopic D3 dissection were demonstrated. The primary endpoint will be reported after the primary analysis, planned for 2014.

DNA methylation alterations of AXIN2 in serrated adenomas and colon carcinomas with microsatellite instability.

BACKGROUND: Recent work led to recognize sessile serrated adenomas (SSA) as precursor to many of the sporadic colorectal cancers with microsatellite instability (MSI). However, comprehensive analyses of DNA methylation in SSA and MSI cancer have not been conducted. METHODS: With an array-based methylation sensitive amplified fragment length polymorphism (MS-AFLP) method we analyzed 8 tubular (TA) and 19 serrated (SSA) adenomas, and 14 carcinomas with (MSI) and 12 without (MSS) microsatellite instability. MS-AFLP array can survey relative differences in methylation between normal and tumor tissues of 9,654 DNA fragments containing all NotI sequences in the human genome. RESULTS: Unsupervised clustering analysis of the genome-wide hypermethylation alterations revealed no major differences between or within these groups of benign and malignant tumors regardless of their location in intergenic, intragenic, promoter, or 3' end regions. Hypomethylation was less frequent in SSAs compared with MSI or MSS carcinomas. Analysis of variance of DNA methylation between these four subgroups identified 56 probes differentially altered. The hierarchical tree of this subset of probes revealed two distinct clusters: Group 1, mostly composed by TAs and MSS cancers with KRAS mutations; and Group 2 with BRAF mutations, which consisted of cancers with MSI and MLH1 methylation (Group 2A), and SSAs without MLH1 methylation (Group 2B). AXIN2, which cooperates with APC and ß-catenin in Wnt signaling, had more methylation alterations in Group 2, and its expression levels negatively correlated with methylation determined by bisulfite sequencing. Within group 2B, low and high AXIN2 expression levels correlated significantly with differences in size (P = 0.01) location (P = 0.05) and crypt architecture (P = 0.01). CONCLUSIONS: Somatic methylation alterations of AXIN2, associated with changes in its expression, stratify SSAs according to some clinico-pathological differences. We conclude that hypermethylation of MLH1, when occurs in an adenoma cell with BRAF oncogenic mutational activation, drives the pathway for MSI cancer by providing the cells with a mutator phenotype. AXIN2 inactivation may contribute to this tumorigenic pathway either by mutator phenotype driven frameshift mutations or by epigenetic deregulation contemporary with the unfolding of the mutator phenotype.

Effect of left colonic artery preservation on anastomotic leakage in laparoscopic anterior resection for middle and low rectal cancer.

BACKGROUND: High morbidity rates related to anastomotic leakage and other factors restrict the application of laparoscopic rectal excision. The aim of the present study was to assess the effect of left colonic artery (LCA) preservation on postoperative complications after laparoscopic rectal excision. METHODS: Data from 888 patients from 28 leading hospitals in Japan who underwent laparoscopic-assisted sphincter-preserving resection of middle and low rectal cancers between 1994 and 2006 were analyzed. The effects of LCA preservation were analyzed among all anterior resection (AR) cases (n = 888) and among AR cases with radical lymph node excision (n = 411). RESULTS: Among all AR cases, the tumor size, number of lymph nodes collected with evidence of metastasis, TNM factor, and TNM staging were smaller in the LCA preservation group. Regarding complications, the rate of anastomotic leak was significantly higher in the LCA non-preservation group among all AR cases, as well as among AR cases with radical lymph node excision. Nevertheless, there was no difference in survival rate between LCA preservation group and non-preservation group, as measured by the Kaplan-Meier method. CONCLUSIONS: Our data suggest that the preservation of the LCA in laparoscopic AR for middle and low rectal cancer is associated with lower anastomotic leak rates.

Interleukin-13 damages intestinal mucosa via TWEAK and Fn14 in mice-a pathway associated with ulcerative colitis.

