Recurrence of rectal cancer on the pelvic sidewall after lateral lymph node dissection.

PURPOSE: Although lateral lymph node dissection has been performed to prevent lateral pelvic recurrence in locally advanced lower rectal cancer, the incidence of lateral pelvic recurrence after this procedure has not been investigated. Therefore, this study aimed to investigate the long-term outcomes of patients who underwent lateral pelvic lymph node dissection, with a particular focus on recurrence patterns. METHODS: This was a retrospective study conducted at a single high-volume cancer center in Japan. A total of 493 consecutive patients with stage II-III rectal cancer who underwent lateral lymph node dissection between January 2005 and August 2022 were included. The primary outcome measures included patterns of recurrence, overall survival, and relapse-free survival. Patterns of recurrence were categorized as lateral or central pelvic. RESULTS: Among patients who underwent lateral lymph node dissection, 18.1% had pathologically positive lateral lymph node metastasis. Lateral pelvic recurrence occurred in 5.5% of patients after surgery. Multivariate analysis identified age > 75 years, lateral lymph node metastasis, and adjuvant chemotherapy as independent risk factors for lateral pelvic recurrence. Evaluation of the recurrence rate by dissection area revealed approximately 1% of recurrences in each area after dissection. CONCLUSION: We demonstrated the prognostic outcome and limitations of lateral lymph node dissection for patients with advanced lower rectal cancer, focusing on the incidence of recurrence in the lateral area after the dissection. Our study emphasizes the clinical importance of lateral lymph node dissection, which is an essential technique that surgeons should acquire.

Risk factors of bleeding during rectal cancer surgery in obese patients in Japan.

BACKGROUND: According to several clinical trials for patients with rectal cancer, laparoscopic surgery significantly reduces intraoperative complications and bleeding compared with laparotomy and demonstrated comparable long-term results. However, obesity is considered one of the risk factors for increased surgical difficulty, including complication rate, prolonged operation time, and bleeding. METHODS: Patients with clinical pathological stage II/III rectal cancer and a body mass index of ≥25 kg/m2 who underwent laparotomy or laparoscopic surgery between January 2009 and December 2013 at 51 institutions participating in the Japan Society of Laparoscopic Colorectal Surgery were included. These patients were divided into major bleeding (>500 mL) group and minor bleeding (≤500 mL) group. The risk factors of major bleeding were evaluated by univariate and multivariate analyses. RESULTS: This study included 517 patients, of which 74 (19.9%) experienced major bleeding. Patient characteristics did not significantly differ between the two groups. The major bleeding group had a longer operative time (p < 0.001) and a larger tumor size than the minor bleeding group (p = 0.011). In the univariate analysis, age >65 years, laparotomy, operative time >300 min, and multivisceral resection were significantly associated with intraoperative massive bleeding. In the multivariate analysis, age >65 years (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.13-4.82), laparotomy (OR, 20.82; 95% CI, 11.56-39.75), operative time >300 min (OR, 5.39; 95% CI, 1.67-132), and multivisceral resection (OR, 10.72; 95% CI, 2.47-64.0) showed to be risk factors for massive bleeding. CONCLUSION: Age >65 years, laparotomy, operative time >300 min, and multivisceral resection were risk factors for massive bleeding during rectal cancer surgery in patients with obesity.

Clinicopathological characteristics of Lynch-like syndrome.

BACKGROUND: Lynch-like syndrome (LLS) has recently been proposed as a third type of microsatellite instability (MSI) tumor after Lynch syndrome (LS) and sporadic MSI colorectal cancer (CRC) without either a germline variant of mismatch repair (MMR) genes or hypermethylation of the MLH1 gene. The present study aimed to clarify and compare the clinicopathological characteristics of LLS with those of the other MSI CRC subtypes. METHODS: In total, 2634 consecutive patients with CRC who underwent surgical resection and subsequently received universal tumor screening (UTS), including MSI analysis were enrolled between January 2008 and November 2019. Genetic testing was performed in patients suspected of having Lynch syndrome. RESULTS: UTS of the cohort found 146 patients with MSI CRC (5.5%). Of these, excluding sporadic MSI CRC, 30 (1.1%) had a diagnosis of LS, and 19 (0.7%) had no germline pathogenic variants of the MMR gene. The CRC type in the latter group was identified as LLS. LLS occurred significantly more often in young patients, was left-sided, involved a KRAS variant and BRAF wild-type, and had a higher concordance rate with the Revised Bethesda Guidelines than sporadic MSI CRC. No significant differences were observed in terms of the clinicopathological factors between LLS and LS-associated MSI CRC; however, LLS had a lower frequency of LS-related neoplasms compared with LS. CONCLUSIONS: Distinguishing clinically between LS and LLS was challenging, but the incidence of neoplasms was higher in LS than in LLS, suggesting the need for different screening and surveillance methods for the two subtypes.

