Short-term outcomes of robotic tumor-specific mesorectal resection of rectal cancer: surgical techniques in mesorectal division using rolling division of the mesorectum.

BACKGROUND: This study aims to report our surgical techniques for robot-assisted laparoscopic anterior resection, specifically focusing on mesorectal division using rolling division of the mesorectum, and to elucidate short-term outcomes at a single institution. Tumor-specific mesorectal excision (TSME) is commonly performed for resection of a tumor located in the upper rectum. However, especially in a narrow pelvis, it is difficult to perform appropriate mesorectal division at an adequate distance from the tumor in robot-assisted laparoscopic anterior resection. METHODS: Retrospective case series of patients with rectal cancer who underwent robot-assisted TSME using rolling division of mesorectum. Patient characteristics, perioperative clinical results, surgical and pathological details were recorded. RESULTS: A total of 198 patients underwent robot-assisted TSME for rectal cancer using rolling division of mesorectum between May 2019 and December 2023.The tumor was located in the upper rectum in 45 patients, middle rectum in 115 patients and lower rectum in 38 patients. The types of resections were 40 high anterior resection and 158 low anterior resections. The median operation time was 175 (range 109-310) min, and median mesorectal division time was 24 (range 15-45) min. Median blood loss was 3 (range 0-20) ml; no patients required blood transfusion. The overall complication rate of Clavien-Dindo classification grades I-IV was 7.1%. Anastomotic leakage was observed in two patients (1.0%) with grade III. There was no surgical mortality in this series. CONCLUSION: This robotic technique for anterior resection is a feasible and reliable procedure for achieving sufficient and safe TSME in this cohort.

Robotic-assisted surgery may be a useful approach to protect urinary function in the modern era of diverse surgical approaches for rectal cancer.

BACKGROUND: Urinary dysfunction (UD) remains a significant complication of rectal cancer surgery. In modern surgical treatment for rectal cancer, multiple operative approaches are used. Such approaches include open, laparoscopic, and robotic-assisted surgery; and multiple procedures, including anterior, intersphincteric, and abdominoperineal resection. Thus, modern surgical treatments for rectal cancer have diversified. This study aimed to identify risk factors for early UD (EUD) after total mesorectal excision (TME) and to explore the methods for decreasing postoperative EUD in diverse surgical treatments for rectal cancer. METHODS: In our retrospective cohort study, we enrolled patients with lower rectal cancer who underwent TME alone at a single high-volume cancer center between 2010 and 2017. EUD was defined as the presence of ≥ 50 mL residual urine volume. Multivariate analysis was performed to determine clinicopathological factors significantly associated with postoperative EUD. RESULTS: Of a total of 337 eligible patients, 32 patients (10%) had postoperative EUD. Multivariate analysis revealed that only the operative approach (laparoscopic surgery: odds ratio [OR], 8.93; 95% confidence interval [CI], 2.94-27.14, open surgery: OR, 11.55; 95% CI 2.10-63.83) was significantly associated with an increase in postoperative EUD. Robotic-assisted surgery was associated with significant reduction in postoperative EUD. CONCLUSION: Only robotic-assisted surgery was inversely correlated with postoperative EUD. Robotic-assisted surgery may be a useful approach to protect urinary function in lower rectal cancer surgery.

Effect of preoperative chemoradiotherapy on the immunological status of rectal cancer patients.

The aim of the study was to investigate the effect of chemo-radiation on the genetic and immunological status of rectal cancer patients who were treated with preoperative chemoradiotherapy (CRT). The expression of immune response-associated genes was compared between rectal cancer patients treated (n = 9) and not-treated (n = 10) with preoperative CRT using volcano plot analysis. Apoptosis and epithelial-to-mesenchymal transition (EMT) marker genes were analysed by quantitative PCR (qPCR). Other markers associated with the tumor microenvironment (TME), such as tumor-infiltrating lymphocytes (TIL) and immune checkpoint molecules, were investigated using immunohistochemistry (IHC). The clinical responses of preoperative CRT for 9 rectal cancer patients were all rated as stable disease, while the pathological tumor regression score (TRG) revealed 6 cases of grade2 and 3 cases of grade1. According to the genetic signature of colon cancers, treated tumors belonged to consensus molecular subtype (CMS)4, while not-treated tumors had signatures of CMS2 or 3. CRT-treated tumors showed significant upregulation of EMT-associated genes, such as CDH2, TGF-beta and FGF, and cancer stem cell-associated genes. Additionally, qPCR and IHC demonstrated a suppressive immunological status derived from the upregulation of inflammatory cytokines (IL-6, IL-10 and TGF-beta) and immune checkpoint genes (B7-H3 and B7-H5) and from M2-type macrophage accumulation in the tumor. The induction of EMT and immune-suppressive status in the tumor after strong CRT treatment urges the development of a novel combined therapy that restores immune-suppression and inhibits EMT, ultimately leading to distant metastasis control.