BACKGROUND & AIMS: TWEAK, a member of the tumor necrosis factor (TNF) superfamily, promotes intestinal epithelial cell injury and signals through the receptor Fn14 following irradiation-induced tissue damage and during development of colitis in mice. Interleukin (IL)-13, an effector of tissue damage in similar models, has been associated with the pathogenesis of ulcerative colitis (UC). We investigated interactions between TWEAK and IL-13 following mucosal damage in mice. METHODS: We compared patterns of gene expression in intestinal tissues from wild-type and TWEAK knockout mice following γ-irradiation. Intestinal explants from these mice were used to detect cell damage induced by IL-13 and TNF-α. Levels of messenger RNA for IL-13, TWEAK, and Fn14 were measured in mucosal samples from patients with UC. RESULTS: Based on gene expression analysis, TWEAK mediates γ-irradiation-induced epithelial cell cycle arrest and apoptosis. However, TWEAK alone did not induce damage or apoptosis of primary intestinal epithelial cells. On the other hand, exogenous IL-13 activated caspase-3 in naïve intestinal explants; this process required TWEAK, Fn14, and secretion of endogenous TNF-α which was mediated by ADAM17. Conversely, activation of caspase by exogenous TNF-α required IL-13, TWEAK, and Fn14. In mucosa from patients with UC, messenger RNA levels of IL-13, TWEAK, and Fn14 increased with level of disease severity. CONCLUSIONS: IL-13-induced damage of intestinal epithelial cells requires TWEAK, its receptor (Fn14), and TNF-α. IL-13, TNF-α, TWEAK, and Fn14 could perpetuate and aggravate intestinal inflammation in patients with UC.

Risk factors for intra-abdominal infection after pancreaticoduodenectomy - a retrospective analysis to evaluate the significance of preoperative biliary drainage and postoperative pancreatic fistula.

BACKGROUND/AIMS: Intra-abdominal infection (IAI) after pancreaticoduodenectomy (PD) is a common cause of prolongation of postoperative hospital stay and readmission to the hospital following discharge. METHODOLOGY: Two hundred and six patients undergoing PD were reviewed to investigate the risk factors for IAI after PD. Patients were separated into two groups: those who developed IAI after PD (Group A; n=44), and those who had not developed IAI after PD (Group B; n=162), the two groups were then compared to identify the risk factors for IAI after PD. A hundred and six patients (51.5%) underwent preoperative biliary drainage (PBD). RESULTS: Multivariate analysis revealed that pancreatic fistula (PF) was an independent risk factor for IAI after PD (p<0.001; odds ratio=9.58; 95% confidence interval=4.37-21.0), but PBD was not a significant risk factor. CONCLUSIONS: We demonstrated that the adequate PBD might not affect IAI after PD. On the other hand, PF was an independent risk factor for IAI after PD. A large randomized controlled trial, which would prove the effect of early removal of a prophylactic placed drain to prevent IAI, should be planned.

Risk factor for pancreatic fistula after pancreaticoduodenectomy performed by a surgeon during a learning curve: analysis of a single surgeon's experiences of 100 consecutive patients.

BACKGROUND/AIMS: Among several kinds of morbidities, pancreatic fistula (PF) is the most common complication of pancreaticoduodenectomy (PD). However, it has not been clarified what kind of perioperative factors are risk factors of PF after PD is performed by a training surgeon. METHODOLOGY: We evaluated the risk factors of PF after PD in which all procedures for 100 consecutive patients were performed by a single training surgeon, retrospectively. The 100 cases were divided into two groups and the first 50 cases were named Group A and the latter 50 cases were named Group B. RESULTS: Multivariate analysis demonstrated that the absence of main pancreatic duct dilatation was an independent risk factor for grade B and grade C PF (p=0.0080; OR=5.311; 95% CI=1.116-7.025). There was no significant difference of the frequencies of grade B and grade C PF between Group A and Group B (p=0.13361). CONCLUSIONS: We demonstrated that the absence of main pancreatic duct dilatation was an independent risk factor for grade B and grade C PF after PD was performed by a training surgeon; for those without pancreatic duct dilatation, PD can be performed by a surgeon in the earlier training period with an acceptable rate of PF.