Modified neoadjuvant rectal score as a novel prognostic model for rectal cancer patients who underwent chemoradiotherapy.

BACKGROUND: The neoadjuvant rectal score (NAR score) has recently been proposed as a better prognostic model than the conventional TNM classification for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy. We recently developed an apoptosis-detection technique for assessing the viability of residual tumors in resected specimens after chemoradiotherapy. This study aimed to establish an improved prognostic classification by combining the NAR score and the assessment of the apoptosis of residual cancer cells. METHODS: We retrospectively enrolled 319 rectal cancer patients who underwent chemoradiotherapy followed by radical surgery. The recurrence-free survival and overall survival of the four models were compared: TNM stage, NAR score, modified TNM stage by re-staging according to cancer cell viability, and modified NAR score also by re-staging. RESULTS: Downstaging of the ypT stage was observed in 15.5% of cases, whereas only 4.5% showed downstaging of ypN stage. C-index was highest for the modified NAR score (0.715), followed by the modified TNM, TNM, and NAR score. Similarly, Akaike's information criterion was smallest in the modified NAR score (926.2), followed by modified TNM, TNM, and NAR score, suggesting that the modified NAR score was the best among these four models. The overall survival results were similar: C-index was the highest (0.767) and Akaike's information criterion was the smallest (383.9) for the modified NAR score among the four models tested. CONCLUSION: We established a novel prognostic model, for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy, using a combination of apoptosis-detecting immunohistochemistry and neoadjuvant rectal scores.

Hazard function analysis of prognosis after recurrent colorectal cancer.

BACKGROUND AND OBJECTIVES: Mean survival time (MST) is used as the indicator of prognosis in patients with a colorectal cancer (CRC) recurrence. The present study aimed to visualize the changes in death risk after a CRC recurrence using hazard function analysis (HFA) to provide an alternative prognostic indicator to MST. METHODS: The medical records of 725 consecutive patients with a recurrence following R0 radical surgery for CRC were retrospectively reviewed. RESULTS: The five-year, post-recurrence survival rate was 37.8%, and the MST was 3.5 years while the risk of death peaked at 2.9 years post-recurrence. Seven variables were found to predict short-term survival, including the number of metastatic organs ≥ 2, non-surgical treatment for the recurrence, and a short interval before recurrence. In patients with a recurrence in one organ, the MST was four years, the peak time of death predicted by HFA was 2.9 years, and the five-year survival rate was 45.8%. In patients with a surgical resection of the recurrence, the MST was 8 years, the peak time of death was 3.3 years, and the five-year survival rate was 62%. CONCLUSIONS: The present study established a novel method of assessing changes in mortality risk over time using HFA in patients with a CRC recurrence.

A rare case of localized peliosis hepatis during adjuvant chemotherapy including oxaliplatin mimicking a liver metastasis of colon cancer.

BACKGROUND: Oxaliplatin-based regimens are commonly used as adjuvant chemotherapy following surgery for colorectal cancer. Adverse events associated with oxaliplatin include blue liver, which is caused by sinusoidal dilation and diffuse peliosis hepatis. We report herein a case of localized peliosis hepatis closely resembling a metastatic liver tumor. CASE PRESENTATION: The patient, a 50-year-old male, underwent a robotically assisted colectomy for rectosigmoid colon cancer, which was discovered when hematochezia occurred. The patient received a diagnosis of pStage IIIb and was treated with four courses of CAPOX as adjuvant chemotherapy starting at postoperative month 1. At postoperative month 4, contrast-enhanced computed tomography (CT) of the abdomen revealed a 20-mm, low-density area with heterogeneous internal structure in S6/7 of the liver. Abdominal ultrasound and gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) findings led to a diagnosis of metastatic liver tumor, for which a laparoscopic partial hepatectomy was performed. The resected lesion was a dark reddish-brown nodule with indistinct margins that appeared to be continuous with the surrounding area. Histopathological analysis revealed severe, localized dilatation of the sinusoids and congestion consistent with the gross nodule. Based on these findings, localized peliosis hepatis associated with oxaliplatin-induced sinusoidal damage was diagnosed. CONCLUSIONS: Localized peliosis hepatis associated with oxaliplatin use can be difficult to distinguish from a metastatic liver tumor on imaging studies.