[Neutrophil-Lymphocyte Ratio as a Prognostic Indicator in Patients Treated with Nivolumab for Gastric Cancer].

BACKGROUND: Immune checkpoint inhibitors(nivolumab)have been recommended as third-line chemotherapy for advanced gastric cancer(AGC)according to the Guidelines of Gastric Cancer(5th edition). Therefore, they have been used in daily clinical practice. On the other hand, the neutrophil-lymphocyte ratio(NLR)has been reported to be associated with the prognosis of cancer patients. METHODS: Twenty patients treated with nivolumab for AGC between January 2018 and November 2019 were retrospectively examined. RESULTS: Median age of the 20 patients(18 males, 2 females)was 70 years(55- 84 years). Nivolumab was administered as second-, third-, fourth-, and fifth-line therapy in 1, 11, 7, and 1 case, respectively. The best tumor response evaluation was observed in PR 1, SD 7 and PD 10 cases. Median overall survival(OS)was 10 months, and median progression-free survival(PFS)was 3 months. No serious adverse events occurred. Compared to the NLR>2.0 group, OS significantly prolonged(2.2 months vs 21.9 months)and PFS tended to prolong(1.4 months vs 6.2 months)in the NLR≤2.0 group. CONCLUSION: NLR may be an effective prognostic factor in patients with AGC receiving nivolumab treatment.

Metabolomic profiling of gastric cancer tissues identified potential biomarkers for predicting peritoneal recurrence.

BACKGROUND: Metabolomics is useful for analyzing the nutrients necessary for cancer progression, as the proliferation is regulated by available nutrients. We studied the metabolomic profile of gastric cancer (GC) tissue to elucidate the associations between metabolism and recurrence. METHODS: Cancer and adjacent non-cancerous tissues were obtained in a pair-wise manner from 140 patients with GC who underwent gastrectomy. Frozen tissues were homogenized and analyzed by capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). Metabolites were further assessed based on the presence or absence of recurrence. RESULTS: Ninety-three metabolites were quantified. In cancer tissues, the lactate level was significantly higher and the adenylate energy charge was lower than in non-cancerous tissues. The Asp, ß-Ala, GDP, and Gly levels were significantly lower in patients with recurrence than in those without. Based on ROC analyses to determine the cut-off values of the four metabolites, patients were categorized into groups at high risk and low risk of peritoneal recurrence. Logistic regression and Cox proportional hazard analyses identified ß-Ala as an independent predictor of peritoneal recurrence (hazard ratio [HR] 5.21 [95% confidence interval 1.07-35.89], p = 0.029) and an independent prognostic factor for the overall survival (HR 3.44 [95% CI 1.65-7.14], p < 0.001). CONCLUSIONS: The metabolomic profiles of cancer tissues differed from those of non-cancerous tissues. In addition, four metabolites were significantly associated with recurrence in GC. ß-Ala was both a significant predictor of peritoneal recurrence and a prognostic factor.

Endoscopic resection of T1 colorectal cancer prior to surgery does not affect surgical adverse events and recurrence.