Factors influencing improved patient outcomes after pancreaticoduodenectomy--a single institute experience of 209 consecutive patients in a decade.

BACKGROUND/AIMS: Postoperative mortality and morbidity after pancreaticoduodenectomy (PD) remain major issues today and we discuss the factors influencing improved patient outcome after PD. METHODOLOGY: Two hundred and nine patients underwent PD between 2001 and 2010 In our hospital. The first 58 cases between 2001 and 2004 were named Group A and the latter 151 cases between 2005 and 2010 were named Group B. Then, we compared the intraoperative outcomes and postoperative mortality and major morbidities between two groups. RESULTS: Between 2005 and 2010, the annual volume of PD has been over 20 continuously. In Group A, 58 PDs were performed by five surgeons but in Group B, the main surgeon performed 131 of 151 (86.8%) PDs. The mortality rate in Group A (1.7%) was not different from that in Group B (1.3%). The frequency of patients with all postoperative morbidities in Group B (43.7%) was significantly lower than that in Group A (70.7%) (p=0.00048). The frequencies of DGE and SSI in Group B (8.6%, 23.8%) were significantly lower than those in Group A (25.8%, 37.9%) (p=0.010, p=0.042). CONCLUSIONS: The increases of surgeon and hospital volume and the change of the mode of PD were factors influencing improved patient outcomes after PD.

Comprehensive analysis of chemokines and cytokines secreted in the peritoneal cavity during laparotomy.

We recently found that chemokine-driven peritoneal cell aggregation is the primary mechanism of postoperative adhesion in a mouse model. To investigate this in humans, paired samples of peritoneal lavage fluid were obtained from seven patients immediately after incision (preoperative) and before closure (postoperative), and were assayed for the presence of 27 cytokines and chemokines using multiplex beads assay. As a result, IL-6 and CCL5 showed the most striking increase during operation. Recombinant CCL5 or lavage fluid induced chemotaxis of human peripheral blood mononuclear cells. We propose that CCL5 is possibly involved in the mechanism of postoperative adhesion in humans.

Enhancement of DNA hypomethylation alterations by gastric and bile acids promotes chromosomal instability in Barrett's epithelial cell line.

Gastric and bile acid reflux leads to chronic inflammation, resulting in methylation alterations in Barrett's esophagus (BE) together with chromosomal instability (CIN). We investigated DNA hypomethylation following acid exposure and confirmed its significance in BE-related carcinogenesis by inducing CIN in vitro. OACP4C, an esophageal cancer cell line, and CP-A, a non-dysplastic cell line originating from BE, were exposed to acidic conditions using deoxycholic acid. CP-A exhibited substantially increased DNA hypomethylation of alpha satellite sequences in the centromere region, as well as increased levels of alpha satellite transcripts, but no changes were observed in the long interspersed nucleotide element-1 sequences distributed throughout the entire genome. These changes were not clearly found in OACP4C. Copy number changes at specific chromosomes were identified in CP-A, along with an increased number of cells exhibiting abnormal segregations, whereas these changes were rarely observed in OACP4C. The changes were maintained after several cell divisions. These findings suggest that alpha satellites are likely targets of DNA hypomethylation induced by acid exposure. CP-A was more sensitive to acid exposure than OACP4C, indicating that acid-induced DNA hypomethylation is involved in cancer development rather than progression, which could be involved in the underlying mechanism of esophagogastric junction carcinoma development.

Overexpression of satellite RNAs in heterochromatin induces chromosomal instability and reflects drug sensitivity in mouse cancer cells.