Comprehensive data of 4502 patients newly diagnosed with colorectal liver metastasis between 2015 and 2017, and prognostic data of 2427 patients newly diagnosed with colorectal liver metastasis in 2013 and 2014: Third report of a nationwide survey in Japan.

To improve treatment outcomes in patients with colorectal liver metastasis (CRLM), the Joint Committee for Nationwide Survey on CRLM was established by the Japanese Society for Cancer of the Colon and Rectum and the Japanese Society of Hepato-Biliary-Pancreatic Surgery. The aim of the study was to evaluate transition in the characteristics and treatment strategy in CRLM patients and analyze prognostic factors using large-scale data. The present study summarizes the data of patients newly diagnosed between 2015 and 2017 and presents prognostic data of patients newly diagnosed in 2013 and 2014. Survival curves were generated by the Kaplan-Meier method and compared by log-rank test. Multivariate analyses were carried out using Cox proportional hazard modeling. The data of 4502 patients newly diagnosed with CRLM between 2015 and 2017 and the prognostic data of 2427 patients diagnosed in 2013 and 2014 are included. Regarding the 2013 and 2014 prognostic data, the 5-year overall survival (OS) rates of patients who underwent hepatectomy alone was 59.8%. Multivariate analyses identified age at diagnosis of CRLM ≥70 years, concomitant extrahepatic metastasis at diagnosis of CRLM, tumor depth of primary lesion ≥subserosa/pericolic or perirectal tissue, mutant KRAS status, number of CRLM ≥5, maximum diameter of CRLM >5 cm, and surgical curability R1/R2 as independent predictors of OS. Analysis of the latest nationwide database of patients diagnosed with CRLM revealed changes in patients and oncological characteristics, a transition in treatment strategy, and different independent prognosticators to those reported previously.

Validation study of the JSHBPS nomogram for patients with colorectal liver metastases who underwent hepatic resection in the recent era - a nationwide survey in Japan.

BACKGROUND: The Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS) nomogram was developed to predict disease-free survival in patients with colorectal liver metastases (CRLM) undergoing upfront hepatectomy. However, the utility of the nomogram in patients with resected CRLM remains unknown in the current situation in which treatment strategies are changing with advances in drugs. METHODS: Patients in the initial nomogram cohort (n = 727) and validation cohort (n = 2225) were divided into the upfront hepatectomy and preoperative chemotherapy groups. The nomogram was validated by measuring calibration and discrimination in the two cohorts. Calibration curves were plotted, and survival probabilities were compared. Finally, to quantify the discrimination power, we estimated the concordance index (C-index). RESULTS: In the upfront hepatectomy group, the C-index was 0.63, the suitable cutoff value of the Beppu score was 7, and adjuvant chemotherapy was significantly effective limited to high-risk patients (Beppu score ≥7). The C-index was 0.56 in the preoperative chemotherapy group. CONCLUSIONS: The JSHBPS nomogram remains beneficial for patients undergoing upfront hepatectomy in the recent era but is less effective for patients undergoing hepatectomy after chemotherapy. Patients with a Beppu score ≥7 showed high-risk recurrence, and adjuvant chemotherapy should be recommended for these patients.

Germline deletion of chromosome 2p16-21 associated with Lynch syndrome.

We identified a Japanese patient with Lynch syndrome with a novel large germline deletion of chromosome 2p16-21, including the EPCAM, MSH2, and KCNK12 genes. The proband was a 46-year-old man with ascending colon cancer. The clinical significance of germline KCNK12 gene deletion, which encodes one of the subfamilies of two-pore-domain potassium channels, is still unknown.

Long-term outcome of liver resection for colorectal metastases in the presence of extrahepatic disease: A multi-institutional Japanese study.