BACKGROUND: Although a "no-touch isolation" technique is used in colorectal cancer surgery to reduce the risk of metastatic induction, endoscopic resection (ER) prior to surgery may work against this aim. This study evaluated the effects of initial ER on short- and long-term outcomes in T1 colorectal cancer. METHODS: This retrospective cohort study enrolled patients with pathological T1 colorectal cancer who underwent colorectal surgical resection at a Japanese tertiary cancer center between 2002 and 2012. A total of 548 eligible patients were divided into two groups: patients initially treated using surgical resection with lymph node dissection (LND) (primary group, n = 304) and patients treated using initial ER and additional surgical resection with LND (secondary group, n = 244). The inverse probability of treatment weighting (IPTW) method based on propensity score was used to compare postoperative complications and long-term recurrence. RESULTS: The incidence of postoperative complications with Clavien-Dindo classification grade ≥ II was 10.9% and 7.4% in the primary and secondary groups, respectively (p = 0.16). Multivariate analysis with a logistic proportional hazard regression model using IPTW revealed no significant differences in postoperative complications between the two groups (p = 0.79). During a median follow-up after surgery of 61.4 months, recurrence was observed in 3 (1.0%) and 8 (3.3%) patients, respectively (p = 0.06). Multivariate analysis with a Cox proportional hazard regression model using IPTW revealed no significant differences in recurrence between the two groups (p = 0.07). CONCLUSION: Our results suggest no significant adverse effects of initial ER prior to surgery on surgical complications and long-term recurrence in T1 colorectal cancer.

Diagnostic value of computed tomography (CT) and positron emission tomography (PET) for paraaortic lymph node metastasis from left-sided colon and rectal cancer.

BACKGROUND/OBJECTIVE: Paraaortic lymph node (PALN) metastasis influences treatment strategy for colorectal cancer. The aims of this study were to elucidate the diagnostic value of computed tomography (CT) and positron emission tomography (PET) for PALN metastasis from left-sided colorectal cancer. METHODS: A total of 108 patients who underwent radical surgery including PALN dissection were included. Size and morphology of PALN were evaluated using CT, and presence of higher FDG uptake was evaluated using PET. Findings of CT and PET were compared with pathological status. RESULTS: The largest major axis ≥11 mm and heterogeneous internal density were predictive factors on multivariate analysis. Eighty five percent of the PALNs ≥11 mm with heterogeneous internal density were pathologically metastatic, whereas 94.1% without them were not metastatic. PET had an accuracy, sensitivity, and specificity of 85.7%, 66.7%, and 94.1%, respectively. In patients with PALNs <11 mm without heterogeneous internal density, the accuracy and specificity of PET improved to 93.8% and 96.6%, respectively. Conversely, in patients with some predictive CT findings, although the positive predictive value of PET increased from 83.3% to 88.9%, the accuracy and sensitivity remained at 70.6% and 66.7%, respectively, and 50.0% were false-negatives. CONCLUSION: CT had high NPV and relatively high PPV. PET had high specificity but low sensitivity. The addition of PET could be useful to confirm no PALN metastasis in patients with no predictive CT findings. Conversely, the improvement of diagnostic ability was limited in patients with some predictive CT findings.

Laparoscopic high anterior resection for rectal cancer with rare variations of the left renal vessels: A case report.

We present a case of rectal cancer with rare variations of the left renal vessels. A man in his 60s underwent endoscopic mucosal resection for an Ip-type lesion in the upper rectum. Histologically, the lesion was a well-differentiated adenocarcinoma that had invaded the deep submucosal layer. Therefore, additional resection of the rectum with regional lymph node dissection was recommended. Preoperative CT revealed rare variations of the left renal vessels. There were two left renal arteries and veins; the caudal left renal artery and vein were located between the inferior mesenteric artery and the abdominal aorta. During the operation, these renal vessels were confirmed, and laparoscopic high anterior resection was performed safely without any injury to these renal vessels. To avoid the risk of unexpected intraoperative injuries, it is important to preoperatively check whether there are any variations in the renal vessels, even before colorectal surgery.

Clinicopathological and mutational analyses of colorectal cancer with mutations in the POLE gene.