Overexpression of satellite RNAs in heterochromatin induces chromosomal instability (CIN) through the DNA damage response and cell cycle checkpoint activation. Although satellite RNAs may be therapeutic targets, the associated mechanisms underlying drug sensitivity are unknown. Here, we determined whether satellite RNAs reflect drug sensitivity to the topoisomerase I inhibitor camptothecin (CPT) via CIN induction. We constructed retroviral vectors expressing major satellite and control viruses, infected microsatellite stable mouse colon cancer cells (CT26) and MC38 cells harboring microsatellite instability, and assessed drug sensitivity after 48 h. Cells overexpressing satellite RNAs showed clear features of abnormal segregation, including micronuclei and anaphase bridging, and elevated levels of the DNA damage marker γH2AX relative to controls. Additionally, overexpression of satellite RNAs enhanced MC38 cell susceptibility to CPT [half-maximal inhibitory concentration: 0.814 µM (control) vs. 0.332 µM (MC38 cells with a major satellite), p = 0.003] but not that of CT26. These findings imply that MC38 cells, which are unlikely to harbor CIN, are more susceptible to CIN-induced CPT sensitivity than CT26 cells, which are characterized by CIN. Furthermore, CPT administration upregulated p53 levels but not those of p21, indicating that overexpression of major satellite transcripts likely induces CPT-responsive cell death rather than cellular senescence.

Genome­wide DNA hypomethylation drives a more invasive pancreatic cancer phenotype and has predictive occult distant metastasis and prognosis potential.

Genome­wide DNA hypomethylation is the most common molecular feature in human cancers associated with chromosomal instability (CIN), which is involved in the mechanisms that regulate pancreatic cancer (PC) metastasis. It was investigated whether genome­wide DNA hypomethylation affects the phenotype in PC via CIN in vitro, and its significance on the biological behavior of PC was verified. The relative demethylation level (RDL) of long interspersed nucleotide element­1 (LINE­1) in human PC cell lines was used to characterize DNA hypomethylation using methylation­specific quantitative (q)PCR. CIN was estimated by changes in chromosomal copy number using comparative genomic hybridization analysis. Abnormal segregation of chromosomes was assessed by immunocytochemistry, and the DNA damage response was evaluated using the number of anti­Î³H2AX positive cells. Invasion ability was assessed using a Matrigel invasion assay. Clinical specimens from 49 patients with PC who underwent curative surgery were evaluated for a correlation of DNA hypomethylation with clinical outcome. Successful induction of genome­wide DNA hypomethylation in PC cells led to copy number changes in specific chromosomal regions. The number of cells with abnormal segregation of chromosomes significantly increased with the number of anti­Î³H2AX positive cells. The invasive potential of these cells also significantly increased. The occurrence of occult distant metastasis in the clinical specimens and receiver operating characteristic analysis clearly identified those who were and were not likely to have occult distant metastasis, with high LINE­1 RDL significantly correlated with the presence of occult distant metastasis (P=0.035) and poor prognosis (P=0.048). The significance of genome­wide DNA hypomethylation on the biological behavior of PC, which promotes a more invasive phenotype via CIN in vitro and predicts the susceptibility to occult distant metastasis and poor prognosis in patients with PC was revealed.

OSNA-based novel molecular testing for lymph node metastases in colorectal cancer patients: results from a multicenter clinical performance study in Japan.