BACKGROUND/PURPOSE: The purpose of the present study was to assess long-term outcomes following liver resection for colorectal liver metastases (CRLM) with concurrent extrahepatic disease and to identify the preoperative prognostic factors for selection of operative candidates. METHODS: In this retrospective, multi-institutional study, 3820 patients diagnosed with CRLM during 2005-2007 were identified using nationwide survey data. Data of identified patients with concurrent extrahepatic lesions were analyzed to estimate the impact of liver resection on overall survival (OS) and to identify preoperative, prognostic indicators. RESULTS: Three- and 5-year OS rates after liver resection in 251 CRLM patients with extrahepatic disease (lung, n = 116; lymph node, n = 51; peritoneal, n = 37; multiple sites, n = 23) were 50.2% and 32.0%, respectively. Multivariate analysis revealed that a primary tumor in the right colon, lymph node metastasis from the primary tumor, serum carbohydrate antigen (CA) 19-9 level >37 UI/mL, the site of extrahepatic disease, and residual liver tumor after hepatectomy were associated with higher mortality. We proposed a preoperative risk scoring system based on these factors that adequately discriminated 5-year OS after liver resection in training and validation datasets. CONCLUSIONS: Performing R0 liver resection for colorectal liver metastases with treatable extrahepatic disease may prolong survival. Our proposed scoring system may help select appropriate candidates for liver resection.

[A Case of Transverse Colon Cancer Undergoing Laparoscopic Right Hemicolectomy after Distal Gastrectomy with Billroth â ¡ Reconstruction].

A 79-year-old man was diagnosed with transverse colon cancer who had a history of distal gastrectomy and antecolic Billroth Ⅱ(B-Ⅱ)reconstruction for duodenal ulcer. We performed laparoscopic right hemicolectomy. Surgical findings indicated that the tumor was located in the center of the transverse colon. After we performed mobilization of right colon and lymph node dissection, we performed mobilization of left colon and we peeled off those adhesions with the jejunal limb and transverse colon mesentery. Then, we resected transverse colon and removed right hemicolon. We reconstructed a functional end-to-end anastomosis on the ventral side of the jejunal limb. The patient was discharged without complications on the 10th postoperative day. In post B-Ⅱ reconstruction cases, we can perform laparoscopic colectomy safely with preoperative CT confirmation and adequate colon mobilization.

Clinicopathological and molecular differences between right-sided and left-sided colorectal cancer in Japanese patients.

BACKGROUND: The aim of this study was to clarify clinicopathological features, frequencies of molecular biomarkers, and prognoses in Japanese colorectal cancer patients and compare them with right-sided colon cancer (RCC) and left-sided colorectal cancer (LCRC). METHODS: We consecutively selected 575 colorectal cancer patients who underwent surgical resection from 2008 to 2011. RCC was located from the cecum to the transverse colon, and LCRC was located from the splenic flexure to the rectum. Frequencies of KRAS gene mutation, BRAF gene mutation, microsatellite instability (MSI), l18qLOH and CpG island methylator phenotype (CIMP) were statistically analyzed between groups. RESULTS: Tumors were located in the RCC in 26.3% of patients and in the LCRC in 73.7%. Elderly patients, females and advanced diseases were significantly more frequent in the RCC group than in the LCRC group. However, venous invasion was significantly more frequent in LCRC than in RCC. Between groups, BRAF mutant type, KRAS mutant type, MSI and CIMP+ were significantly more frequent in RCC, whereas 18qLOH was significantly more frequent in LCRC. In overall survival, RCC demonstrated poor prognosis compared with LCRC; however, age, gender, stage, lymphatic invasion, KRAS status and BRAF status rather than tumor location were independent prognostic factors. In addition, the independent prognostic factors in RCC were different from those in LCRC in each stage. However, the consistency between OS and DFS was not observed in this study, excluding lymphatic invasion in LCRC. CONCLUSION: Comparing RCC with LCRC, RCC is different from LCRC in clinicopathological features, molecular biomarkers and prognostic factors in Japanese colorectal cancer patients. Since the proportions of molecular biomarkers of CRC in this study are different from Western CRCs, further studies are required to clarify the clinicopathological differences between Japanese CRCs and Western CRCs.

Predictive model for high-frequency microsatellite instability in colorectal cancer patients over 50 years of age.