Here, we investigated the clinicopathological and mutation profiles of colorectal cancer (CRC) with POLE mutations. Whole-exome sequencing was performed in 910 surgically resected primary CRCs. Tumors exceeding 500 counts of nonsynonymous single nucleotide variants (SNVs) were classified as hypermutators, whereas the remaining were classified as nonhypermutators. The hypermutators were subdivided into 2 groups. CRCs harboring more than 20% C-to-A and less than 3% C-to-G transversions were classified as POLE category tumors, whereas the remaining were classified as common-hypermutators. Gene expression profiling (GEP) analysis was performed in 892 (98.0%) tumors. Fifty-seven (6.3%) and 10 (1.1%) tumors were classified common-hypermutators and POLE category tumors, respectively. POLE category tumors harbored a significantly higher SNV count than common-hypermutators, and all POLE category tumors were associated with exonuclease domain mutations, such as P286R, F367C, V411L, and S297Y, in the POLE gene. Patients with POLE category tumors were significantly younger than those with nonhypermutators and common-hypermutators. All POLE mutations in the early-onset (age of onset ≤50 years old) POLE category (7 tumors) were P286R mutations. GEP analysis revealed that PD-L1 and PD-1 gene expression levels were significantly increased in both common-hypermutators and POLE category tumors compared with those in nonhypermutators. CD8A expression was significantly upregulated in POLE category tumors compared with that in nonhypermutators. Thus, we concluded that CRCs with POLE proofreading deficiency had characteristics distinct from those of other CRCs. Analysis of POLE proofreading deficiency may be clinically significant for personalized management of CRCs.

Mesorectal fat area as a useful predictor of the difficulty of robotic-assisted laparoscopic total mesorectal excision for rectal cancer.

BACKGROUND: Various predictors of the difficulty of total mesorectal excision for rectal cancer have been described. Although a bulky mesorectum was considered to pose technical difficulties in total mesorectal excision, no studies have evaluated the influence of mesorectum morphology on the difficulty of total mesorectal excision. Mesorectal fat area at the level of the tip of the ischial spines on magnetic resonance imaging was described as a parameter characterizing mesorectum morphology. This study aimed to evaluate the influence of clinical and anatomical factors, including mesorectal fat area, on the difficulty of total mesorectal excision for rectal cancer. METHODS: This study enrolled 98 patients who underwent robotic-assisted laparoscopic low anterior resection with total mesorectal excision for primary rectal cancer, performed by a single expert surgeon, between 2010 and 2015. Magnetic resonance imaging-based pelvimetry data were collected. Linear regression was performed to determine clinical and anatomical factors significantly associated with operative time of the pelvic phase, which was defined as the time interval from the start of rectal mobilization to the division of the rectum. RESULTS: The median operative time of the pelvic phase was 68 min (range 33-178 min). On univariate analysis, the following variables were significantly associated with longer operative time of the pelvic phase: male sex, larger tumor size, larger visceral fat area, larger mesorectal fat area, shorter pelvic outlet length, longer sacral length, shorter interspinous distance, larger pelvic inlet angle, and smaller angle between the lines connecting the coccyx to S3 and to the inferior middle aspect of the pubic symphysis. On multiple linear regression analysis, only larger mesorectal fat area remained significantly associated with longer operative time of the pelvic phase (p = 0.009). CONCLUSIONS: Mesorectal fat area may serve as a useful predictor of the difficulty of total mesorectal excision for rectal cancer.

Short- and long-term outcomes of robotic-assisted laparoscopic surgery for rectal cancer: results of a single high-volume center in Japan.

PURPOSE: Scientific evidence supporting robotic-assisted laparoscopic surgery (RALS) for rectal cancer remains inconclusive because most previous reports were retrospective case series or case-control studies, with few reports focusing on long-term oncological outcomes with a large volume of patients. The aim of this study was to clarify the short- and long-term outcomes of a large number of consecutive patients with rectal cancer who underwent RALS in a single high-volume center. METHODS: The records of 551 consecutive patients who underwent RALS for rectal adenocarcinoma between December 2011 and March 2017 were examined to reveal the short-term outcomes. The oncological outcomes of the 204 patients who underwent surgery between December 2011 and March 2014 were evaluated. RESULTS: Most patients had tumors located in the lower or mid-rectum (86.0%). Only 7.6% of patients underwent neoadjuvant chemoradiotherapy. Lateral lymph node dissection was performed for 191 patients (34.7%). The median operative time was 257 min, median blood loss was 10 mL, and no transfusions were needed. No conversion to open surgery was necessary. Eighteen patients (3.3%) had Clavien-Dindo grade III postoperative complications. Six patients (1.1%) had positive resection margins. The mean follow-up duration of the 204 patients was 43.6 ± 9.8 (months). The 5-year cancer-specific survival rate for stage I/II/III/IV was 100%/100%/100%/not reached, respectively. The 5-year relapse-free survival rate for stage I/II/III/IV was 93.6%/75.0%/77.6%/ not reached, respectively. The rate of local recurrence was 0.5%. CONCLUSIONS: Our results suggest that RALS is technically feasible for rectal cancer and has good short- and long-term outcomes.