BACKGROUND: Lymph node (LN) metastasis in colorectal cancer (CRC) is a critical factor in making accurate prognoses and therapeutic decisions. This study evaluated the clinical performance of the one-step nucleic acid amplification (OSNA) assay in accurately diagnosing LN metastases in CRC patients through the specific detection of cytokeratin 19 mRNA levels in LNs. METHODS: The OSNA assay was performed on 121 LNs dissected from early-stage CRC patients (pStage 0 or I) or from patients with benign colorectal disease (study 1). Separately, 385 LNs were dissected from 85 CRC patients (any stage); the OSNA assay was performed on half of each LN, and the results were compared with histopathological examination in 2-mm intervals of the other LN half (study 2). RESULTS: In study 1, all 121 histopathologically negative LNs were also negative by the OSNA assay (concordance rate for metastasis negative: 1.0, 95% confidence interval [95% CI]: 0.976-1.0). In study 2, the concordance rate between the OSNA assay and the 2-mm-interval histopathological examination was 0.971 (95% CI: 0.950-0.984), with a sensitivity of 0.952 (95% CI: 0.881-0.987) and a specificity of 0.977 (95% CI: 0.953-0.991). CONCLUSIONS: The OSNA assay provided a judgment performance equivalent to a 2-mm-interval histopathological examination, a more detailed assay than the common pathological examination. Therefore, the OSNA assay is considered a new molecular examination method for the diagnosis of LN metastases in CRC patients in clinical settings.

Early gastric cancer combined with multiple metachronous osteosclerotic bone and bone marrow metastases that responded to chemoradiotherapy.

We report a 75-year-old woman who suffered multiple metachronous osteosclerotic bone metastases 4 years after a distal gastrectomy for early gastric cancer (EGC). The primary tumor was a poorly differentiated adenocarcinoma, which had invaded the submucosal layer, and only one lymph node metastasis was noted. To the best of our knowledge, cases of EGC combined with metachronous osteosclerotic multiple bone and bone marrow metastases that respond to chemoradiotherapy are very rare. In this case, the multiple bone metastases were diagnosed 4 years after surgery. The patient's metastatic tumor was successfully treated using S-1, paclitaxel, and camptothecin, with subsequent irradiation. The patient survived for 24 months after the treatment, without having any major symptoms.

Biliary Peritonitis Caused by Spontaneous Bile Duct Rupture in the Left Triangular Ligament of the Liver after Endoscopic Sphincterotomy for Choledocholithiasis.

Spontaneous bile duct rupture is a rare condition in adults, with only 70 cases reported. Increased bile duct wall pressure may lead to rupture and biliary peritonitis. In this patient, the bile duct ruptured in the hepatic left triangular ligament. A 91-year-old man underwent endoscopic retrograde cholangiopancreatography for choledocholithiasis and endoscopic retrograde biliary drainage (ERBD) placement. One week later, removal of the ERBD and common bile duct stones and an endoscopic sphincterotomy (EST) were performed. Four days later, the patient had abdominal pain, increased inflammatory reaction, and jaundice. Abdominal computed tomography showed ascites, bile duct dilatation and fluid collection under the liver (10 cm in diameter). Emergency surgery was performed to drain the fluid. On laparotomy, encapsulated biliary ascites was seen. To search for the site of the leak, after cholecystectomy, a tube (C-tube) was inserted into the common bile duct via cystic duct stump. Because of uncontrollable bleeding, after packing with surgical gauze, the operation was temporarily stopped. The next day, reoperation was performed. Intraoperative cholangiography with contrast dye revealed the perforation site in the left triangular ligament and a partial resection was performed. Bile excretion from the C-tube was subsequently observed, but the patient's jaundice did not improve. Although endoscopic retrograde cholangiopancreatography revealed that the EST site was normal, ERBD was placed again, and the jaundice gradually improved. Although EST was performed in this case, biliary peritonitis resulting from spontaneous bile duct rupture occurred. This case was very informative because biliary perforation may occur even after EST.

Optimal value of CA19-9 determined by KRAS-mutated circulating tumor DNA contributes to the prediction of prognosis in pancreatic cancer patients.