Microsatellite instability (MSI) is an important biomarker for screening for Lynch syndrome, and also of response to immune checkpoint inhibitors. The aim of this study is to create a predictive model to determine which elderly patients with colorectal cancer (CRC) should undergo MSI and/or immunohistochemistry testing on the basis of clinicopathological data. We analyzed a test cohort of CRC patients aged ≥50 years (n = 2219) by multivariate logistic regression analyses to identify predictors of high-frequency MSI (MSI-H). The created prediction model was validated in an external cohort (n = 992). The frequency of MSI-H was 5.5% among CRC patients aged ≥ 50 years. The following five predictors of MSI-H were identified in the test cohort: female (1 point), mucinous component (2 points), tumor size ≥ 60 mm (2 points), location in proximal colon (3 points), and BRAF mutation (6 points). The area under curve (AUC) in the receiver-operating characteristic (ROC) analysis of this prediction model was 0.832 (95% confidence interval: 0.790-0.874). The sensitivity and specificity were 74.4% and 77.7%, respectively, for a cut-off score of 4 points. The receiver-operating characteristic curve of the validation cohort also showed an AUC of 0.856 (95% CI: 0.806-0.905). This prediction model is useful to select elderly CRC patients who should undergo MSI testing, and who may benefit from treatment with 5-FU-based adjuvant chemotherapy and cancer immunotherapy.

Colorectal Cancer with BRAF D594G Mutation Is Not Associated with Microsatellite Instability or Poor Prognosis.

OBJECTIVE: BRAF D594G mutations in colorectal cancer patients are not clearly understood. We retrospectively investigated the clinicopathological features of colorectal cancers with BRAF D594G mutations. METHODS: We selected 908 colorectal cancer patients who underwent surgical resection from January 2008 to January 2013, and assessed BRAF, KRAS, microsatellite instability, and CpG island methylator phenotype (CIMP). RESULTS: We detected BRAF D594G in 7 patients and BRAF V600E in 45 patients. The clinicopathological features of cancers with BRAF D594G mutation were similar to those with BRAF wild-type, but differed from those with BRAF V600E mutations. Regarding microsatellite instability status, 44.4% of cases with BRAF V600E mutations exhibited high microsatellite instability, compared to 14.3% of those with BRAF D594G mutations and 4.4% of those with BRAF wild-type. There were no CIMP-positive tumors in cancers with BRAF D594G mutations, whereas 67.8% of tumors with BRAF V600E mutations were CIMP-positive. In stage IV cancers, the survival rates of patients at 2 years were 8.5, 50.0, and 68.2% in the BRAF V600E mutation, BRAF D594G mutation, and BRAF wild-type groups, respectively. CONCLUSION: Colorectal cancers with BRAF D594G mutations exhibit similar clinicopathological features, microsatellite instability status, and prognosis as those with BRAF wild-type.

Pulmonary amyloidosis mimicking prostate cancer metastasis.

Localized nodular pulmonary amyloidosis is rare. However, the disease should be considered in the differential diagnosis of multiple lung nodules.

[Effectiveness of chemoradiotherapy for a patient with local recurrence of advanced gastric cancer followed by curable gastrectomy].

We report here the effectiveness of chemoradiotherapy for a patient with local recurrence followed by curable gastrectomy. A 57-year-old man presented with a history of total gastrectomy with distal pancreatectomy and splenectomy, D2 lymphadenectomy, and Roux-en-Y reconstruction for advanced gastric cancer arising from the cardia. Esophageal intramural metastasis and lymph node metastasis around the right recurrent nerve were detected by chest-abdominal computed tomography and gastrointestinal endoscopy 27 months after the initial gastrectomy. Stable disease was achieved following 7 courses of chemotherapy using S-1 plus CDDP. Concurrent chemoradiotherapy including administration of S-1 and radiation of total 50 Gy (2 Gy/25 Fr) was selected for local tumor control. The patient was not able to eat solid food because of esophageal stenosis from regrowth of intramural metastasis of the esophagus 60 months after the chemotherapy. A WallFlex™ Duodenal Stent was placed to improve the dysphagia 67 months after chemotherapy. The patient died from recurrence of gastric cancer 69 months after completion of the initial chemotherapy and 2 months after the stent insertion.