Oncological outcomes of robotic-assisted laparoscopic versus open lateral lymph node dissection for locally advanced low rectal cancer.

BACKGROUND: The long-term outcomes of robotic-assisted laparoscopic lateral lymph node dissection (RALLD) have not been fully investigated. This study aimed to assess the oncological and long-term outcomes of RALLD for rectal cancer through comparison with those of open lateral lymph node dissection (OLLD) in a retrospective study. METHODS: Between September 2002 and October 2014, the medical data of 426 patients who underwent total mesorectal excision with lateral lymph node dissection for primary rectal cancer were collected. Of these, 115 patients were excluded after data collection (stage IV, n = 61; total pelvic exenteration, n = 31; multiple cancer, n = 20; conventional laparoscopic surgery, n = 3). Before matching, 311 patients with clinical stage II/III were analyzed. Using exact matching, patients were stratified into RALLD (n = 78) and OLLD (n = 78) groups. Pathological findings and long-term outcomes were compared between the groups. RESULTS: The pathological stage and number of harvested lymph nodes showed no significant differences between the groups. The rate of positive resection margin in the RALLD group tended to be lower compared with that of the OLLD group (p = 0.059). The median follow-up duration was 54.0 months in 156 patients. The 5-year overall survival rate was 95.4 and 87.8% in the RALLD and OLLD groups, respectively (p = 0.106). The 5-year relapse-free survival rate was 79.1 and 69.9% in the RALLD and OLLD groups, respectively (p = 0.157). The 5-year local relapse-free survival rate was 98.6 and 90.9% in the RALLD and OLLD groups, respectively (p = 0.029). CONCLUSIONS: The short- and long-term outcomes indicated that RALLD may be a useful modality for locally advanced low rectal cancer.

Safety and feasibility of laparoscopic reoperation for treatment of anastomotic leakage after laparoscopic colorectal cancer surgery.

INTRODUCTION: The safety and feasibility of laparoscopic reoperation for anastomotic leakage remain unclear. METHODS: A total of 3321 patients underwent laparoscopic surgery for primary colorectal cancer at a tertiary referral center from September 2002 to May 2016. Of these, 31 patients who underwent reoperation for treatment of anastomotic leakage were enrolled in this study and divided into two reoperation groups: laparoscopic (n = 15) and open (n = 16). Data regarding patient demographics, operative outcomes, morbidity, length of hospital stay, mortality, and stoma closure after reoperation in the two groups were compared. RESULTS: No significant difference was observed in the primary surgery procedure between the two groups. Estimated blood loss (1 vs 9 mL, P = 0.020), total postoperative complications (26.7% vs 68.8%, P = 0.032), wound infection (0.0% vs 31.2%, P = 0.043), and postoperative hospital stay (18 vs 31 days, P = 0.017) were significantly better in the laparoscopic group than in the open group. Although the rate of stoma closure after reoperation was higher in the laparoscopic group, the difference was not significant (86.7% vs 62.5%, P = 0.220). CONCLUSIONS: Laparoscopic reoperation exhibited better short-term outcomes than open reoperation for selected patients with anastomotic leakage.

[A Case Report of Robotic Assisted Laparoscopic Low Anterior Resection in a Patient with Rectal Cancer and Polysplenia Syndrome].

Polysplenia syndrome is a rare congenital disease characterized by variable thoracic and abdominal anomalies. A man in his 70s was diagnosed with rectal cancer by close exploration for fecal occult blood. A barium enema revealed a type 1 rectal tumor andwith non-rotation of intestine. CT revealed multiple abnormalities: a polyspleen, preduodenal portal vein, congenital absence of the pancreatic tail, bilateral superior vena cava, andbilateral bilobedlung. Basedon these findings, the patient was diagnosedas having rectal cancer with polysplenia syndrome andtreatedwith robotic assistedlaparoscopic low anterior resection. At operation, the whole colon was located in the left side of the abdominal cavity. The whole colon adhered with each other. The ileocecum adheredto the front of the aorta andthe right iliac artery. In the pelvis, anatomical abnormality was not detectedandrectal mobilization andresection was performedas usual. The patient hadno signs of recurrence of the rectal cancer. This is the first case presentation of laparoscopic low anterior resection in a patient with rectal cancer and polysplenia syndrome.