Despite the acceptance of carbohydrate antigen 19-9 (CA19-9) as a valuable predictor for the prognosis of pancreatic ductal adenocarcinoma (PDAC), its cutoff value remains controversial. Our previous study showed a significant correlation between CA19-9 levels and the presence of KRAS-mutated ctDNA in the blood of patients with PDAC. Based on this correlation, we investigated the optimal cutoff value of CA19-9 before surgery. Continuous CA19-9 values and KRAS-mutated ctDNAs were monitored in 22 patients with unresectable PDAC who underwent chemotherapy between 2015 and 2017. Receiver operating characteristic curve analysis identified 949.7 U/mL of CA19-9 as the cutoff value corresponding to the presence of KRAS-mutated ctDNA. The median value of CA19-9 was 221.1 U/mL. Subsequently, these values were verified for their prognostic values of recurrence-free survival (RFS) and overall survival (OS) in 60 patients who underwent surgery between 2005 and 2013. Multivariate analysis revealed that 949.7 U/mL of CA19-9 was an independent risk factor for OS and RFS in these patients (P = 0.001 and P = 0.010, respectively), along with lymph node metastasis (P = 0.008 and P = 0.017), unlike the median CA19-9 level (P = 0.150 and P = 0.210). The optimal CA19-9 level contributes to the prediction of prognosis in patients with PDAC before surgery.

Patient's appetite is a good indicator for postoperative feeding: a proposal for individualized postoperative feeding after surgery for colon cancer.

BACKGROUND: In modern postoperative management, early and enforced feeding has been implemented. The aim of this study is to determine the feasibility of individualized feeding according to the patient's appetite. METHODS: Patients who underwent elective surgery for colon cancer from January 2007 to December 2008 were studied. Liquid intake was allowed on the day of operation and solid normal meal (1800 Kcal) was served according to the recovery of appetite. RESULTS: Two hundred and nine patients were included. Open and laparoscopic surgeries were performed in 104 and 105 patients, respectively. Solid meal was started by the second postoperative day in 81.3% of patients. Intravenous drip infusion was completed within 1 day of the start of the solid meal in 86.6% of the patients and 182 out of 209 patients (87.1%) did not require drip infusion by the third postoperative day. There were no mortalities and readmission rate was 1.0% (2/209). CONCLUSION: The introduction of feeding according to the recovery of appetite was safe and feasible with no delay in establishing oral intake.

Accelerated learning curve for colorectal resection, open versus laparoscopic approach, can be attained with expert supervision.

BACKGROUND: Laparoscopic colorectal resection (LCR) is gaining popularity. Nonetheless, open surgery remains an important technique. Thus, surgeons should be technically proficient in both open and laparoscopic surgery. One question however remains unanswered: Can training for open and LCR occur simultaneously? The objective of this paper is to review the learning curve for open and laparoscopic colon resection of one surgeon who underwent a rigorous training program. METHODS: A review of consecutive patients who underwent surgery for colon and rectosigmoid junction cancers by one trainee surgeon was performed. This surgeon had completed his basic surgical residency but had limited experience in colorectal cancer surgery. In total, 75 patients were included in this study. All operations were supervised by at least one staff surgeon with experience of more than 300 LCR cases. The trainee surgeon was allowed to train in both laparoscopic and open colorectal resection simultaneously. RESULTS: Forty-three patients underwent laparoscopic resection, while 32 patients underwent open surgery. Age, gender, mean body mass index (BMI), preoperative risk, and history of past abdominal surgery showed no significant difference between laparoscopic and open groups. There were no differences in tumor stage [International Union against Cancer (UICC)] or tumor size (p = 0.068 and 0.228, respectively). The morbidity rate for open and laparoscopic surgery was 3.1% (1/32) and 4.7% (2/43), respectively (p = 0.484). Operation time decreased with increasing experience, and plateaued after 25 cases in the laparoscopic group and 22 cases in the open group. The learning curve for open cases was 11 cases, and 7 for laparoscopic surgery. CONCLUSIONS: Surgeons who have completed a basic surgical residency but have limited colorectal surgery experience can learn both open and laparoscopic colorectal surgery simultaneously in an effective manner under supervision by well-experienced surgeons.