The distribution of lymph node metastases and their size in colon cancer.

PURPOSE: The purpose of this study is to clarify the optimal extent of lymph node dissection for colon cancer by evaluating the distributions of lymph node metastases and lymph node size according to tumor location and T stage. METHODS: This study enrolled 662 patients who underwent curative resection for primary colon cancer between 2013 and 2015. Lymph node regions were classified into pericolic, intermediate, and main nodes. The short-axis diameter of each dissected lymph node was measured. The distributions of lymph node metastases and lymph node size were evaluated according to tumor location and T stage. RESULTS: In the overall cohort, the incidence of metastases in pericolic nodes located more than 5 cm but no more than 10 cm from tumor and in pericolic nodes located more than 10 cm from tumor was 3.6 and 0.2%, respectively. More than 2% of patients with ≥ T2 tumor had metastases in main lymph nodes, and no patients with T1 tumor had metastases in main lymph nodes. Only 0.7% of patients with T1 tumor had lymph node metastases in pericolic nodes located more than 5 cm from the tumor. Both metastatic and non-metastatic lymph node sizes were significantly larger in right-sided colon cancer than in left-sided colon cancer, and both metastatic and non-metastatic lymph node sizes were significantly larger in ≥ T2 tumor than in T1 tumor. CONCLUSION: It is necessary to resect 10 cm of normal bowel both proximal and distal to the tumor and to perform D3 lymph node dissection for ≥ T2 colon cancer.

Preoperative chemoradiotherapy changes the size criterion for predicting lateral lymph node metastasis in lower rectal cancer.

PURPOSE: The purpose of this study was to identify the size criteria of lateral lymph node metastasis in lower rectal cancer both in patients who underwent preoperative CRT and those who did not. METHODS: This study enrolled 150 patients who underwent resection for primary lower rectal adenocarcinoma with lateral lymph node dissection between 2013 and 2015. Patients were divided into two groups: the CRT group, treated with preoperative chemoradiotherapy before surgery, and the non-CRT group, treated with surgery alone. The short-axis diameter of each dissected lateral lymph node was measured. Receiver-operating characteristic curves were generated to reveal the optimal cutoff values for determining lateral lymph node metastasis in both groups. RESULTS: In the non-CRT group (n = 131), the ROC curve demonstrated that the optimal cutoff value for determining metastasis was 6.0 mm, with a sensitivity of 78.5% and specificity of 82.9%, and the AUC was 0.845. In comparison, in the CRT group (n = 19), the optimal cutoff value was 5.0 mm, with a sensitivity of 71.4% and specificity of 85.3% and an AUC of 0.836. CONCLUSION: The cutoff size for determining lateral lymph node metastasis was smaller in the CRT group than in the non-CRT group.

Index of Estimated Benefit from Lateral Lymph Node Dissection for Middle and Lower Rectal Cancer.

AIM: To evaluate the clinical benefit from lateral lymph node dissection for middle and lower rectal cancer. PATIENTS AND METHODS: A total of 229 patients who underwent bilateral lateral lymph node dissection during resection with curative intent for cT3-4 middle or lower rectal cancer from 2002 to 2013 were retrospectively reviewed. The index of estimated benefit from lymph node dissection for all, and each (common iliac, internal iliac and obturator), lateral lymph nodes were compared with the index for mesenteric lymph nodes (perirectal, intermediate and main lymph nodes). RESULTS: The overall incidence of lateral lymph node metastasis was 14.0%. The index for all lateral lymph nodes (10.6) was lower than perirectal lymph nodes (45.3), but higher than intermediate lymph nodes (4.8). CONCLUSION: Lateral lymph node dissection provides considerable clinical benefit, similar to the benefit provided by intermediate lymph node dissection.

Long-term outcomes after resection of para-aortic lymph node metastasis from left-sided colon and rectal cancer.

PURPOSE: Para-aortic lymph node (PALN) metastasis from colorectal cancer is rare and often not suitable for surgery. However, in selected patients, radical resection may bring about longer survival. The aim of this study was to evaluate long-term outcomes of resection of left-sided colon or rectal cancer with simultaneous PALN metastasis. METHODS: The study included 2122 patients with left-sided colon or rectal cancer (30 patients with and 2092 patients without PALN metastasis) who underwent resection with curative intent between 2002 and 2013. Clinicopathological characteristics, long-term outcomes of resection, and factors related to poor postoperative survival in patients with PALN metastasis were investigated. RESULTS: Of a total of 2122 total patients, 16 of 50 patients (32.0%) with lymph node metastasis at the root of the inferior mesenteric artery had PALN metastasis. The 5-year overall survival rates for 18 patients who underwent R0 resection and 12 patients who did not were 29.1 and 10.4%, respectively (p = 0.017). Factors associated with poor postoperative survival among patients who underwent R0 resection were presence of conversion therapy, lack of adjuvant chemotherapy, carcinoembryonic antigen >20 ng/mL, and lateral lymph node metastasis in rectal cancer patients. The 5-year recurrence-free survival rate was 14.8%. CONCLUSIONS: Although recurrence was frequent, R0 resection for left-sided colon or rectal cancer with PALN metastasis was associated with longer survival than R1/R2 resection. Furthermore, the 5-year overall survival rate in the R0 group was relatively favorable for stage IV. Therefore, R0 resection may prolong survival compared with chemotherapy alone in selected patients.

CD44 variant 9 expression as a predictor for gastric cancer recurrence: immunohistochemical and metabolomic analysis of surgically resected tissues.

CD44 variant 9 (CD44v9) and the heavy chain of 4F2 cell-surface antigen (CD98hc) appear important for regulation of reactive oxygen species defence and tumor growth in gastric cancer. This study examined the roles of CD44v9 and CD98hc as markers of gastric cancer recurrence, and investigated associations with energy metabolism. We applied capillary electrophoresis time-of-flight mass spectrometry to metabolome profiling of gastric cancer specimens from 103 patients who underwent resection with no residual tumor or microscopic residual tumor, and compared metabolite levels to immunohistochemical staining for CD44v9 and CD98hc. Positive expression rates were 40.7% for CD44v9 and 42.7% for CD98hc. Various tumor characteristics were significantly associated with CD44v9 expression. Five-year recurrence-free survival rate was significantly lower for CD44v9-positive tumors (39.1%) than for CD44v9-negative tumors (73.5%; P < 0.0001), but no significant differences in recurrence-free survival were seen according to CD98hc expression. Uni- and multivariate analyses identified positive CD44v9 expression as an independent predictor of poorer recurrence-free survival. Metabolome analysis of 110 metabolites found that levels of glutathione disulfide were significantly lower and reduced glutathione (GSH)/ glutathione disulfide (GSSG) ratio was significantly higher in CD44v9-positive tumors than in CD44v9-negative tumors, suggesting that CD44v9 may enhance pentose phosphate pathway flux and maintain GSH levels in cancer cells.

Is it important to palpate lymph nodes in open surgery for colorectal cancer?

INTRODUCTION: In laparoscopic or robotic surgery, surgeons cannot directly palpate lymph nodes (LN), which could be considered a shortcoming in that procedure. This study was performed to evaluate the importance of palpation diagnosis of LN metastasis in colorectal cancer surgery. METHODS: This study enrolled 408 patients who underwent curative resection for primary colorectal cancer in our department in 2014. The diameter of each manually dissected LN was measured, and the LN was then examined by palpation to determine whether it was metastatic based on its consistency. The palpation and pathological diagnoses of each LN were compared. Sensitivities, specificities, positive predictive values, negative predictive values, and accuracies were calculated for palpation diagnosis of LN metastasis in a node-by-node analysis, according to LN size. RESULTS: Of the 13 750 dissected LN, 444 LN (3.2%) were metastatic. Overall, palpation diagnosis of LN metastasis revealed node-by-node sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 50%, 98%, 52%, 98%, and 97%, respectively. The sensitivity for LN 3 mm and smaller and for LN 15 mm and larger was 3% and 90%, respectively. CONCLUSION: Palpation diagnosis of LN metastasis in colorectal cancer surgery was unreliable. Although poor haptics is considered to be a disadvantage in laparoscopic and robotic surgery, they are not inferior to open surgery in terms of LN dissection.